Miscible Flood Forecasting Technique at Judy Creek

Abstract

Summary A simplified forecasting technique was developed to predict the recovery performance of a hydrocarbon miscible flood in the Judy Creek Beaverhill Lake (BHL) A Pool in Alberta. This technique incorporates the physics of the hydrocarbon miscible-displacement process as well as the complex geological reservoir description across the entire pool. The advantages of the technique over conventional three-dimensional (3D) reservoir simulation include cost-effectiveness, speed, and flexibility of parametric evaluations. A single-layer areal reservoir simulation model described the areal sweep; oil recovery performance as a function of injection and solvent bank size; and solvent, chase gas, and postmiscible water breakthrough times. A cross-sectional reservoir model determined the effect of gravity override. A geological model provided the porosity and permeability distribution for every 0.6-m [2-ft] interval in each injection pattern as well as the continuous PV-i.e., the volume that is available for miscible displacement. These results were combined into a simplified algorithm (the Forecast Model) to predict tertiary recovery. The Forecast Model adds the tertiary recovery forecast to the waterflood forecast developed from decline analysis to generate a total oil forecast under miscible flooding. This miscible flood forecast is physically reasonable and predicts recovery levels consistent with observed performance of large-scale miscible projects. This technique is being extended for use in other reservoirs that are candidates for miscible flooding.