The buried remains of ancient ocean costal regions hold significant amounts of the potentially recoverable oil of the United States. Many of these reservoirs, classed as shallow-shelf carbonates, share a geologic character and producing behavior that should respond to a focused research effort designed to reduce the technical and economic constraints on the recovery of their remaining oil. The U.S. DOE is currently preparing to announce the opportunity for industry to participate with government in a series of research projects to contribute to this goal. This report provides background information regarding DOE's current understanding of the reservoir and geologic characteristics of shallow-shelf carbonates and the principal impediments to increased production from these reservoirs.