Methods of enhanced oil recovery using dense carbon dioxide compositions

Patent metadata

Field	Value
Publication number	US-2022154562-A1
Application number	US-202017097537-A
Country	US
Kind code	A1
Filing date	Nov 13, 2020
Priority date	Nov 13, 2020
Publication date	May 19, 2022
Grant date	—

Abstract

A method for enhanced oil recovery from a hydrocarbon bearing subterranean formation includes withdrawing hydrocarbons from a production well extending into the formation, identifying a high permeability streak in the formation, and injecting a dense CO2 composition from an injection well into the high permeability streak. The dense CO2 composition includes dense CO2 and a thickener soluble in the dense CO2. The thickener includes copolymer. The method includes, after injecting the dense carbon dioxide composition into the high permeability streak, injecting an aqueous treatment fluid into the formation. The dense CO2 composition blocks the high permeability streak to divert at least a portion of the aqueous treatment fluid into bypassed regions of the formation during the injecting of the aqueous treatment fluid, and the injecting of the aqueous treatment fluid into the hydrocarbon bearing subterranean formation drives hydrocarbons in the hydrocarbon bearing subterranean formation towards the production well.

First claim

1 . A method for enhanced oil recovery from a hydrocarbon bearing subterranean formation, the method comprising:
withdrawing hydrocarbons from a production well extending into the hydrocarbon bearing subterranean formation; identifying a high permeability streak in the hydrocarbon bearing subterranean formation; injecting a dense carbon dioxide composition from an injection well into the high permeability streak of the hydrocarbon bearing subterranean formation, where:
the dense carbon dioxide composition comprises dense carbon dioxide and a thickener soluble in the dense carbon dioxide, and
the thickener comprises a copolymer, the copolymer being the polymerized reaction product of monomers that include:
at least one alkenyl ether or dialkenyl ether monomer;
at least one acrylate or methacrylate monomer;
at least one structural monomer; and
at least one allyl ester monomer; and

after injecting the dense carbon dioxide composition into the high permeability streak, injecting an aqueous treatment fluid from the injection well into the hydrocarbon bearing subterranean formation, wherein:
the dense carbon dioxide composition blocks the high permeability streak to divert at least a portion of the aqueous treatment fluid into bypassed regions of the hydrocarbon bearing subterranean formation during the injecting of the aqueous treatment fluid into the hydrocarbon bearing subterranean formation; and
the injecting of the aqueous treatment fluid into the hydrocarbon bearing subterranean formation drives hydrocarbons in the hydrocarbon bearing subterranean formation towards the production well.

2 . The method of claim 1 , where the dense carbon dioxide is supercritical carbon dioxide.

3 . The method of claim 1 , where the co-solvent comprises:
at least one carbon dioxide compatible solvent selected from propylene carbonate and dimethyl carbonate; and at least one oil-dissolving solvent selected from white oil, silicon oil, petroleum ether, or combinations of these.

4 . The method of claim 3 , where the thickener comprises from 45 weight percent to 65 weight percent carbon dioxide compatible solvent and from 10 weight percent to 15 weight percent oil dissolving solvent.

5 . The method of claim 1 , where the copolymer of the thickener comprises an average molecular weight of from 500,000 grams per mole to 800,000 grams per mole.

6 . The method of claim 1 , where the thickener has a pH of from 5.0 to 8.0, a specific gravity of from 0.90 to 1.10, or both.

7 . The method of claim 1 , where 1 percent by weight of the thickener dissolves in supercritical carbon dioxide in less than or equal to 3 minutes at 25 degrees Celsius.

8 . The method of claim 1 , where the dense carbon dioxide composition comprises from 0.05 weight percent to 3.0 weight percent thickener based on the total weight of the dense carbon dioxide composition.

9 . The method of claim 1 , where the thickener increases the viscosity of the dense carbon dioxide by at least 100 times the viscosity of the dense carbon dioxide without the thickener.

10 . The method of claim 1 , where the dense carbon dioxide composition has a viscosity of from 50 millipascal seconds to 150 millipascal seconds.

11 . The method of claim 1 , where the dense carbon dioxide composition reduces the permeability of carbonate rock by greater than or equal to 50%.

12 . The method of claim 1 , where the dense carbon dioxide composition is injected at a pressure of from 900 pounds per square inch to 3,000 pounds per square inch.

13 . The method of claim 1 , where the dense carbon dioxide composition is injected at a temperature of from 20° C. to 150° C.

14 . The method of claim 1 , where the aqueous treatment fluid comprises one or more of freshwater, seawater, natural brine, synthetic brine, salt water, municipal water, well water, formation water, produced water, brackish water, distilled water, deionized water, or combinations of these.

15 . The method of claim 1 , where the aqueous treatment fluid comprises one or more oilfield additives selected from viscosifiers, surfactants, stabilizers, pH control agents, scale inhibitors, polymers, nanoparticles, tracer compounds, or combinations of these.

16 . The method of claim 1 , where injecting the dense carbon dioxide composition comprises isolating a portion of the injection well that is in fluid communication with the high permeability streak from other portions of the injection well before injecting the dense carbon dioxide composition into the high permeability streak.

17 . The method of claim 16 , where isolating the portion of the injection well that is in fluid communication with the high permeability streak from other portions of the injection well comprises installing one or more temporary plugs in the injection well.

18 . The method of claim 17 , where the one or more temporary plugs are disposed downhole of the portion of the injection well in fluid communication with the high permeability streak or both uphole and downhole of the portion of the injection well in fluid communication with the high permeability streak.

19 . The method of claim 17 , where the one or more temporary plugs comprise gel plugs.

20 . The method of claim 16 , where, after injecting the dense carbon dioxide composition, removing the isolation from the portion of the injection well.

Assignees

• Saudi Arabian Oil Co

Inventors

• Alyousif Zuhair
• Almajid Muhammad Majid

Classifications

• E21B47/11

  using tracers; using radioactivity · CPC title

• E21B33/134

  Bridging plugs · CPC title

• E21B43/164 Primary

  Injecting CO2 or carbonated water (in combination with organic material C09K8/594) · CPC title

• C09K8/594

  Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) · CPC title

• C09K8/588

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title