Case Study: Northern Prudhoe Bay Development Planning Using Three-Dimensional Seismic Data

Thomas P. Walsh

Three three-dimensional seismic surveys have been acquired by the Prudhoe Bay unit working interest owners for the purpose of development planning. The most recent of these surveys, the Northern Tier three-dimensional seismic survey, was acquired in 1986 and provides the subject matter for this paper.

A new dual-source recording method was extensively field tested prior to its application in production data acquisition. This method of acquisition reduced costs by approximately 25% as compared to conventional (single-source) recording. The 54 mi² subsurface coverage area consists of 118,000 depth points, and cost $4.2 million for acquisition and processing, roughly twice the cost of two development wells in this area.

Interactive interpretation of the data volume helps in placing the 80-acre infill wells in the main development area, and helps to identify areas of development potential in the structurally complex northern portion of the field. Traverses are created along the proposed paths of horizontal and high-angle wells to reduce the risk of structural complications during drilling and completion. Predicting target depths to within ±25 ft and ensuring standoff from faults of 300-500 ft are the primary goals of the interpretation. Interaction among the various geo-science and engineering disciplines is common in all phases of this project.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.