An Overview of the Point Thomson Field, North Slope, Alaska

By

B.L. Faulkner, J.W. Erickson, and N.C. Lian (ExxonMobil Production Company)

The Point Thomson Field straddles the coastline of the North Slope of Alaska and is approximately 55 miles east of the Prudhoe Bay Field. The primary reservoir is the Lower Cretaceous Thomson Sandstone, which occurs at 12,750 feet subsea. The Thomson lithologies range from conglomerates to sandstones and siltstones, and the depositional setting is interpreted as shallow marine. Reservoir quality varies from excellent to poor. The Thomson reservoir contains gas condensate with a thin oil leg and is severely overpressured. Secondary reservoirs include the oil-bearing Brookian (Paleocene) turbidite sandstones. Several development scenarios for the Thomson reservoir are being studied and include: 1) gas cycling followed by gas sales, and 2) gas sales.

A number of measures are being evaluated to minimize the environmental impact and the cost of development in this remote location. While the thickest parts of the Thomson accumulation lie offshore under the Flaxman Lagoon, all of the proposed facilities and drillsites will be located onshore. Extended-reach drilling will be used to access the development targets under the lagoon. Large well bores are planned in order to achieve maximum production and injection rates from a minimum number of wells. Footprints for the drill sites and production facilities will be minimized. Providing operational support by barge and airlift is under consideration and would eliminate the need for a permanent year-round supply road back to Prudhoe.

AAPG Search and Discovery Article #90008©2002 AAPG Pacific Section/SPE Western Region Joint Conference of Geoscientists and Petroleum Engineers, Anchorage, Alaska, May 18–23, 2002.