US 12,139,664 B2
Thermal stimuli-responsive surfactants for enhanced oil recovery
Limin Xu, Beijing (CN); Ming Han, Dhahran (SA); and Tianping Huang, Beijing (CN)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Mar. 3, 2023, as Appl. No. 18/117,171.
Prior Publication US 2024/0294822 A1, Sep. 5, 2024
Int. Cl. E21B 43/34 (2006.01); C09K 8/584 (2006.01)
CPC C09K 8/584 (2013.01) 15 Claims
OG exemplary drawing
 
1. A method of recovering oil from a subterranean formation, comprising:
providing an aqueous solution comprising a thermal stimuli-responsive surfactant mixture into a reservoir of the subterranean formation containing oil, wherein the thermal stimuli-responsive surfactant mixture comprises an anionic surfactant and a cationic surfactant, wherein at least one of the anionic surfactant or cationic surfactant comprises one or more nonionic groups;
contacting the aqueous solution with the oil in the reservoir; and
producing a fluid from the reservoir comprising the aqueous solution and the oil;
wherein:
the thermal stimuli-responsive surfactant mixture reduces the interfacial tension between the aqueous solution and the oil in the reservoir to about 10−2 mN/m or lower at temperatures of about 60° C. to about 200° C.; and
the interfacial tension between the aqueous solution containing the thermal stimuli-responsive surfactant mixture and the oil in the produced fluid increases to about 0.1 mN/m or higher at temperatures of about 20° C. to about 50° C.