Evaluation of Reservoir and Production System Integration in Production Strategy Selection

Abstract

Abstract In offshore petroleum field studies, the integration between reservoir and production system simulators may improve production forecasts. Therefore, it is important to check if this integration is necessary and a methodology to do it adequately. In this work, we analyzed the influence of this integration in the development of a petroleum field focusing on the effects on the production strategy parameters for a benchmark model based on an offshore field in Brazil. The methodology is based on a 12-step procedure for closed loop reservoir development and management. The production facilities are integrated with the reservoir in Step 11 and we propose to re-optimize the production strategy using information about pressure gradients inside the satellite well pipes for production forecast, while evaluating net present value as the objective-function. We adapted an assisted optimization workflow to include the optimization of new variables such as, pipe diameters of production system, platform position and artificial lift application, and compared this with the production strategy obtained from the same benchmark in a nonintegrated approach. Comparing nonintegrated and integrated production strategies, we observed changes that indicate the need to integrate reservoir and production systems in the decision making process. (1) Platform position was more affected by economic indicators than production loss due to pressure drop in flowlines. (2) Economic return and field oil recovery were significantly affected by the diameters of the production pipes. Artificial lift application with high gas injection rates enhanced well performance. (3) A re-optimization of the number of wells had little effect on the cumulative oil production but larger influence on net present value, indicating potentially unnecessary wells in a nonintegrated project. (4) The integration demanded further optimization of well placement, significantly impacting both net present value and the recovery factor. The integrating production facilities with the reservoir, generated a significant increase in the net present value, maintained the same oil recovery factor and required less investment.