Process for well cleaning

• US 20080287324A1
• Filed: 05/30/2008
• Published: 11/20/2008
• Est. Priority Date: 03/01/2002
• Status: Abandoned Application

• Current Assignee: CESI Chemical, Inc. (Flotek Industries Incorporated)
• Original Assignee: CESI Chemical, Inc. (Flotek Industries Incorporated)
• Inventors: Holcomb, David L., Pursley, John Thomas, Penny, Glenn S.
• Application Number:
  US12/156,201
• Publication Number:
  US 20080287324A1
• Time in Patent Office: Days
• US Class Current: 507/218
• CPC Class Codes: C09K 8/52 Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning

Abstract

Disclosed is a method for treating an oil or gas well having a wellbore that includes the steps of forming a solvent-surfactant blend by combining a solvent and a surfactant, adding a diluent to the solvent-surfactant blend to form an emulsified solvent-surfactant blend; combining the emulsified solvent-surfactant blend with a water-based carrier fluid to form a well treatment microemulsion, and injecting the well treatment microemulsion into the oil or gas well. In a preferred embodiment, the step of forming a solvent-surfactant blend includes combining a surfactant with a solvent selected from the group consisting of terpenes and alkyl or aryl esters of short chain alcohols.

Claims

1. A method for treating an oil or gas well having a wellbore, comprising:

forming a solvent-surfactant blend by combining a solvent and a surfactant;

adding a diluent to the solvent-surfactant blend to form an emulsified solvent-surfactant blend;

combining the emulsified solvent-surfactant blend with a water-based carrier fluid to form a well treatment microemulsion; and

injecting the well treatment microemulsion into the oil or gas well.

2. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that has a hydrophile-lipophile balance of between about 8 to 20.

3. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a cationic surfactant.

4. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with an anionic surfactant.

5. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a zwitterionic surfactant.

6. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a nonionic surfactant.

7. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that is selected from the group consisting of ethoxylated castor oil, polyoxyethylene sorbitan monopalmitate, and polyethylene glycol.

8. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that is selected from the group consisting of linear alcohol alkoxylates, alkyl ether sulfates, dodecylbenzene sulfonic acid, and linear nonyl-phenols.

9. The method of claim 1, wherein the carrier fluid comprises one or more acids selected from the group of hydrochloric, acetic, formic, hydrochloric-hydrofluoric, hydrofluoric, and fluoboric acids.

10. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and an alcohol, wherein the alcohol comprises 1 to 20 carbon atoms.

11. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and an alcohol that is selected from the group consisting of t-butanol, n-butanol, n-hexanol, 2-ethyl-hexanol, n-pentanol, and isopropyl alcohol.

12. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and a freeze prevention additive that is selected from the group consisting of detergent range alcohol ethoxylates, ethylene glycols, polyethylene glycols, propylene glycols, and triethylene glycols.

13. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent selected from the group consisting of terpenes, alkyl esters of short chain alcohols and aryl esters of short chain alcohols with a surfactant to form a solvent-surfactant blend.

14. The method of claim 1, wherein the step of adding a diluent to the solvent-surfactant blend comprises adding a diluent that is selected from the group consisting of water and a water-triethylene glycol mixture to the solvent-surfactant blend to form an emulsified solvent-surfactant blend.

15. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant, an alcohol and a salt that is selected from the group consisting of potassium salts, sodium salts, zinc salts, bromine salts, strontium salts, cesium salts, lithium salts, and calcium salts to form a solvent-surfactant blend.

16. The method of claim 1, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant, an alcohol and a salt that is selected from the group consisting of NaCl, KCl, CaCl₂ and MgCl₂ to form a solvent-surfactant blend.

17. The method of claim 1, wherein the steps of forming a solvent-surfactant blend and adding a diluent are carried out such that the emulsified solvent-surfactant blend comprises:

18% to 76% by volume surfactant;

7% to 54% by volume solvent;

up to 20% by volume alcohol; and

up to 50% by volume diluent.

18. The method of claim 17, wherein the step of combining the emulsified solvent-surfactant blend with a water-based carrier fluid is carried out such that the well treatment microemulsion comprises:

from about 0.05% to about 50% by volume of emulsified solvent-surfactant blend; and

from about 50% to about 99.95% by volume of water-based carrier fluid.

19. The method of claim 17, wherein the step of combining the emulsified solvent-surfactant blend with a water-based carrier fluid is carried out such that the well treatment microemulsion comprises:

from about 0.2% to about 2% by volume of emulsified solvent-surfactant blend; and

from about 98% to about 99.8% by volume of water-based carrier fluid.

20. A method for treating an oil or gas well having a wellbore, comprising:

forming a solvent-surfactant blend by combining a solvent and a surfactant;

adding a diluent to the solvent-surfactant blend to form an emulsified solvent-surfactant blend;

combining the emulsified solvent-surfactant blend with an oil-based carrier fluid to form a well treatment microemulsion; and

injecting the well treatment microemulsion into the oil or gas well.

21. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that has a hydrophile-lipophile balance of between about 3 to 8.

22. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a cationic surfactant.

23. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with an anionic surfactant.

24. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a zwitterionic surfactant.

25. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a nonionic surfactant.

26. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that is selected from the group consisting of ethoxylated castor oil, sorbitan monopalmitate, and polyethylene glycol.

27. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent with a surfactant that is selected from the group consisting of sorbitan monopalmitate, sorbitan monostearate, sorbinate monooleate, and linear alcohol alkoxylates.

28. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and an alcohol, wherein the alcohol comprises 1 to 20 carbon atoms.

29. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and an alcohol that is selected from the group consisting of t-butanol, n-butanol, n-hexanol and 2-ethyl-hexanol, n-pentanol, and isopropyl alcohol.

30. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant and a freeze prevention additive that is selected from the group consisting of detergent range alcohol ethoxylates, ethylene glycols, polyethylene glycols, propylene glycols, and triethylene glycols.

31. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent selected from the group consisting of terpenes, alkyl esters of short chain alcohols and aryl esters of short chain alcohols with a surfactant to form a solvent-surfactant blend.

32. The method of claim 20, wherein the step of adding a diluent to the solvent-surfactant blend comprises adding a diluent that is selected from the group consisting of diesel and condensate to the solvent-surfactant blend to form an emulsified solvent-surfactant blend.

33. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant, an alcohol and a salt that is selected from the group consisting of potassium salts, sodium salts, zinc salts, bromine salts, strontium salts, cesium salts, lithium salts, and calcium salts to form a solvent-surfactant blend.

34. The method of claim 20, wherein the step of forming a solvent-surfactant blend comprises combining a solvent, a surfactant, an alcohol and a salt that is selected from the group consisting of NaCl, KCl, CaCl₂ and MgCl₂ to form a solvent-surfactant blend.

35. The method of claim 20, wherein the steps of forming a solvent-surfactant blend and adding a diluent are carried out such that the emulsified solvent-surfactant blend comprises:

18% to 76% by volume surfactant;

7% to 54% by volume solvent;

up to 20% by volume alcohol; and

up to 50% by volume diluent.

36. The method of claim 35, wherein the step of combining the emulsified solvent-surfactant blend with an oil-based carrier fluid is carried out such that the well treatment microemulsion comprises:

from about 0.05% to about 50% by volume of emulsified solvent-surfactant blend; and

from about 50% to about 99.95% by volume of oil-based carrier fluid.

37. The method of claim 35, wherein the step of combining the solvent-surfactant blend with an oil-based carrier fluid is carried out such that the well treatment microemulsion comprises:

from about 0.2% to about 2% by volume of emulsified solvent-surfactant blend; and

from about 98% to about 99.8% by volume of oil-based carrier fluid.

38. A method of treating an oil or gas well with a well treatment microemulsion, wherein the oil or gas well has a well bore that contains a water-based fluid, the method comprising:

forming a solvent-surfactant blend by combing a solvent with a surfactant having a hydrophile-lipophile balance of about 8 to 20; and

forming the well treatment microemulsion by injecting the solvent-surfactant blend into the wellbore, wherein the solvent-surfactant blend mixes in situ with the water-based fluid.

39. A method of treating an oil or gas well with a well treatment microemulsion, wherein the oil or gas well has a well bore that contains an oil-based fluid, the method comprising:

forming a solvent-surfactant blend by combing a solvent with a surfactant having a hydrophile-lipophile balance of about 3 to 8; and

forming the well treatment microemulsion by injecting the solvent-surfactant blend through a capillary injection assembly into the wellbore, wherein the solvent-surfactant blend mixes in situ with the oil-based fluid.