OIL RECOVERY PROCESS

A process for recovering petroleum from a subterranean hydrocarbon containing reservoir by flooding with a surfactant wherein the adsorption of surfactant by the reservoir rock is inhibited by treating the reservoir with a water soluble, strongly basic material having an oxygenated anion prior to injecting the surfactant. Preferably, treatment is accomplished by injecting an aqueous solution of sodium hydroxide or sodium meta silicate into the reservoir in an amount sufficient to satisfy substantially all of the adsorption capacity of the reservoir matrix followed by injection of an aqueous solution of the surfactant. The aqueous solution of sodium hydroxide or sodium meta silicate and the surfactant solution can be subsequently displaced through the formation by any convenient aqueous drive fluid including water.