COMPOSITION AND METHOD FOR RECOVERING HYDROCARBON FLUIDS FROM A SUBTERRANEAN RESERVOIR

• US 20130192826A1
• Filed: 01/27/2012
• Published: 08/01/2013
• Est. Priority Date: 01/27/2012
• Status: Active Grant

• Current Assignee: ChampionX USA Inc. (ChampionX Corporation)
• Original Assignee: Nalco Company LLC (Ecolab, Inc.)
• Inventors: Wei, Mingli, Chang, Kin-Tai, Kurian, Pious
• Granted Patent: US 9,120,965 B2
• Time in Patent Office: Days
• US Class Current: 166/279
• CPC Class Codes: C09K 8/588 characterised by the use of specific polymers polymeric surfactants C09K8/584
• CPC Class Codes: C09K 8/594 Compositions used in combination with injected gas , e.g. CO2 orcarbonated gasC09K8/592 takes precedence
• CPC Class Codes: E21B 43/164 Injecting CO2 or carbonated water in combination with organic material C09K8/594

Abstract

A composition comprising crosslinked expandable polymeric microparticles capable of hydrolysis at or below neutral pH and a method of modifying the permeability to water of a subterranean formation by introducing such compositions into the subterranean formation is disclosed and claimed. This invention further relates to compositions and methods for the recovery of hydrocarbon fluids from a subterranean reservoir or formation subjected to CO₂ or CO₂ Water Alternating Gas flooding at low pH and increases the mobilization and/or recovery rate of hydrocarbon fluids present in the subterranean formations.

Claims

1. A composition comprising:

crosslinked expandable polymeric microparticles having (i) an unexpanded volume average particle size diameter from about 0.05 to about 2,000 microns and (ii) a crosslinking agent content from about 50 to about 200,000 ppm of at least one labile crosslinker based on a molar ratio of said polymeric microparticles capable of cleavage at or below neutral pH and from 0 to about 900 ppm of at least one non-labile crosslinker based on a molar ratio.

2. The composition of claim 1, wherein at least a portion of the crosslinked expandable polymeric microparticles is highly crosslinked.

3. The composition of claim 1, wherein the unexpanded volume average particle size diameter is from about 0.05 to about 10 microns.

4. The composition of claim 1, wherein the unexpanded volume average particle size diameter is from about 0.05 to about 1 micron.

5. The composition of claim 1, wherein the at least one labile crosslinker comprises a crosslinker with at least two functional sites.

6. The composition of claim 1, wherein the at least one labile crosslinker is selected from at least one of the structures 1-26 of FIG 1.

7. The composition of claim 1, wherein the expandable polymeric microparticle comprises at least one of the following properties:

anionic, amphoteric, ion-pair, betaine-containing, and combinations thereof.

8. The composition of claim 1, further comprising an emulsion, a dry powder, or an aqueous suspension.

9. The composition of claim 1, wherein the crosslinked expandable polymeric microparticles are prepared by free-radical polymerization from about 95 to about 10 mole percent of nonionic monomers and from about 5 to about 90 mole percent anionic monomers.

10. The composition of claim 8, wherein the anionic monomer is 2-acrylamido-2-methyl-1-propanesulfonic acid and the nonionic monomer is acrylamide.

11. The composition of claim 1, wherein said at or below neutral pH is from about pH 3 to about pH 6.

12. A method of modifying the permeability to water of a subterranean formation, the method comprising:

introducing into the subterranean formation a composition comprising crosslinked expandable polymeric microparticles according to claim 1 wherein the microparticles have a smaller diameter than the pores of the subterranean formation and wherein the labile crosslinkers break under the conditions in the subterranean formation to form expanded polymeric microparticles.

13. The method of claim 12, further comprising wherein the composition comprises an aqueous medium introduced into the subterranean formation and wherein the aqueous medium includes from about 100 ppm to about 50,000 ppm of said microparticles based on total weight of the aqueous medium.

14. The method of claim 12, wherein the composition is added to injection water as part of a secondary or tertiary process for the recovery of hydrocarbon from the subterranean formation.

15. The method of claim 12, wherein the injection water is added to the subterranean formation at a temperature lower than the temperature of the subterranean formation.

16. The method of claim 12, wherein the diameter of the expanded polymeric microparticles is greater than one tenth of the controlling pore throat radius of the rock pores in the subterranean formation.

17. The method of claim 12, wherein the subterranean formation is a sandstone or carbonate hydrocarbon reservoir.

18. The method of claim 12, wherein the composition is used in a carbon dioxide and water tertiary recovery project.

19. The method of claim 12, wherein the subterranean reservoir was subjected to CO₂ flooding or alternating CO₂ gas and water flooding.