Asphaltene solvation and dispersion process

Abstract

The capacity of a crude oil to solvate and/or disperse asphaltenes is increased by providing a crude oil which includes an additive comprising (i) a poly(butylenyl)bezene sulphonic acid; or, (ii) a poly(propylenyl)benzene sulphonic acid; or, (iii) a combination of a poly(butylenyl)bezene sulphonic acid and a poly(propylenyl)benzene sulphonic acid.

Claims

1. A method for enhancing the capacity of a crude oil to solvate and/or disperse asphaltenes in said crude oil, the method comprising adding an effective minor amount of Additive A or Additive B, or an effective minor amount of a combination of Additive A and Additive B, to the crude oil; wherein: (i) Additive A, when present, is present in an effective minor amount of from 1 to 10000 ppm by mass, based on the total mass of the crude oil, and Additive A comprises one or more 4-poly(butylenyl)benzene sulphonic acid(s), wherein the poly(butylenyl) substituent group of greater than 50 mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acid(s), has greater than or equal to 32 total carbon atoms in said substituent group, as determined by GC, a number average molecular weight (M.sub.n) of from 550 to 800 daltons, and a polydispersity index of from 1.1 to 1.5; and (ii) Additive B, when present, is present in an effective minor amount of from 1 to 10000 ppm by mass, based on the total mass of the crude oil, and Additive B comprises one or more 4-poly(propylenyl)benzene sulphonic acids, wherein the poly(propylenyl) substituent group of greater than 50 mass % of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B, based on the total mass of all said one or more 4-poly(propylenyl)benzene sulphonic acid(s), has greater than or equal to 21 total carbon atoms in said substituent group, as determined by GC.

2. The method as claimed in claim 1, wherein the crude oil has an asphaltene content.

3. The method as claimed in claim 1, wherein the crude oil comprises a single type of crude oil or a crude oil blend comprising two or more different types of crude oil.

4. The method as claimed in claim 1, wherein Additive A or Additive B, or a combination of Additive A and Additive B, is each independently added to the crude oil before said crude oil arrives at a petroleum refinery.

5. The method as claimed in claim 1, wherein Additive A or Additive B, or a combination of Additive A and Additive B, is each independently added to the crude oil at one or more crude oil production and/or processing stages, selected from: (i) to the crude oil residing in a subterranean crude oil reservoir; (ii) to the crude oil during storage of the crude oil; (iii) to the crude oil during transportation of the crude oil; and (iv) to the crude oil before or during a blending process of the crude oil.

6. The method as claimed in claim 1, wherein Additive A is added to the crude oil.

7. The method as claimed in claim 1, wherein Additive A and Additive B are used in combination.

8. The method as claimed in claim 7, wherein the mass:mass ratio of Additive A to Additive B is in the range of 10:1 to 1:10.

9. The method as claimed in claim 7 wherein the combined treat rate of Additive A and Additive B is from 2 to 10000 ppm by mass, based on the total mass of the crude oil.

10. The method as claimed in claim 8, wherein the combined treat rate of Additive A and Additive B is from 2 to 10000 ppm by mass, based on the total mass of the crude oil.

11. The method as claimed in claim 1, wherein the poly(butylenyl) substituent group of less than 30 mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A, has greater than or equal to 60 total carbon atoms in said substituent group, as determined by GC.

12. The method as claimed in claim 1, wherein the poly(butylenyl) substituent group of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A is derived from the polymerization of but-1-ene and has a branched chain structure.

13. The method as claimed in claim 1, wherein the poly(propylenyl) substituent group of less than or equal to 25 mass % of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B, based on the total mass of all said one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B, has greater than 30 total carbon atoms in said substituent group, as determined by GC.

14. The method as claimed in claim 1, wherein the poly(propylenyl) substituent group of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B has a number average molecular weight (M.sub.n) of from 400 to 600 daltons.

15. The method as claimed in claim 1, wherein the poly(propylenyl) substituent group of said one or more 4-poly(propylenyl)benzene sulphonic acids of Additive B is derived from the polymerization of prop-1-ene and has a branched chain structure.

16. The method as claimed in claim 1, wherein the crude oil is at ambient temperature.

17. The method as claimed in claim 1, wherein Additive A or Additive B, or a combination of Additive A and Additive B, are used with or as emulsion-breakers (for demulsification), corrosion inhibitors, hydrate inhibitors, scale inhibitors, flow improvers, wax deposition inhibitors (or paraffin suppressants), pour-point depressants, viscosity improvers and/or other additives.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Additive A

(2) Additive A is one or more 4-poly(butylenyl)benzene sulphonic acid(s). The one or more 4-poly(butylenyl)benzene sulphonic acid(s) have a single sulphonic acid group and a single substituent group being the poly(butylenyl) substituent group attached to the para-position of the benzene ring with respect to the sulphonic acid group (i.e. the remainder of the benzene ring is not substituted and includes hydrogen atoms). It has been found that use of such mono-substituted one or more 4-poly(butylenyl)benzene sulphonic acid(s) typically increases the capacity of a crude oil to solvate and/or disperse asphaltenes, and/or increases the solubility and/or dispersancy of asphaltenes in a crude oil, compared to the use of one or more 4-poly(alkylenyl)benzene sulphonic acid additive(s) which also include one or more further alkyl substituents ortho and/or meta to the poly(alkylenyl) substituent group (i.e. mono-substituted 4-poly(butylenyl)benzene sulphonic acid(s) are typically more effective).

(3) The one or more 4-poly(butylenyl)benzene sulphonic acid(s) (Additive A) includes the sulphonic acid group as the free acid. Additive A is ashless and does not include salts (e.g. metal salts) of the sulphonic acid.

(4) Suitably, Additive A is derived from the polymerization of butene, preferably but-1-ene.

(5) Typically, Additive A may be synthesized by standard experimental techniques which are well-known to those skilled in the art, for example, the intermediate one or more 4-poly(butylenyl)benzene(s) having the desired mass % of poly(butylenyl) substituent group having a particular total number of carbon atoms may be synthesized by reacting butene, especially but-1-ene, with benzene using a Friedal-Crafts reaction (e.g. using a Friedal-Crafts catalyst such as a slurry of AlCl.sub.3/HCl, at a reduced temperature, such as 3 to 10° C.). The intermediate one or more 4-poly(butylenyl)benzene(s) may then be sulphonated with a sulphonating agent (e.g. oleum, SO.sub.2, SO.sub.3), using standard techniques, to form the one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A having the desired characteristics, especially the desired mass % of poly(butylenyl) substituent group with a particular total number of carbon atoms. Suitably, the integrity of the poly(butylenyl) substituent group of the intermediate one or more poly(butylenyl)benzene(s) (e.g. the mass % of poly(butylenyl) substituent group having a particular total number of carbon atoms) is essentially maintained during the sulphonation reaction of the intermediate. Accordingly, the mass % of poly(butylenyl) substituent group having a particular total number of carbon atoms in the intermediate one or more 4-poly(butylenyl)benzene(s) is essentially identical to the mass % of poly(butylenyl) substituent group having a particular total number of carbon atoms in the one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A.

(6) The appropriate poly(butylene) reactant used to form the intermediate one or more 4-poly(butylenyl)benzene(s) may be produced by polymerizing butene, particularly but-1-ene, using an appropriate catalyst system e.g. EtAlCl.sub.3 and HCl. A suitable source of butene, particularly but-1-ene, is the Raffinate II stream obtained as a by-product from the synthesis of poly(isobutylene), for example as disclosed in U.S. Pat. No. 4,952,739. Suitably, the characteristics of the poly(butylene) reactant (e.g. M.sub.n, M.sub.w, mass % of poly(butylene) having a particular number of total carbon atoms) should be substantially the same as the corresponding desired characteristics of the poly(butylenyl) substituent group in the intermediate one or more 4-poly(butylenyl)benzene(s) and in the one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A. Suitably, a preferred poly(butylene) is obtained by polymerizing but-1-ene wherein the poly(butylene) has: (i) a M.sub.n of from 450 to 650, preferably 500 to 600, daltons as measured by gel permeation chromatography (see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979); (ii) a polydispersity of from 1.1 to 1.5, preferably 1.2 to 1.4; (iii) greater than 55, preferably greater than 60, mass % of the poly(butylene), based on the total mass of poly(butylene), has greater than or equal to 32 total carbon atoms as determined by GC in accordance with ASTM D2887; and, (iv) less than 35 mass % of the poly(butylene), based on the total mass of poly(butylene), has greater than or equal to 60 total carbon atoms as determined by GC in accordance with ASTM D2887.

(7) Suitably, a high proportion of the poly(butylenyl) substituent groups of Additive A have a relatively narrow total carbon chain length distribution in which the poly(butylenyl) substituent group of greater than or equal to 50, preferably greater than or equal to 55, more preferably greater than or equal to 60, more preferably greater than or equal to 65, mass % of said one or more 4-poly(butylenyl)benzene sulphonic acids, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acids, has greater than or equal to 32 total carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887. Suitably, the poly(butylenyl) substituent group of less than or equal to 35, preferably less than or equal to 30, more preferably less than or equal to 25, more preferably less than or equal to 20, mass % of said one or more 4-poly(butylenyl)benzene sulphonic acids of Additive A, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acids, has greater than or equal to 60 total carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887.

(8) Suitably, the poly(butylenyl) substituent group of from 40 to 70, preferably 40 to 65, mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) of Additive A, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acid(s), has from 32 to 56 total carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887.

(9) Suitably, the poly(butylenyl) substituent group of said one or more 4-poly(butylenyl)benzene sulphonic acids includes a poly(butylenyl) substituent group having 32, 36, 40, 44 and/or 48, preferably 32, 36 and/or 40, total carbon atoms.

(10) Suitably, Additive A has a number average molecular weight (M.sub.n) of greater than or equal to 550, preferably greater than or equal to 600, more preferably greater than or equal to 650, daltons, as determined by the liquid-liquid extraction and two-phase potentiometric titration method described herein.

(11) Suitably, Additive A has a number average molecular weight (M.sub.n) of less than or equal to 800, preferably less than or equal to 750, more preferably less than or equal to 700, daltons, as determined by the liquid-liquid extraction and two-phase potentiometric titration method described herein.

(12) Suitably, Additive A has a polydispersity index of from 1.1 to 1.5, preferably 1.2 to 1.4.

(13) Suitably, the poly(butylenyl) substituent groups of said one or more 4-poly(butylenyl)benzene sulphonic acids have a branched chain structure. In other words, the poly(butylenyl) substituent group of said one or more 4-poly(butylenyl)benzene sulphonic acids comprises one or more branched chain butanediyl repeating radicals.

(14) Suitably, the poly(butylenyl) substituent groups of the one or more 4-poly(butylenyl)benzene sulphonic acids comprises poly(butylenyl) substituent groups bonded by the C-2 or C-1 position of the poly(butylenyl) group to the para-position of benzene ring.

(15) Additive A may be present in the crude oil in an amount of from 1 to 10000, preferably 1 to 5000, more preferably 1 to 1000, even more preferably 1 to 500, even more preferably 1 to 100, even more preferably 1 to less than 100, ppm by mass, based on the total mass of the crude oil.

(16) Suitably, Additive A, as defined herein, may be represented by one or more compounds of Formula I

(17) ##STR00001##
where each R.sub.1 independently represents a poly(butylenyl) substituent group, as defined herein.

(18) Additive A is added to the crude oil before the crude oil is refined in a petroleum refinery operation at a petroleum refinery. Additive A may be added to the crude oil when the crude oil is at the petroleum refinery and/or before the crude oil arrives at the petroleum refinery. Preferably, Additive A is added to the crude oil before the crude oil arrives at the petroleum refinery.

(19) Suitably, Additive A is added to the crude oil at one or more crude oil production and/or processing stages before the crude oil arrives at a petroleum refinery selected from: (i) to a crude oil in a subterranean crude oil reservoir during an extraction process of the crude oil from the reservoir, for example, by injecting the additive(s) into the crude oil reservoir via the wellbore; (ii) to a crude oil during the storage of the crude oil, for example, to a crude oil being stored in storage tanks, which tanks may be located at the wellbore region, or at intermediate locations between the wellbore region and the petroleum refinery; (iii) to a crude oil during the transportation of a crude oil, for example, to a crude oil being transported by pipeline, ship, rail, oil tanker, especially to a crude oil being transported from the wellbore region to a petroleum refinery; (iv) to a crude oil before or during the processing of a crude oil before the crude oil is at a petroleum refinery, for example, to a crude oil being blended with a different type of crude oil, and/or hydrocarbon fluid, to form a crude oil blend. Preferably, Additive A is added to the crude oil at one or more crude oil production process stages before the crude oil is at a petroleum refinery selected from: (i) to a crude oil during the storage of a crude oil at the wellbore region and locations between the wellbore region and petroleum refinery; (ii) to a crude oil during the transportation of a crude oil being transported from the wellbore region to a petroleum refinery; and, (iii) to a crude oil before or during the processing of a crude oil before the crude oil is at a petroleum refinery, for example, to a crude oil being blended with a different type of crude oil, and/or hydrocarbon fluid, to form a crude oil blend.

(20) Additive A may be added to a crude oil by methods well known to those skilled in the art. For example, Additive A may be blended into the crude oil and/or injected into a flowline transporting the crude oil.

(21) Suitable Additives A for use in the invention are available from Infineum UK Limited.

(22) Additive B

(23) Additive B is one or more 4-poly(propylenyl)benzene sulphonic acid(s). The one or more 4-poly(propylenyl)benzene sulphonic acid(s) have a single sulphonic acid group and a single substituent group being the poly(propylenyl) substituent group attached to the para-position of the benzene ring with respect to the sulphonic acid group (i.e. the remainder of the benzene ring is not substituted and includes hydrogen atoms). It has been found that use of such mono-substituted one or more 4-poly(propylenyl)benzene sulphonic acid(s) typically increases the capacity of a crude oil to solvate and/or disperse asphaltenes, and/or increases the solubility and/or dispersancy of asphaltenes in a crude oil.

(24) The one or more 4-poly(propylenyl)benzene sulphonic acid(s) includes the sulphonic acid group as the free acid. Additive B is ashless and does not include salts (e.g. metal salts) of the sulphonic acid.

(25) Suitably, Additive B is derived from the polymerization of prop-1-ene.

(26) Typically, Additive B may be synthesized by standard experimental techniques which are well-known to those skilled in the art. For example, Additive B may be synthesized by analogous techniques as described herein for Additive A by substituting the poly(butylene) reactant with the appropriate poly(propylene) reactant. Suitably, the integrity of the poly(propylenyl) substituent group of the intermediate one or more poly(propylenyl)benzene(s) (e.g. the mass % of poly(propylenyl) substituent group having a particular total number of carbon atoms) is essentially maintained during the sulphonation reaction of the intermediate. Accordingly, the mass % of poly(propylenyl) substituent group having a particular total number of carbon atoms in the intermediate one or more 4-poly(propylenyl)benzene(s) is essentially identical to the mass % of poly(propylenyl) substituent group having a particular total number of carbon atoms in the one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B.

(27) The appropriate poly(propylene) reactant used to form the intermediate one or more 4-poly(propylenyl)benzene(s) may be produced by polymerizing propene, using an appropriate catalyst system e.g. boron trifluoride and water. Suitably, the characteristics of the poly(propylene) reactant (e.g. M.sub.n, M.sub.w, mass % of poly(butylene) having a particular number of total carbon atoms) should be substantially the same as the corresponding desired characteristics of the poly(propylenyl) substituent group in the intermediate one or more 4-poly(propylenyl)benzene(s) and in the one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B, Suitably, a preferred poly(propylene) reactant is obtained by polymerizing prop-1-ene wherein the poly(propylene) has: (i) a M.sub.n of from 250 to 400, preferably 300 to 375, daltons as measured by GC in accordance with ASTM D2887; (ii) greater than 55, preferably greater than 60, mass % of the poly(propylene), based on the total mass of poly(propylene), has greater than or equal to 21 total carbon atoms as determined by GC in accordance with ASTM D2887; and, (iii) less than 25 mass % of the poly(propylene), based on the total mass of poly(propylene), has greater than or equal to 30 total carbon atoms as determined by GC in accordance with ASTM D2887.

(28) Suitably, a high proportion of the poly(propylenyl) substituent groups of Additive B have a narrow total carbon chain length distribution in which the poly(propylenyl) substituent group of greater than or equal to 55, preferably greater than or equal to 60, more preferably greater than or equal to 65, more preferably greater than or equal to 70, even more preferably greater than or equal to 75, mass % of said one or more 4-poly(propylenyl)benzene sulphonic acids of Additive B, based on the total mass of all said one or more 4-poly(propylenyl)benzene sulphonic acids, has greater than or equal to 21 total carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887. Suitably, the poly(propylenyl) substituent group of less than or equal to 30, preferably less than or equal to 25, more preferably less than or equal to 20, mass % of said one or more 4-poly(propylenyl)benzene sulphonic acids of Additive B, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acids, has greater than or equal to 30 total carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887.

(29) Suitably, the poly(propylenyl) substituent group of from 60 to 95, preferably 65 to 95, more preferably 70 to 90, mass % of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) of Additive B, based on the total mass of all said one or more 4-poly(butylenyl)benzene sulphonic acid(s), has from 21 to 27 carbon atoms in said substituent group, as determined by GC in accordance with ASTM D2887.

(30) Suitably, the poly(propylenyl) substituent group of said one or more poly(propylenyl)benzene sulphonic, acids of Additive B includes a poly(propylenyl) substituent group having 21, 24 and/or 27 total carbon atoms.

(31) Suitably, Additive B has a number average molecular weight (M.sub.n) of greater than or equal to 400, preferably greater than or equal to 450, more preferably greater than or equal to 475, daltons, as determined by the liquid-liquid extraction and two-phase potentiometric titration method described herein.

(32) Suitably, Additive B has a number average molecular weight (M.sub.n) of less than or equal to 600, preferably less than or equal to 550, more preferably less than or equal to 525, daltons as determined by the liquid-liquid extraction and two-phase potentiometric titration method described herein.

(33) Suitably, Additive B has a polydispersity index of from 1.1 to 1.5.

(34) Suitably, the poly(propylenyl) substituent group of said one or more 4-poly(propylenyl)benzene sulphonic acids have a branched chain structure. In other words, the poly(propylenyl) substituent group comprises one or more branched chain propanediyl repeating radicals.

(35) Suitably, the poly(propylenyl) substituent group of the one or more 4-poly(propylenyl)benzene sulphonic acids comprises poly(propylenyl) substituent groups bonded by the C-2 or C-1 position of the poly(propylenyl) group to the para-position of the benzene ring.

(36) Suitably, Additive B, as defined herein, may be represented by one or more compounds of Formula II

(37) ##STR00002##
wherein each R.sub.2 independently represents a poly(propylenyl) substituent group as defined herein.

(38) Additive B may be present in the crude oil in an amount of from 1 to 10000, preferably 1 to 5000, more preferably 1 to 1000, even more preferably 1 to 500, even more preferably 1 to 100, even more preferably 1 to less than 100, ppm by mass, based on the total mass of the crude oil.

(39) Additive B is added to the crude oil before the crude oil is refined in a petroleum refinery operation at a petroleum refinery. Additive B may be added to the crude oil when the crude oil is at the petroleum refinery and/or before the crude oil arrives at the petroleum refinery. Preferably, Additive B is added to the crude oil before the crude oil arrives at the petroleum refinery.

(40) Suitably, Additive B is added to the crude oil at one or more crude oil production and/or processing stages before the crude oil arrives at a petroleum refinery selected from: (i) to a crude oil in a subterranean crude oil reservoir during an extraction process of the crude oil from the reservoir, for example, by injecting the additive(s) into the crude oil reservoir via the wellbore; (ii) to a crude oil during the storage of the crude oil, for example, to a crude oil being stored in storage tanks, which tanks may be located at the wellbore region, or at intermediate locations between the wellbore region and the petroleum refinery; (iii) to a crude oil during the transportation of a crude oil, for example, to a crude oil being transported by pipeline, ship, rail, oil tanker, especially to a crude oil being transported from the wellbore region to a petroleum refinery; (iv) to a crude oil before or during the processing of a crude oil before the crude oil is at a petroleum refinery, for example, to a crude oil being blended with a different type of crude oil, and/or hydrocarbon fluid, to form a crude oil blend. Preferably, Additive B is added to the crude oil at one or more crude oil production process stages before the crude oil is at a petroleum refinery selected from: (i) to a crude oil during the storage of a crude oil at the wellbore region and locations between the wellbore region and petroleum refinery; (ii) to a crude oil during the transportation of a crude oil being transported from the wellbore region to a petroleum refinery; and, (iii) to a crude oil before or during the processing of a crude oil before the crude oil is at a petroleum refinery, for example, to a crude oil being blended with a different type of crude oil, and/or hydrocarbon fluid, to form a crude oil blend.

(41) Additive B may be added to a crude oil by methods well known to those skilled in the art. For example, Additive B may be blended into a crude oil and/or injected into a flowline transporting the crude oil.

(42) Suitable Additives B for use in the invention are available from Infineum UK Limited.

(43) Additive B, when used in combination with Additive A, may be added to the crude oil simultaneously or sequentially to Additive A. For example, a blend containing both of Additives A and B may be added to the crude oil; Additive A may be added to the crude oil initially followed by Additive B; or, Additive B may be added to the crude oil initially followed by Additive A. In a preferred embodiment when a combination of Additive A and Additive B is also added to the crude oil, both Additive A and Additive B are added to the crude oil essentially simultaneously.

(44) Additive B, when used in combination with Additive A, may be added to the crude oil at the same one or more crude oil production and/or processing stages before the crude oil arrives at a petroleum refinery as Additive A, or Additive B may be added to the crude oil at a different one or more crude oil production and/or processing stages before the crude oil arrives at a petroleum refinery as Additive A. Preferably, Additive B is added to the crude oil at the same one or more crude oil production and/or processing stages as Additive A, more preferably Additive A and Additive B are added essentially simultaneously to the crude oil at the same stage of the refinery operation.

(45) Suitably, when a combination of Additive A and Additive B is used, the combined treat rate of Additive A and Additive B is from 2 to 10000, preferably 2 to 5000, more preferably 2 to 1000, more preferably 2 to 200, even more preferably 2 to less than 100, ppm by mass, based on the total mass of the crude oil.

(46) Suitably, when a combination of Additive A and Additive B is used, the mass:mass ratio of Additive A to Additive B is in the range of 20:1 to 1:20, such as 10:1 to 1:10, preferably 3:1 to 1:3. More preferably, Additive A is used in an amount in excess of Additive B and the mass:mass ratio of Additive A to Additive B is in the range of 20:1 to 1:1, such as 10:1 to 1:1, preferably 3:1 to 1:1.

(47) Compositions

(48) Additive A and/or Additive B may be used in compositions; the compositions may further contain a hydrophobic oil solubilizer and/or a dispersant for the additive(s). Such solubilizers may include, for example, surfactants and/or carboxylic acid solubilizers.

(49) The compositions may further include, for example, viscosity index improvers, an i-foamants, antiwear agents, demulsifiers, anti-oxidants, and other corrosion inhibitors.

EXAMPLES

(50) The present invention is illustrated by but in no way limited to the following examples.

(51) Liquid-Liquid Extraction and Potentiometric Titration to Determine M.sub.n

(52) The M.sub.n of a 4-poly(alkylenyl)benzene sulphonic acid, such as Additive A and Additive B as defined herein, is determined by the following method.

(53) The 4-poly(alkylenyl)benzene sulphonic acid (typically 3 g) is weighed, the sample weight in grams is recorded (sample weight recorded as P.sub.1) and the sample dissolved in propan-2-ol (15 ml). An alcoholic solution of phenolphthalein indicator is added to the 4-poly(alkylenyl)benzene sulphonic acid/propan-2-ol solution and the solution titrated with aqueous sodium hydroxide (1 N) until the indicator turns pink (the volume of sodium hydroxide added is recorded as V.sub.1). Aqueous hydrochloric acid (1 N) is then added dropwise to this solution until the pink colour of the indicator disappears. The resulting solution, taking into account the combined volume of aqueous sodium hydroxide and aqueous hydrochloric acid added to the original 4-poly(alkylenyl)benzene sulphonic acid/propan-2-ol solution, is made up to form a solution containing a volume to volume ratio of water to propan-2-ol of 1:1, by the addition of the minimum volume of water if the combined volume of aqueous sodium hydroxide and aqueous hydrochloric acid added is less than 15 ml or by the addition of the minimum volume of propan-2-ol if the combined volume of aqueous sodium hydroxide and aqueous hydrochloric acid added is more than 15 ml. The resulting solution is extracted with pentane (1×40 mL and then 2×20 mL) and the combined pentane extracts washed with a water/propan-2-ol solution (1:1 ratio by volume, 3×15 ml). The combined water/propan-2-ol extracts are warmed at 60° C. to remove any traces of pentane, allowed to cool to room temperature and made up to 100 mL with a water/propan-2-ol solution (1:1 by volume) to form the final poly(alkylenyl)benzene sulphonic acid-water/propan-2-ol solution.

(54) 40 mL of the final poly(alkylenyl)benzene sulphonic acid-water/propan-2-ol solution is transferred to an empty pre-weighed beaker (empty beaker weight recorded in grams as P.sub.2), the solution evaporated to dryness under a stream of nitrogen at 70° C., the product dried in an oven at 130-150° C. for at least 1 hour and then cooled to room temperature in a desiccator for 1 hour. The weight of the beaker and sample in grams is recorded as P.sub.3. A further 40 mL of the final poly(alkylenyl)benzene sulphonic acid-water/propan-2-ol solution is transferred to a separating funnel, water (75 mL) and p-toluidine hydrochloride (2 g) added thereto and the resulting solution extracted with dichloromethane (1×40 mL and 2×20 ml). The combined dichloromethane extracts are added to a water/propan-2-ol solution (100 mL, 3:7 by volume) to form a two-phase solution. The two-phase solution is stirred and potentiometrically titrated against aqueous sodium hydroxide (0.1 N) using a Metrohm titration unit set to titrate at 20 microlitres; the volume of aqueous sodium hydroxide added to reach the end point is recorded as V.sub.2.

(55) To calibrate the potentiometric two-phase titration method, 40 mL of a water/propan-2-ol (1:1 by volume) solution not including any sample is transferred to a separating funnel, water (75 mL) and p-toluidine hydrochloride (2 g) added thereto and the resulting solution extracted with dichloromethane (1×40 mL and 2×20 ml). The dichloromethane extracts are added to a water/propan-2-ol solution (100 mL, 3:7 by volume) to form a two-phase solution. The two-phase solution is stirred and potentiometrically titrated against aqueous sodium hydroxide (0.1 N) using a Metrohm titration unit; the volume of aqueous sodium hydroxide added to reach the end point is recorded as V.sub.3.

(56) The number average molecular (M.sub.n) of the 4-poly(alkylenyl)benzene sulphonic acid is calculated by the following equation:

(57) $Mn = (((P_{3} - P_{2}) - \frac{A \times P_{1} \times 71}{100 \times 49 \times 2.5}) \times \frac{1000}{(V_{2} - V_{3}) \times N}) - 22$
wherein:
P.sub.3=weight (g) of beaker plus sample;
P.sub.2=weight (g) of empty beaker;
A=mineral acidity of the 4-poly(alkylenyl)benzene sulphonic acid expressed as mass % of sulphuric acid as determined from ASTM D4711;
P.sub.1=sample weight (g);
V.sub.2=volume (ml) of NaOH (0.1 N) added to the sample during potentiometric titration;
V.sub.3=volume (ml) of NaOH (0.1 N) added to two-phase solution during calibration of potentiometric titration;
N=Normality of sodium hydroxide solution use in potentiometric titration which is 0.1.
Gel Permeation Chromatography to Determine M.sub.n of Poly(Butylene)

(58) M.sub.n of poly(butylene) is determined by gel permeation chromatography (see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979) using a MIXED-D PLgel HPLC column from Agilient Technologies Inc, a refractive index detector (30° C.), a tetrahydrofuran mobile phase of 1 ml/minute and calibrated with an EasiCal PS-2 polystyrene standard from Agilient Technologies Inc.

(59) Gas Chromatography and FID in Accordance with ASTM D2887

(60) M.sub.w of Additive A, M.sub.w of Additive B, M.sub.w of the poly(butylene) used to synthesise Additive A, and M.sub.w and M.sub.n of the poly(propylene) used to synthesise Additive B, is determined by gas chromatography (GC) and simulated distillation using a flame ionization detector (FID) in accordance with ASTM D2887. Suitably, this analytical method yields the mass % distribution of poly(alkylenyl) substituent groups in Additive A and Additive B, respectively, having a specific total number of carbon atoms. Suitably, this analytical method yields the mass % distribution of poly(alkylene) chains in poly(butylene) and in poly(propylene) having a specific total number of carbon atoms.

(61) The ASTM D2887 equipment and operating conditions are as follows: the chromatograph is not equipped with cryogenics since the starting temperature is 35° C.; samples are diluted in pentane instead of carbon disulfide; the equipment is calibrated using reference Boiling Point Calibration Sample 1 from Agilent Technologies Inc, Part Number 5080-8716, dissolved in carbon disulfide (i.e. a n-parrafinic sample of known composition); the gas chromatograph is a Hewlett Packard 5890 Series 2 Plus Chromatograph having a Restek MXT-1HT SimDist column, length 5 m, diameter 0.53 mm, film thickness 10 μm; the carrier gas is helium and an output flow of 6 ml/minute; the detector is a flame ionization detector; the oven temperature is set at 35° C. for 2 minutes then heated at a rate of 8° C./min to reach 410° C. and then held at this temperature for 15 minutes; injector type: on-column; the initial injector temperature is 38° C. and final temperature is 413° C. (injector temperature=oven temperature+3° C.); the FID detector temperature is 400° C.

(62) Components

(63) The following additive components and crude oil were used.

(64) Component (A)

(65) Component A represents Additive A as defined herein.

(66) (i) Synthesis of Poly(butylene)

(67) In a continuous process, a Raffinate II stream is polymerised using a concentrated hydrochloric acid and ethyl aluminium dichloride catalyst system (mass to mass ratio of HCl to EtAlCl.sub.2 of 3:1) in Isopar-L solvent at a temperature of 25 to 45° C. for 30 minutes. The reactor product is washed with water and sodium hydroxide, and the product stripped of unreacted C.sub.4 butylene/butanes (temperature of 200 to 230° C., pressure less than 0.5 bar) to produce poly(butylene) having: a M.sub.n of 540 daltons as measured by gel permeation chromatography; a polydispersity index of 1.3; greater than 55 mass of the poly(butylene), based on the total mass of poly(butylene), has greater than or equal to 32 total carbon atoms as determined by GC in accordance with ASTM D2887.

(68) (ii) Synthesis of 1-poly(butylenyl)benzene

(69) In a continuous process, poly(butylene) (I mole) from step (i) and benzene (14.5 mole) are reacted in the presence of an aluminium trichloride/hydrochloric acid catalyst slurry at a temperature of 3 to 8° C. for 45 minutes. The sludge is removed from the reactor and the remaining liquid phase in the reactor is washed multiple times with aqueous sodium hydroxide (7 wt %) at a temperature of 90 to 100° C., then washed with water and then the organic liquid phase distilled at 160 to 170° C. (atmospheric pressure) to remove excess benzene and to remove the lower boiling 1-poly(butylenyl)benzenes in which the poly(butylenyl) substituent group has less than 16 total carbon atoms. The desired 1-poly(butylenyl)benzene product is obtained by distillation at 320° C. under reduced pressure (20 to 40 mm Hg) to produce 1-poly(butylenyl)benzenes having: (i) a polydispersity of 1.3; (ii) the poly(butylenyl) substituent group of greater than or equal to 55 mass % of said one or more 1-poly(butylenyl)benzenes has greater than or equal to 32 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (iii) the poly(butylenyl) substituent group of from 40 to 70 mass % of said one or more 1-poly(butylenyl)benzenes has from 32 to 56 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (iv) the poly(butylenyl) substituent group of less than or equal to 25 mass % of said one or more 1-poly(butylenyl)benzenes has greater than or equal to 60 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (v) the poly(butylenyl) substituent group comprises a poly(butylenyl) substituent group having 32, 36 and/or 40 total carbon atoms; and, (vi) the poly(butylenyl) substituent group comprises poly(butylenyl) substituents having a branched chain structure.

(70) (iii) Synthesis of 4-poly(butylenyl)benzene Sulphonic Acid

(71) A reactor is charged with the 1-poly(butylenyl)benzene product from step (ii), an excess of sulfur dioxide introduced with stirring (volume ratio of sulfur dioxide to 4-poly(butylenyl)benzene of 4:1) while maintaining the reaction temperature between 0 and −5° C., after which an excess of sulfur trioxide (mole ratio of sulfur trioxide to 4-poly(butylenyl)benzene of 120:1) is introduced while maintaining the reaction temperature between 0 and −5° C. The reaction mixture is then allowed to stand for 1 hour at a temperature of −2 to 5° C. The excess sulfur dioxide/sulfur trioxide is stripped off at 120° C. at 0.1 bar and the reaction mixture cooled to 60° C. to yield the title compound. The title compound may be diluted in diluent oil, such as SN80 (commercially available from Repsol).

(72) The isolated 4-poly(butylenyl)benzene sulphonic acid has: (i) a M.sub.n of between 600 to 700 daltons; (ii) a polydispersity of 1.3; (iii) the poly(butylenyl) substituent group of greater than or equal to 55 mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) has greater than or equal to 32 total carbon atoms in said substituent group as determined by GC in accordance with ASTM 02887; (iv) the poly(butylenyl) substituent group of from 40 to 70 mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) has from 32 to 56 total carbon atoms in said substituent group as determined by GC in accordance with ASTM 02887; (v) the poly(butylenyl) substituent group of less than or equal to 25 mass % of said one or more 4-poly(butylenyl)benzene sulphonic acid(s) has greater than or equal to 60 total carbon atoms in said substituent group as determined by GC in accordance with ASTM 02887; (vi) the poly(butylenyl) substituent group comprises a poly(butylenyl) substituent group having 32, 36 and/or 40 total carbon atoms; and, (vii) the poly(butylenyl) substituent group comprises poly(butylenyl) substituents having a branched chain structure.

(73) Suitable Additives A are available from Infineum UK Ltd, for example, comprising 83 mass % a.i. of 4-poly(butylenyl)benzene sulphonic acids.

(74) Component (B)

(75) Component B represents Additive B as defined herein.

(76) (i) Synthesis of Poly(propylene)

(77) A sealed reactor is charged with propene, boron trifluoride catalyst and water as cocatalyst (molar ratio of boron trifluoride to water of 1:2) at 24 to 28° C. and a pressure of 16 bar, and the resulting reaction mixture agitated for 1 hour. The reaction mixture is then heated to 50° C. (atmospheric pressure) initially, and then to 90 to 120° C. under vacuum (60 mbar) to distil off residual propane, boron trifluoride and boron trifluoride/water complex. The residual purified poly(propylene) remaining in the reactor is cooled and stored at 60° C., the poly(propylene) has: (i) a M.sub.n of 340 daltons as measured by GC in accordance with ASTM D2887; (ii) greater than 65 mass % of the poly(propylene), based on the total mass of poly(propylene), has greater than or equal to 21 total carbon atoms as determined by GC in accordance with ASTM D2887; and, (iii) less than 25 mass % of the poly(propylene), based on the total mass of poly(propylene), has greater than or equal to 30 total carbon atoms as determined by GC in accordance with ASTM D2887.

(78) (ii) Synthesis of 1-poly(propylenyl)benzene

(79) The title compound is synthesised from poly(propylene) obtained from step (i) using the same procedure to form 1-poly(butylenyl)benzene as described in step (ii) for Component A using a mole to mole ratio of benzene to poly(propylene) of 7.5:1.

(80) The 1-poly(propylenyl)benzene product is obtained by distillation at 295° C. under reduced pressure (20 to 40 mm Hg) to produce 1-poly(propylenyl)benzenes wherein: (i) the poly(propylenyl) substituent group of greater than or equal to 60 mass % of said one or more 1-poly(propylenyl)benzenes has greater than or equal to 21 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (ii) the poly(propylenyl) substituent group of from 65 to 90 mass % of said one or more 1-poly(propylenyl)benzenes has from 21 to 27 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (iii) the poly(propylenyl) substituent group of less than or equal to 25 mass % of said one or more 1-poly(propylenyl)benzenes has greater than or equal to 30 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (v) the poly(propylenyl) substituent group comprises a poly(propylenyl) substituent group having 21, 24 and/or 27 total carbon atoms; and, (v) the poly(propylenyl) substituent group comprises poly(propylenyl) substituents having a branched chain structure.
(iii) Synthesis of 4-Poly(Propylenyl)Benzene Sulphonic Acid

(81) The title compound is synthesised from the 1-poly(propylenyl)benzene product of step (ii) using the same procedure to form 4-poly(butylenyl)benzene sulphonic acid as described in step (iii) for Component A.

(82) The isolated 4-poly(propylenyl)benzene sulphonic acid has: (i) a M.sub.n of between 450 to 550 daltons; (ii) the poly(propylenyl) substituent group of greater than or equal to 60 mass % of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) has greater than or equal to 21 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (iii) the poly(propylenyl) substituent group of from 65 to 90 mass of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) has from 21 to 27 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (iv) the poly(propylenyl) substituent group of less than or equal to 25 mass % of said one or more 4-poly(propylenyl)benzene sulphonic acid(s) has greater than or equal to 30 total carbon atoms in said substituent group as determined by GC in accordance with ASTM D2887; (v) the poly(propylenyl) substituent group comprises a poly(propylenyl) substituent group having 21, 24 and/or 27 total carbon atoms; and, (vi) the poly(propylenyl) substituent group comprises poly(propylenyl) substituents having a branched chain structure

(83) Suitable Additives B are available from Infineum UK Ltd, for example, comprising 85 mass % a.i. of 4-poly(propylenyl)benzene sulphonic acids.

(84) Crude Oil Blend

(85) A blend of a Columbian heavy crude oil (asphaltene content 10 wt %) and a shale oil in a weight to weight ratio of 1:1.

(86) Crude Oil Asphaltene Stability Test

(87) The test is performed using an Automated Stability Analyser from Rofa France in accordance with ASTM D7157. The test demonstrates the ability of a crude oil to resist destabilisation upon the addition of heptane. Results are recorded as ‘S’ values, the intrinsic stability of the oil with respect to precipitation of asphaltenes therefrom. Higher ‘S’ values indicate that the oil has a higher capacity to solvate and/or disperse asphaltenes, and the oil is more stable in respect of asphaltene flocculation and/or precipitation. The results herein are reported as a “Relative ‘S’ Value” with respect to the crude oil blend not including Additive A and/or Additive B.

(88) Results

(89) TABLE-US-00001 Additive(s) Ratio of A:B (treat rate; ppm a.i.) (treat rate; ppm a.i.) Relative S-Value None — 1.00 A (2075 ppm) — 1.19 A (830 ppm) — 1.14 B (850 ppm) — 1.05 A + B (835 ppm) 3:1 1.14

(90) The results show that, when a single additive is used Additive A gave the best results (14% improvement over the control at a treat rate of 830 ppm by mass a.i.). Additive B also provided an improvement; albeit not as significant as Additive A, over the control (5% improvement at a treat rate of 850 ppm by mass a.i.). Increasing the treat rate of Additive A from 830 ppm by mass a.i. to 2075 ppm by mass a.i., provided a further marginal improvement in performance.

Asphaltene solvation and dispersion process

Assignee

Inventors

Cpc classification

Classification Explorer

C10L10/18

CHEMISTRY; METALLURGY

Classification Explorer

C09K8/524

CHEMISTRY; METALLURGY

Classification Explorer

C10L10/08

CHEMISTRY; METALLURGY

Classification Explorer

C10L1/2437

CHEMISTRY; METALLURGY

Classification Explorer

C10G75/02

CHEMISTRY; METALLURGY

Classification Explorer

C10G2300/80

CHEMISTRY; METALLURGY

Classification Explorer

C10G75/04

CHEMISTRY; METALLURGY

Classification Explorer

C10G2300/206

CHEMISTRY; METALLURGY

Classification Explorer

C10L10/04

CHEMISTRY; METALLURGY

International classification

Classification Explorer

C10L1/24

CHEMISTRY; METALLURGY

Classification Explorer

C10L10/04

CHEMISTRY; METALLURGY

Classification Explorer

C09K8/524

CHEMISTRY; METALLURGY

Classification Explorer

C10G75/02

CHEMISTRY; METALLURGY

Classification Explorer

C10G75/04

CHEMISTRY; METALLURGY

Classification Explorer

C10L10/18

CHEMISTRY; METALLURGY

Classification Explorer

C10L10/08

CHEMISTRY; METALLURGY

Abstract

Claims

Description