Efficient Development Method for High-Viscosity, Complex Fault-Block Reservoir

Abstract

Abstract XXX unit of Huabei oilfield, a complex fault-block and high viscosity reservoir, has stepped into middle period of development. Though the water cut has reached 81%, only 4.7% of the original oil in place (OOIP) has been produced, indicating that the current development method for this block may be inappropriate. In order to improve the production performance of this block, we studied the proper development technique on the basis of its geologic features. We examined the applicability of combining individual layers, and determined the upper limit for the segments of an injector as well as the optimal injection rate for each segment. In addition, we estimated the reasonable well density, the oil production rate, the injection-production ratio, and formation pressure using both numerical simulation and reservoir engineering method. We further coupled reservoir simulation with an optimization algorithm to provide proper measures for the improvement of oil recovery. The first measure examined is to divide layering segments and complete the well pattern. Our simulations give the optimized position of new wells. The primary oil recovery of two layering segments increases by 2.33% and 1.75%, respectively. The second one is the optimization of liquid production rate. In comparison with the current development state, the optimized schedule will increase the primary oil recovery of the two segments by 2.1% and 1.2%. Therefore, the optimized technique may serve as an effective approach to develop other fault-block reservoirs. In this work, several development methods demonstrate a significant effect to enhance oil recovery for complex fault-block reservoir, which can give a good guidance for other similar reservoirs.