Gelled Oil: New Chemistry Using Surfactants

Abstract Water-based fluids can damage some sandstone formations due to various reasons including clay swelling, emulsions, water-block, and wettability alternations. Oil-based fluids are less damaging than water-based systems to the hydrocarbon bearing formations. Conventional gelled oils (GO) have numerous limitations; however, they are used in formations that are highly sensitive to water. Aluminum carboxylate technology has been used for several decades, aluminum phosphate ester, however, has remained the preferred gelled oil system for the last thirty years. This paper describes the development of novel surfactant-based gelled oil (S-GO). This new technology uses surfactants to develop the viscosity of diesel. Unlike conventional gelled oil systems, this gelled oil is not sensitive to the nature of base oil or additive concentrations. The S-GO system, with an order of magnitude higher low shear viscosity, has much better solids suspension characteristics. This cleaner fluid also exhibits low friction characteristics, allowing pumping at higher rates. These unique features make the new S-GO system highly attractive for fracturing, frac-packing, sand control, coiled tubing cleanouts, and as kill pills. This fluid system can be used for applications up to 300°F.