Abstract: A valve for downhole use allows flow of mud or completion fluids but closes when subjected to produced hydrocarbons. The flow through the valve is through an annular passage that features a sleeve preferably made of rubber. The passage remains open during completion operations, but when hydrocarbons are produced the rubber swells and the passage is closed off. Applications include completions involving long horizontal runs and small inside diameter laterals where access to a sliding sleeve with coiled tubing or a wireline run tool is not practical.