INVERT EMULSION WITH ENCAPSULATED BREAKER FOR WELL TREATMENT

摘要

An emulsion including: (a) an external oil phase, wherein the oil phase has a viscosity of less than 200 cP; (b) an internal water phase adjacent the external phase, wherein the internal water phase has a pH in the range of 5 to 9; (c) an emulsifier having a hydrophilic-lipophilic balance in the range of 3 to 7 on the Davies scale; and (d) a Bronsted-Lowry base having a pKb(1) less than 12, wherein the base is encapsulated with an encapsulated breaker composition comprising: an encapsulant that comprises an ether cellulose. A method of treating a well includes the steps of: forming a treatment fluid including the emulsion; and introducing the treatment fluid into the well. In a preferred embodiment, the emulsion has a viscosity greater than 200 cP.