Oil recovery process usable in high temperature formations containing high salinity water which may include high concentrations of polyvalent ions

摘要

A fluid containing a dual surfactant system and a process using the fluid for recovering petroleum from petroleum formations containing high salinity water, e.g. from 50,000 to 225,000 parts per million which may include from about 200 to about 14,000 parts per million polyvalent ions such as calcium and/or magnesium dissolved therein and a method of using said fluid in a surfactant flooding oil recovery process. The surfactant system comprises a water-soluble salt of petroleum sulfonate or an alkyl or alkylaryl sulfonate wherein the alkyl chain may have from 5 to 25 carbon atoms, plus a phosphate ester surfactant with an average molecular weight not to exceed 1000. The surfactant combination is stable up to at least 225 DEG F and resistant to bacterial attack and inhibits scale formation.