Method and composition for enhanced hydrocarbons recovery

Abstract

An injectable fluid for treating a hydrocarbon containing formation is described. The injectable fluid includes ((i) when the salinity of the brine is from about 2 wt % to about 4 wt %, a composition that comprises a blend of a C20-24 internal olefin sulfonate and a C24-28 internal olefin sulfonate wherein the weight ratio of the C20-24 internal olefin sulfonate to the C24-28 internal olefin sulfonate is from about 90:10 to about 70:30 and (ii) when the salinity of the brine is greater than about 4 wt % up to about 13 wt %, a composition comprises a blend of a C20-24 internal olefin sulfonate and a C15-18 internal olefin sulfonate wherein the weight ratio of the C20-24 internal olefin sulfonate to the C15-18 internal olefin sulfonate is from about 90:10 to about 70:30.

Dependencies are inferred from the claim text.