Schlumberger Technology Corporation

Keng Chan

Pia-Angela Francini

Christopher N Fredd

Mark Brady

A method is given for diverting acids in matrix acidizing and acid fracturing. The acids are diverted with a diverting agent that is an energized or foamed acidic viscoelastic surfactant system that contains a viscoelastic surfactant that gels and increases in viscosity when the acid in the foamed acidic viscoelastic surfactant system is spent. The method provides a synergistic combination of the diverting capabilities of foams and the diverting capabilities of viscoelastic gel systems. The resistance to flow of the gelled foamed viscoelastic surfactant system is greater than expected from a foam or a viscoelastic gel system alone.

Self-diverting foamed system

A method for preferentially treating a subterranean formation having at least one primarily oil producing layer and at least one primarily water producing layer. The method involves the steps of providing a water shut-off gel into the formation to preferentially treat the water producing layers. This is followed by providing a viscoelastic fluid into the formation, where the viscoelastic fluid is broken by hydrocarbon, thereby remaining and viscosifying primarily in the water producing layers. Finally, a reactive fluid, such as an acid fluid, is provided. The reactive fluid treats primarily the oil producing layers because the viscoelastic fluid and the water shut-off gel prevent the reactive fluid from substantially entering the water producing layers.

Growing community of inventors

Sugar Land, TX, United States of America

Keng Chan