Filter cake removal composition for drilling fluids and method of use thereof

Patent metadata

Field	Value
Publication number	US-2016376491-A1
Application number	US-201615258091-A
Country	US
Kind code	A1
Filing date	Sep 7, 2016
Priority date	Dec 7, 2011
Publication date	Dec 29, 2016
Grant date	—

Abstract

Disclosed is a filter cake removal composition, and method of use thereof, for use in a wellbore for controlled removal of a filter cake present in a target production zone. The filter cake removal composition includes hydrochloric acid and an organic acid. The filter cake removal composition, when a mixture of the hydrochloric acid and the organic acid is applied to the filter cake in the target production zone, is operable to dissolve the filter cake in the target production zone over an extended reaction time. The mixture includes the hydrochloric acid present in an amount of between about 0.1% and 5% by weight and the organic acid present in an amount of between about 0.1% and 10% by weight.

First claim

What is claimed is:

1 . A method for the controlled removal of a filter cake from a target production zone of a wellbore using a filter cake removal composition, the method comprising:
delivering the filter cake removal composition to the target production zone, wherein the delivering comprises applying the filter cake removal composition to the filter cake for an extended reaction time during which extended time the filter cake removal composition acts to dissolve the filter cake and after which extended time the filter cake removal composition acts to control fluid loss from the wellbore into the target production zone, wherein the delivering comprises applying a mixture of hydrochloric acid and an organic acid to the filter cake in the target production zone, and wherein the mixture comprises the hydrochloric acid present in an amount of between about 0.1% and 5% by weight and the organic acid present in an amount of between about 0.1% and 10% by weight.

2 . The method of claim 1 , wherein the delivering further comprises applying the mixture to the filter cake in the target production zone, wherein the mixture comprises the hydrochloric acid present in an amount of about 1% by weight.

3 . The method of claim 1 , wherein the delivering further comprises applying the mixture to the filter cake in the target production zone, wherein the mixture comprises the organic acid being selected from the group consisting of formic acid, lactic acid, and malonic acid.

4 . The method of claim 1 , wherein the delivering further comprises applying the mixture to the filter cake in the target production zone, wherein the mixture comprises the organic acid present in an amount of about 4% by weight.

5 . The method of claim 1 , wherein the delivering further comprises applying the mixture of the hydrochloric acid present in an amount of about 1% by weight and the organic acid present in an amount of about 4% by weight.

6 . The method of claim 1 , wherein the delivering further comprises applying the mixture of the hydrochloric acid and the organic acid to the filter cake in the target production zone in a single treatment for about 18 hours at about 250° F.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al Moajil Abdullah Mohammed
• Nasr-El-Din Hisham A

Classifications

• C09K2208/24

  Bacteria or enzyme containing gel breakers · CPC title

• E21B37/08

  cleaning in situ of down-hole filters, screens, {e.g. casing perforations,} or gravel packs (E21B37/06 takes precedence) · CPC title

• C09K8/524 Primary

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

• E21B37/00

  Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence) · CPC title

• E21B21/003

  Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138) · CPC title