SURFACTANT OIL RECOVERY PROCESS

摘要

SURFACTANT OIL RECOVERY PROCESS (D#74,495-1-F) Surfactant oil recovery process in which an aqueous fluid containing petroleum sulfonate is injected into an oil formation containing water which is naturally fresh or which has been reduced to an acceptable salinity level by a pre-flush with fresh water is disclosed. Optimum oil recovery is achieved by determining the average equivalent weight petroleum sulfonate which produces the minimum interfacial tension in an oil-brine system similar to that present in the formation in which the surfactant is to be injected, and a petroleum sulfonate sample having an average equivalent weight which is from 2 to 20 percent and preferably from 5 to 15 percent less than the average equivalent weight of the sample which produced the minimum interfacial tension, or from 20 to 100 and preferably from 30 to 70 equivalent weight units less than the average equivalent weight of the sample which produced the minimum interfacial tension is used in the oil recovery process. I