基于面通量的储层时变数值模拟研究

Numerical Simulation of Reservoir Time-Variation Based on Surface Flux

针对油田注水开发过程中,长期水驱冲刷使储层物性发生改变,影响油田开发效果和剩余油分布的问题,开展室内实验研究、传统黑油模型改造、软件编制等工作,建立了物性参数随面通量连续性变化的定量表征方法,形成了能够描述储层物性时变的数值模拟技术。通过建立概念模型对新模拟器进行应用,结果表明:考虑储层物性变化后,主流线区水淹程度增大,油藏采出程度提高6.4%;模拟器计算结果基本不受网格尺寸影响,2种网格模型采出程度和含水率的计算误差仅为0.079%和0.157%。该技术解决了现有数值模拟方法在连续性表征、方向性表征、计算结果稳定性方面存在的问题,对水驱油藏开发指标预测和剩余油分布研究具有重要的应用价值。

Long-period waterflooding leads to variation of reservoir properties during oilfield waterflooding development,which directly influence waterflooding performance and remaining oil distribution. The continuous variation of reservoir physical properties with surface flux is quantitatively characterized by laboratory experimental test,conventional black-oil model refinement,software development,etc. A numerical simulation technology is developed to describe time-variation of reservoir properties. Conceptual model is established and simulated by using this new reservoir simulation software,and the simulation result demonstrates that the main-streamline zone is more severely watered out and reservoir recovery degree is increased by6. 4% after considering the time-variation of reservoir properties. The simulation is basically independent on grid size and the errors of reservoir recovery degree and water-cut between two conceptual models with different grid sizes are only 0. 079% and 0. 157% respectively. The continuity characterization,direction characterization and simulation stability of available simulation methods are significantly improved by this new reservoir simulation technology,which is favorable to the forecasts of reservoir waterflooding performance and remaining oil distribution.