Abstract: Application of Geostatistical and Fluid Flow Simulations to Evaluate Options for Well Placement

PATHAK, RAKESH, Univ. of Alaska, Fairbanks, Fairbanks, AK; DAVID OGBE, Univ of Alaska, Fairbanks, Fairbanks, AK; JERRY JENSEN

In this study, we apply geostatistical and flow simulations to a section of the Endicott field, Alaska to study options for well placement. Geostatistical techniques of sequential Gaussian simulations and sequential indicator simulations were used to generate one hundred equally likely realizations of permeability and porosity in Zones 2A and 2B of the Endicott field. We observed continuous horizontal permeabilities from porosity and permeability distributions in the section of the field selected for study. This is interpreted as reflecting laterally continuous sandstones with rare siltstones, consistent with the braided stream depositional environment of the Endicott reservoir.

Three realizations of porosity and permeability, representing high, medium, and low cases, were selected for fluid flow simulations. Fluid flow simulations were conducted to evaluate 15 potential well locations in the reservoir. We analyzed the performance of fully penetrating vertical well and 600-ft, 1800-ft, and 3000-ft horizontal wells at each location considering various well orientations, kV/kh ratios, and reservoir thickness. The flow simulation results show that the 3000-ft horizontal well gives the best performance in most of the cases. However, the performance of the horizontal wells deteriorated rapidly with decrease in the permeability anisotropy (kV/kh). In that case, a vertical well is a better option, especially for thick reservoirs. The proposed methodology should find application in targeting infill wells in a new development.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California