ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,391,866, issued on Aug. 19, was assigned to Saudi Arabian Oil Co. (Dhahran, Saudi Arabia).
"Surfactant mixtures for enhanced oil recovery" was invented by Limin Xu (Beijing), Ming Han (Dhahran, Saudi Arabia) and Tianping Huang (Beijing).
According to the abstract* released by the U.S. Patent & Trademark Office: "A system and a method for making and using an enhanced oil recovery (EOR) fluid. The EOR fluid includes a base fluid, an anionic-nonionic surfactant including one of sodium alkylphenol ethoxylate carboxylate (APEC), sodium alkyl ethoxylate carboxylate (AEC), sodium alkylphenol ethoxylate sulfate (APES), or sodium alkyl ethoxylate sulfate (AES), and a second surfactant includi...