Patent ID: 7306041

Claim:
A method of stimulating a sandstone subterranean formation comprising: a. preparing an aqueous viscous dissolving fluid comprising: i. viscosifier incorporated in an amount suitable to provide measured fluid viscosity from about 20 mPa-s to about 400 mPa-s at a shear rate of 100 s −1 over a temperature range from about 80° F. to about 300° F.; ii. at least one formation dissolving agent; and, iii. a chelant selected from the group consisting of aminopolycarboxylic acid, and aminopolycarboxylic acid salt; b. injecting the viscosified fluid into a wellbore penetrating the formation at a pressure that exceeds the fracture initiation pressure of the formation; c. relieving the initiation pressure and allowing a hydraulic fracture to at least partially close; and d. flowing back the wellbore to produce a substantial amount of the viscosified fluid.