PRUDHOE BAY FIELD – CORNERSTONE OF NORTH SLOPE GAS RESOURCES

DING, Eric R. and POSPISIL, Gordon, BP Exploration (Alaska) Inc, P.O. Box 196612, Anchorage, AK 99519-6612, [email protected]

The Prudhoe Bay field, Alaska is the largest accumulation of oil and gas in North America. As plans for a Major Gas Sale from the North Slope of Alaska progress, Prudhoe Bay will be the key source of export gas for the foreseeable future, with approximately 24 TSCF in saleable gas.

The field has already produced over 11 billion STB of liquid hydrocarbons, well above the initial estimates of 9.6 billion STB per the Plan of Development in 1977. Prudhoe Bay field operations are currently at a mature stage with production wells at high watercuts and gas-oil-ratios (GOR's). Waterflood operations cycle over 1.5 million BPD of produced water and gas cycling operations reinject over 7 billion SCFD of produced gas. While major gas sales remain years away pending development of a gas transportation system, gas development will support extended field life and significantly increase total hydrocarbon recovery.

This paper presents the development and oil production history of Prudhoe Bay, along with the reservoir description and a summary of the oil and gas resources in this super giant field. Over the past 29 years, Prudhoe Bay has seen extensive surface and subsurface development with over 2500 well penetrations, 42 drill sites, and 6 liquid processing centers. With this extensive development, the wells and facilities needed for major gas sales are largely already in place. As a part of the oil development activities, vast amounts of reservoir description data in the form of well logs, drilling core, seismic, fluid samples, and analysis have been obtained and interpreted. As a result, the Prudhoe Bay reservoir is well described and well understood. The reservoir description and depletion plans to date fully utilize this information, which supports a comprehensive understanding of the volume and deliverability of the oil and gas resources.