PROCESSS TO OBTAIN RANDOM TERPOLYMERS DERIVED FROM ITACONIC ACID, ACONITIC ACID AND/OR ITS ISOMERS, AND ALKENYL SULFONATES AND USE OF THE PRODUCT THEREOF

Abstract

Random terpolymers are characterized for being tolerant to high concentrations of divalent ions, such as calcium, magnesium, strontium and barium, and that for their application in the reservoir or production rig, treated water, sea water and/or connate water can be used as means of transportation. Furthermore, the terpolymer also can be used to inhibit and disperse mineral scales presents in cooling system and boiler employed in the chemical and oil industry.

Also, random terpolymers of the present invention have the characteristic of complying with environmental standards established internationally and are classified as particularly non-toxic, so it can be used in pipes and equipment of the petrochemical industry and with the use characteristic freshwater and seawater from offshore and onshore facilities.

Claims

1. A terpolymer, comprising: ##STR00006## wherein R.sub.1=—H, —CH.sub.3, R2=—H, —CH.sub.2COOH, —COOH, R3=—COOH, R4=—CH2COOH, H, R5=—H, R6=—H, R7=—H, —CH3, R8=—SO.sub.3Na, —CH.sub.2SO.sub.3Na, —CONHC(CH3).sub.2CH2S03Na, C.sub.6H.sub.4SO.sub.3Na, Rg=H, R.sub.10=—COOH, R1.sub.1=—COOH y R12=—CH.sub.2COOH and n is between 2 and 70, and wherein the terpolymer is derived from at least one of itaconic acid or isomers, aconitic acid, or alkenylsuiphonates.

2. The terpolymer, according to claim 1, wherein the terpolymer is an active agent for inhibiting and dispersing mineral scales of at least one of calcium carbonate, calcium sulphates, barium and strontium and disperse clays, calcium carbonate, calcium sulphates, barium and strontium and iron oxides.

3. The terpolymer, according to claim 2, wherein the terpolymer inhibits and disperses mineral scales present in equipment used in oilfields.

4. The terpolymer, according to claim 1, wherein the terpolymer is administered at high pressure and ultra-high salinity.

5. The terpolymer, according to claim 1, wherein itaconic acid isomers include at least one of cis-glutaconic acid, trans-glutaconic acid, citraconic acid and mesaconic acid.

6. The terpolymer according to claim 1, wherein aconitic acid isomers include at least one of cis-aconitic acid and trans-aconitic acid.

7. The terpolymer according to claim 1, wherein sodium alkyl sulphonates include at least one of vinyl sulfonic acid, allyl sulfonic add, styrene sulfonic add, 2-acrylamido-2-methyl-1-propane sulfonic and salts thereof.

8. The terpolymer according to claim 5, wherein the salts include at least one of sodium or potassium.

9. The terpolymer, according to claim 1, wherein terpolymer chemical structure is a random-type structure.

10. The terpolymer, according to claim 1, wherein the average molecular weight by number is between about 500 AMU and about 31,000 AMU.

11. A method of inhibiting and dispersing carbonate and calcium sulfate mineral scale, comprising: adding a terpolymer to a cooling system or a boiler system, wherein the terpolymer, comprises: ##STR00007## wherein R.sub.1=—H, —CH.sub.3, R2=—H, —CH.sub.2COOH, —COOH, R3=—COOH, R4=—CH2COOH, H, R5=—H, R6=—H, R7=—H, —CH.sub.3, R8=—SO.sub.3Na, —CH.sub.2SO.sub.3Na, —CONHC(CH.sub.3).sub.2CH.sub.2S0.sub.3Na, C.sub.6H.sub.4SO.sub.3Na, R9=H, R.sub.10=—COOH, R.sub.11=—COOH y R12=—CH.sub.2COOH and n is between 2 and 70.

12. The method of claim 11, wherein the cooling system or the boiler system is used in the chemical or oil industry.

13. The method of claim 11, wherein the method includes adjusting the temperature to an operating temperature of up to about 220° C.

14. The method of claim 11, wherein method includes adjusting the pressure to a pressure of up to about 8000 psi.

15. The method of claim 11, wherein the method includes a brine of salt.

16. The method of claim 11, wherein in the brine salt has a concentration up to about 450,000 ppm.

17. The method of claim 11, wherein in the brine of salt is calcium carbonate having a concentration of about 250,000 ppm as a total hardness.

18. The method of claim 11, wherein the concentration of the terpolymer is between about 1 to about 10.000 ppm.

19. The method of claim 11, wherein the terpolymer is diluted in an aqueous medium.

20. The method of claim 11, wherein the terpolymer meets the Mexican NRF-005-PEMEX-2009 standard for use in at least one of equipment and pipelines that use fresh water and are built on land.

21. The method of claim 11, wherein the equipment or the pipelines are used in at least one of a chemical or an oil industry.

22. The method of claim 11, wherein the terpolymer meets the Mexican NRF-005-PEMEX-2009 standard for use in off shore applications that use sea water or formation water from oil reservoirs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION

[0057] In order to have a better understanding as to the application of terpolymers as inhibitors and dispersants of mineral scale of the present invention, in the following step will be referenced to the drawings made and described below:

[0058] In the FIG. 1 the infrared spectrum of the product 1 is shown.

[0059] In the FIG. 2 .sup.1H Resonance Magnetical Nuclear (RMN) of the product 1 is shown.

[0060] In the FIG. 3 .sup.13C Resonance Magnetical Nuclear (RMN) del producto 1 is shown.

[0061] In the FIG. 4 morphology and composition of calcium sulfate crystals are shown, a) without chemical and b) 200 ppm of product 1.

[0062] In the FIG. 5 morphology and composition of calcium carbonate crystals are shown, a) without chemical and b) 200 ppm of product 1.

[0063] In the FIG. 6 the operation basis of a photometer are shown In FIG. 7 a chemical structure A representing a random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1 is shown.

[0064] In FIG. 8 a surface B chemical structure representing calcium carbonate crystals in their calcite polymorphic form is shown.

[0065] In FIG. 9 a supramolecular complex C obtained using computational chemistry and after the compound A surface B interaction process is shown.

[0066] In FIG. 10 a supramolecular complex C formation from compound A and surface D molecular interaction is shown.

[0067] In FIG. 11 a chemical structure of surface D representing barium sulfate crystals in its polymorphic form of barite is shown.

[0068] In FIG. 12 a supramolecular complex E obtained using computational chemistry after compound A with surface F interaction process is shown.

[0069] In FIG. 13 a supramolecular complex E formation from compound A and surface D molecular interaction is shown.

[0070] In FIG. 14 a chemical structure of the F surface representing crystals of calcium sulfate in its polymorphic form of anhydrite is shown.

[0071] In FIG. 15 a supramolecular complex G obtained using computational chemistry after compound A with surface F interaction process is shown.

[0072] In FIG. 16 a supramolecular complex G formation from compound A and surface F molecular interaction is shown.

DETAILED DESCRIPTION OF THE INVENTION

[0073] The present invention is related to the process of obtaining random terpolymers based on itaconic acid or its isomers, aconitic acid or their isomers and sodium alkenyl sulphonates of structural formula (5), through a polymerization in aqueous solution via free radicals at acid pH in the range of 1.0 to 3.5 and as initiator a redox system, and their use as inhibitors of mineral scale such as calcium carbonate, calcium sulphate, strontium and barium, and clay dispersing, iron oxides, carbonate and calcium sulfate.

[0074] The terpolymers prevent and control the formation damage and obstruction by hydrocarbons in production rigs, which are caused by mineral salt deposits present in oilfields and whose origin is the contained high salinity in formation water, incompatible mixtures of water injection and formation water, pressure changes, temperature and pH.

[0075] The terpolymers are used to inhibit and disperse presented mineral scales in cooling systems and boilers employed in the oil and chemical industry and are characterized by being tolerant to high concentrations of divalent ions, such as calcium, magnesium, strontium and barium ions and for the application in the field or in production rig, treated water, sea water and/or feature water from the site is used as a transport medium. The random terpolymers of the present invention have the characteristic of being used under high temperature, high salinity and have low toxicity.

##STR00005##

[0076] Where: R.sub.1=—H, —CH.sub.3, R.sub.2=—H, —CH.sub.2COOH, —COOH, R.sub.3=—COOH, R.sub.4=—CH.sub.2COOH, H, R.sub.5=—H, R.sub.6=—H, R.sub.7=—H, —CH.sub.3, R.sub.8=—SO.sub.3Na, —CH.sub.2SO.sub.3Na, —CONHC(CH.sub.3).sub.2CH.sub.2SO.sub.3Na, C.sub.6H.sub.4SO.sub.3Na, R.sub.9=H, R.sub.10=—COOH, R.sub.11=—COOH, R.sub.12=—CH.sub.2COOH and n is between 2 and 70.

[0077] For the development of the present invention a method comprising the following steps was followed: 1) molecular design through computational chemistry, 2) Synthesis and characterization of random terpolymers and 3) experimental evaluation of anti-scaling and dispersant properties

[0078] The selection of this methodology is based on the fact that the key to develop agents tolerant anti-scaling at high salinities and concentrations of divalent ions and able to withstand conditions of high temperatures and pressures is the understanding at the molecular level of as random terpolymers based on itaconic acid or isomers thereof, aconitic acid or their isomers and sodium alkenyl sulphonates are adsorbed on mineral salt crystals with anti-scaling properties and give rise to the supramolecular complex formation capable of:

[0079] 1) Inhibiting on the threshold of precipitation just after a nucleation center is formed. The terpolymer will be adsorbed in one of the faces from the microcrystalline nucleation center in the inorganic salt and the formed ion pair will prevent the diffusion of ions to the growth centers; 2) To distort or alter the crystal lattice. If the terpolymer is adsorbed on a crystal from an inorganic salt, alterations will be occurred in the surface properties such as size, adhesion, hardness, toughness, crystal structure, etc.; consequently resulting in fragmented crystals, become amorphous, soft and slightly sticky, and therefore facilitate its removal by the continuous flow of water and 3) To disperse. Sulfonates functional groups and di-carboxylic acids of the terpolymers will be adsorbed on the active sites of the growing crystals and through the polymer chains, repulsion effects, will be generated so steric and electrostatic which will increase the colloidal stability of the inorganic particles to keep them dispersed and avoid its agglomeration, so its removal will be provided through the continuous flow of water.

[0080] Nowadays before to develop new chemicals with improved properties, the molecule which seeks to solve a particular problem can be designed through theoretical studies of computational chemistry, according with the following explanation: [0081] a) The chemical structure from A compound shown in FIG. 7, representing a random terpolymer based itaconic acid, sodium vinyl sulfonate and aconitic acid with 903 AMU as molecular weight and polydispersity index of 1 was used. [0082] b) The chemical structure of the B surface shown in FIG. 8, representing calcium carbonate crystals in its polymorphic form of calcite was used. [0083] c) The geometries of the chemical structure of A compound and the B surface were minimized considering energy in a solvated medium by water (dielectric constant 78.54) through quantum chemical methods using Density Functional Theory and LDA-VW Functional. [0084] d) Through computational chemistry and using a water solvated medium (dielectric constant 78.54) with quantum chemical methods using Functional Theory Density and LDA-VW Functional, the compound A was interacted with the surface B, resulting in the C supramolecular complex formation shown in FIG. 9, and the energy results that are shown in Table 2. [0085] e) The analysis of the results in Table 2 shown that the formation of C supramolecular complex from the molecular interaction between the A compound and the B surface (9) is strongly favored from the thermodynamic point of view. Also, the interaction energy of −113.12 kcal/mol (−473.29 kJ/mol) indicated that ion-ion supramolecular interactions are presented so as well a combination of ion-dipole interactions and hydrogen bonding type.

TABLE-US-00002 TABLE 2 Energy of Compound A, surface B and supramolecular complex C obtained through quantum chemical methods using Density Functional Theory and LDA-VW Functional. Density Functional Theory, and LDA-VW Functional Compounds Total Energy Interaction Energy or Complex (kcal/mol) (kcal/mol) A −2,641,697.44 B −70,629,855.35 C −73,271,665.91 −113.12

[0086] Where:

[0087] A=Random terpolymer based on itaconic acid, sodium vinyl sulphonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1.

[0088] B=Calcium carbonate surface in theft polymorphic form of calcite.

[0089] C=Supramolecular complex derived from the interaction of the random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1, corresponding to compound A, as shown in FIG. 7, and the surface of calcium carbonate in its polymorphic form calcite B, as shown in FIG. 8.

[0090] Determination of the Interaction Between Random Terpolymer Based on Itaconic Acid, Sodium Vinyl Sulfonate and Aconitic Acid with Barium Sulfate.

[0091] In order to determine the capacity that random terpolymers based on itaconic acid, sodium vinyl sulfonate and aconitic acid would have in order to form supramolecular complexes with barium sulfate crystals and control their growth, we proceeded to simulate through computational chemistry and using a solvated medium by water (dielectric constant 78.54) with quantum chemical methods using Density Functional Theory and the LDA-VW functional, the process of interaction from a random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid, with 903 as molecular weight and polydispersity of 1, corresponding to the chemical structure of compound A, as shown in FIG. 7, with the surface D that is shown in FIG. 11 and that represents barium sulfate crystals in its polymorphic form of Barite, obtaining as result the E supramolecular complex shown in FIG. 12, and the energy results shown in Table 3.

[0092] The analysis of the results in Table 3 show that the E supramolecular complex formation shown in FIG. 13 from the molecular interaction of the compound A and the D surface shown in FIGS. 6 and 11, respectively, is strongly favored from the thermodynamic point of view. Also, the interaction energy of −127.22 kcal/mol (−532.29 kJ/mol) indicated that these ion-ion supramolecular interactions and a combination of ion-dipole interactions and hydrogen bonds could be presented.

TABLE-US-00003 TABLE 3 Energy of compound A, Surface D and E supramolecular complex obtained through quantum chemical methods using Density Functional Theory and LDA-VW Functional. Density Functional Theory, and LDA-VW Functional Compounds or Total Energy Interaction Energy Complex (kcal/mol) (kcal/mol) A −2,641,697.44 D −40,730,112.93 E −43,371,937.59 −127.22

[0093] Where:

[0094] A=Random terpolymer based on itaconic acid, sodium vinyl sulphonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1.

[0095] D=Barium sulphate surface in their polymorphic form of baryta.

[0096] E=Supramolecular complex derived from the interaction of the random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid with molecular weight of 903 AMU and polydispersity of 1, corresponding to compound A (6), and the surface of barium sulphate in its polymorphic form of baryta B (7).

[0097] Determination of Interaction Between Random Terpolymer Based on Itaconic Acid, Sodium Vinyl Sulfonate and Aconitic Acid with Calcium Sulphate.

[0098] In order to determine the capacity that random terpolymers based on itaconic acid, vinyl sulfonate sodium and aconitic acid would have to form supramolecular complexes with crystals of calcium sulfate and control their growth, in a first step it was proceeded to simulate through computational chemistry and using a solvated medium by water (dielectric constant 78.54) with quantum methods employing the Density Functional Theory and LDA-VW functional the process of interaction between a random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid, possessing 903 AMU as molecular weight and polydispersity index of 1, corresponding to the chemical structure of compound A, as shown in FIG. 7, with the surface F shown in FIG. 14 and representing crystals of calcium sulfate in its polymorphic form of anhydrite, obtained as result shown in the supramolecular complex G shown in FIG. 15, and the energy results that are shown in Table 4.

[0099] The analysis of the results presented in Table 4 show that the formation of G supramolecular complex, shown in FIG. 15, through the molecular interaction between the A compound shown in FIG. 7 and the F surface shown in FIG. 14 would be strongly favored from the thermodynamic point of view. Also, −136.14 kcal/mol (−569.61 kJ/mol) as the result of interaction energy indicated that supramolecular interactions of ion-ion type and a combination of ion-dipole interactions and hydrogen bonds would be presented.

[0100] The analysis of the results from the Tables 2 to 4 indicated that the random terpolymers based on itaconic acid, sodium vinyl sulfonate and aconitic acid (6), objects of the present invention, have the ability to form supramolecular complexes with calcium carbonate crystals in its polymorphic form of calcite, barium sulfate in its polymorphic form of barite and calcium sulfate in its polymorphic form of anhydrite; so as well control the growth and morphology change thereof.

TABLE-US-00004 TABLE 4 Energy of compound A, Surface D and G supramolecular complex obtained through quantum chemical methods using Density Functional Theory and LDA-VW Functional. Density Functional Theory, and LDA-VW Functional Compounds or Total Energy Interaction Energy Complex (kcal/mol) (kcal/mol) A −2,641,697.44 D −92,952,242.47 G −95,594,076.05 −136.14

[0101] Where:

[0102] A=Random terpolymer based on itaconic acid, sodium vinyl sulphonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1.

[0103] D=Calcium sulphate surface in their polymorphic form of Anhydrite.

[0104] G=Supramolecular complex derived from the interaction of the random terpolymer based on itaconic acid, sodium vinyl sulfonate and aconitic acid with molecular weight of 903 AMU and polydispersity index of 1, corresponding to compound A (6), and the surface of calcium sulphate in its polymorphic form of Anhydrite D (14).

[0105] Random Terpolymer synthesis and spectroscopic characterization. The random terpolymer based on itaconic acid, aconitic acid or its isomers and sodium vinyl sulfonate having the structural formula (5), object of the present invention are obtained by means of a polymerization process in aqueous solution via free radicals and a redox system as initiator. The polimerization is carried out at an acid pH in the range of 1.0 to 3.5, under atmospheric pressure and at temperatures ranging from 50 to 100° C. The obtained terpolymers are characterized for having a low polydispersity index ranging from 1 to 1.4 and low average molecular weights under 31,000 AMU.

EXAMPLES

[0106] The following examples will serve to illustrate the synthesis of the random terpolymer based on itaconic acid, aconitic acid or its isomers and sodium vinyl sulfonate object of the present invention.

Example 1 (Product 1)

[0107] In a 1000 mL four-mouth round flask with a magnetic stirrer, a condenser, an addition funnel and a thermometer, 298 g of a solution containing 25% by weight of sodium vinyl sulfonate, 60 g of itaconic acid and 100 g of aconitic acid are mixed at room temperature and atmospheric pressure. Afterwards, the reaction mixture is stirred vigorously and heated up to a temperature of 90° C. under atmospheric pressure in order to obtain a mixture with homogeneous and clear appearance. Once these conditions are attained, 1.24 g of ammonium ferric sulphate dodecahydrate are added and vigorous stirring is maintained for 10 minutes. At a temperature of 90° C., 167 g of an aqueous solution containing 35% by weight of hydrogen peroxide is added to the system. The reaction is exothermic so the temperature of the system was held at 92° C. (+/−2° C.). Once the addition process is completed, the reaction mixture is maintained under vigorous stirring and at a temperature of 92° C. (+/−2° C.), for 6 hours, time after which, 640 g of a clear reddish liquid are obtained, which contains the random terpolymer derived from itaconic acid, aconitic acid or its isomers and sodium vinyl sulfonate referred to as product 1, with and average molecular weight of 984 AMU by number, an average molecular weight of 1090 AMU by weight and a polydispersity index of 1.11. These values were obtained by means of size exclusion chromatography (SEC) using a chromatography column with the trade name plaquagel MIXED-OH and an aqueous solution comprising sodium nitrate (0.2 M) and sodium phosphate, monobasic (0.01 M) al a pH of 7 as the mobile phase. Spectroscopic characteristics are the following: FTIR (cm.sup.−1): 3431, 2942, 1714, 1402, 1155, 1036 y 724 (FIG. 1). .sup.1H NMR (D.sub.2O), 200 MHz, δ (ppm): multiple signals at the 1.77 a 2.37, 2.38 a 3.25, 3.93 (FIG. 2). .sup.13C NMR (D.sub.2O), 50 MHz, δ (ppm): signals at the 21.5 a 33.3, 37.5 a 46.5, 50.5 a 65.7 y 174.3 a 177.1 (FIG. 3).

Example 2 (Product 2)

[0108] In a 1000 mL four mouth round flask supplied with a magnetic stirrer, a condenser an addition funnel and a thermometer, 298 g a solution containing 25% by weight of sodium vinyl sulfonate, 149 g of itaconic acid and 100 g of aconitic acid are mixed at room temperature and atmospheric pressure. Afterwards, the reaction mixture is stirred vigorously and heated up to a temperature of 90° C. under atmospheric pressure in order to obtain a mixture with a homogeneous and clear appearance. Once these conditions are attained, 1.62 g of ammonium ferric sulphate dodecahydrate is added and vigorous stirring is maintained for 10 minutes. At a temperature of 90° C., 167 g of an aqueous solution containing 35% by weight of hydrogen peroxide is added to the system. The reaction is exothermic so the temperature of the system was held at 92° C. (+/−2° C.). The reaction is exothermic so the temperature of the system was held at 92° C. (+/−2° C.). Once the addition process is completed, the reaction mixture is maintained under vigorous stirring and at a temperature of 92° C. (+/−2° C.), for 6 hours, time after which, 838 g of a clear reddish liquid are obtained, which contains the random terpolymer derived from itaconic acid, aconitic acid or its isomers and sodium vinyl sulfonate referred to as product 2, with and average molecular weight of 918 AMU by number, an average molecular weight of 1010 AMU by weight and a polydispersity index of 1.11. These values were obtained by means of size exclusion chromatography (SEC) using a chromatography column with the trade name plaquagel MIXED-OH and an aqueous solution comprising sodium nitrate (0.2 M) and sodium phosphate, monobasic (0.01 M) al a pH of 7 as the mobile phase. Spectroscopic characteristics are the following: FTIR (cm.sup.−1): 3431, 2939, 1713, 1407, 1154, 1036 y 71. .sup.1H NMR (D.sub.2O), 200 MHz, δ (ppm): multiple signals at the 1.77 a 2.33, 2.72 a 3.02, 3.37 a 3.44. .sup.13C NMR (D20), 50 MHz, δ (ppm): signals at the 23.2 a 31.5, 39.9 a 43.6, 49.1 a 58.5 y 176.9 a 181.4 intervals.

Example 3 (Product 3)

[0109] In a 1000 mL four mouth round flask supplied with a magnetic stirrer, a condenser an addition funnel and a thermometer, 298 g a solution containing 25% by weight of sodium vinyl sulfonate, 37.3 g of itaconic acid and 100 g of aconitic acid are mixed at room temperature and atmospheric pressure. Afterwards, the reaction mixture is stirred vigorously and heated up to a temperature of 90° C. under atmospheric pressure in order to obtain a mixture with a homogeneous and clear appearance. Once these conditions are attained, 1.06 g of ammonium ferric sulphate dodecahydrate is added and vigorous stirring is maintained for 10 minutes. At a temperature of 90° C., 142 g of an aqueous solution containing 35% by weight of hydrogen peroxide is added to the system. The reaction is exothermic so the temperature of the system was held at 92° C. (+/−2° C.). Once the addition process is completed, the reaction mixture is maintained under vigorous stirring and at a temperature of 92° C. (+/−2° C.), for 6 hours, time after which, 575 g of a clear reddish liquid are obtained, which contains the random terpolymer derived from itaconic acid, aconitic acid or its isomers and sodium vinyl sulfonate referred to as product 3, with and average molecular weight of 1061 AMU by number, an average molecular weight of 1220 AMU by weight and a polydispersity index of 1.15. These values were obtained by means of size exclusion chromatography (SEC) using a chromatography column with the trade name plaquagel MIXED-OH and an aqueous solution comprising sodium nitrate (0.2 M) and sodium phosphate, monobasic (0.01 M) al a pH of 7 as the mobile phase. Spectroscopic characteristics are the following: FTIR (cm.sup.−1): 3431, 2939, 1713, 1407, 1154, 1036 y 715. .sup.1H NMR (D.sub.2O), 200 MHz, δ (ppm): multiple signals at the 1.77 a 2.33, 2.72 a 3.02, 3.37 a 3.44. .sup.13C NMR (D.sub.2O), 50 MHz, δ (ppm): signals at the 23.2 a 31.5, 39.9 a 43.6, 49.1 a 58.5 y 176.9 a 181.4 intervals.

[0110] 3) Experimental evaluation of mineral salts scale inhibiting and dispersing properties of the random terpolymers. The assessment of the terpolymer anti-scaling and dispersant capabilities were performed by means of five different tests: a) Determination of calcium sulfate scale inhibition, b) Determination of calcium sulfate and carbonate crystal distortion and modification by scanning electron microscopy, c) Determination of calcium carbonate scale inhibition in a medium with the characteristics of cooling systems d) Determination of efficiency as inorganic salts dispersant, e) Determination of mineral scale inhibition of calcium carbonate and calcium sulphates, barium and strontium, f) Determination of prevention and remediation of formation damage by calcium sulphate precipitation with incompatible brine mixture in a limestone cores under high temperature, high pressure and high salinity conditions.

[0111] a) Determination of Calcium Sulfate Mineral Scale Inhibition. For Calcium Sulfate.

[0112] The method consists in mixing two solutions to induce the formation of calcium sulfate.

[0113] 1.—Two solutions are prepared containing the calcium and sulfate ions, respectively. [0114] a) Solution containing calcium ions: it contains 7.5 gL.sup.−1 of NaCl and 11.1 gL.sup.−1 of CaCl.sub.2.2H.sub.2O. [0115] b) Solution containing sulfate ions: it contains 7.5 gL.sup.−1 of NaCl and 10.66 gL.sup.−1 of NA.sub.2SO.sub.4.

[0116] 2.—The desired inhibitor concentration is prepared in the solution containing the sulphate ions.

[0117] 3.—10 mL of each solution and the desired inhibitor concentration are mixed and everything is poured into a 25 mL hermetically sealed vial.

[0118] 4.—The vials are placed in an oven for 24 hours at a constant temperature of 70° C.

[0119] 5.—After 24 hours, the vials are allowed to cool down to room temperature. Solids that may have been formed are filtered and a 1 ml sample is taken and completed to 10 ml with ultra-pure water.

[0120] 6.—The solution is analyzed by means atomic absorption, in order to obtain the remaining concentration of calcium ions in the solution. A control is prepared, containing only the amount of calcium ions present in the blank. The inhibition percentage was estimated with the expression (1).

[00001]$\begin{array}{cc}\%\mathrm{Inhibition}=\frac{\begin{array}{c}{\mathrm{Ca}}_{\mathrm{sample}-\mathrm{after}-\mathrm{the}-\mathrm{precipitation}-\mathrm{ion}}^{+2}-\\ {\mathrm{Ca}}_{\mathrm{Reference}-\mathrm{after}-\mathrm{the}-\mathrm{lprecipitation}}^{+2}\end{array}}{{\mathrm{Ca}}_{\mathrm{control}}^{+2}-{\mathrm{Ca}}_{\mathrm{Reference}-\mathrm{after}-\mathrm{the}-\mathrm{precipitation}}^{+2}}*100& \left(1\right)\end{array}$

Example 4

[0121] The determination of the calcium sulfate scale inhibitory capability was carried out for product 1 and 3. Table 5 shown the results for product 1 and 3 at different concentrations for products 1 and 3 and the derived copolymer from itaconic acid/sodium vinyl sulfonate (proportion 1:3).

TABLE-US-00005 TABLE 5 Calcium sulphate inhibition results Calcium concentration Efficiency Product Concentration (ppm) (%) Control solution — 1509 — Reference — 1012 0 Producto 1 200 1495 97.2 400 1500 98.2 600 1504 98.9 Producto 5 200 1493 96.8 400 1501 98.4 600 1503 98.8 Derived Copolymer 200 1410 81.0 from itaconic acid/ 400 1425 83.1 sodium vinyl 600 1430 84.1 sulphonate (1:3 ratio)

[0122] A comparison of the results obtained with the terpolymers described as products 1 and 3, with the derived copolymer based on itaconic acid/sodium vinyl sulphonate in 1:3 ratio that it was described in the Mexican Patent Application MX/a/2013/004644 which shown that new terpolymers have a better performance and that the chemical structure is a key element in the development of new anti-scaling agents with improved properties. It is a key element in the development of new anti-scaling agents with improved properties.

[0123] c) Determination of calcium sulphate and carbonate crystals distortion or modification by scanning electron microscopy. The solutions containing the calcium and sulphate ions are the following: [0124] i. Solution containing the calcium ions: it contains: 7.5 gL.sup.−1 de NaCl and 21.32 gL.sup.−1 of CaCl.sub.2.2H.sub.2O. [0125] ii. Solution containing the sulphate ions: it contains: 7.5 gL.sup.−1 de NaCl and 21.32 gL.sup.−1 of Na.sub.2SO.sub.4.

[0126] 1.—The desired inhibitor concentration is prepared in the solution containing the sulphate ions.

[0127] 2.—10 ml of each solution and the desired inhibitor concentration are mixed and everything is poured into a 25 mL hermetically sealed tube.

[0128] 3.—The tubes are placed in an oven for 24 hours at a constant temperature of 70° C.

[0129] 4.—After 24 hours, the containers are allowed to cool down to room temperature without exceeding 2 hours. Subsequently the solids formed are filtered.

[0130] 5.—Solids formed in the tubes are analyzed and their morphology is observed by scanning electron microscopy (SEM).

Example 5

[0131] In order to determine the effect of the terpolymers derived from the present invention on calcium sulphate crystals, product 1 was evaluated using two brines with high concentrations of calcium and sulphate ions.

[0132] FIG. 4 shows the images and compositions of the crystals resulting from the mixture of the solution for: [0133] a) without chemical product and b) with 200 ppm of product 1. Noteworthy, it is possible to observe clearly how the product 1 breaks up and distorts the calcium sulphate crystals, thereby inhibiting the growth of larger crystals.

[0134] For Calcium Carbonate

[0135] Solutions containing the calcium and bicarbonate ions are the following:

[0136] a) Solution containing the calcium ions: 12.15 gL.sup.−1 CaCl.sub.2.2H.sub.2O, 3.68 gL.sup.−1MgCl.sub.2.6H.sub.2O and 33 gL.sup.−1 de NaCl.

[0137] b) Solution containing the bicarbonate ions: 7.36 gL.sup.−1 de NaHCO.sub.3 and 33 gL.sup.−1 of NaCl.

[0138] 2.—The desired inhibitor concentration is prepared in the solution containing the bicarbonate ions.

[0139] 3.—10 mL of each solution and the desired inhibitor concentration are mixed and everything is poured into a 25 mL hermetically sealed tube.

[0140] 4.—The tubes are placed in an oven for 24 hours at a constant temperature of 70° C.

[0141] 5.—After 24 hours, the tubes are allowed to cool down to room temperature without exceeding 2 hours. Solids that may have formed are filtered.

[0142] 6.—Solids formed in the tubes are analyzed and their morphology is observed by scanning electron microscopy (SEM).

Example 6

[0143] In order to determine the effect of the derived terpolymers from the present invention on calcium carbonate crystals, product 1 was evaluated using two brines with high concentrations of calcium and bicarbonate ions.

[0144] FIG. 5 shows the images and compositions of the crystals resulting from the mixture of the solutions without chemical product and from the mixture of the solutions with product 1, for: a) without chemical product and at 200 ppm concentration of product 1.

[0145] It is possible to observe clearly how product 1 breaks up and distorts the calcium carbonate crystals at the concentration of 200 ppm, thereby inhibiting the growth of the crystals. Furthermore, the chemical compound obtained by means of chemical analysis shows the presence of sulfur in all solids, which confirms the presence of product 1 and hence the formation of supramolecular complexes and their effect on the calcium carbonate crystals morphology distortion.

[0146] c) Determination of Inhibition of the Characteristic Calcium Carbonate Scale (CaCO3) of a Cooling System.

[0147] This method determines the efficiency of calcium carbonate salts scale inhibitors.

[0148] Preparation of Solutions

[0149] Sodium carbonate solution (Na.sub.2CO.sub.3)

[0150] 0.424 g of Na.sub.2CO.sub.3 is weighted in 1 L of demineralized water.

[0151] Calcium chloride solution (CaCl.sub.2))

[0152] 0.444 g of CaCl.sub.2) is weighted in 1 L of demineralized water.

[0153] Preparation of Samples. [0154] 1. 100 mL of the Na.sub.2CO.sub.3 solution are poured in a 250 mL flask with an air-tight cap. [0155] 2. The concentration to be evaluated is adden in mL (ppm). [0156] 3. 100 mL of the CaCl.sub.2) solution are poured and the flask is shaken. [0157] 4. A blank is prepared as in points 1 and 3 composed of Na.sub.2CO.sub.3 and CaCl.sub.2) solutions without inhibitor and shaken. [0158] 5. All the flasks are closed and placed in the oven for 24 hours at 70° C. [0159] 6. Once the testing time is completed, the flasks are removed from the oven and left to cool down. [0160] 7. A reference solution without inhibitor composed of NaCO.sub.3 and CaCl.sub.2) solutions is prepared as in points 1 and 3. [0161] 8. The amount of calcium ions in solution is determined for the stock solution, for the blank and for the samples.

[0162] Table 6 shows a summary of the testing conditions.

TABLE-US-00006 TABLE 6 Testing conditions Calcium Hardness (CaCO.sub.3) 200 ppm Temperature 70° C. Test time 24 h Scale inhibitor concentration 5 and 10 ppm

[0163] Determination of Hardness as CaCO.sub.3. [0164] 1. An aliquot is taken from the center of the sample bottle at room temperature and at rest without having shaken since its removal from the oven. [0165] 2. The amount of calcium ions is determined by titration with EDTA (ethylenediaminetetraacetic acid disodic salt).

[0166] Efficiency Percentage Calculation:

[00002]$\mathrm{Efficiency}\text{:}\frac{\mathrm{sample}\mathrm{EDTA}\mathrm{mL}\mathrm{spent}-\mathrm{blank}\mathrm{EDTA}\mathrm{mL}\mathrm{spent}}{\begin{array}{c}\mathrm{Reference}\mathrm{solution}\mathrm{EDTA}\mathrm{mL}\mathrm{spent}-\\ \mathrm{blank}\mathrm{EDTA}\mathrm{mL}\mathrm{spent}\end{array}}*100$

Example 7

[0167] The determination of the inhibitory capability of calcium carbonate scale typical of cooling systems was carried out for products 1 and 2 and for polymers commercially used as scale inhibitors. Following Table 7 shows the efficiency results at different concentrations

TABLE-US-00007 TABLE 7 Efficiency results of polymers as scale inhibitors Efficiency at Efficiency Sample 5 ppm at 10 ppm Poly (acrylic acid) 63.8 81.6 Product 1 93.5 95.1 Product 2 92.4 94.1

[0168] d) Determination of Efficiency as Inorganic Salts Dispersants

[0169] These methods consist in determining the performance of the synthesized terpolymers to disperse calcium carbonate, iron oxides and clays through the measurement of turbidity in NTU (nephelometric turbidity units), where the dispersant action is more efficient at higher turbidity values. The measurement is founded on applying the nephelometric technique using a photometer (FIG. 6). The standard method is based on the comparison of the amount of light dispersed by colloidal particles present in a water sample, with the intensity of the light emerging through the same sample. Turbidity is expressed in turbidity units (NTU), where a turbidity unit equals a formalin suspension in water with a concentration of 1 ppm. The measurements of turbidity allow evaluating the dispersant effect for the polymeric chains.

[0170] Calcium Carbonate Dispersion Evaluation

[0171] For this test, it was employed a brine with a hardness of 200 ppm as calcium carbonate from sodium carbonate and calcium chlorides salts, and 750 ppm reactive-degree calcium carbonate was added in order to measure the effect of the terpolymer on calcium carbonate dispersion, at a dispersant concentration of 10 ppm for a 2 hours as period time.

Example 8

[0172] The determination of the characteristic calcium carbonate dispersant capability was carried out for the product 1. The dispersant effect results for the product 1 of the present invention and for a commercial polymer used as inorganic salts dispersants and their respective molecular weights are shown in Table 8. The results show that the product 1 work better at dispersing calcium carbonate than acrylic poly (acrylic acid).

TABLE-US-00008 TABLA 8 Turbidity results. Sample Turbidity (NTU) Poly (acrylic acid) 23.5 Product 1 152.1

[0173] Iron Oxide Dispersion Assessment.

[0174] One of the problems that most affect aqueous systems is the presence of iron oxides, due to the dissolution of metal by corrosion effects. This method consists in evaluating the dispersant power of the synthesized terpolymer as follows:

[0175] A solution is prepared with hardness as calcium carbonate of 200 ppm, 750 ppm of iron oxide and with the dispersant product added. The mixture is shaken and left to rest for a 4 hour time period. At the conclusion of the test, an aliquot is taken and turbidity is measured.

Example 9

[0176] The determination of the iron oxide-dispersant capability was carried out for the product 1 at 25 ppm of concentration. The results of the iron oxide dispersion test by the product 1 of the present invention and by a commercial polymer used as inorganic salts dispersants and their respective molecular weights are shown in Table 9.

[0177] Table 9 results show that product 1 work better than the poly (acrylic acid).

TABLE-US-00009 TABLE 9 Turbidity results. Sample Turbidity (NTU) Poly (acrylic acid) 345.2 Product 1 750.3

Clay Dispersion Assessment

[0178] For the purpose of this test, brine with a hardness of 200 ppm as calcium carbonate and 1000 ppm of clay (kaolin) was prepared by putting these substances in contact and adding the dispersant, prepared at a 25 ppm concentration.

[0179] Once mixed, the compounds is vigorously stirred in a magnetic stirring plate for 5 minutes and left to rest for 2 hours; once this time is elapsed, the respective turbidity measurements are performed.

Example 10

[0180] A determination of the clay-dispersing capability was carried out for the product 1 at 25 ppm as concentration. The results of the clay (kaolin) dispersion test for the product 1 of the present invention and for a commercial polymer used as inorganic salts dispersants are shown in Table 10.

TABLE-US-00010 TABLE 10 Results of turbidity. Sample Turbidity (NTU) Poly (acrylic acid) 550.6 Product 1 850.1

[0181] Table 10 results show that product 1 of the present invention perform better at dispersing clays than the poly (acrylic acid) which is commonly used as inorganic salts dispersants.

[0182] e) Determination of the Mineral Scale Inhibition of Calcium Carbonate and Calcium, Barium and Strontium Sulfates Scale Inhibition.

[0183] This evaluation involves the mixture preparation of 20 mL sea water and connate water in a 3 to 1 ratio. The mixture water is heated at 70° C. for 8 hours and then observed whether or not crystals forming.

[0184] The product to evaluate is added into the sea water at the required concentration.

[0185] Tables 11 and 12 show the brines compositions employed in this experiment.

[0186] The product to evaluate is added into the sea water at the required concentration.

[0187] Tables 11 and 12 show the brines compositions employed in this experiment.

TABLE-US-00011 TABLE 11 Compositions of the brines Sea water Connate water Cations mg L.sup.−1 mg L.sup.−1 Sodium 11742 59809 Calcium 448 31880 Magnesium 1288 1944 Iron 0.1 0.1 Barium — 25.37 Strontium 7.84 1450 Anions mg/L mg/L Chlorides 19900 154000 Sulfates 3650 300 Carbonates 13 0 Bicarbonates 84 149

TABLE-US-00012 TABLE 12 Brines hardness and salinity Sea Water Connate Water (mg L.sup.−1) (mg L.sup.−1) Total hardness as CaCO.sub.3 6420 87700 Salinity as NaCl 32804 253859

Example 11

[0188] The qualitative determination of calcium carbonate inhibition and calcium sulfate, barium and strontium was made for the Product 1.

[0189] The results are shown in Table 13.

TABLE-US-00013 TABLE 13 Crystal Formation Reference High amount Product 1 No evidencie

[0190] Determination of Prevention and Remediation of Damage Caused by Calcium Sulphate Precipitation with Incompatible Mixture of Brines in Limestone Cores at High Temperature and High Salinity Conditions

[0191] Prevention of damage by calcium sulphate precipitation in limestone cores at reservoir conditions.

[0192] The damage-prevention study was carried out using brines 1 and 2, the composition of which is shown in Table 14.

TABLE-US-00014 TABLE 14 Composition of the brines Brine 1 Brine 2 Cations mg/L mg/L Sodium 2949 2949 Calcium 3020 — Anions mg/L mg/L Chlorides 4551  4551 Sulphates — 10080

[0193] f) Procedure [0194] 1.—In a limestone saturated cores with brine 1 at 150° C. and 2000 psi, permeability was determined under such conditions. [0195] 2.—Subsequently, brine 2 enriched with chemical product 1 from the present invention was injected to the limestone cores saturated with brine 1 in order for them come in contact and, afterwards, permeability was measured under the temperature and pressure conditions described in point 1.

Example 12

[0196] The damage remediation by precipitation of calcium sulfate in limestone core at reservoir conditions.

[0197] Remediation of Damaged Caused by Calcium Sulphate Precipitation in Calcite Cores at Reservoir Conditions.

[0198] The damage-prevention study by calcium sulphate precipitation was carried out at 150° C. and 2000 psi in an incompatible mixture brines (Brine 1 and 2) from the terpolymer described in Example 1 (product 1) according to this following procedure: [0199] 1.—In a calcite saturated core with brine 1 at 150° C. and 2000 psi, permeability was determined under such conditions. [0200] 2.—Subsequently, brine 2 was injected to the limestone cores saturated with brine 1 in order for them come in contact and, afterwards, permeability was measured under the temperature and pressure conditions described in point 1. [0201] 3.—Finally the brine 2 containing 200 ppm of product 1 was injected to the calcite core and the permeability was measured.

[0202] Permeability at the beginning of the test with the limestone core saturated with brine 1 yielded a result of 55 mD, and with the mixture of brine 1 and 2 enriched with 200 ppm of product 1, permeability was 57 mD.

[0203] This fact indicates that the injection of product 1 to the calcite core had prevented the damage and even had an 3% increase in the initial permeability.

Example 13

[0204] The effect of terpolymer described in Example 1 (product 1) was determined in the prevention of damage caused by calcium sulfate in calcites cores at 150° C. and 2000 psi due to a mixture of incompatible brines and after to the product 1 injection.

[0205] The effect of terpolymer described in Example 1 (product 1) was determined in the prevention of damage caused by calcium sulfate in calcites cores at 150° C. and 2000 psi due to a mixture of incompatible brines and after to the product 1 injection. The compositions of brine are shown in Table 14.

[0206] Permeability at the beginning of the test with the calcite core saturated with brine 1 yielded a result of 58 mD, and with the mixture of brine 1 and 2, permeability was 27 mD. This fact indicated that the incompatibility of brines generated a 47% reduction in permeability.

[0207] When brine 2 additivated with 200 ppm of the product 1, was injected, the permeability was 62 mD, so there was an increase of 6.9% compared to the initial permeability (58 mD) system.

[0208] Assessment of acute toxicity with Daphnia magna and Artemia franciscana. This method is applicable to acute toxicity assessment in water and water soluble substances. In fresh water bodies, industrial and municipal wastewater, agricultural runoff and pure or combined substances or lixiviates and the solubilizable fraction in soils and sediments.

[0209] Within the cladocera group, the Daphnia gender species are the most widely used as bioindicators in toxicity tests, due to their wide geographic distribution, the important role they play within the zooplankton community, and because they are easy to culture in a laboratory and they are responsive to a wide range of toxics.

[0210] The acute toxicity determination was carried out by means of the Mexican NMX-AA-0087-SCFI-2010 standard, which establishes the method for measuring acute toxicity, using the freshwater organism Daphnia magna (Crustacea-Cladocera) and the Artemia franciscana organism.

Example 14

[0211] The acute toxicity determination was carried out with Daphnia magna for product 1, using the testing procedure established and described in the NMX-AA-087-2010 standard. Table 15 shows the average toxicity result of a total of three repetitions. The acute toxicity result indicates that the product 1 is in the category of not particularly toxic The result indicates that acute toxicity of the product 1 is in the category of particularly not toxic for the organism Daphnia magna sweet aquaculture.

TABLE-US-00015 TABLE 15 Toxicity to Daphnia magna. Chemical product CL.sub.50 (ppm) *Toxicity Category Product 1 102 Particularly Non-toxic 101 Particularly Non-toxic 100 Particularly Non-toxic Average 101 Particularly Non-toxic *Concentration range in ppm, classification.sup.a, category 5: 0.01-0.10, extremely toxic; 4: 0.1-1.0, highly toxic; 3: 1-10, moderately toxic; 2: 10-100, slightly toxic; 1: 100-1000, particularly non-toxic and 0: >1000, non-toxic. *CNS (UK) toxicity category for the application of chemical products used in hydrocarbon production in the North Sea.

[0212] In addition to these facts, based on the NRF-005-PEMEX-2009 Mexican standard, where it is established that to use chemicals products in the oil industry it must meet the following environmental criteria.

[0213] For sweet environment for aquaculture, using daphnia magna the limit in units of microorganism toxicity (UT), must not exceed 20 units. The toxicity units (UT) are calculated with CL50 value from the test toxicity, from the following relationship:

UT=(1/CL.sub.50)×100

[0214] Where:

[0215] TU=Acute toxicity units

[0216] CL.sub.50=Inhibitor concentration (in mgL−1 that causes the mortality of 50% of exposed organism).

[0217] Therefore, the terpolymer of the present invention has a TU=0.32, and hence it meets the Mexican NRF-005-PEMEX-2009 standard and can be used in equipment and pipelines of oil and chemical industry that uses fresh water and is built in land

Example 15

[0218] The acute toxicity determination was carried out with Artemia franciscana for product 1, using the test procedure established and described in the NMX-AA-087-2010 standard. Table 16 shows the average toxicity result of a total of three repetitions.

TABLE-US-00016 TABLE 16 Toxicity to Artemia franciscana. Chemical product CE.sub.50 (ppm) *Toxicity Category Product 1 220 Particularly Non-toxic 218 Particularly Non-toxic 221 Particularly Non-toxic Average 219.7 Particularly Non-toxic *Concentration range in ppm, classification.sup.a, category 5: 0.01-0.10, extremely toxic; 4: 0.1-1.0, highly toxic; 3: 1-10, moderately toxic; 2: 10-100, slightly toxic; 1: 100-1000, particularly non-toxicand 0: >1000, non-toxic. *CNS (UK) toxicity category for the application of chemical products used in hydrocarbon production in the North Sea.

[0219] The acute toxicity result indicates that product 1 is particularly non-toxic to the Artemia franciscana organism. Moreover, based on the Mexican NRF-005-PEMEX-2009 standard, which establishes that, in order chemical products to be suitable for use in the oil industry, they must meet the following environmental criterion. For sea water environments, using the Artemia franciscana microorganism, the maximum limit in toxicity units should not be higher than 2.

[0220] Therefore, the terpolymer of the present invention has a TU=0.46, and hence it meets Mexican NRF-005-PEMEX.2009 standard and can be used in equipment and pipelines of oil and chemical industry that used sea water or formation water from oil reservoirs and that is built offshore.

[0221] Determination of Acute Toxicity by Means of the Microtox Method.

[0222] The microtox bacterial bio-assay, designed by Strategic Diagnostic Inc. (Azur Environmental) is based on monitoring changes in the emissions of natural light by a luminescent bacteria, Vibrio fischeri (Photobacterium phosphoreum).

[0223] The Microtox assay measures the acute toxicity of the test substance present in aqueous solution that uses a suspension of approximately one million of luminescent bacteria (Photobacterium phosphoreum) as test organism. The suspension of micro-organisms is added to a series of tubes of dilutions at controlled temperature with different concentrations of the test substance, to subsequently read, in a photometric device, the intensity of light emitted by each dilution, considering a reference blank where the test substance is not present.

[0224] With the obtained data, a dose-response graph can be drawn, by means of which the CE.sub.50 value is a measure of the decrease in the light emitted by the bioluminescent bacteria by means of the analyzing equipment, and specifically represents the concentration at which a 50 percent decrease of the light was obtained, with regard to a reference blank. Concretely, the CE.sub.50 value indicates the relative toxicity of the test substance.

Example 16

[0225] The determination of acute toxicity was carried out with Vibrio fischeri (Photobacterium phosphoreum) for the product 1, using the test procedure established in the NMX-AA-112-1995-SCFI Mexican standard, used for the assessment of toxicity of natural and residual waters, as well as pure of combined substances, by means of the bio-luminescent bacteria Photobacterium phosphoreum. Table 17 shows the average toxicity result of a total of three repetitions.

TABLE-US-00017 TABLE 17 CE.sub.50 15 min. (ppm) *Toxicity Category 21.8 Slightly toxic 21.6 Slightly toxic 21.7 Slightly toxic

[0226] Toxicity results shown in Table 17 indicate that the derived product 1 from the Example 1 is slightly toxic for Photobacterium phosphoreum bioluminescent bacteria.