ABSTRACT
Recent developments in foamed fluids have improved fracturing success on several formations within the North Texas, East Texas, Oklahoma, and Bakersfield, California areas. Laboratory results indicate the foaming of a delayed cross-linking gel increases apparent viscosities, as well as sand transport and fluid loss properties beyond those of foamed linear gels.
A detailed explanation of a 1,100 foot high pressure single pass pipe viscometer and fluid loss apparatus is provided. Results suggest foam cross-linked gels follow power law fluid behavior, possessing 44% higher viscosities than conventional foams. Fluid loss testing also shows a 40% reduction in leakoff beyond conventional foams. Dynamic proppant support for foams is not perfect according to parallel plate observation. Fall rates for conventional foams while affected by foam quality are two orders of magnitude greater than foam cross-linked fluids. Resulting proppant profiles are believed to be superior to conventional foams due to virtually infinite static proppant support.
More than 100 treatments have been completed using a delayed cross-linking foam. A review of local formation characteristics and treatment conditions are di scussed regarding the success of a cross-linked versus conventional linear gel foam.
