スチーム攻法シミュレーション技術の実油田への適用例 その１

Abstract

In this paper, application of simulation techniques for the evaluation of a steam flood pilot test is described. The pilot test has been conducted with a single inverted five spot pattern in a heavy oil reservoir.Thermal reservoir simulators generally take more calculation time than isothermal ones because both energy balance equations and material balance equations have to be solved; small time step sizers are required to establish numerical stability due to steep reduction in heavy oil viscosity with temperature increment. Thus, most of the application of the simulation to real field has been aimed at such a limited area as 1/8 symmetric element of a whole flood pattern.In the previous issue, the process and the results of simulation study using 1/8 symmetric model was presented. The results were examined and proved to be basically reasonable in comparison with actual reservoir performance observed by several monitoring methods.In this paper, a full pattern model including all pattern wells is constructed. History match for about two years of steamflood performance is done where some knowledge obtained in the previous issue is utilized. Furthermore, influence of fluid conductivity across a fault suggested in a geological study of the field is investigated with the model. At last, the importance of reservoir monitoring, for instance, bottomhole temperature survey, for the restriction of degree of freedom of the full pattern model, is discussed.