This volume assembles information on giant (>500 MOEB recoverable reserves) hydrocarbon reservoirs that will be of value to a wide audience. Although far from exhaustive, this compilation includes a wide range of reservoirs when examined from any perspective, such as location, geology, and production history. Reservoirs described in this volume are located in the Middle East, Asia, West Africa, North America, and South America. The authors explore historical and alternative approaches to reservoir description, characterization, and management, as well as examining appropriate levels and timing of data gathering, technology applications, evaluation techniques, and management practices in various stages in the life of individual development projects. Enhanced recovery of hydrocarbons requires a critical understanding of reservoir heterogeneity by both geoscientists and engineers. The giant fields discussed in this Memoir address issues important to reservoir description, characterization, and management from both geologic and engineering perspectives.