Methods and compositions related to gelled layers in oil and/or gas wells

Patent metadata

Field	Value
Publication number	US-9957779-B2
Application number	US-201514811504-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Jul 28, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Methods and compositions for the prevention of the formation, breakdown, and/or removal of gelled layers in an oil and/or gas well are provided. In some embodiments, the compositions and methods comprise a concentrate, as described in more detail herein, where the concentrate comprises two or more surfactants. In certain embodiments, the compositions and methods comprise an emulsion or a microemulsion. The emulsion or microemulsion may include a surfactant, optionally a solvent, and optionally a freezing point depression agent or other components.

First claim

What is claimed is:

1. A method of breaking down a gelled layer in an oil or gas well having a wellbore, comprising:
injecting at least a concentrate comprising a first type of surfactant and a second type of surfactant into the wellbore,
wherein the first type of surfactant comprises an ethylene oxide/propylene oxide block copolymer;
wherein the second type of surfactant comprises an ethoxylated quaternary ammonium compound;
wherein the wellbore comprises the gelled layer; and
wherein the gelled layer comprises a partially broken crosslinked guar polymer; and
breaking down the gelled layer.

2. The method according to claim 1 , wherein the concentrate is combined with a first type of dilution fluid during the injecting step to form a concentrate solution.

3. The method according to claim 2 , wherein the first type of dilution fluid comprises a freezing point depression agent.

4. The method according to claim 3 , wherein the freezing point depression agent is present in the first type of dilution fluid in an amount between about 0 wt % and about 80 wt %.

5. The method according to claim 2 , wherein the pH of the first type of dilution fluid is about neutral or greater.

6. The method according to claim 2 , wherein the first type of dilution fluid comprises a base.

7. The method according to claim 6 , wherein the base is present in the first type of dilution fluid in an amount between about 1 wt % and about 60 wt %.

8. The method according to claim 6 , wherein the base comprises potassium chloride.

9. The method according to claim 2 , wherein the first type of dilution fluid comprises an aqueous phase.

10. The method according to claim 9 , wherein the aqueous phase comprises water.

11. The method according to claim 9 , wherein the aqueous phase is present in the first type of dilution fluid in an amount between about 1 wt % and about 90 wt %.

12. The method according to claim 2 , wherein the first type of dilution fluid comprises a salt.

13. The method according to claim 1 , wherein the concentrate is combined with a second type of dilution fluid during the injecting step.

14. The method according to claim 1 , wherein each of the first type of surfactant and the second type of surfactant are individually present in the concentrate in an amount between about 1 wt % and about 100 wt %.

15. The method according to claim 1 , wherein the crosslinked guar polymer comprises a borate crosslinker.

16. The method according to claim 1 , wherein the concentrate comprises a breaking additive.

17. The method according to claim 16 , wherein the breaking additive comprises ammonium persulfate.

18. The method according to claim 1 , wherein the concentrate does not comprise an emulsion or a microemulsion.

Assignees

• Flotek Chemistry Llc

Inventors

• Fursdon-Welsh Angus
• Silas James
• Gonzalez-Roldan Monica

Classifications

• C09K2208/26

  Gel breakers other than bacteria or enzymes · CPC title

• C09K8/602

  containing surfactants · CPC title

• E21B37/06 Primary

  using chemical means for preventing or limiting {, e.g. eliminating,} the deposition of paraffins or like substances · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title

• C09K8/52

  Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning · CPC title