IP Library › Granted Patent US 9,611,420
Granted Patent B2
US 9,611,420 · App. 13/887,536 · Granted Apr 4, 2017

Crosslinking chitosan for reducing permeability in a well

Inventors: Shoy C. George (Thrissur, IN); Prajakta Ratnakar Patil (Pune, IN); Prasanta Das (Laskarpur, IN)
Assignee: Halliburton Energy Services, Inc.
C09K8/514C09K8/512C09K8/5756C09K8/5758
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Quick Facts
Patent No.
US 9,611,420
App. No.
13/887,536
Granted
Apr 4, 2017
Kind
B2
Abstract

A composition including: (a) an aqueous phase; (b) a chitosan-based compound dispersed or dissolved in the aqueous phase; and (c) a crosslinker dispersed or dissolved in the aqueous phase, wherein the crosslinker has at least two functional groups independently selected from the group consisting of aldehyde, carboxylic acid, and carboxylate. A method including the step of introducing a composition according to the invention into a treatment zone of a well.

Claims (15)

1. A method of treating a treatment zone in a well, the method comprising:

introducing into the treatment zone a treatment fluid consisting of:

(a) an aqueous phase having a pH below about 6;

(b) a chitosan-based compound dispersed or dissolved in the aqueous phase; and

(c) a crosslinker dispersed or dissolved in the aqueous phase, wherein the crosslinker is selected from the group consisting of: ethanedial, malondialdehyde, glutaraldehyde, citric acid, alkali metal citrate, and any combination thereof;

allowing the crosslinker to crosslink the chitosan-based compound to form a crosslinked-treatment fluid; and

allowing the crosslinked-treatment fluid to reduce the permeability of the treatment zone,

wherein the aqueous phase has a pH of below about 6 when the treatment fluid is introduced into the treatment zone.

2. The composition according to claim 1 , wherein the aqueous phase has a pH in the range of about 1 to about 4.

3. The method according to claim 1 , wherein the treatment zone includes a portion of a subterranean formation that is a gas reservoir having permeability greater than 0.1 milliDarcy.

4. The method according to claim 1 , wherein the treatment zone includes a portion of a subterranean formation that is an oil reservoir having permeability greater than 15 milliDarcy.

5. The method according to claim 1 , further comprising, after the step of introducing, the step of shutting in the treatment zone for at least one hour.

6. The method according to claim 5 , further comprising the step of flowing back from the treatment zone after the step of introducing.

7. The method according to claim 1 , further comprising the step of flowing back from the treatment zone after the step of introducing.

8. The method according to claim 1 , wherein the chitosan-based compound is chitosan.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 5, 2013
From: GEORGE, SHOY C.; PATIL, PRAJAKTA RATNAKAR; DAS, PRASANTA
To: HALLIBURTON ENERGY SERVICES, INC.
Reel/Frame 030557/0001 →
Continuity (1)
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