Fracturing fluid comprising a (co)polymer of a hydrated crystalline form of 2-acrylamido-2-methylpropane sulphonic acid and hydraulic fracturing method

Patent metadata

Field	Value
Publication number	US-10968171-B2
Application number	US-201816494605-A
Country	US
Kind code	B2
Filing date	Mar 19, 2018
Priority date	Mar 20, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

The present invention relates to a fracturation fluid comprising at least one propping agent and at least one water-soluble (co)polymer prepared from the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and/or at least one of its salts. The invention relates to a process to prepare said fluid, and to a hydraulic fracturation process using said fluid.

First claim

The invention claimed is:

1. A fracturing fluid comprising water, at least one propping agent and at least one water-soluble (co)polymer prepared from a hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and/or of at least one of its salts;
wherein the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid has a 2-theta powder X-ray diffraction diagram comprising peaks at 10.58°, 11.2°, 12.65°, 13.66°, 16.28°, 18.45°, 20°, 20.4°, 22.5°, 25.5°, 25.88°, 26.47°, 28.52°, 30.28°, 30.8°, 34.09°, 38.19°, 40.69°, 41.82°, 43.74°, and 46.04° degrees, all peak values being +/−0.1°.

2. The fracturing fluid according to claim 1 , wherein the water-soluble (co)polymer is obtained at least from 2-acrylamido-2-methylpropane sulfonic acid and/or from at least one of its salts, 50 mol % to 100 mol % of 2-acrylamido-2-methylpropane sulfonic acid being in the hydrated crystalline form and/or at least from one of its salts.

3. The fracturing fluid according to claim 1 , wherein the water-soluble (co)polymer is obtained from the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and/or from at least one of its salts, and from at least one nonionic monomer, and/or at least one anionic monomer, and/or at least one cationic monomer and/or at least one zwitterionic monomer.

4. The fracturing fluid according to claim 1 , wherein the at least one water-soluble (co)polymer is prepared by polymerization of one or more monomers including the 2-acrylamido-2-methylpropane sulfonic acid in hydrated crystalline form, wherein said 2-acrylamido-2-methylpropane sulfonic acid in hydrated crystalline form is partially or totally salified before polymerization.

5. The fracturing fluid according to claim 1 , wherein the water-soluble (co)polymer is anionic or amphoteric and comprises between 1 and 99 mol % of anionic monomers.

6. The fracturing fluid according to claim 1 , wherein the water-soluble (co)polymer is a copolymer of a salt of the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and acrylamide.

7. The fracturing fluid according to claim 1 , wherein the water-soluble (co)polymer is an anionic polymer obtained by copolymerization of a salt in the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid with an acrylic acid salt, or an anionic polymer obtained by copolymerization of a salt of 2-acrylamido-2-methylpropane sulfonic acid in hydrated crystalline form with a nonionic hydrolyzable monomer.

8. The fracturing fluid according to claim 1 , wherein the fracturing fluid comprises between 0.001% and 1% by weight of water-soluble (co)polymer prepared from the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and/or of at least one of its salts.

9. A preparation process for the fracturing fluid according to claim 1 , the process comprising using, in water or brine, at least one water-soluble (co)polymer prepared from the hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid and/or of at least one of its salts, and in which the water-soluble (co)polymer is, before formation of the fracturing fluid:
either in powder form;
or in the form of a water-in-oil inverse emulsion;
or in the form of an aqueous or oil particulate polyphasic suspension.

10. The process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in powder form having a particle size less than 1.5 millimeters.

11. The process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in the form of an inverse water-in-oil emulsion, the (co)polymer concentration in the emulsion being inclusively between 5 and 60% by weight relative to the weight of the emulsion.

12. The process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in the form of an inverse water-in-oil emulsion containing by weight from 0.01 to 70% of an organic and/or inorganic salt, relative to the weight of the emulsion.

13. The process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in the form of an aqueous particulate polyphasic suspension comprising:
i 15 to 60% by weight of at least one water-soluble (co)polymer in the form of solid particles with average size inclusively between 5 and 500 μm;
ii 15 to 45% by weight of at least one alkali metal salt and/or of at least one alkaline earth metal salt;
iii at least one viscosifying agent other than the water-soluble (co)polymer;
iv at least 10% by weight of water;
said suspension having a Brookfield viscosity inclusively between 500 and 20,000 cps at a temperature of 20° C., and
said suspension having a density inclusively between 1.1 and 2 kg·L −1 .

14. The preparation process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in form of an oil particulate polyphasic suspension comprising:
i 15 to 60% by weight of at least one water-soluble (co)polymer in the form of solid particles with average size inclusively between 5 and 500 μm;
ii at least one viscosifying agent other than the water-soluble (co)polymer;
iii at least 10% by weight of oil;
said suspension having a Brookfield viscosity inclusively between 500 and 20,000 cps at a temperature of 20° C., and
said suspension having a density inclusively between 0.6 and 1.4 kg·L −1 .

15. A hydraulic fracturing process for an unconventional underground oil or gas reservoir comprising preparing the fracturing fluid according to claim 1 , and injecting said fracturing fluid in an underground formation.

16. A friction reduction process for a fracturing fluid in a hydraulic fracturing operation for unconventional underground oil or gas reservoirs comprising preparing the fracturing fluid according to claim 1 , and injecting said fracturing fluid in an underground formation.

17. The process according to claim 10 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in powder form having a particle size less than 850 micrometers.

18. The process according to claim 17 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in powder form having a particle size less than 200 micrometers.

19. The process according to claim 9 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in the form of an inverse water-in-oil emulsion, the (co)polymer concentration in the emulsion being inclusively between 15 and 40% by weight relative to the weight of the emulsion.

20. The process according to claim 19 , wherein the water-soluble (co)polymer is, before formation of the fracturing fluid, in the form of an inverse water-in-oil emulsion containing by weight from 0.01 to 70% of an organic and/or inorganic salt.

Assignees

• Spcm Sa

Inventors

• Favero Cédrick
• Kieffer Johann

Classifications

• C07C309/15 Primary

  the nitrogen atom of at least one of the amino groups being part of any of the groups [IMAGE cpc-sch-C07C-0975.gif], X being a hetero atom, Y being any atom · CPC title

• E21B43/26

  by forming crevices or fractures · CPC title

• C08F20/56

  Acrylamide; Methacrylamide · CPC title

• C07C309/21 Primary

  containing nitrogen atoms, not being part of nitro or nitroso groups, bound to the carbon skeleton · CPC title

• C07C303/44

  Separation; Purification · CPC title