Viscosity control additives for foaming mixtures

摘要

The method for the enhanced recovery of hydrocarbons from a hydrocarbon bearing reservoir during gas injunction into the reservoir comprises the at least periodic injection of steam and a foam-forming mixture into the reservoir from a known depth interval in a well source to provide a foam in the presence of residual oil and high gas permeable channels of the reservoir. The mixture comprises water, an effective foam forming amount of an alkyl aromatic sulfate component having an average molecular weight from about 400 to about 600 and at least one alkyl group comprising 18 to 24 carbon atoms and a viscosity control agent. The viscosity control agent comprises a surfactant which is present in an amount effective to prevent gelling of the mixture during storage. The reservoir fluids are contacted with the resulting foam so as to assist movement of the hydrocarbons toward a producing interval and the hydrocarbons are recovered from the producing interval.