ABSTRACT: Lisburne Porosity-Thickness Determination and Reservoir Management from 3-D Seismic Data.

S. F. Stanulonis, H. V. Tran

A method has been designed which calculated total pore footage directly from seismic amplitude for the highly stratified Lisburne pool located at Prudhoe Bay field on the North Slope of Alaska. The approach is unique in that it uses the peak-to-trough seismic amplitudes to calculate the accumulated product of carbonate thickness and porosity (pore footage) Thus, the reservoir fluid volume can be directly calculated from seismic amplitude. Thirty-three wells were used to calibrate the seismic amplitude to pore footage. Direct application of this method has produced a detailed pore-foot map using the 40,000 three-dimensional seismic traces with an independent pore-foot value calculated every 220 ft. The map is used in selecting well locations and in successfully predicting redrill pore footage within 4% of postdrill log values. Approximately 15 wells have been drilled with successful predictions so far.

Because the well data offers excellent vertical resolution and three-dimensional seismic data offers excellent lateral resolution, a more complete three-dimensional geologic model has resulted by integrating both types of data. Further modifications were made to the method so it could be applied to areas outside of well control to better define delineation prospects. Seismic character has also been used to examine porosity development along faults, to examine vertical porosity distribution within the reservoir, and to properly constrain porosity cross sections between wells. Seismic data also allows mapping of gas-prone areas of high productivity and areas of truncation due to a major unconformity.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990