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US 4,232,738 AGranted
Petroleum recovery process using native petroleum surfactants
AssigneeUniversity of Southern California
InventorsTeh F. Yen, Paul A. Farmanian
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AssigneeUniversity of Southern California
InventorsTeh F. Yen, Paul A. Farmanian
Estimating the term…
Isolation of native petroleum surfactants for lowering interfacial tensions in aqueous-alkaline systems. Petroleum of the type having reduced interfacial tension with water at high pH is subjected to fractionation by distillation including distillation under vacuum in the temperature range of 100.degree.-200.degree. C. to recover a surfactant fraction of the petroleum distilled in that temperature range. The fraction can be further concentrated by removing benzene-soluble components to obtain an ether-soluble residue having a density greater than water. The fraction alone, mixed with petroleum, or enriched with the residue, or the residue mixed with petroleum, can be injected as a slug into a subterranean oil reservoir to enhance tertiary recovery by alkaline water flooding. The amenability of a reservoir for alkaline flooding can be determined by separating the native surfactant fraction and measuring its interfacial tension with water at the proposed alkalinity of the floodwater.
In a process for recovering petroleum from a subterranean reservoir thereof penetrated by at least one injection well and at least one production well spaced apart in the reservoir in which a liquid slug is injected through said injection well into said reservoir followed by the injection of alkaline floodwater whereby to displace oil from said reservoir for recovery through said production well, the improvement according to which said slug is non-aqueous and comprises at least a surfactant portion of a fraction consisting essentially of natural components of petroleum, said fraction being distilled under conditions equivalent to vacuum of about 1 Torr in the temperature range of 100.degree.-200.degree. C. from petroleum of the type having reduced interfacial tension with water at high pH.
In a process for tertiary recovery of petroleum from a subterranean reservoir containing petroleum of a type having reduced interfacial tension with water at high pH, which reservoir has been penetrated by at least one production well, and by at least one injection well into which has been injected flooding medium for recovery of petroleum native to said reservoir, the improvement comprising:
Dependencies are inferred from the claim text.