裂缝-孔隙油藏蒸汽辅助重力泄油过程的自适应网格数值计算

摘要

为提高裂缝-孔隙双重介质油藏蒸汽辅助重力泄油(SAGD)过程数值模拟的计算速度,根据温度、各相饱和度随空间变化的快慢在不同区域采用不同尺度网格,提出双孔双渗模型下的自适应网格算法及裂缝-基质方程的解耦方法.对给出的算例分别采用全精细网格及自适应网格算法进行计算.结果表明:自适应网格法处理这类带峰面非线性问题有很好的计算精度和计算速度;裂缝-孔隙双重介质油藏SAGD开采可能较早出现蒸汽窜顶这一不利于蒸汽能量利用率的现象.%To improve the numerical simulation calculation speed for steam assisted gravity drainage (SAGD) process in fracture-pore dual-porosity reservoirs, the adaptive mesh refinement (AMR) algorithm as well as the fracture-matrix equation decomposition approach under a dual-porosity(DK) model was proposed by using different grid sizes in different regions based upon the spatial variations of the temperature and phase-saturations. The numerical results show that the proposed AMR technique dealing with such nonlinear problems with the front is fast and can give good precision compared with the fine-grid solution. It is also shown that the steam chamber could reach the top of the reservoir, which is harmful to the thermal efficiency of steam energy for the SAGD process in fracture-pore dual-porosity reservoirs.