Abstract: A Structurally Complex and Dynamic Reservoir Description for Reservoir Simulation, Kuparuk River Field, Alaska

Thomas P. Walsh, Mark H. Leander, Terry C. Wilcox, Thomas J. Lasseter

The Kuparuk River Field is a structurally complex giant oil field adjacent to the Prudhoe Bay Field on Alaska's North Slope. Oil is reservoired within two Early Cretaceous shallow marine sandstone formations, separated stratigraphically by an erosionally truncated marine silt/shale. Subjected to several phases of tectonism, this highly compartmentalized reservoir has been developed on regular 160 acre direct line drive patterns.

An integrated team of geoscientists and engineers from BP Exploration (Alaska) Inc. and ARCO Alaska Inc. is presently quantifying the benefits of infill drilling at Kuparuk, and identifying the best locations for well placement. The two primary reservoir characteristics believed to impact the effectiveness of infill drilling are large-scale reservoir heterogeneity, and reservoir compartmentation due to faulting. Multiple thin pay zones within the two reservoir intervals are isolated laterally by faults with magnitudes greater than pay zone thickness. A process and tools designed to construct and maintain a structurally complex reservoir description, shared by the geoscientists and reservoir engineers, are described. Cross-discipline integration is aided by the use of Tech*Logic's IREX 3-D reservoir modeling and visualization application.

The unique architecture of the IREX model allows for representation of very complex structural geometries, and facilitates iteration between reservoir description and simulation, along the seismic to simulation continuum Modifications to the reservoir description are guided by well-level history matching within the constraints of all available geoscience information. The techniques described will be of particular interest to those working on reservoir description and simulation of structurally complex fields.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France