1. n. []

A condition in oil recovery processes whereby the mobility of the injectant is lower than that of the oil or preceding chemical slug, leading to a stable displacement by the injectant. Commonly the injectant is water containing a soluble polymer that increases its viscosity. Micellar-polymer floods incorporate a mobility buffer to maximize the sweep efficiency of the injected chemical and associated oil bank.

Synonyms: sweep efficiency

See related terms: mobility