Breaker and displacement fluid and method of use

Patent metadata

Field	Value
Publication number	US-RE47649-E
Application number	US-201715406393-A
Country	US
Kind code	E1
Filing date	Jan 13, 2017
Priority date	Feb 19, 2007
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A method of cleaning a wellbore prior to the production of oil or gas is disclosed, wherein the wellbore has been drilled with an invert emulsion drilling mud that forms an invert emulsion filter cake. The method may include the steps of circulating a breaker fluid into the wellbore, where the breaker fluid includes an aqueous fluid, and imino diacetic acid or salt thereof. Optionally an acid buffering agent, and a weighting age are also included. The breaker fluid is formulated such that after a predetermined period of time and the filter cake present in the wellbore or on the wellbore face is substantially degraded. Other methods may also include drilling the wellbore with a water-based drilling mud that forms a water-based filter cake, wherein the method may include the steps of circulating a breaker fluid into the wellbore, where the breaker fluid may include an aqueous fluid, and an iminodiacetic acid or a salt thereof.

First claim

What is claimed:

1. A method of cleaning a wellbore, wherein the wellbore has been drilled with an invert emulsion drilling mud that forms an invert emulsion filter cake, the method comprising:
circulating a breaker fluid into the wellbore, the breaker fluid comprising:
an aqueous fluid; and
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; and M each independently represents a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group;

wherein the breaker fluid is selected so that after a predetermined period of time the invert emulsion of the filter cake substantially degrades.

2. The method of claim 1 , wherein the breaker fluid further includes an acidic buffering agent so as to maintain the pH below a value of about 3.

3. The method of claim 2 , wherein acidic buffering agent is selected from the group consisting of mineral acids including hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid and mixtures of these, organic acids including carboxylic acids such as formic, acetic, propionic, butyric acids, fatty acids in the C5 to C30 range, haloacetic acids, alkyl phosphonic acids, alkyl sulfonic acids; compounds that hydrolyze to form acids in situ including hydrolysable anhydrides of carboxylic acids, hydrolysable esters of carboxylic acids; hydrolysable esters of phosphonic acid, hydrolysable esters of sulfonic acid and combinations thereof.

4. The method of claim 2 , wherein the acidic buffering agent is a hydrolysable ester of the carboxylic acid is a formic acid ester of a C4 to C30 alcohol.

5. The method of claim 1 , wherein the breaker fluid further includes a weighting agent that is a high density brine containing water soluble salts of alkali and alkaline earth metals.

6. The method of claim 1 , further comprising:
removing the broken invert emulsion filter cake from the wellbore.

7. A method of producing a hydrocarbon from a formation, the method comprising:
drilling a wellbore through the formation with an invert emulsion drilling mud and thereby forming an invert emulsion filter cake on the formation;
performing at least one completion operation in the wellbore;
emplacing a breaker fluid in the wellbore, the breaker fluid comprising:
an aqueous fluid;
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; and M each independently represents a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group; and
a weighting agent; and

shutting the well for a predetermined time to allow the substantial degradation of the invert emulsion filter cake.

8. The method of claim 7 , further comprising:
allowing the formation fluids to enter into the well wellbore; and
producing fluids from the well wellbore.

9. The method of claim 8 , wherein the completed wellbore contains at least one of a slotted liner, a predrilled liner, a wire wrapped screen, an expandable screen, a sand screen filter, a open hole gravel pack, and casing.

10. The method of claim 7 , wherein the breaker fluid further includes an acidic buffering agent.

11. The method of claim 10 , wherein the acidic buffering agent is a mixture of mineral acid and organic acid.

12. The method of claim 11 10, wherein the acidic buffering agent is a hydrolysable ester of a carboxylic acid.

13. A solution, comprising:
an aqueous fluid;
at least one iminodiacedtic acid or a salt thereof represented by the formula

wherein Y represents a divalent alkyl group having from 2 to 7 carbon atoms and the divalent alkyl group may be substituted by a COOM group, W represents a hydroxyl group or a COOM group, wherein each M independently represent a hydrogen atom, an alkali metal atom, an ammonium group or a substituted ammonium group;

an acidic buffering agent; and
a weighting agent,
wherein the aqueous fluid forms the discontinuous phase of an invert emulsion fluid.

Assignees

• Mi Llc

Inventors

• Jones Andrew G K
• Luyster Mark
• Navarro-Mascarell Raul

Classifications

• C09K8/528

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

• C09K2208/26

  Gel breakers other than bacteria or enzymes · CPC title

• C09K8/524 Primary

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