High temperature stable gels
AssigneeUnion Oil Company of California
InventorsBurton B. Sandiford, Hoai T. Dovan, Richard D. Hutchins
Life of this patent
Estimating the term…
Abstract
Gels stable in a subterranean formation at a temperature greater than about 175.degree. F. are formed using, inter alia, a stabilizing agent (e.g., a buffer having a buffering capacity at a pH of at least about 8 and/or a chelating agent).
Claims60
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the steps of:
- (A) injecting a composition into at least a portion of a subterranean formation, the composition comprising (i) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a crosslinkable polymer and (ii) water;
- (B) injecting a crosslinking agent into at least a portion of the subterranean formation;
- and
- (C) injecting a stabilizing amount of a buffering agent into at least a portion of the subterranean formation, the buffering agent having a buffering capacity at a pH greater than about 8 and being selected from the group consisting of water soluble bicarbonate salts, carbonate salts, phosphate salts, and mixtures thereof,
- wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the step of injecting a composition into at least a portion of a subterranean formation, the composition comprising (A) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a corsslinkable polymer, (B) a crosslinking agent, (C) water, and (D) a stabilizing amount of a buffering agent having a buffering capacity at a pH greater than about 8 and selected from the group consisting of water soluble bicarbonate salts, carbonate salts, phosphate salts, and mixtures thereof, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the step of injecting a composition into at least a portion of a subterranean formation, the composition comprising (A) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a crosslinkable polymer, (B) a crosslinking agent, (C) hard water, and (D) a buffering agent having a buffering capacity at a pH of at least bout 8 and selected from the group consisting of water-soluble bicarbonate salts, carbonate salts, phosphate salts, and mixtures thereof, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the step of injecting a composition into at least a portion of a subterranean formation, the composition comprising (A) an ingredient selected from the group consisting of a water soluble, crosslinkable polymer selected from the group consisting of polymethacrylamides, polyacrylamides, acrylic acid acrylamide copolymers, and acrylic acid-methacrylamide copolymers and polymerizable monomers capable of forming a crosslinkable polymer selected from the group consisting of polymethacrylamides, polyacrylamides, acrylic acid-acrylamide copolymers, and acrylic acid-methacrylamide copolymers, (B) a crosslinking agent, (C) hard water, and (D) a chelating agent, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A recovery system comprising:
- (a) a subterranean formation at a temperature of at least about 175.degree. F.;
- (b) a well penetrating at least a portion of the subterranean formation;
- and
- (c) a gel located in at least a portion of the subterranean formation, the gel comprising:
- (i) a crosslinked polymer;
- (ii) hard water;
- and
- (iii) a buffering agent having a buffering capacity at a pH greater than about 8 and selected from the group consisting of water soluble bicarbonte salts, carbonate salts, phosphate salts, and mixtures thereof.
A recovery system comprising;
- (a) a subterranean formation;
- (b) a well penetrating at least a portion of the subterranean formation;
- and
- (c) a gel located in at least a portion of the subterranean formation, the gel comprising:
- (i) an organic crosslinking agent corsslinked polymer;
- (ii) water;
- and
- (iii) a chelating agent.
A recovery system comprising:
- (a) a subterranean formation;
- (b) a well penetrating at least a portion of the subterranean formation;
- and
- (c) a composition located in at least a portion of the well, the composition comprising:
- (i) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a crosslinkable polymer;
- (ii) hexamethylenetetramine;
- (iii) hard water;
- and
- (iv) a stabilizing agent selected from the group consisting of buffering agents having a buffering capacity at a pH greater than about 8, chelating agents, and mixtures thereof.
A recovery system comprising;
- (a) a subterranean formation;
- (b) a well penetrating at least a portion of the subterranean formation;
- and
- (c) a composition located in at least a portion of the well, the composition comprising:
- (i) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a crosslinkable polymer;
- (ii) an organic crosslinking agent;
- (iii) water;
- and
- (iv) a chelating agent.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the steps of:
- (A) injecting a composition into at least a portion of a subterranean formation, the composition comprising (i) an ingredient selected from the group consisting of polymethacrylamides, polyacrylamides, acrylic acid-acrylamide copolymers, and acrylic acid methacrylamide copolymers and polymerizable monomers capable of forming a crosslinkable polymer selected from the group consisting of polymethacrylamides, polyacrylamides, acrylic acid-acrylamide copolymers, and acrylic acid-methacrylamide copolymers and (ii) water;
- (B) injecting a crosslinking agent into at least a portion of the subterranean formation;
- and
- (C) injecting a stabilizing amount of a stabilizing agent into at least a portion of the subterranean formation, the stabilizing agent being selected from the group consisting of buffering agents having a buffering capacity at a pH greater than about 8, chelating agents, and mixtures thereof, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the steps of:
- (A) injecting a composition into at least a portion of a subterranean formation, the composition comprising (i) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable monomers capable of forming a crosslinkable polymer and (ii) water;
- (B) injecting an organic crosslinking agent into at least a portion of the subterranean formation;
- and
- (C) injecting a stabilizing amount of stabilizing agent into at least a portion of the subterranean formation, the stabilizing agent being selected from the group consisting of buffering agents having a buffering capacity at a pH greater than about 8, chelating agents, and mixtures thereof, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
A method for forming a gel in at least a portion of a subterranean formation, the method comprising the steps of:
- (A) injecting a composition into at least a portion of a subterranean formation, the composition comprising (i) an ingredient selected from the group consisting of water soluble, crosslinkable polymers and polymerizable momoner capable of forming a crosslinkable polymer and (ii) water;
- (B) injecting an inorganic crosslinking agent into at least a portion of the subterranean formation, the inorganic crosslinking agent being selected from the group consisting of polyvalent metals, chelated polyvalent metals, and compounds capable of yielding polyvalent metals;
- and
- (C) injecting a stabilizing amount of a stabilizing agent into at least a portion of the subterranean formation, the stabilizing agent being selected from the group consisting of buffering agents having a buffering capacity at a pH greater than about 8, chelating agents, and mixtures thereof, wherein the subterranean formation is at a temperature of at least about 175.degree. F.
Dependencies are inferred from the claim text.