Surfactant composition, and manufacturing method and application of same

Abstract

This invention relates to a surfactant composition, production and use thereof in tertiary oil recovery. The present surfactant composition comprises a cationic surfactant and an anionic-nonionic surfactant, and exhibits significantly improved interfacial activity and stability as compared with the prior art. With the present surfactant composition, a flooding fluid composition for tertiary oil recovery with improved oil displacement efficiency and oil washing capability as compared with the prior art could be produced.

Claims

1. A surfactant composition, comprising a cationic surfactant and an anionic-nonionic surfactant, wherein a molar ratio of the cationic surfactant and the anionic-nonionic surfactant is 1:0.01 to 1:100, wherein the cationic surfactant is one or more selected from the group consisting of quaternary ammonium salts and quaternary ammonium hydroxides, wherein the anionic-nonionic surfactant is a compound of formula (I-1), a compound of formula (I-3), or a compound of formula (I-4), ##STR00160## wherein, in the formula (I-1): Ra is identical with or different from one another, each independently selected from the group consisting of a C.sub.1-20 linear or branched alkyl, a C.sub.2-20 linear or branched alkenyl, and a C.sub.6-10 aryl; Ra′ is identical with or different from one another, each independently selected from the group consisting of a single bond and a C.sub.1-6 linear or branched alkylene; b is an integer of from 1 to 3; and x′ is an integer from 1 to 6, ##STR00161## wherein, in the formula (I-3): x′″ is an integer of from 1 to 10, and ##STR00162## wherein, in the formula (I-4): x″” represents an integer of from 1 to 9, and wherein, in the formulae (I-1), (I-3), or (I-4), Rc is identical with or different from one another, each independently selected from the group consisting of a C.sub.1-20 linear or branched alkyl, a C.sub.2-20 linear or branched alkenyl, a C.sub.1-20 linear or branched alkyl carbonyl, and a C.sub.2-20 linear or branched alkenyl carbonyl; Rd is identical with or different from one another, each independently selected from the group consisting of a C.sub.1-5 linear or branched alkylene and a C.sub.1-5 linear or branched alkylene carbonyl; Y is N, and a=1; m′ is identical with or different from one another, each independently being a value of from 0 to 100, excluding 0, n′ is identical with or different from one another, each independently being a value of from 0 to 100, excluding 0, m″ is identical with or different from one another, each independently being a value of from 0 to 100, n″ is identical with or different from one another, each independently being a value of from 0 to 100, m′” is identical with or different from one another, each independently being a value of from 0 to 100, n′” is identical with or different from one another, each independently being a value of from 0 to 100; L is identical with or different from one another, each independently being a C.sub.1-5 linear or branched alkylene; Salt is identical with or different from one another, each having a formula -A.sup.−(M).sub.r.sup.+, wherein A.sup.−is a carboxylate ion (COO.sup.−) or a sulfonate ion (SO.sub.3.sup.−), with the proviso that A.sup.−in at least one of the Salt groups is the carboxylate ion (COO.sup.−); M is alkali metal, alkaline earth metal, or ammonium (NH.sub.4), when M is alkali metal or ammonium, r=1; and when M is alkaline earth metal, r=0.5.

2. The surfactant composition according to claim 1, wherein the cationic surfactant is one or more compound of formula (II), ##STR00163## wherein, in formula (II), N.sup.+ represents a quaternary nitrogen cation; R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are identical or different, each independently selected from the group consisting of an optionally substituted C.sub.1-50 linear or branched alkyl, an optionally substituted C.sub.5-50 monocyclic or polycyclic cycloalkyl, an optionally substituted C.sub.2-50 linear or branched alkenyl, an optionally substituted C.sub.6-20 aryl, and a compound of formula ##STR00164## with the proviso that at least one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is an optionally substituted C.sub.8-50 linear or branched alkyl or an optionally substituted C.sub.8-50 linear or branched alkenyl, and optionally, at least one of the groups R.sub.1 to R.sub.4 represents a group represented by the formula ##STR00165## L.sub.1 is a single bond or a C.sub.1-5 linear or branched alkylene oxy; y′ is a value of from 0 to 200, excluding 0; Ru′ is identical with or different from one another, each independently being a C.sub.2-6 linear or branched alkylene; L.sub.2 is hydrogen, an optionally substituted C.sub.1-10 linear or branched alkyl, an optionally substituted C.sub.2-10 linear or branched alkenyl, or an optionally substituted C.sub.6-10 aryl; and X.sup.−is a halogen ion or hydroxide ion (OH.sup.−).

3. The surfactant composition according to claim 2, where in the formula (II), at least one R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is an optionally substituted C.sub.8-20 linear or branched alkyl or an optionally substituted C.sub.8-20 linear or branched alkenyl.

4. The surfactant composition according to claim 1, wherein, in the formula (I-1), Ra is identical with or different from one another, each independently selected from the group consisting of a C.sub.5-15 linear or branched alkyl and a C.sub.6-10 aryl.

5. The surfactant composition according to claim 1, wherein M represents an alkali metal or alkaline-earth metal.

6. The surfactant composition according to claim 2, wherein, in formula (II), R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are identical or different, each independently selected from the group consisting of an optionally substituted C.sub.1-50 linear or branched alkyl, an optionally substituted C.sub.6-20 aryl, and a compound of formula ##STR00166## with the proviso that two of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is an optionally substituted C.sub.8-50 linear or branched alkyl or an optionally substituted C.sub.8-50 linear or branched alkenyl, and at least one of the groups R.sub.1 to R.sub.4 represents a group represented by the formula ##STR00167##

7. A surfactant composition, produced by mixing the cationic surfactant recited in claim 1 and the anionic-nonionic surfactant recited in claim 1 at a molar ratio of 1:0.01 to 1:100.

8. A flooding fluid composition for tertiary oil recovery, comprising the surfactant composition according to claim 1, and water, wherein the surfactant composition accounts for 001-10 wt %, relative to a total weight of the flooding fluid composition for tertiary oil recovery.

9. The flooding fluid composition for tertiary oil recovery according to claim 8, comprising no inorganic alkali.

10. A process for producing a flooding fluid composition for tertiary oil recovery, comprising: mixing the surfactant composition according to claim 1 with at least water, wherein the surfactant composition accounts for 0.001-10 wt %, relative to a total weight of the flooding fluid composition for tertiary oil recovery.

Description

EXAMPLE

(1) The present invention is further illustrated by using the following examples, but not limiting to same.

Example I-1a

(2) Alkyl phenol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:3 were introduced into a reactor, alkalized at 60 degrees Celsius for 5 h, and then at a ratio by molar between alkyl phenol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:1 there was added chloroacetic acid, heated to 100 degrees Celsius and reacted for 1 h, upon completion of the reaction, neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain a sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate.

(3) Polyoxypropylene ether (n=2) triethyl ammonium hydroxide and the thus produced sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:10 were mixed till homogenous, to obtain the surfactant composition 1a, the particulars of which were listed in Table 1a.

Example I-2a

(4) Alkyl phenol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:4 were introduced into a reactor, alkalized at 80 degrees Celsius for 2 h, and then at a ratio by molar between alkyl phenol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:1.5 there was added chloropropionic acid, cooled to 50 degrees Celsius and reacted for 18h, and then neutralized with a HCl solution to a pH value of less than 3, and then oil-aqueous phase separated, the oil phase was neutralized with a 10 wt % aqueous Ca(HCO.sub.3).sub.2 solution, upon completion of the reaction, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Ca(OH).sub.2 suspension to a pH value of 8, dried under vacuum, to obtain a calcium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate.

(5) Dodecyl trimethyl ammonium chloride and the thus produced calcium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then these solutions at a ratio by molar of 1:0.9 between the cationic surfactant and the anionic-nonionic surfactant were mixed till homogenous, to obtain the surfactant composition 2a, the particulars of which were listed in Table 1a.

Example I-3a

(6) Alkyl phenol polyoxypropylene polyoxyethylene ether and KOH at a ratio by molar of 1:1 were introduced into a reactor, alkalized at the room temperature for 10 h, and then at a ratio by molar between alkyl phenol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:3 there was added sodium chloroacetate, heated to 80 degrees Celsius and reacted for 8 h, upon completion of the reaction, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous KOH solution to a pH value of 8, dried under vacuum, to obtain a potassium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate.

(7) Bisoctadecyl (polyoxypropylene ether (n=3.1)) dimethyl ammonium chloride and the thus produced potassium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:4 were mixed till homogenous, to obtain the surfactant composition 3a, the particulars of which were listed in Table 1a.

Example I-4a

(8) Alkyl phenol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:3 were introduced into a reactor, alkalized at 65 degrees Celsius for 2 h, and then at a ratio by molar between alkyl phenol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:2 there was added chloropropionic acid, heated to 75 degrees Celsius and reacted for 9 h, upon completion of the reaction, then neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain a sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate.

(9) Tetraoctyl ammonium chloride and the thus produced sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition 4a, the particulars of which were listed in Table 1a.

Example I-5a

(10) Alkyl phenol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:3 were introduced into a reactor, alkalized at 65 degrees Celsius for 2 h, and then at a ratio by molar between alkyl phenol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:2 there was added chloropropionic acid, heated to 75 degrees Celsius and reacted for 9 h, upon completion of the reaction, then neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain a sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate. The sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate was formulated into a 10 wt % dichloromethane solution, and then sulfonated in a falling-film sulfonation reactor into a sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate sulfonic acid. The solvent dichloromethane was removed by rotary evaporation, the resultant was adjusted with a 50 wt % NaOH solution, to obtain a sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate sulfonate.

(11) Dodecyl trimethyl ammonium chloride and the thus produced sodium alkyl phenol polyoxypropylene polyoxyethylene ether carboxylate sulfonate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:4 were mixed till homogenous, to obtain the surfactant composition I-5a, the particulars of which were listed in Table I-1a.

Example I-6a

(12) Alkyl naphthol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:3 were introduced into a reactor, alkalized at 65 degrees Celsius for 2 h, and then at a ratio by molar between alkyl naphthol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:2 there was added chloropropionic acid, heated to 75 degrees Celsius and reacted for 9 h, upon completion of the reaction, then neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain a sodium alkyl naphthol polyoxypropylene polyoxyethylene ether carboxylate. The sodium alkyl naphthol polyoxypropylene polyoxyethylene ether carboxylate was formulated into a 10 wt % dichloromethane solution, then sulfonated in a falling-film sulfonation reactor into a sodium alkyl naphthol polyoxypropylene polyoxyethylene ether carboxylate disulfonic acid. The solvent dichloromethane was removed by rotary evaporation, then the resultant was adjusted with a 50 wt % NaOH solution, to obtain a sodium alkyl naphthol polyoxypropylene polyoxyethylene ether carboxylate disulfonate. Benzyl triethyl ammonium chloride and the thus produced sodium alkyl naphthol polyoxypropylene polyoxyethylene ether carboxylate disulfonate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2 were mixed till homogenous, to obtain the surfactant composition I-6a, the particulars of which were listed in Table I-1a.

Example I-7a

(13) Alkyl benzenediol polyoxypropylene polyoxyethylene ether and NaOH at a ratio by molar of 1:3 were introduced into a reactor, alkalized at 65 degrees Celsius for 2 h, and then at a ratio by molar between alkyl benzenediol polyoxypropylene polyoxyethylene ether and the carboxylating agent of 1:2 there was added chloropropionic acid, heated to 75 degrees Celsius and reacted for 9 h, upon completion of the reaction, then neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain a sodium alkyl benzenediol polyoxypropylene polyoxyethylene ether carboxylate. The sodium alkyl benzenediol polyoxypropylene polyoxyethylene ether carboxylate was formulated into a 10 wt % dichloromethane solution, and then sulfonated in a falling-film sulfonation reactor into alkyl benzenediol di(sodium polyoxypropylene polyoxyethylene ether carboxylate) sulfonic acid. The solvent dichloromethane was removed by rotary evaporation, then the resultant was adjusted with a 50 wt % NaOH solution, to obtain a sodium alkyl benzenediol di(sodium polyoxypropylene polyoxyethylene ether carboxylate) sulfonate.

(14) Trioctyl (polyoxyethylene ether (n=2) polyoxypropylene ether (n=3.6)) ammonium chloride and the thus produced sodium alkyl benzenediol di(sodium polyoxypropylene polyoxyethylene ether carboxylate) sulfonate were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:3 were mixed till homogenous, to obtain the surfactant composition I-7a, the particulars of which were listed in Table I-1a.

Example I-8a

(15) The surfactant composition produced by Example I-3a and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26,000,000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(16) TABLE-US-00001 TABLE 1a The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Ex- ample I- the structure of the cationic surfactant 0 ratio by molar between cationic surfactant and anionic- nonionic surfactant 1a polyoxypropylene ether m = 50, n = 34.5, R.sub.1 = R.sub.2 = R.sub.3 = H,  1:10 (n = 2) triethyl R.sub.4 = —CH.sub.2—, r = 1, M = Na ammonium hydroxide 2a dodecyl trimethyl m = 28, n = 7.6, R.sub.1 = —C.sub.6H.sub.4SO.sub.3(Ca).sub.0.5,   1:0.9 ammonium chloride R.sub.2 = R.sub.3 = H, R.sub.4 = —C.sub.2H.sub.4—, r = 0.5, M = Ca 3a bis(polyoxypropylene m = 39, n = 50, R.sub.1 = —C.sub.6H.sub.5, R.sub.1 = R.sub.2= H, 1:4 ether (n = 3.1)) dimethyl R.sub.4 = CH.sub.2, r = 1, M = K ammonium chloride 4a tetraoctyl ammonium m = 20, n = 20, R.sub.1 = —C.sub.6H.sub.4COONa, 1:6 chloride R.sub.1 = R.sub.2 = H, R.sub.4 = C.sub.3H.sub.6, r = 1, M = Na 5a dodecyl trimethyl m = 5, n = 14.5, R.sub.1 = —C.sub.12H.sub.25, 1:4 ammonium chloride R.sub.2 = —SO.sub.3Na, R.sub.3 = H, R.sub.4 = —CH.sub.2—, 6a benzyl triethyl m = 15, n = 25, R.sub.1 = —C.sub.18H.sub.37, 1:2 ammonium chloride R.sub.2 = R.sub.3 = —SO.sub.3Na, R.sub.4 = —CH.sub.2— 7a trioctyl (polyoxyethylene R.sub.1 = —C.sub.17H.sub.35, R.sub.2 = —SO.sub.3Na, R.sub.3 = 1:3 ether (n = 2), —(OCH(CH.sub.3)CH.sub.2).sub.m1(OCH.sub.2CH.sub.2).sub.n1CH.sub.2COONa, polyoxypropylene ether R.sub.4 = —CH.sub.2—, m + m1 = 25, (n = 3.6)) ammonium n + n1 = 11 chloride

Example I-5a Interfacial Performance Test of the Surfactant Composition

(17) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L, a surfactant composition concentration of 0.3 wt %.

(18) TABLE-US-00002 TABLE 1a The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example I- interfacial tension (mN/m) 1a 0.0059 2a 0.0068 3a 0.0001 4a 0.0062 5a 0.0003 6a 0.0030 7a 0.0070 8a 0.0010

(19) As can be seen from Table 1a, the surfactant composition produced by each of Example I-1a to 4a exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example I-8a reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(20) The surfactant composition produced by Example I-3a was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table 2a.

(21) TABLE-US-00003 TABLE 2a The oil-water interfacial tension between the surfactant composition 3a (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 interfacial tension 0.006 0.003 0.0008 0.0003 0.0002 0.0001 (mN/m)

(22) These results reveal that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity with the crude oil from the Henan Oilfield.

(23) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example I-4a and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.002 mN/m. This tensiometer was further used to identify the oil-water interfacial tension between the surfactant composition produced by Example I-6a and a crude oil from the fifth oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 200000 mg/L, a Ca.sup.2+ content of 800 mg/L, a Mg.sup.2+ content of 3600 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.0006 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

(24) TABLE-US-00004 TABLE 1a The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield crude oil from the crude oil from the third oil plant of the fifth oil plant of the Example I- Zhongyuan Oilfield Zhongyuan Oilfield 1a 0.008 0.01 2a 0.009 0.015 3a 0.01 0.009 4a 0.009 0.02 5a 0.0087 0.012 6a 0.0008 0.007 7a 0.0005 0.0006

Example I-6a Oil Washing Capability Test of the Surfactant Composition

(25) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours. Then 5 g of the thus aged oil sand and a 0.3 wt % surfactant solution at an oil sand:solution ratio by weight of 1:10 were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(26) TABLE-US-00005 TABLE 3a The oil washing performance of the surfactant composition Example I- oil washing rate % 1a 61.5 2a 63.5 3a 68.9 4a 66.7 5a 72.4 6a 75.6 7a 77.3 8a 65.2

Example I-7a Study on the Oil Displacement Performance of the Surfactant Composition

(27) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5 μm.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table 4a.

(28) TABLE-US-00006 TABLE 5a The test results of the oil displacement surfactant composition No. Increased oil recovery % OOIP 1a 7.2 2a 7.5 3a 7.9 4a 7.3 5a 8.2 6a 8.8 7a 9.5 8a 10.3

Comparative Example I-1a

(29) According to Gong Yujun et. al, Journal of Northwest University (Natural Science Edition), Vol. 30 (1), pp. 28 to 31, February 2000, hexadecyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were combined at a ratio by molar of 1:1.5, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(30) TABLE-US-00007 TABLE 6a The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.03 45.6 2.8

Comparative Example I-2a

(31) According to Huang Hongdu et. al, Journal of Oil and Gas Technology, Vol. 29(4), August 2007 (pp. 101 to 104), 0.01 wt % hexadecyl trimethyl ammonium bromide, 0.02 wt % anionic petroleum sulfonate salt and 1.8 wt % Na.sub.2CO.sub.3 were combined, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(32) TABLE-US-00008 TABLE 7a The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.008 56.3 4.2

Example I-1b

(33) C.sub.5H.sub.11OH and NaOH at a ratio by molar of 1:5 were mixed and stirred for 30 minutes, and then there was added a predetermined amount of propylene oxide, reacted at 140 degrees Celsius for 10 h, and then there was added a predetermined amount of ethylene oxide, further reacted at 140 degrees Celsius for 1 h; and then at a ratio by molar between C.sub.5H.sub.11OH and the carboxylating agent of 1:1 there was added sodium chloroacetate, further reacted at 50 degrees Celsius for 20 h, then neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(34) Phenyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:10 were mixed till homogenous, to obtain the surfactant composition 1b, the particulars of which were listed in Table 1b.

Example I-2b

(35) Fatty alcohol C.sub.20H.sub.41OH and KOH at a ratio by molar of 1:2.5 were mixed and stirred for 30 minutes, then there was added a predetermined amount of propylene oxide, reacted at 100 degrees Celsius for 10 h; and then there was added a predetermined amount of ethylene oxide, reacted at 140 degrees Celsius for 10 h, and then at a ratio by molar between the fatty alcohol and the carboxylating agent of 1:1.5 there was added ClCH.sub.2CH.sub.2COOH, further reacted at 100 degrees Celsius for 1 h, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous KOH solution to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(36) Decyl triethyl ammonium hydroxide and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:7 were mixed till homogenous, to obtain the surfactant composition 2b, the particulars of which were listed in Table 1b.

Example I-3b

(37) Fatty alcohol C.sub.14H.sub.29OH and NaOH at a ratio by molar of 1:4 were mixed and stirred for 30 minutes, then there was added a predetermined amount of propylene oxide, reacted at 140 degrees Celsius for 5 h; and then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 6 h; and then at a ratio by molar between the fatty alcohol and the carboxylating agent of 1:1.5 there was added ClCH.sub.2COOH, further reacted at 70 degrees Celsius for 8 h, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Mg(OH).sub.2 suspension to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(38) Triethyl (polyoxyethylene ether (n=2) polyoxypropylene ether (n=3)) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.3 were mixed till homogenous, to obtain the surfactant composition 3b, the particulars of which were listed in Table 1b.

Example I-4b

(39) Fatty alcohol C.sub.16H.sub.33OH and NaOH at a ratio by molar of 1:5 were mixed and stirred for 30 minutes, and then there was added a predetermined amount of propylene oxide, reacted at 140 degrees Celsius for 1 h, and then there was added a predetermined amount of ethylene oxide, further reacted at 140 degrees Celsius for 4 h; and then at a ratio by molar between the fatty alcohol and the carboxylating agent of 1:2 there was added ClCH.sub.2COOH, further reacted at 80 degrees Celsius for 5 h, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Ca(OH).sub.2 suspension to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(40) Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:5 were mixed till homogenous, to obtain the surfactant composition 4b, the particulars of which were listed in Table 1b.

Example I-5b

(41) Fatty alcohol C.sub.10H.sub.21OH and NaOH at a ratio by molar of 1:5 were mixed and stirred for 30 minutes, then there was added a predetermined amount of propylene oxide, reacted at 140 degrees Celsius for 10 h, and then there was added a predetermined amount of ethylene oxide, further reacted at 150 degrees Celsius for 8 h; and then at a ratio by molar between the fatty alcohol and the carboxylating agent of 1:2 there was added ClCH.sub.2COONa, then neutralized with a 5 wt % aqueous solution of HCl to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous ammonia to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(42) Tetrabutyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.4 were mixed till homogenous, to obtain the surfactant composition 5b, the particulars of which were listed in Table 1b.

Example I-6b

(43) The surfactant composition produced by Example I-5b and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26000000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(44) TABLE-US-00009 TABLE 1b The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Example I- the structure of the cationic surfactant ratio by molar between cationic surfactant and anionic-nonionic surfactant 1b phenyl trimethyl R = —C.sub.5H.sub.11, R′ = —CH.sub.2, m = 16, n = 0.5, 1:10  ammonium chloride r = 1, M = Na 2b decyl triethyl R = —C.sub.20H.sub.41, R′ = —CH.sub.2CH.sub.2, m = 2.3, r = 1, 1:7   ammonium hydroxide n = 8.2, M = K 3b triethyl R = —C.sub.14H.sub.29, R′ = —CH.sub.2, m = 50, n = 30, 1:1.3 (polyoxyethylene r = 0.5, M = Mg ether (n = 2)) polyoxypropylene ether (n = 3) ammonium chloride 4b benzyl triethyl R = —C.sub.16H.sub.33, R′ = —CH.sub.2, m = 0.5, n = 7, 1:5   ammonium chloride r = 0.5, M = Ca 5b tetrabutyl ammonium R = —C.sub.10H.sub.21, R′ = —CH.sub.2, m = 3.2, n = 10, 1:0.4 chloride r = 1, M = NH.sub.4

Example I-7b Interfacial Performance Test of the Surfactant Composition

(45) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, at a surfactant composition concentration of 0.3 wt %, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L.

(46) TABLE-US-00010 TABLE 2c The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example I- interfacial tension (mN/m) 1b 0.0075 2b 0.0062 3b 0.0040 4b 0.0003 5b 0.0075 6b 0.0005

(47) As can be seen from Table 2c, the surfactant composition produced by each of Example I-1b to 5b exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example I-6b reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(48) The surfactant composition produced by Example I-5b was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table 3b.

(49) TABLE-US-00011 TABLE 3b The oil-water interfacial tension between the surfactant composition 3b (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 interfacial tension 0.005 0.003 0.002 0.0003 0.0002 0.0001 (mN/m)

(50) These results reveal that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity for the crude oil from the Henan Oilfield.

(51) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example I-3c and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.001 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

Example I-6b Oil Washing Capability Test of the Surfactant Composition

(52) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours. Then 5 g of the thus aged oil sand and a 0.3 wt % solution of is the surfactant composition at an oil sand:solution ratio of 1:10 (by weight) were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(53) TABLE-US-00012 TABLE 4b The oil washing performance of the surfactant composition Example I- oil washing rate % 1b 64.0 2b 59.4 3b 55.9 4b 65.1 5b 52.9 6b 60.8

Example I-6b Study on the Oil Displacement Performance of the Surfactant Composition

(54) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5 μm.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table 5b.

(55) TABLE-US-00013 TABLE 5b Oil displacement test results of the surfactant composition increased oil recovery Example I- % OOIP 1b 7.9 2b 6.2 3b 7.0 4b 9.1 5b 6.3 6b 8.2

Example II-1

(56) Dodecyl amine and KOH at a ratio by molar of 1:2 were introduced into a reactor, stirred for 30 minutes, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h; finally there was added chloroacetic acid at a ratio by molar between dodecyl amine and the carboxylating agent of 1:1, further reacted at 50 degrees Celsius for 20 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 1, allowed to stand for layer separation. separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous KOH solution to a pH value of 8, water was removed by vacuum evaporation, to obtain an anionic-nonionic surfactant.

(57) Octadecyl dimethyl benzyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.1 were mixed till homogenous, to obtain the surfactant composition II-1, the particulars of which were listed in Table II-1.

Example II-2

(58) o-phenyl aniline and NaOH at a ratio by molar of 1:6 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 7 h; finally there was added a mixture of sodium chloroacetate and sodium chloromethyl sulfonate (at a ratio by molar of 1:1) at a ratio by molar between o-phenyl aniline and the carboxylating agent of 1:5, further reacted at 50 degrees Celsius for 14 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 1, allowed to stand for layer separation. separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, water was removed by vacuum evaporation, to obtain an anionic-nonionic surfactant.

(59) Tetrabutyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.5 were mixed till homogenous, to obtain the surfactant composition II-2, the particulars of which were listed in Table II-1.

Example II-3

(60) Cyclohexylamine and NaOH at a ratio by molar of 1:4 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 100 degrees Celsius for 20 h, then there was added a predetermined amount of ethylene oxide, reacted at 150 degrees Celsius for 8 h; finally there was added chloroacetic acid at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:2, further reacted at 150 degrees Celsius for 16 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation. separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, removing the solvent under vacuum, to obtain an anionic-nonionic surfactant.

(61) Tributyl (polyoxyethylene ether (n=1.6)) polyoxypropylene ether (n=2.7) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:10 were mixed till homogenous, to obtain the surfactant composition II-3, the particulars of which were listed in Table II-1.

Example II-4

(62) 2-naphthyl amine and NaOH at a ratio by molar of 1:4 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 120 degrees Celsius for 15 h, then there was added a predetermined amount of ethylene oxide, reacted at 130 degrees Celsius for 15 h; finally there was added sodium chloroacetate at a ratio by molar between 2-naphthyl amine and the carboxylating agent of 1:7, further reacted at 75 degrees Celsius for 16 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation. separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 8, dried under vacuum, to obtain an anionic-nonionic surfactant.

(63) Decyl triethyl ammonium hydroxide and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition II-4, the particulars of which were listed in Table II-1.

Example II-5

(64) Hexadecyl amine and NaOH at a ratio by molar of 1:2 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 150 degrees Celsius for 10 h, then there was added sodium chloroacetate at a ratio by molar between hexadecyl amine and the carboxylating agent of 1:5, further reacted at 60 degrees Celsius for 14 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation. separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Ca(OH).sub.2 suspension to a pH value of 9, dried under vacuum, to obtain an anionic-nonionic surfactant.

(65) Phenyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.4 were mixed till homogenous, to obtain the surfactant composition II-5, the particulars of which were listed in Table II-1.

Example II-6

(66) Octadecyl amine and NaOH at a ratio by molar of 1:2 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide reacted at 180 degrees Celsius for 3 h, then there was added a predetermined amount of ethylene oxide, reacted at 100 degrees Celsius for 20 h; then there was added sodium chloroacetate at a ratio by molar between octadecyl amine and the carboxylating agent of 1:3, further reacted at 70 degrees Celsius for 12 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation. separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Mg(OH).sub.2 suspension to a pH value of 9, dried under vacuum, to obtain an anionic-nonionic surfactant.

(67) Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.8 were mixed till homogenous, to obtain the surfactant composition II-6, the particulars of which were listed in Table II-1.

Example II-7

(68) Oleyl amine and NaOH at a ratio by molar of 1:2 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added a predetermined amount of ethylene oxide, reacted at 120 degrees Celsius for 12 h; finally there was added a mixture of sodium chloroacetate and sodium chloromethyl sulfonate (at a ratio by molar of 1:1) at a ratio by molar between oleyl amine and the carboxylating agent of 1:5, further reacted at 55 degrees Celsius for 12 h. Upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 3, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous ammonia to a pH value of 10, water was removed by vacuum evaporation, to obtain an anionic-nonionic surfactant.

(69) Dodecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.5 were mixed till homogenous, to obtain the surfactant composition II-7, the particulars of which were listed in Table II-1.

Example II-8

(70) Octadecyl amine and NaOH at a ratio by molar of 1:4 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 4 h, then there was added a predetermined amount of ethylene oxide; then there was added sodium chloroacetate at a ratio by molar between octadecyl amine the carboxylating agent of 1:5, further reacted at 50 degrees Celsius for 14 h. Upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous Mg(OH).sub.2 suspension to a pH value of 9, water was removed by vacuum evaporation, to obtain an anionic-nonionic surfactant.

(71) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:8 were mixed till homogenous, to obtain the surfactant composition II-8, the particulars of which were listed in Table II-1.

Example II-9

(72) Aniline and NaOH at a ratio by molar of 1:3 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 7 h; finally there was added sodium chloroacetate at a ratio by molar between aniline and the carboxylating agent of 1:3, further reacted at 80 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation. separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, dried under vacuum, to obtain an anionic-nonionic surfactant.

(73) Bisoctadecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:4 were mixed till homogenous, to obtain the surfactant composition II-9, the particulars of which were listed in Table II-1.

Example II-10

(74) Cyclohexylamine and NaOH at a ratio by molar of 1:3 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 5 h, then there was added a predetermined amount of ethylene oxide, reacted at 150 degrees Celsius for 8 h; finally there was added sodium chloroacetate at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:3, further reacted at 80 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous ammonia to a pH value of 9, dried under vacuum, to obtain an anionic-nonionic surfactant.

(75) Dodecyl dimethyl (polyoxyethylene ether (n=3.1)) polyoxypropylene ether (n=1.8) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.3 were mixed till homogenous, to obtain the surfactant composition II-10, the particulars of which were listed in Table II-1.

Example II-11

(76) Aniline and NaOH at a ratio by molar of 1:2 were introduced into a reactor, stirred for 30 minutes, there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 5 h, then there was added a predetermined amount of ethylene oxide, reacted at 150 degrees Celsius for 8 h; finally there was added sodium chloroacetate at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:2, further reacted at 60 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, dried under vacuum, to obtain an intermediate. The intermediate was formulated into a 10 wt % dichloromethane solution, sulfonated in a falling-film sulfonation reactor. The solvent dichloromethane was removed by rotary evaporation, then the resultant was adjusted with a 50 wt % NH.sub.4OH solution, to obtain an anionic-nonionic surfactant.

(77) Bisdodecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.3 were mixed till homogenous, to obtain the surfactant composition II-11, the particulars of which were listed in Table II-1.

Example II-12

(78) The surfactant composition produced by Example II-6 and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26000000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(79) TABLE-US-00014 TABLE II-1 The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Example II- the structure of the cationic surfactant ratio by molar between cationic surfactant and anionic-nonionic surfactant 1 octadecyl dimethyl benzyl R = —C.sub.12H.sub.25, R.sub.1 = R= CH.sub.2, m.sub.1 + m.sub.2 = 30, n.sub.1 + n.sub.2 = 40, 1:0.1 ammonium chloride Y.sub.1 = Y.sub.2 = —COOK 2 tetrabutyl ammonium R = —C.sub.12H.sub.9, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 = m.sub.2 = 10, n.sub.1 + n.sub.2 = 5, one out of Y.sub.1 1:0.5 chloride and Y.sub.2 representing —COONa, while the other representing —SO.sub.3Na. 3 tributyl (polyoxyethylene R = —C.sub.6H.sub.11, R.sub.1 = R.sub.2 = (CH.sub.2).sub.5, m.sub.1 + m.sub.2 = 22, n.sub.2 + n.sub.2 = 40, 1:10  ether (n = 1.6)) Y.sub.1 = Y.sub.2 = —COONa polyoxypropylene ether (n = 2.7) ammonium chloride 4 decyl triethyl ammonium R = —C.sub.10H.sub.7, R.sub.1 = R.sub.2 = CH.sub.2CH(OH)CH.sub.2, m.sub.1 + m.sub.2 = 8, n.sub.1 + n.sub.2 = 15, 1:6   hydroxide Y.sub.1 = Y.sub.2 = —COONa 5 phenyl trimethyl R = —C.sub.16H.sub.33, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 0.5, n.sub.1 + n.sub.2 = 5, 1:1.4 ammonium chloride Y.sub.1 = Y.sub.2 = —COO(Ca).sub.0.5 6 benzyl triethyl ammonium R = —C.sub.18H.sub.37, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 8, n.sub.1 + n.sub.2 = 2, 1:1.8 chloride Y.sub.1 = Y.sub.2 = —COO(Mg).sub.0.5 7 dodecyl trimethyl R = —C.sub.18H.sub.35, R.sub.1 = R.sub.2 = CH.sub.2CH.sub.2, m.sub.1 + m.sub.2 = 12, n.sub.1 + n.sub.2 = 6, one out of 1:2.5 ammonium chloride Y.sub.1 and Y.sub.2 representing —COONH.sub.4, while the other representing —SO.sub.3NH.sub.4. 8 hexadecyl trimethyl R = —C.sub.18H.sub.37, R.sub.1 = R.sub.2 = CH.sub.2CH.sub.2, m.sub.1 + m.sub.2 = 8, n.sub.1 + n.sub.2 = 0, 1:8   ammonium chloride Y.sub.1 = Y.sub.2 = —COO(Mg).sub.0.5 9 bisoctadecyl dimethyl R = —C.sub.6H.sub.5, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 50, n.sub.1 + n.sub.2 = 32, Y.sub.1 = Y.sub.2 = —COONa 1:4   ammonium chloride 10 dodecyl dimethyl R = —C.sub.6H.sub.11, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 35, n.sub.1 + n.sub.2 = 50, 1:13  (polyoxyethylene ether Y.sub.1 = Y.sub.2 = —COONH.sub.4 (n = 3.1))(polyoxypropylene ether (n = 1.8)) ammonium chloride 11 decyl triethyl ammonium R = —C.sub.6H.sub.4SO.sub.3Na, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 35, n.sub.1 + n.sub.2 = 50, 1:1.7 hydroxide Y.sub.1 = Y.sub.2 = —COONH.sub.4

Example II-12 Interfacial Performance Test of the Surfactant Composition

(80) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, at a surfactant composition concentration of 0.3 wt %, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L.

(81) TABLE-US-00015 TABLE II-1 The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example II- interfacial tension (mN/m) 1 0.0071 2 0.0060 3 0.0055 4 0.0041 5 0.0008 6 0.0002 7 0.0028 8 0.0009 9 0.0005 10 0.0004 11 0.0037 12 0.0023

(82) As can be seen from Table II-1, the surfactant composition produced by each of Example II-1 to 10 exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example II-11 reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(83) The surfactant composition produced by Example II-10 was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table II-2.

(84) TABLE-US-00016 TABLE II-2 The oil-water interfacial tension between the surfactant composition II-10 (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 interfacial tension 0.0056 0.004 0.002 0.001 0.0006 0.0004 (mN/m)

(85) These results reveals that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity for the crude oil from the Henan Oilfield.

(86) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example II-6 and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.002 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

Example II-13 Oil Washing Capability Test of the Surfactant Composition

(87) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours. Then 5 g of the thus aged oil sand and a 0.3 wt % solution of the surfactant composition at an oil sand:solution ratio of 1:10 (by weight) were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(88) TABLE-US-00017 TABLE II-4 The oil washing performance of the surfactant composition Example II- oil washing rate % 1 53.1 2 54.8 3 56.2 4 59.0 5 66.8 6 68.8 7 66.5 8 65.1 9 69.7 10 68.9 11 73.6

Example II-14 Study on the Oil Displacement Performance of the Surfactant Composition

(89) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5μ,m.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table II-5.

(90) TABLE-US-00018 TABLE II-5 Oil displacement test results of the surfactant composition increased oil recovery Example II- % OOIP 1 5.5 2 5.8 3 6.1 4 6.3 5 8.0 6 9.2 7 7.4 8 8.2 9 7.9 10 8.6 11 9.3

Example II-15

(91) Cyclohexylamine and NaOH at a ratio by molar of 1:3 were introduced into a reactor, stirred for 30 minutes, at a ratio by molar of cyclohexylamine:ethylene oxide:propylene oxide=1:10:34, firstly there was added propylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added ethylene oxide, reacted at 160 degrees Celsius for 7 h; finally there was added sodium chloroacetate at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:1.5, further reacted at 80 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, water was removed by vacuum evaporation, whereby obtaining the following anionic-nonionic surfactant, wherein m.sub.1+m.sub.2=34, n.sub.1+n.sub.2=10:

(92) ##STR00154##

Comparative Example II-1

(93) According to Gong Yujun et. al, Journal of Northwest University (Natural Science Edition), Vol. 30 (1), pp. 28 to 31, February 2000, hexadecyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were combined at a ratio by molar of 1:1.5, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(94) TABLE-US-00019 TABLE 6 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.03 45.6 2.8

Comparative Example II-2

(95) According to Huang Hongdu et. al, Journal of Oil and Gas Technology, Vol. 29(4), August 2007 (pp. 101 to 104), 0.01 wt % hexadecyl trimethyl ammonium bromide, 0.02 wt % anionic petroleum sulfonate salt and 1.8 wt % Na.sub.2CO.sub.3 were combined, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(96) TABLE-US-00020 TABLE 7 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.008 56.3 4.2

Example II-1a

(97) C.sub.5H.sub.11COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added NaOH at an amount of 0.8% relative to the total weight of this mass, reacted at 200 degrees Celsius for 3 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 150 degrees Celsius for 5 h; then there was added sodium chloroacetate at a ratio by molar between C.sub.5H.sub.11COOCH.sub.3 and the carboxylating agent of 1:1, further reacted at 50 degrees Celsius for 20 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 1, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 1.0 wt % aqueous NaOH solution to a pH value of 7, to obtain an anionic-nonionic surfactant.

(98) Tetraethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:8 were mixed till homogenous, to obtain the surfactant composition II-1a, the particulars of which were listed in Table II-1a.

Example II-2a

(99) C.sub.20H.sub.41COOH and diisopropanol amine at a ratio by molar of 1:1.8 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.5% relative to the total weight of this mass, reacted at 180 degrees Celsius for 5 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 5 h; then there was added sodium chloroacetate at a ratio by molar between C.sub.20H.sub.41COOH and the carboxylating agent of 1:1.5, further reacted at 80 degrees Celsius for 8 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 3, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was adjusted with a 10 wt % aqueous KOH solution to a pH value of 9, to obtain an anionic-nonionic surfactant.

(100) Tetrabutyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:10 were mixed till homogenous, to obtain the surfactant composition II-2a, the particulars of which were listed in Table II-1a.

Example II-3a

(101) C.sub.14H.sub.29COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1 were introduced into a reactor, at the same time, there was added KOH at an amount of 15% relative to the total weight of this mass, reacted at 160 degrees Celsius for 8 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 150 degrees Celsius for 5 h, there was added a predetermined amount of ethylene oxide, reacted at 150 degrees Celsius for 5 h; then there was added Br(CH.sub.2).sub.5COOH at a ratio by molar between C.sub.14H.sub.29COOCH.sub.3 and the carboxylating agent of 1:2, further reacted at 100 degrees Celsius for 1 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous Mg(OH).sub.2 suspension to a pH value of 8, to obtain an anionic-nonionic surfactant.

(102) Tetraoctyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.4 were mixed till homogenous, to obtain the surfactant composition II-3a, the particulars of which were listed in Table II-1a.

Example II-4a

(103) C.sub.16H.sub.33COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:2 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.5% relative to the total weight of this mass, reacted at 160 degrees Celsius for 5 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 6 h, there was added a predetermined amount of ethylene oxide, reacted at 150 degrees Celsius for 3 h; then there was added a mixture of sodium chloroacetate and sodium chloromethyl sulfonate (at a ratio by molar of 1:1) at a ratio by molar between C.sub.20H.sub.41COOH and the carboxylating agent of 1:1.5, further reacted at 70 degrees Celsius for 10 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous Ca(OH).sub.2 suspension to a pH value of 8, to obtain an anionic-nonionic surfactant.

(104) Decyl triethyl ammonium hydroxide and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition II-4a, the particulars of which were listed in Table II-1a.

Example II-5a

(105) C.sub.10H.sub.21COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added NaOH at an amount of 1.0% relative to the total weight of this mass, reacted at 150 degrees Celsius for 6 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 140 degrees Celsius for 2 h, there was added a predetermined amount of ethylene oxide, reacted at 140 degrees Celsius for 5 h; then there was added sodium chloroacetate at a ratio by molar between C.sub.10H.sub.21COOCH.sub.3 and the carboxylating agent of 1:3, further reacted at 60 degrees Celsius for 16 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous ammonia to a pH value of 8, to obtain an anionic-nonionic surfactant.

(106) Phenyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.5 were mixed till homogenous, to obtain the surfactant composition II-5a, the particulars of which were listed in Table II-1a.

Example II-6a

(107) C.sub.18H.sub.37COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.8% relative to the total weight of this mass, reacted at 180 degrees Celsius for 3 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 180 degrees Celsius for 2 h, there was added a predetermined amount of ethylene oxide, reacted at 180 degrees Celsius for 2 h; then at a ratio by molar between C.sub.18H.sub.37COOCH.sub.3 and the sulfonating agent of 1:3 there was added sodium chloromethyl sulfonate, reacted at 120 degrees Celsius for 12 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous NaOH solution to a pH value of 8, to obtain an anionic-nonionic surfactant.

(108) Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.8 were mixed till homogenous, to obtain the surfactant composition II-6a, the particulars of which were listed in Table II-1a.

Example II-7a

(109) C.sub.18H.sub.37COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.8% relative to the total weight of this mass, reacted at 180 degrees Celsius for 3 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 180 degrees Celsius for 2 h, there was added a predetermined amount of ethylene oxide, reacted at 180 degrees Celsius for 2 h; then at a ratio by molar between C.sub.18H.sub.37COOCH.sub.3 and the sulfonating agent of 1:4 there was added hydroxyethyl sodium sulfonate, reacted at 180 degrees Celsius for 10 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous Ca(OH).sub.2 suspension to a pH value of 8, to obtain an anionic-nonionic surfactant.

(110) Tributyl (polyoxyethylene ether (n=1.6)) polyoxypropylene ether (n=2.7) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.5 were mixed till homogenous, to obtain the surfactant composition II-7a, the particulars of which were listed in Table II-1a.

Example II-8a

(111) C.sub.8H.sub.17COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.6% relative to the total weight of this mass, reacted at 160 degrees Celsius for 8 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 3 h, there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h; then at a ratio by molar between C.sub.8H.sub.17COOCH.sub.3 and the sulfonating agent of 1:5 there was added 3-chloro-2-hydroxyl sodium propanesulfonate, reacted at 190 degrees Celsius for 10 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous NaOH solution to a pH value of 8, to obtain an anionic-nonionic surfactant.

(112) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:4 were mixed till homogenous, to obtain the surfactant composition II-8a, the particulars of which were listed in Table II-1a.

Example II-9a

(113) C.sub.18H.sub.35COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:2 were introduced into a reactor, at the same time, there was added NaOH at an amount of 0.8% relative to the total weight of this mass, reacted at 160 degrees Celsius for 8 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 3 h, there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h; then at a ratio by molar between C.sub.18H.sub.35COOCH.sub.3 and the sulfonating agent of 1:5 there was added sodium chloropentyl sulfonate, reacted at 120 degrees Celsius for 20 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous NaOH solution to a pH value of 8, to obtain an anionic-nonionic surfactant.

(114) Bisoctadecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.1 were mixed till homogenous, to obtain the surfactant composition II-9a, the particulars of which were listed in Table II-1a.

Example II-10a

(115) C.sub.18H.sub.33COOCH.sub.3 and diisopropanol amine at a ratio by molar of 1:1.5 were introduced into a reactor, at the same time, there was added KOH at an amount of 0.6% relative to the total weight of this mass, reacted at 160 degrees Celsius for 8 h; and then excess diisopropanol amine was remove under vacuum; and then there was added a predetermined amount of propylene oxide, reacted at 160 degrees Celsius for 3 h, there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h; then at a ratio by molar between C.sub.18H.sub.33COOCH.sub.3 and the sulfonating agent of 1:5 there was added a mixture of 3-chloro-2-hydroxyl sodium propanesulfonate and sodium chloroacetate (at a ratio by molar of 1:1), reacted at 180 degrees Celsius for 8 h, finally neutralized with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, the oil phase was neutralized with a 10 wt % aqueous NaOH solution to a pH value of 8, to obtain an anionic-nonionic surfactant.

(116) Octadecyl dimethyl benzyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.3 were mixed till homogenous, to obtain the surfactant composition II-10a, the particulars of which were listed in Table II-1a.

Example II-11a

(117) The surfactant composition produced by Example II-10a and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26000000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(118) TABLE-US-00021 TABLE II-1a The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Example II- the structure of the cationic surfactant ratio by molar between cationic surfactant and anionic-nonionic surfactant 1a tetraethyl ammonium R = —OCC.sub.5H.sub.11, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 10, n.sub.1 + n.sub.2 = 0, Y.sub.1 = Y.sub.2 = —COONa 1:8   chloride 2a tetrabutyl ammonium R = —OCC.sub.20H.sub.41, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 0, n.sub.1 + n.sub.2 = 6.2, Y.sub.1 = Y.sub.2 = —COOK 1:1 0 chloride 3a tetraoctyl ammonium R = —OCC.sub.14H.sub.29, R.sub.1 = R.sub.2 == C.sub.5H.sub.10, m.sub.1 + m.sub.2 = 15, n.sub.1 + n.sub.2 = 33, 1:1.4 chloride Y.sub.1 = Y.sub.2 = —COO(Mg).sub.0.5 4a decyl triethyl R = —OCC.sub.16H.sub.33, R.sub.1 = R.sub.2 = CH.sub.2, m.sub.1 + m.sub.2 = 28, n.sub.1 + n.sub.2 = 37, one out of Y.sub.1 1:6   ammonium hydroxide and Y.sub.2 representing —COO(Ca).sub.0.5, while the other representing —SO.sub.3(Ca).sub.0.5. 5a phenyl trimethyl R = —OCC.sub.10H.sub.21, R.sub.1 = R.sub.2 = CH.sub.2, n.sub.1 + n.sub.2 = 6, m.sub.1 + m.sub.2 = 10, 1:0.5 ammonium chloride Y.sub.1 = Y.sub.2 = —COONH.sub.4 6a benzyl triethyl R = —OCC.sub.18H.sub.37, R.sub.1 = R.sub.2 = —CH.sub.2, m.sub.1 + m.sub.2 = 12, n.sub.1 + n.sub.2 = 12.5, x = 1, 1:1.8 ammonium chloride Y.sub.1 = Y.sub.2 = —COONa 7a tributyl R = —OCC.sub.12H.sub.23, R.sub.1 = R.sub.2 = —CH.sub.2CH.sub.2, m.sub.1 + m.sub.2 = 18 .2, n.sub.1 + n.sub.2 = 16.5, 1:2.5 1:2.5 (polyoxyethylene ether Y.sub.1 = Y.sub.2 = —COO(Ca).sub.0.5 (n = 1.6)) polyoxypropylene ether (n = 2.7) ammonium chloride 8a hexadecyl trimethyl R = —OCC.sub.8H.sub.17, R.sub.1 = R.sub.2 = —CH.sub.2CH(OH)CH.sub.2, m.sub.1 + m.sub.2 = 12, n.sub.1 + n.sub.2 = 4, 1:4   ammonium chloride Y.sub.1 = Y.sub.2 = —COONa 9a bisoctadecyl dimethyl R = —OCC.sub.18H.sub.35, R.sub.1 = R.sub.2 = —C.sub.5H.sub.10, m.sub.1 + m.sub.2 = 20, n.sub.1 + n.sub.2 = 50, Y.sub.1 = Y.sub.2 = 1:0.1 ammonium chloride —COONa 10a octadecyl dimethyl R = —OCC.sub.18H.sub.33, R.sub.1 = R.sub.2 = —CH.sub.2CH(OH)CH.sub.2, m.sub.1 + m.sub.2 = 50, n.sub.1 + n.sub.2 = 42, 1:1.3 benzyl ammnoium one out of R.sub.1Y.sub.1 and R.sub.2Y.sub.2 representing —CH.sub.2COONa, while the chloride other representing —CH.sub.2CH(OH)CH.sub.2SO.sub.3Na.

Example II-12a Interfacial Performance Test of the Surfactant Composition

(119) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, at a surfactant composition concentration of 0.3 wt %, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L.

(120) TABLE-US-00022 TABLE II-2a The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example II- interfacial tension (mN/m) 1a 0.0088 2a 0.0070 3a 0.0054 4a 0.0041 5a 0.0028 6a 0.0004 7a 0.0049 8a 0.0024 9a 0.0009 10a  0.0004 11a  0.0043

(121) As can be seen from Table II-2a, the surfactant composition produced by each of Example II-1a to 10a exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example II-11a reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(122) The surfactant composition produced by Example II-10a was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table II-3a.

(123) TABLE-US-00023 TABLE II-3a The oil-water interfacial tension between the surfactant composition 10a (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 interfacial tension 0.008 0.005 0.002 0.001 0.0007 0.0004 (mN/m)

(124) These results reveals that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity with the crude oil from the Henan Oilfield.

(125) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example II-6a and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.001 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

Example II-13a Oil Washing Capability Test of the Surfactant Composition

(126) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours. Then 5 g of the thus aged oil sand, and a 0.3 wt % solution of the surfactant composition at an oil sand:solution ratio of 1:10 (by weight) were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(127) TABLE-US-00024 TABLE II-4a The oil washing performance of the surfactant composition Example II- oil washing rate % 1a 50.6 2a 53.0 3a 55.3 4a 57.1 5a 60.2 6a 61.9 7a 61.4 8a 63.1 9a 65.4 10a  66.3

Example II-14a Study on the Oil Displacement Performance of the Surfactant Composition

(128) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5 μm.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table II-5a.

(129) TABLE-US-00025 TABLE II-5a The test results of the oil displacement increased oil recovery Example II- % OOIP 1a 4.5 2a 4.7 3a 5.8 4a 6.2 5a 6.9 6a 7.5 7a 6.9 8a 7.1 9a 8.4 10a  9.1

Example III-1

(130) 1-bromododecane, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-dodecyl diethylenetriamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromododecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 7-di(dodecyl) diethylenetriamine. 1, 7-di(dodecyl) diethylenetriamine and KOH at a ratio by molar of 1:6 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Octadecyl dimethyl benzyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.1 were mixed till homogenous, to obtain the surfactant composition III-1, the particulars of which were listed in Table III-1.

Example III-2

(131) 1-bromododecane, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-dodecyl triethylenetetramine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromododecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 10-di(dodecyl) triethylenetetramine. 1, 10-di(dodecyl) triethylenetetramine and NaOH at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(132) Tetrabutyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.5 were mixed till homogenous, to obtain the surfactant composition the particulars of which were listed in Table III-1.

Example III-3

(133) 1-bromocyclohexane, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:110 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-cyclohexyl tetraethylenepentamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromocyclohexane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 13-di(cyclohexyl) diethylenetriamine. 1, 13-di(cyclohexyl) tetraethylenepentamine and NaOH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(134) Trioctyl (polyoxyethylene ether (n=2)) polyoxypropylene ether (n=3) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:10 were mixed till homogenous, to obtain the surfactant composition III-3, the particulars of which were listed in Table III-1.

Example III-4

(135) 1-bromodecane, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-decanyl diethylenetriamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromodecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 7-di(decanyl) diethylenetriamine. 1, 7-di(decanyl) diethylenetriamine and NaOH at a ratio by molar of 1:6 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added a mixture of chloromethyl sulfonic acid and chloroacetic acid (at a ratio by molar of 1:1) at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Decyl triethyl ammonium hydroxide and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition III-4, the particulars of which were listed in Table III-1.

Example III-5

(136) 1-bromohexadecane, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-hexadecyl diethylenetriamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromohexadecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1,7-di(hexadecyl) diethylenetriamine. 1, 7-di(hexadecyl) diethylenetriamine and Ca(OH).sub.2 at a ratio by molar of 1:6 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(137) Phenyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.4 were mixed till homogenous, to obtain the surfactant composition III-5, the particulars of which were listed in Table III-1.

Example III-6

(138) Lauroyl chloride, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-lauroyl triethylenetetramine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and lauroyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 10-di(lauroyl) triethylenetetramine. 1, 10-di(lauroyl) triethylenetetramine, and Mg(OH).sub.2 at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(139) Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.8 were mixed till homogenous, to obtain the surfactant composition III-6, the particulars of which were listed in Table III-1.

Example III-7

(140) Stearoyl chloride, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-stearoyl triethylenetetramine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and stearoyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 10-di(stearoyl) triethylenetetramine. 1, 10-di(stearoyl) triethylenetetramine and NH.sub.4OH at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(141) Dodecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.5 were mixed till homogenous, to obtain the surfactant composition III-7, the particulars of which were listed in Table III-1.

Example III-8

(142) Benzyl chloride, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-benzyl tetraethylenepentamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and benzyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 12-di(benzyl) tetraethylenepentamine. 1, 12-di(benzyl) tetraethylenepentamine and Mg(OH).sub.2 at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(143) Hexadecyl dimethyl (polyoxyethylene ether (n=2)) polyoxypropylene ether (n=3) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:8 were mixed till homogenous, to obtain the surfactant composition III-8, the particulars of which were listed in Table III-1.

Example III-9

(144) Benzoyl chloride, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-benzyl tetraethylenepentamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and benzoyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 12-di(benzoyl) tetraethylenepentamine. 1, 12-di(benzoyl) tetraethylenepentamine and NaOH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(145) Bisoctadecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:4 were mixed till homogenous, to obtain the surfactant composition III-9, the particulars of which were listed in Table III-1.

Example III-10

(146) p-methyl benzoyl chloride, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-p-methyl benzoyl tetraethylenepentamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and p-methyl benzoyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1, 12-di(p-methyl benzoyl) tetraethylenepentamine. 1, 12-di(p-methyl benzoyl) tetraethylenepentamine and NH.sub.4OH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Bisdodecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.3 were mixed till homogenous, to obtain the surfactant composition III-10, the particulars of which were listed in Table III-1.

Example III-11

(147) Benzoyl chloride, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-benzoyl tetraethylenepentamine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromodecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1-benzoyl-2-decanyl tetraethylenepentamine. 1-benzoyl-2-decanyl tetraethylenepentamine and NH.sub.4OH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.1 were mixed till homogenous, to obtain the surfactant composition III-11, the particulars of which were listed in Table III-1.

Example III-12

(148) Stearoyl chloride, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-stearoyl triethylenetetramine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and lauroyl chloride were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1-stearoyl-10-lauroyl triethylenetetramine. 1-stearoyl-10-lauroyl triethylenetetramine and NH.sub.4OH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(149) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition III-12, the particulars of which were listed in Table III-1.

Example III-13

(150) 1-bromododecane, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-dodecyl triethylenetetramine was purified by extraction. Then at a ratio by molar of 10:1:1, the intermediate, Na.sub.2CO.sub.3 and 1-bromohexadecane were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, to obtain 1-dodecyl-10-hexadecyl triethylenetetramine. 1-dodecyl-10-hexadecyl triethylenetetramine and NH.sub.4OH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(151) Tetraoctyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.4 were mixed till homogenous, to obtain the surfactant composition III-13, the particulars of which were listed in Table III-1.

Example III-14

(152) The surfactant composition produced by Example III-6 and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26000000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(153) TABLE-US-00026 TABLE III-1 The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Example III- the structure of the cationic surfactant ratio by molar between cationic surfactant and anionic-nonionic surfactant 1 octadecyl dimethyl benzyl R.sub.1 = R.sub.2 = —C.sub.12H.sub.25, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 30, xn + n′ = 1:0.1 ammonium chloride 40, x = 2, Y = —COOK 2 tetrabutyl ammonium R.sub.1 = R.sub.2 = —C.sub.12H.sub.25, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 10, xn + n′ = 5, 1:0.5 chloride x = 3, Y = —COONa 3 trioctyl (polyoxyethylene R.sub.1 = R.sub.2 = —C.sub.6H.sub.11, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 22, xn + n′ = 40, 1: 10 ether (n = 2)) x = 4, Y = —COONa polyoxypropylene ether (n = 3) ammonium chloride 4 decyl triethyl ammonium R.sub.1 = R.sub.2 = —C.sub.10H.sub.21, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 8, xn + n′ = 15, 1:6   hydroxide x = 2, wherein two Y represent —SO.sub.3Na, one Y represents 1:6   COONa 5 phenyl trimethyl R.sub.1 = R.sub.2 = —C.sub.16H.sub.33, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 5, 1:1.4 ammonium chloride x = 2, Y = —COO(Ca).sub.0.5 6 benzyl triethyl ammonium R.sub.1 = R.sub.2 = C.sub.11H.sub.21CO—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 8, 1:1.8 chloride xn + n′ = 2, x = 3, Y = —COO(Mg).sub.0.5 7 dodecyl trimethyl R.sub.1 = R.sub.2 = —C.sub.17H.sub.35CO—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2CH.sub.2, xm + m′ = 12, 1:2.5 ammonium chloride xn + n′ = 6, x = 3, Y = —COONH.sub.4 8 hexadecyl dimethyl R.sub.1 = R.sub.2 = C.sub.6H.sub.5CH.sub.2—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2CH.sub.2, xm + m′ = 8, 1:8   (polyoxyethylene ether xn + n′ = 0, x = 4, Y = —COO(Mg).sub.0.5 (n = 2))polyoxypropylene ether (n = 3) ammonium chloride 9 bisoctadecyl dimethyl R.sub.1 = R.sub.2 = C.sub.6H.sub.5CO—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 50, 1:4   ammonium chloride xn + n′ = 32, x = 4, Y = —COONa 10 bisdodecyl dimethyl R.sub.1 = R.sub.2 = CH.sub.3C.sub.6H.sub.5CO—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 35, 1:1.3 ammonium chloride xn + n′ = 50, x = 2, Y = —COONH.sub.4 11 benzyl triethyl ammonium R.sub.1 = C.sub.6H.sub.5CO—, R.sub.2 = —C.sub.10H.sub.21, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, 1:1.1 chloride xm + m′ = 50, xn + n′ = 32, x = 4, Y = —COONa 12 hexadecyl trimethyl R.sub.1 = —C.sub.17H.sub.35CO—, R.sub.2 = C.sub.11H.sub.21CO—, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2CH.sub.2, 1:6   ammonium chloride xm + m′ = 12, xn + n′ = 6, x = 3, Y = —COONH.sub.4 13 tetraoctyl ammonium R.sub.1 = —C.sub.12H.sub.25, R.sub.2 = —C.sub.16H.sub.33, R.sub.3 = —CH.sub.2CH.sub.2—, R.sub.4 = CH.sub.2, xm + m′ = 10, 1:2.4 chloride xn + n′ = 5, x = 3, Y = —COONa

Example III-15 Interfacial Performance Test of the Surfactant Composition

(154) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, at a surfactant composition concentration of 0.3 wt %, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L.

(155) TABLE-US-00027 TABLE III-2 The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example III- interfacial tension (mN/m) 1 0.0061 2 0.0052 3 0.0043 4 0.0090 5 0.0007 6 0.0005 7 0.0023 8 0.0009 9 0.0006 10 0.0004 11 0.0031 12 0.0005 13 0.0007 14 0.0002

(156) As can be seen from Table III-2, the surfactant composition produced by each of Example III-1 to 10 exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example III-14 reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(157) The surfactant composition produced by Example III-10 was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table III-3.

(158) TABLE-US-00028 TABLE III-3 The oil-water interfacial tension between the surfactant composition III-10 (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 0.4 0.5 interfacial tension 0.009 0.005 0.001 0.0008 0.0004 0.0005 0.0009 0.0009 (mN/m)

(159) These results reveals that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity for the crude oil from the Henan Oilfield.

(160) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example III-6 and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.002 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

Example III-16 Oil Washing Capability Test of the Surfactant Composition

(161) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours; and then 5 g of the thus aged oil sand and a 0.3 wt % solution of the surfactant composition at an oil sand:solution ratio of 1:10 (by weight) were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(162) TABLE-US-00029 TABLE III-4 The oil washing performance of the surfactant composition Example III- oil washing rate % 1 58.6 2 54.3 3 63.2 4 66.6 5 58.9 6 62.4 7 63.5 8 68.1 9 49.8 10 57.3 11 76.5 12 82.4 13 79.8

Example III-17 Study on the Oil Displacement Performance of the Surfactant Composition

(163) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5 μm.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table III-5.

(164) TABLE-US-00030 TABLE III-5 Oil displacement test results of the surfactant composition increased oil recovery Example III- % OOIP 1 7.1 2 7.2 3 7.5 4 7.9 5 7.9 6 8.5 7 8.4 8 8.7 9 8.2 10 8.4 11 9.1 12 10.4 13 11.2

Example III-18

(165) Cyclohexylamine and NaOH at a ratio by molar of 1:3 were introduced into a reactor, stirred for 30 minutes, at a ratio by molar of cyclohexylamine:ethylene oxide:propylene oxide=1:10:34, firstly there was added propylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added ethylene oxide, reacted at 160 degrees Celsius for 7 h; finally there was added sodium chloroacetate at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:1.5, further reacted at 80 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, water was removed by vacuum evaporation, whereby obtaining the following anionic-nonionic surfactant, wherein m.sub.1+m.sub.2=34, n.sub.1+n.sub.2=10:

(166) ##STR00157##

Comparative Example III-1

(167) According to Gong Yujun et. al, Journal of Northwest University (Natural Science Edition), Vol. 30 (1), pp. 28 to 31, February 2000, hexadecyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were combined at a ratio by molar of 1:1.5, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(168) TABLE-US-00031 TABLE III-6 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.03 45.6 2.8

Comparative Example III-2

(169) According to Huang Hongdu et. al, Journal of Oil and Gas Technology, Vol. 29(4), August 2007 (pp. 101 to 104), 0.01 wt % hexadecyl trimethyl ammonium bromide, 0.02 wt % anionic petroleum sulfonate salt and 1.8 wt % Na.sub.2CO.sub.3 were combined, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(170) TABLE-US-00032 TABLE III-7 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.008 56.3 4.2

Example IV-1

(171) 1-bromododecane, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-dodecyl diethylenetriamine was purified by extraction. The intermediate and KOH at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(172) Octadecyl dimethyl benzyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.2 were mixed till homogenous, to obtain the surfactant composition IV-1, the particulars of which were listed in Table IV-1.

Example IV-2

(173) 1-bromocyclohexane, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-cyclohexyl diethylenetriamine was purified by extraction. The intermediate and KOH at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(174) Tetraoctyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:0.5 were mixed till homogenous, to obtain the surfactant composition IV-2, the particulars of which were listed in Table IV-1.

Example IV-3

(175) p-methyl benzoyl chloride, Na.sub.2CO.sub.3, tetraethylenepentamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-p-methyl benzoyl tetraethylenepentamine was purified by extraction. 1-p-methyl benzoyltetraethylenepentamine and NaOH at a ratio by molar of 1:12 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between tetraethylenepentamine and the carboxylating agent of 1:6, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Trioctyl (polyoxyethylene ether (n=2.2)) polyoxypropylene ether (n=1.8) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:9 were mixed till homogenous, to obtain the surfactant composition IV-3, the particulars of which were listed in Table IV-1.

Example IV-4

(176) Lauroyl chloride, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-lauroyl diethylenetriamine was purified by extraction. 1-lauroyl diethylenetriamine and NaOH at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added a mixture of chloromethyl sulfonic acid and chloroacetic acid (at a ratio by molar of 2:1) at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(177) Decyl triethyl ammonium hydroxide and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:6 were mixed till homogenous, to obtain the surfactant composition IV-4, the particulars of which were listed in Table IV-1.

Example IV-5

(178) Benzyl chloride, Na.sub.2CO.sub.3, diethylenetriamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-benzyl diethylenetriamine was purified by extraction. The intermediate and Ca(OH).sub.2 at a ratio by molar of 1:8 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between diethylenetriamine and the carboxylating agent of 1:4, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(179) Phenyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.4 were mixed till homogenous, to obtain the surfactant composition IV-5, the particulars of which were listed in Table IV-1.

Example IV-6

(180) 1-bromooctadecane, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-octadecyl triethylenetetramine was purified by extraction. 1-octadecyl triethylenetetramine and Mg(OH).sub.2 at a ratio by molar of 1:5 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(181) Benzyl triethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.8 were mixed till homogenous, to obtain the surfactant composition IV-6, the particulars of which were listed in Table IV-1.

Example IV-7

(182) 1-bromo-cis-9-octadecene, Na.sub.2CO.sub.3, triethylenetetramine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-(cis-9-octadecenyl) triethylenetetramine was purified by extraction. The intermediate and NH.sub.4OH at a ratio by molar of 1:10 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between triethylenetetramine and the carboxylating agent of 1:5, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(183) Trimethyl (polyoxyethylene ether (n=1.6)) polyoxypropylene ether (n=3.7) ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.5 were mixed till homogenous, to obtain the surfactant composition IV-7, the particulars of which were listed in Table IV-1.

Example IV-8

(184) 1-bromo-cis-9-octadecene, Na.sub.2CO.sub.3, hydroxyethyl ethylenediamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-(cis-9-octadecenyl)-2-hydroxyethyl ethylenediamine was purified by extraction. The intermediate and NaOH at a ratio by molar of 1:5 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between hydroxyethyl ethylenediamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(185) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2.1 were mixed till homogenous, to obtain the surfactant composition IV-8, the particulars of which were listed in Table IV-1.

Example IV-9

(186) 1-bromotetradecane, Na.sub.2CO.sub.3, hydroxyethyl ethylenediamine at a ratio by molar of 1:1:10 were introduced into a reactor, reacted at 60 degrees Celsius for 1-15 h, and then the intermediate 1-tetradecanyl-2-hydroxyethyl ethylenediamine was purified by extraction. The intermediate and KOH at a ratio by molar of 1:5 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between hydroxyethyl ethylenediamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant. Bisoctadecyl dimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1.9 were mixed till homogenous, to obtain the surfactant composition IV-9, the particulars of which were listed in Table IV-1.

Example IV-10

(187) Methyl stearate, KOH, hydroxyethyl ethylenediamine at a ratio by molar of 1:1:3 were introduced into a reactor, reacted at 140 degrees Celsius for 1-15 h, and then the intermediate 1-(stearoyl)-2-hydroxyethyl ethylenediamine was purified by extraction. The intermediate and KOH at a ratio by molar of 1:5 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added chloroacetic acid at a ratio by molar between hydroxyethyl ethylenediamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(188) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:1 were mixed till homogenous, to obtain the surfactant composition IV-10, the particulars of which were listed in Table IV-1.

Example IV-11

(189) Methyl benzoate, KOH, hydroxyethyl ethylenediamine at a ratio by molar of 1:1:3 were introduced into a reactor, reacted at 140 degrees Celsius for 1-15 h, and then the intermediate 1-(benzoyl)-2-hydroxyethyl ethylenediamine was purified by extraction. The intermediate and KOH at a ratio by molar of 1:5 were added, and then there was added a predetermined amount of propylene oxide, reacted at 200 degrees Celsius for 1 h, then there was added a predetermined amount of ethylene oxide, reacted at 160 degrees Celsius for 3 h, and then cooled to 50 degrees Celsius, there was added a mixture of chloromethyl sulfonic acid and chloroacetic acid (at a ratio by molar of 1:1) at a ratio by molar between hydroxyethyl ethylenediamine and the carboxylating agent of 1:3, reacted at 50 degrees Celsius for 20 h, to obtain an anionic-nonionic surfactant.

(190) Hexadecyl trimethyl ammonium chloride and the thus produced anionic-nonionic surfactant were dissolved into water respectively, stirred for 30 minutes, and formulated into a 0.3 wt % aqueous solution, and then the thus obtained solutions at a ratio by molar between the cationic surfactant and the anionic-nonionic surfactant of 1:2 were mixed till homogenous, to obtain the surfactant composition IV-11, the particulars of which were listed in Table IV-1.

Example IV-12

(191) The surfactant composition produced by Example IV-7 and a 0.15 wt % aqueous solution of polyacrylamide (having a molecular weight of 26000000) were mixed till homogenous, to obtain a flooding fluid composition for tertiary oil recovery.

(192) TABLE-US-00033 TABLE IV-1 The particulars of the surfactant composition the structure of the anionic-nonionic surfactant Example IV- the structure of the cationc surfactant ratio by molar between cationic surfactant and anionic-nonionic surfactant 1 octadecyl dimethyl benzyl R.sub.1 = —C.sub.12H.sub.25, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 30, xn + n′ + n″ = 40, 1:0.2 ammonium chloride x = 2, Y = N, a = 1, R.sub.2 = R.sub.2′ = R.sub.2′′′ = —CH.sub.2COOK 2 tetraoctyl ammonium R.sub.1 = —C.sub.6H.sub.11, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 10, xn + n′ + n″ = 5, x = 3, 1:0.5 chloride Y = N, a = 1, R.sub.2 = R.sub.2 ′ = R.sub.2′′′ = —CH.sub.2COOK 3 trioctyl (polyoxyethylene R.sub.1 = CH.sub.3C.sub.6H.sub.5CO—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 22, 1:9   ether (n = 2.2)) xn + n′ + n″ = 40, x = 4, Y = N, a = 1, R.sub.2 = R.sub.2′ = R.sub.2′′′ = —CH.sub.2COONa polyoxypropylene ether (n = 1.8) ammonium chloride 4 decyl triethyl ammonium R.sub.1 = C.sub.11H.sub.21CO—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 8, xn + n′ + n″ = 15, 1:6   hydroxide X = 2, Y = N, a = 1, one out of R.sub.2, R.sub.2′ and R.sub.2′′′ being —CH.sub.2COONa, the other two being —CH.sub.2SO.sub.3Na 5 phenyl trimethyl R.sub.1 = C.sub.6H.sub.5CO—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 2, xn + n′ + n″ = 5, x = 2, 1:1.4 ammonium chloride Y = N, a = 1, R.sub.2 = R.sub.2′ = R.sub.2′′′ = —CH.sub.2COO(Ca).sub.0.5 6 benzyl triethyl ammonium R.sub.1 = C.sub.17H.sub.37—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 2, xn + n′ + n″ = 5, x = 3, 1:1.8 chloride Y = N, a = 1, R.sub.2 = R.sub.2′ = R.sub.2′′′ = —CH.sub.2COO(Mg).sub.0.5 7 trimethyl (polyoxyethylene R.sub.1 = (z)-9-C.sub.17H.sub.35—, R.sub.2 = CH.sub.2CH.sub.2, xm + m′ + m″ = 12, xn + n′ + n″ = 6, 1:2.5 ether (n = 1.6)) x = 3, Y = N, a = 1, R.sub.2 = R.sub.2′ = R.sub.2′′′ = —CH.sub.2COONH.sub.4 polyoxypropylene ether (n = 3.7) ammonium chloride 8 octadecyl dimethyl benzyl R.sub.1 = —C.sub.12H.sub.25, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 30, xn + n′ + n″ = 40, 1:2.1 ammonium chloride x = 2, Y = O, a = 0, R.sub.2 = R.sub.2′ = —CH.sub.2COOK 9 tetraoctyl ammonium R.sub.1 = —C.sub.6H.sub.11, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 10, xn + n′ + n″ = 5, x = 3, 1:1.9 chloride Y = O, a = 0, R2 = R2′ = —CH.sub.2COOK 10 tetraoctyl ammonium R.sub.1 = CH.sub.3C.sub.6H.sub.5CO—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 22, 1:1   chloride xn + n′ + n″ = 40, x = 4, Y = O, a = 0, R.sub.2 = R.sub.2′ = —CH.sub.2COONa 11 decyl triethyl ammonium R.sub.1 = C.sub.11H.sub.21CO—, R′ = —CH.sub.2CH.sub.2—, xm + m′ + m″ = 8, xn + n′ + n″ = 15, 1:2   hydroxide x = 2, Y = O, a = 0, one out of R.sub.2 and R.sub.2′ being —CH.sub.2COONa, while the other representing —CH.sub.2SO.sub.3Na

Example IV-13 Interfacial Performance Test of the Surfactant Composition

(193) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between each surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield, at a surfactant composition concentration of 0.3 wt %, with a test temperature of 81 degrees Celsius, a formation water of NaHCO.sub.3 type, a TDS of 7947 mg/L, a chloride ion content of 2002 mg/L, a Ca.sup.2+ content of 20 mg/L, a Mg.sup.2+ content of 12.2 mg/L.

(194) TABLE-US-00034 TABLE IV-2 The oil-water interfacial tension between the surfactant composition and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield Example IV- interfacial tension (mN/m) 1 0.0053 2 0.0062 3 0.0085 4 0.0032 5 0.0028 6 0.0014 7 0.0005 8 0.0003 9 0.0006 10 0.0065 11 0.0009

(195) As can be seen from Table 2, the surfactant composition produced by each of Example IV-1 to 11 exhibits desirable interfacial performance with the crude oil from the Henan Oilfield. Example IV-12 reveals that, the thus produced surfactant composition still exhibits desirable interfacial performance, even after compounded with a polymer.

(196) The surfactant composition produced by Example IV-8 was formulated into different concentrations, each was tested the oil-water interfacial tension with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed in Table IV-3.

(197) TABLE-US-00035 TABLE IV-3 The oil-water interfacial tension between the surfactant composition 8 (at different concentrations) and the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield surfactant composition concentration (wt %) 0.01 0.02 0.05 0.1 0.2 0.3 interfacial tension 0.005 0.002 0.0009 0.0005 0.0004 0.0003 (mN/m)

(198) These results reveals that, the surfactant composition of this invention exhibits a relatively higher oil-water interfacial activity for the crude oil from the Henan Oilfield.

(199) TX-500C type spinning drop interfacial tensiometer was used to identify the oil-water interfacial tension between the surfactant composition produced by Example IV-7 and a crude oil from the third oil plant of the Zhongyuan Oilfield, with a test temperature of 80 degrees Celsius, a formation water with a TDS of 79439 mg/L, a Ca.sup.2+ content of 592 mg/L, a Mg.sup.2+ content of 2871 mg/L, a surfactant composition concentration of 0.3 wt %. The oil-water interfacial tension was observed as low as 0.002 mN/m. This reveals that the surfactant composition of this invention shows versatile applicability, not only to a reservoir with a low TDS, but also to a reservoir at elevated temperatures and high salinity, with desirable interfacial performances.

Example IV-13 Oil Washing Capability Test of the Surfactant Composition

(200) The IV5-11 reservoir oil sand from the Henan Shuanghe Oilfield at an oil:sand ratio of 1:4 (by weight) was aged at 81 degrees Celsius for 7 days, stirred for 5 minutes every 2 hours. Then 5 g of the thus aged oil sand and a 0.3 wt % solution of the surfactant composition at an oil sand:solution ratio of 1:10 (by weight) were mixed till homogenous, aged at the reservoir temperature for 48 h, then crude oil in the solution was extracted with petroleum ether, adjusted with a 50 ml colorimetric tube to a metered volume, colorimetric analysized with a spectrophotometer at a wavelength of 430 nm. The concentration of crude oil in the surfactant solution was calculated by referring to the standard curve.

(201) TABLE-US-00036 TABLE IV-4 The oil washing performance of the surfactant composition Example IV- oil washing rate % 1 57.8 2 62.4 3 82.3 4 81.4 5 65.9 6 71.2 7 78.3 8 76.4 9 75.1 10 72.3 11 77.1

Example IV-14 Study on the Oil Displacement Performance of the Surfactant Composition

(202) The oil displacement test was performed on a cylindrical natural core of sandstone having a length of 30 cm, a diameter of 2.5 cm and a permeability of 1.5 μm.sup.2. The core was firstly injected with the IV5-11 reservoir formation water from the Henan Shuanghe Oilfield till no crude oil was found in the effluent, then with a 0.3 PV (pore volume of the core) of the surfactant composition, then with water till no crude oil was found in the effluent. The results were listed in Table III-5.

(203) TABLE-US-00037 TABLE IV-5 Oil displacement test results of the surfactant composition increased oil recovery Example IV- % OOIP 1 8.2 2 8.3 3 9.3 4 10.1 5 9.7 6 9.9 7 10.3 8 10.4 9 10.3 10 9.5 11 9.6

Example IV-15

(204) Cyclohexylamine and NaOH at a ratio by molar of 1:3 were introduced into a reactor, stirred for 30 minutes, at a ratio by molar of cyclohexylamine:ethylene oxide:propylene oxide=1:10:34, firstly there was added propylene oxide, reacted at 160 degrees Celsius for 3 h, then there was added ethylene oxide, reacted at 160 degrees Celsius for 7 h; finally there was added sodium chloroacetate at a ratio by molar between cyclohexylamine and the carboxylating agent of 1:1.5, further reacted at 80 degrees Celsius for 8 h, upon completion of the reaction, the reaction mixture was adjusted with a 5 wt % aqueous HCl solution to a pH value of 2, allowed to stand for layer separation, separated off the aqueous phase, while the oil phase was adjusted with a 10 wt % aqueous NaOH solution to a pH value of 9, water was removed by vacuum evaporation, whereby obtaining the following anionic-nonionic surfactant, wherein m.sub.1+m.sub.2=34, n.sub.1+n.sub.2=10:

(205) ##STR00159##

Comparative Example IV-1

(206) According to Gong Yujun et. al, Journal of Northwest University (Natural Science Edition), Vol. 30 (1), pp. 28 to 31, February 2000, hexadecyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were combined at a ratio by molar of 1:1.5, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(207) TABLE-US-00038 TABLE IV-6 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.03 45.6 2.8

Comparative Example IV-2

(208) According to Huang Hongdu et. al, Journal of Oil and Gas Technology, Vol. 29(4), August 2007 (pp. 101 to 104), 0.01 wt % hexadecyl trimethyl ammonium bromide, 0.02 wt % anionic petroleum sulfonate salt and 1.8 wt % Na.sub.2CO.sub.3 were combined, and tested at a concentration of 0.3 wt % for its oil-water interfacial tension, oil washing rate and oil displacement performance with the IV5-11 reservoir crude oil from the Henan Shuanghe Oilfield. The results were listed as follows.

(209) TABLE-US-00039 TABLE IV-7 The performance of the reference flooding fluid interfacial tension increased oil recovery (mN/m) oil washing rate % % OOIP 0.008 56.3 4.2

(210) While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.