Patent ID: 6986391
Filing Date: 2006-01-17
Classification: C08F,C09K,Y10S

Abstract:
1. A method of fracturing a subterranean zone comprising: pumping a viscous aqueous fracturing fluid into said subterranean zone by way of a well bore at a rate and pressure sufficient to fracture said zone, said aqueous fracturing fluid comprising water, a terpolymer of 2-acrylamido-2-methylpropane sulfonic acid present in an amount of about 55 to about 65 weight %, acrylamide present in an amount of about 34.5 to about 44.5 weight % and acrylic acid, or its salts present in an amount of about 0.1 to about 1 weight %, a cross-linking agent for said terpolymer and a delayed viscosity breaker for effecting a controlled reduction in the viscosity of said fracturing fluid; and creating a fracture in said formation.