Breaker and displacement fluid

Patent metadata

Field	Value
Publication number	US-9493697-B2
Application number	US-201113807679-A
Country	US
Kind code	B2
Filing date	Jun 30, 2011
Priority date	Jun 30, 2010
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A breaker fluid for breaking a filtercake in a wellbore. The fluid including a hydrolysable ester of carboxylic acid, and a chelant, an alkyl glycoside, or a combination thereof. The breaker fluid may be pre-mixed and include an amount of water less than required to completely hydrolyze the ester.

First claim

What is claimed:

1. A method of breaking a filtercake in a wellbore comprising:
preparing a pre-mixed breaker comprising:
a hydrolysable ester of carboxylic acid;
a chelant; and
an amount of water wherein the weight ratio of water to hydrolysable ester of carboxylic acid is less than 1.3 to 1;

combining the pre-mixed breaker with an aqueous fluid to form a breaker fluid prior to circulating the breaker fluid in the wellbore; and
contacting the filtercake in the wellbore with the breaker fluid.

2. The method of claim 1 wherein the pre-mixed breaker fluid comprises 0 wt % -10 wt % water.

3. The method of claim 1 wherein the hydrolysable ester of carboxylic acid is a formic acid ester of a C2 to C30 alcohol.

4. The method of claim 1 wherein the chelant comprises one or more chelants selected from a group consisting of: ethylenediaminetetraacetic acid; glutamic acid, N, N-diacetic acid; and salts thereof.

5. The method of claim 1 wherein the chelant comprises at least one iminodiacetic acid or a salt thereof, represented by the formula

wherein the M groups each independently represents a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group; Y represents a divalent alkyl group having from 1 to 7 carbon atoms and the divalent alkyl group may be substituted by a hydroxyl group or a COOM group wherein M represents a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group; and W represents a hydrogen atom, a hydroxyl group or a COOM group wherein M represents a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group.

6. The method of claim 1 wherein the pre-mixed breaker fluid comprises 5 -35 wt % chelant.

7. The method of claim 1 wherein the aqueous fluid comprises a divalent brine.

8. The method of claim 1 further comprising circulating an alkyl glycoside.

9. A method of breaking a filtercake in a wellbore, the method comprising:
preparing a breaker fluid comprising:
a hydrolysable ester of carboxylic acid;
an alkyl glycoside; and
optionally, an amount of water, wherein
a weight ratio of water to hydrolysable ester of carboxylic acid is less than 1.3 to 1.

10. The method of claim 9 wherein the hydrolysable ester of carboxylic acid is a formic acid ester of a C2 to C30 alcohol.

11. The method of claim 9 , wherein the alkyl glycoside has the formula RO—(R′O) x Z y where the letter O represents an oxygen atom; R represents a monovalent alkyl radical containing from 8 to 16 carbon atoms; R′ represents a divalent alkyl radical containing 2 to 4 carbon atoms; x represents the number of oxy-alkylene units in the alkyl glycoside varying from 0 to about 12; Z represents a saccharide moiety containing 5 or 6 carbon atoms, and y represents the number of saccharide units in the glycoside.

12. The method of claim 11 , wherein y ranges from 1.3 to 1.8.

13. The method of claim 9 wherein the breaker fluid further comprises a blend of a base oil and at least one of a mutual solvent or a terpene; and the base oil comprises mineral oil or diesel.

14. The method of claim 13 , wherein the mutual solvent comprises at least one compound selected from the group consisting of ethylene glycol, ethylene glycol monobutyl ether, and butyl carbitol.

15. The method of claim 9 further comprising circulating an aqueous fluid to the wellbore.

16. The method of claim 15 wherein the aqueous fluid comprises a divalent brine.

Assignees

• Luyster Mark
• Moore Latosha
• Jones Andrew
• M-I L L C

Inventors

• Luyster Mark
• Moore Latosha
• Jones Andrew

Classifications

• C09K8/524 Primary

  organic depositions, e.g. paraffins or asphaltenes · CPC title

• C09K8/86 Primary

  containing organic compounds · CPC title

• C09K8/528

  inorganic depositions, e.g. sulfates or carbonates · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title

• E21B37/06

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