The invention pertains to the use of a class of acetylenic surfactants to resolve or break water and oil emulsions. The surfactants are of particular advantage in resolving crude oil emulsions of the type encountered in desalter and similar apparatus designed to extract brines from the crude as they partition to the aqueous phase in the desalter. Also, the surfactants may be used to separate oil from oil sands and similar oil/solids matrices.