SIMULATION CHALLENGES IN CONDENSATE GAS FULL FIELD MODEL

摘要

A recent study from the Belanak field fine grid model indicates that productivity reduction can occur in the reservoirs during pressure depletion due to the buildup of a condensate bank near the wellbore. Modeling study indicates that near the wellbore the condensate saturation can be as high as 30% soon after production. As a result, the relative permeability can be drastically reduced. A typical full field simulation with grid block dimensions of 100 ft to several hundred ft cannot capture this near well effects. Therefore it will be very challenging to apply the full field model for prediction of reservoir performance and it can result in overestimation of field productivity and recoverable reserves etc. In order to model the flowing performance accurately, a fine-scale model is required. However, a full field model with the fine-scale resolution required to solve the problem at the field scale is computationally prohibitive and creates problems of convergence when solving. A solution using pseudo relative permeability curves in the full field model is demonstrated in the study to accurately model the condensate blockage effect on a field scale. A work flow and method have been proposed in the paper to improve the full field model accuracy.