Dual Retarded Acid System for Well Stimulation

摘要

A composition in the form of an emulsion having: (i) a continuous oil phase comprising: (a) an oil; (b) an emulsifier; and (ii) an internal aqueous phase comprising: (a) water; (b) acid such that the aqueous phase has an initial pH of less than about 2; (c) a viscosity-increasing agent; and (d) a crosslinker, wherein the crosslinker is selected or controlled to crosslink the viscosity-increasing agent at a pH range somewhere in a range of about 1.5 to about 6.5 and that is at least higher than the initial pH of the aqueous phase. A method of acidizing a treatment zone of a subterranean formation in a well includes the steps of: (A) forming a treatment fluid comprising such a composition; and (B) introducing the treatment fluid into a well.

主权项

1. A composition in the form of an emulsion comprising:
(i) a continuous oil phase comprising:
(a) an oil;(b) an emulsifier; and (ii) an internal aqueous phase comprising:
(a) water;(b) acid such that the aqueous phase has an initial pH of less than about 2;(c) a viscosity-increasing agent; and(d) a crosslinker, wherein the crosslinker is selected or controlled to crosslink the viscosity-increasing agent at a pH range somewhere in a range of about 1.5 to about 6.5 and that is at least higher than the initial pH of the aqueous phase.