US Patent 7893010 Composition and method for fluid recovery from well

A well treatment microemulsion for use in a subterranean formation is disclosed, the microemulsion comprises a solvent blend comprising a solvent and a co-solvent; a surfactant blend comprising a surfactant, wherein the surfactant blend is able to give formation intermediate wettability properties; an alcohol; and a carrier fluid; wherein the alcohol, the solvent and surfactant blends are combined with the carrier fluid to produce the well treatment microemulsion. By intermediate wettability it is meant that the water has an advancing contact angle on the surface between 62 and 133 degrees. The associate method of treating a subterranean formation of a well with the microemulsion and the associate method of modifying the wettability of the formation with the microemulsion are also disclosed.