Nitrogen injection with horizontal wells for enhancing heavy-oil recovery: 2D and 3D model studies

Gas injection is one of the oldest enhanced oil recovery techniques used for the recovery of light oils. Recently, there has been a growing interest in this technique for both light and heavy oil reservoirs. In order for gas injection technique to be successful in improving the recovery of oil, it is important to have a stable front so that early breakthrough can be prevented. In some cases stable fronts may be obtained by the use of horizontal wells. We have investigated the possible application of gas injection with horizontal wells for the recovery of heavy oils from shallow reservoirs found in the Lloydminster area bordering the provinces of Alberta and Saskatchewan in the laboratory using 2 D and 3 D physical models. This paper provides a comparison of the results obtained from these two physical models. Stable fronts could be achieved easily in the case of the 2 D model whereas, it was virtually impossible to obtain perfectly stable front in the case of the 3 D model. Recovery was found to be higher in the case of the 2D model as compared to the 3D models for all the conditions studied.