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AssigneeHalliburton Company
InventorsCharles V. Hunt, Ronald J. Powell, Michael L. Carter, Samuel D. Pelley, Lewis R. Norman
Estimating the term…
The present invention relates to a method of preparing an encapsulated enzyme breaker and method of use in treating a subterranean formation. An encapsulated breaker is prepared by coating an enzyme on a cellulose substrate. A micron-sized particulate is admixed with the enzyme solution to prevent undesired agglomeration of the substrate. The enzyme solution coated substrate is covered with a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide. The membrane contains imperfections through which an aqueous fluid may pass into the breaker to contact the enzyme and diffuse the enzyme outward from the breaker particle.
A method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated enzyme breaker comprising a particulate cellulose substrate having a particle size in the range of from about 10 to 50 mesh, an enzyme solution coated upon said substrate, said enzyme solution including a first micron-sized insert particulate having a particle size below about 15 microns and present in an amount of from about 1 to about 15 percent by weight of the enzyme solution and a membrane encapsulating said enzyme solution and substrate, said membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide and having imperfections through which an aqueous fluid can diffuse to contact said enzyme and subsequently diffuse outward from said breaker with said enzyme to contact and break the fracturing fluid in contact therewith.
Dependencies are inferred from the claim text.