Abstract: The present invention provides low viscosity acid-in-oil emulsions, surfactant systems and methods of using the emulsions and surfactants for stimulating the production of hydrocarbons from subterranean producing formations. The low viscosity acid-in-oil emulsions are basically comprised of a hydrocarbon oil forming the external phase of the emulsion, an emulsifying agent of a type which forms and stabilizes an acid-in-oil emulsion, an emulsion viscosity reducing agent comprising a fatty ammonium salt of a fatty acid and an aqueous acid solution forming the internal phase of the emulsion.

Abstract: An improved shaped charge comprised of a bell-shaped casing, a shaped explosive material disposed within the casing having a cavity formed therein and a liner disposed within the cavity formed of compressed powdered metal is provided. The compressed powdered metal liner includes a coating of an unsaturated organic compound or mixture of such organic compounds thereon whereby the liner is protected from corrosion attack without adversely affecting the performance of the shaped charge. A method of preventing the corrosion of the compressed powdered metal liner of a shaped charge is also provided.