Encapsulated breakers and method for use in treating subterranean formations
AssigneeHalliburton Company
InventorsLewis R. Norman, Steve B. Laramay
Life of this patent
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Abstract
The present invention relates to a method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated breaker said encapsulated breaker comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having imperfections through which an aqueous fluid can diffuse, such that an aqueous fluid in said fracturing fluid can diffuse through said membrane, dissolve at least a portion of said breaker and diffuse outward from said encapsulated breaker to contact and break the fracturing fluid in contact therewith.
Claims20
A method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated breaker said encapsulated breaker comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having imperfections through which an aqueous fluid can diffuse, such that an aqueous fluid in said fracturing fluid can diffuse through said membrane, dissolve at least a portion of said breaker and diffuse outward from said encapsulated breaker to contact and break the fracturing fluid in contact therewith.
A method of breaking an aqueous fracturing fluid having a pH in excess of about 7 and assisting in removing filter cake produced from said fracturing fluid within a subterranean formation comprising introducing into said formation to contact said fracturing fluid and filter cake in said formation an encapsulated breaker, said encapsulated breaker comprising a breaker for said fracturing fluid enclosed within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane including an effective quantity of an in-excess-of 1 micron particulate to create imperfections in said membrane such that said breaker can diffuse through said membrane into the fracturing fluid to break the fracturing fluid.
A method of breaking an aqueous fracturing fluid and assisting in removing filter cake produced therefrom during treatment of a subterranean formation comprising introducing into said formation being fractured with at least a portion of said fracturing fluid an encapsulated breaker, said encapsulated breaker comprising an aqueous soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane containing a diffusion effecting amount of an in excess of 1 micron sized silica particulate whereby imperfection are created in said membrane such that breaker dissolved by an aqueous fluid can diffuse from said encapsulated breaker to contact and break said fracturing fluid in contact therewith.
Dependencies are inferred from the claim text.