Method and composition for enhanced hydrocarbons recovery

• US 7,229,950 B2
• Filed: 04/20/2006
• Issued: 06/12/2007
• Est. Priority Date: 03/11/2003
• Status: Expired due to Term

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Raney, Kirk Herbert, Shpakoff, Paul Gregory
• Primary Examiner(s): Gulakowski; Randy
• Assistant Examiner(s): Kugel; Timothy J.
• Application Number:
  US11/408,118
• Publication Number:
  US 20060189486A1
• Time in Patent Office: 418 Days
• Field of Search: 507/203
• US Class Current: 507/218
• CPC Class Codes: C09K 8/584 characterised by the use of specific surfactants

Abstract

A method of treating a hydrocarbon containing formation is described. The method may include providing a hydrocarbon recovery composition to the hydrocarbon containing formation. Hydrocarbons in the hydrocarbon containing formation may interact with the hydrocarbon recovery composition. The hydrocarbon recovery composition may include an aliphatic anionic surfactant and an aliphatic nonionic additive. In some embodiments, an aliphatic anionic surfactant may be branched. In other embodiments, an aliphatic nonionic additive may be branched.

Claims

1. A method of treating a hydrocarbon containing formation, comprising:

providing a composition to at least a portion of the hydrocarbon containing formation, wherein the composition comprises a branched aliphatic anionic surfactant which has a branched aliphatic group with an average carbon number from 10 to 24 and has an average number of branches per aliphatic group of from about 0.7 to about 2.5 and wherein methyl branches represent from about 20 to about 99 percent of the total number of branches present in the branched aliphatic group and is an acid salt of a primary alcohol; and

an aliphatic nonionic additive; and

allowing the composition to interact with hydrocarbons in the hydrocarbon containing formation.

2. The method claim 1, wherein greater than about 50 percent of the branches of the branched aliphatic anionic surfactant are methyl groups.

3. The method claim 1, wherein less than about 10 percent of the branches of the branched aliphatic anionic surfactant are ethyl groups.

4. The method of claim 1, wherein less than about 0.5 percent of the branches of the branched aliphatic anionic surfactant are neither ethyl or methyl groups.

5. The method of claim 1, wherein the aliphatic group of the branched aliphatic anionic surfactant has less than about 0.5 percent aliphatic quaternary carbon atoms.

6. The method of claim 1, wherein the aliphatic nonionic additive has an average carbon number from 10 to 24.

7. The method of claim 1, wherein the composition comprises greater than about 40 wt. % of the branched aliphatic anionic surfactant.

8. The method of claim 1, wherein the composition comprises less than about 60 wt. % of the aliphatic nonionic additive.

9. The method of claim 1, wherein the aliphatic nonionic additive is an alcohol.

10. The method of claim 1, wherein the aliphatic nonionic additive is a sugar based surfactant.

11. The method of claim 1, wherein the branched aliphatic anionic surfactant is a sulfate.

12. The method of claim 1, wherein providing the composition to at least a portion of the hydrocarbon containing formation comprises combining at least a portion of the composition with at least a portion of a hydrocarbon removal fluid to produce an injectable fluid;

wherein an amount of the composition is less than about 0.5 wt. % based on the weight of the injectable fluid.

13. The method of claim 1, wherein the hydrocarbon containing formation comprises an average permeability thickness product of less than about 1000 millidarcy feet.

14. The method of claim 1, wherein the hydrocarbon containing formation comprises an average temperature of less than 50°

C.

15. The method of claim 1, wherein at least a portion of the hydrocarbon containing formation is oil wet.

16. The method of claim 1, wherein at least a portion of the hydrocarbon containing formation is less than 1000 feet below the earth'"'"'s surface.

17. The method of claim 1, further comprising waterflooding at least a portion of the hydrocarbon containing formation.

18. The method of claim 1, further comprising:

waterflooding at least a portion of the hydrocarbon containing formation before providing the composition to the hydrocarbon containing formation; and

allowing the composition to interact with the water and hydrocarbons.

19. The method of claim 1, further comprising:

waterflooding at least a portion of the hydrocarbon containing formation before providing the composition to the hydrocarbon containing formation; and

allowing the composition to interact with at least a portion of the water and at least a portion of the hydrocarbons, wherein the interaction reduces at least a portion of the interfacial tension between the water and at least a portion of the hydrocarbons to a value less than about 0.1 dyne/cm.

20. The method of claim 1, wherein at least a portion of the hydrocarbon containing formation comprises water and wherein a salinity value for the water is less than about 13,000 ppm.

21. The method of claim 1, further comprising providing a hydrocarbon removal fluid to at least a portion of the hydrocarbon containing formation and allowing the hydrocarbon removal fluid to mobilize at least a portion of the hydrocarbons toward a production well.

22. The method of claim 1, further comprising providing a polymer to at least a portion of the hydrocarbon containing formation.

23. The method of claim 1, wherein the aliphatic portion of the aliphatic nonionic additive has an identical chemical structure as the aliphatic portion of the branched aliphatic anionic surfactant.

24. The method of claim 1, wherein the branched aliphatic anionic surfactant has the general structure (R—

Y)_n M, where R is a branched long chain aliphatic group having an average carbon number from 10 to 24 and having an average number of branches per aliphatic group of from about 0.7 to about 2.5 and wherein methyl branches represent from about 20 to about 99 percent of the total number of branches present in the branched aliphatic group, Y is OSO₃⁻

or OPO₃,⁻

M is a metal ion, and n is a number depending on the valency of M, such that the total electrical charge of the composition is zero.