Oil recovery method using unique salinity for oil recovery surfactant system

摘要

A series of surfactant systems is prepared at varying electrolyte concentrations, each system being mixed with oil to be displaced or its equivalent and allowed to equilibrate to determine the salinity at which the microemulsion phase has approximately equal volumes of oil and water; thereafter additional series of such surfactant systems are prepared utilizing different cosurfactants; thereafter the resulting surfactant systems are used at their optimal salinity (i.e., the salinity at which approximately equal volumes of oil and water are taken up into the microemulsion phase) to recover oil from test cores and the resulting oil recovery plotted versus the salinity to give the unique salinity at which maximum oil recovery is obtained for the particular oil-surfactant combination.