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U.S. Department of Energy
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Lowering viscosity improves oil recovery

Journal Article · · Chem. Eng. News; (United States)

Low interfacial viscosity has been demonstrated to be just as important as low interfacial tension in using surfactant flooding in tertiary oil recovery. Oil yields can be maximized by formulating surfactant mixtures that result in low interfacial viscosity. Ideally, a surfactant reduces the interfacial tension between trapped oil and flooding fluids, insuring displacement of the oil from the rock. However, it also can result in emulsification of the oil in the water, producing emulsions that are quite stable, hard to pump because of high viscosity, and difficult and costly to separate. Evidently, surfactant formulations that insure low interfacial viscosity decrease emulsion stability and promote coalescene of oil droplets, thus enhancing the formation of a continuous oil bank that is pushed ahead by the flooding solutions. Optimum surfactant formulation varies, depending on the nature of the crude oil and the formation in which it is found. Good results have been obtained using Salem (Illinois) crude with a slug containing 3% Petrostep 420 surfactant and a 1.5% salt, with 0.58% n-hexanol as a cosurfactant.

OSTI ID:
5879538
Journal Information:
Chem. Eng. News; (United States), Journal Name: Chem. Eng. News; (United States) Vol. 57:16; ISSN CENEA
Country of Publication:
United States
Language:
English