METHODS AND COMPOSITIONS FOR REDUCING PERMEABILITY OF A SUBTERRANEAN FORMATION

摘要

The present application is directed to an aqueous composition comprising an alkali metal silicate; a hardener containing at least one dibasic ester, at least one non-ionic surfactant, at least one terpene or terpene derivative and optionally at least one polyalkylene glycol; and a retarder. The composition is useful for reducing the permeability in a subterranean formation, so as to reduce or prevent water flow and circulation loss of well fluids such as drilling fluids or cement.