Acid precursor in divalent brines for cleaning up water-based filter cakes

Patent metadata

Field	Value
Publication number	US-2016152884-A1
Application number	US-201414901106-A
Country	US
Kind code	A1
Filing date	Jul 10, 2014
Priority date	Jul 10, 2013
Publication date	Jun 2, 2016
Grant date	—

Abstract

A method may include circulating a breaker fluid into a wellbore, where the breaker fluid includes a base fluid of divalent brine having an amount of free water therein; a primary breaker; and a secondary breaker present in an amount less than the primary breaker, where the primary breaker is either a hydrolysable ester of a carboxylic acid or an iminodiacetic acid, and the secondary breaker is the other of the hydrolysable ester of a carboxylic acid or an iminodiacetic acid.

First claim

What is claimed:

1 . A method comprising:
circulating a breaker fluid into a wellbore, the breaker fluid comprising:
a base fluid of divalent brine having an amount of free water therein;
a primary breaker; and
a secondary breaker present in an amount less than the primary breaker,
where the primary breaker is either a hydrolysable ester of a carboxylic acid or an iminodiacetic acid, and the secondary breaker is the other of the hydrolysable ester of a carboxylic acid or an iminodiacetic acid.

2 . The method of claim 1 , wherein the hydrolysable ester is the primary breaker and present in an amount ranging from 10 to 50 volume percent, and the iminodiacetic acid is the secondary breaker and present in an amount up to 10 volume percent.

3 . The method of claim 1 , wherein the iminodiacetic acid is the primary breaker and present in an amount ranging from 10 to 40 volume percent, and the hydrolysable ester is the secondary breaker and present in an amount up to 10 volume percent.

4 . The method of claim 1 , wherein the free water content is at least 15 volume percent.

5 . The method of claim 1 , wherein the free water content is at least 20 volume percent.

6 . The method of claim 1 , wherein the free water content is at least 25 volume percent.

7 . A method comprising:
circulating a breaker fluid into a wellbore, the breaker fluid comprising:
a base fluid of divalent brine;
a hydrolysable ester of a carboxylic acid in an amount ranging from 10 to 50 volume percent; and
an iminodiacetic acid in an amount ranging up to 10 volume percent,
wherein the breaker fluid has a free water content of at least 25 volume percent.

8 . The method of claim 7 , wherein the hydrolysable ester is present in an amount ranging from 20 to 40 volume percent.

9 . A method comprising:
circulating a breaker fluid into a wellbore, the breaker fluid comprising:
a base fluid of divalent brine;
an acid precursor in an amount ranging up to 10 volume percent; and
an iminodiacetic acid in an amount ranging from 10 to 40 volume percent,
wherein the breaker fluid has a free water content of at least 25 volume percent.

10 . The method of claim 9 , wherein the iminodiacetic acid is present in an amount ranging from 15 to 35 volume percent.

Assignees

• Mi Llc

Inventors

• Ravitz Raymond David
• Luyster Mark R
• Allogo Clotaire-Marie Eyaa

Classifications

• E21B37/06

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

• C09K8/52 Primary

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

• C09K2208/26

  Gel breakers other than bacteria or enzymes · CPC title