Mobil Oil Corporation

Ricky C Ng

Craig H Phelps

Paul Shu

Thurman W McPherson, Ii

Myung K Hwang

Leonard V Grego

A method for zone isolation or replacing a damaged or corroded casing with a solid plastic is described herein. A resin/curing agent mixture sufficient to form a hardened plastic or solid, underwater and/or at low wellbore temperatures that is also able to withstand downhole stresses, is placed into the wellbore so as to bind with the undamaged casing and close off any thief zone. Subsequently, the resin/curing agent mixture forms a hardened solid. The hardened solid is milled out if necessary so as to form a resinous casing the size of the original casing. Later, the hardened resinous casing is perforated to communicate with a targeted zone. Perforation is not required when isolating a zone. The hardened solid is of a strength sufficient to withstand stresses generated during EOR operations such as carbon dioxide or steam-flooding. Said solid is also resistant to workover acids and other chemicals used in EOR operations.

Low temperature underwater epoxy system for zone isolation, remedial

A method for zone isolation, profile modification, remedial cementing, or replacing a damaged or corroded casing with a solid plastic is described. A solidifiable epoxy resin mixture, containing a critical amount of a hardener and curing agent for improved pumpability, is placed into a wellbore so as to bind with undamaged casing and close off any thief zones. Subsequently, the epoxy resin mixture forms a hardened solid underwater and/or at low wellbore temperatures that is able to withstand downhole stresses. The hardened solid is milled out if necessary so as to form a resinous casing the size of the original casing. Later, the hardened resinous casing is perforated to communicate with a targeted zone. Perforation is not required when isolating a zone. The hardened solid is of a strength sufficient to withstand stresses generated during EOR operations such as carbon dioxide or steam-flooding. Said solid is also resistant to workover acids and other chemicals used in EOR operations.

Low temperature epoxy system for through tubing squeeze in profile

A method and composition for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. An aqueous solution of an organoammonium silicate, alkali metal or ammonium silicate is injected into a zone of higher permeability in a formation. Subsequently, a spacer volume of a water-immiscible organic solvent is directed into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the higher permeability zone. A silica cement is formed in-situ thereby substantially closing the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide-flooding, or fire-flooding EOR operation is commenced in a lower permeability zone.

In-situ cementation for profile control

A method for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. Initially, an aqueous solution of an alkali metal hydroxide, ammonium hydroxide or organoammonium hydroxide is injected into a zone of greater permeability in a formation. Thereafter, a spacer volume of a water-miscible organic solvent is injected into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the greater permeability zone. A silica cement is formed in-situ thereby substantially closing off the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide stimulation or fire-flooding EOR operation is commenced in a lower permeability zone.

In-situ silica cementation for profile control during steam injection

A method for replacing a damaged or corroded casing with a solid plastic is described herein. After removing the corroded or damaged casing from the wellbore, the borehole is underreamed to a desired diameter. Thereafter, a resin/curing agent mixture sufficient to form a hardened plastic or resin able to withstand downhole stresses, is placed into the wellbore so as to bind with the undamaged casing and close off any thief zone. Subsequently, the resin/curing agent mixture forms a hardened solid. The hardened solid is milled out so as to form a resinous casing the size of the original casing. Later, the hardened resinous casing is perforated to communicate with a targeted zone. Perforation is not required when isolating a zone.

Casing repair using a plastic resin

A method for selectively closing an intermediate zone of a near wellbore area in a formation. Initially, a drillable mechanical packer is placed into the wellbore below the intermediate zone. The wellbore area adjacent to the intermediate zone is cooled to a critical temperature between about 130.degree. to about 180.degree. F. Subsequently, a novolac or resole-type phenolformaldehyde resin containing an acid catalyst is placed into the wellbore where it forms a solid platform over the packer and intermediate zone in about 2 hours. The critical temperature is maintained in the wellbore and intermediate zone while placing a second resinous material containing an alkaline catalyst into the wellbore and intermediate zone. Thereafter, the second material forms a steam resistant solid gel in the intermediate zone, thereby closing it.

Method for selectively closing an intermediate zone of a near wellbore

A method for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. Initially, an aqueous solution of an alkali metal hydroxide, ammonium hydroxide or organoammonium hydroxide is injected into a zone of greater permeability in a formation. Thereafter, a spacer volume of a water miscible organic solvent is injected into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the greater permeability zone. A silica cement is formed in-situ thereby substantially closing off the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide stimulation or fire-flooding EOR operation is commenced in a lower permeability zone.

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Dallas, TX, United States of America

Ricky C Ng