混合PEBI网格精细油藏数值模拟应用研究

针对原有的PEBI网格在精细油藏数值模拟中出现的问题,提出了综合运用径向网格和PEBI网格的混合PEBI算法.混合PEBI算法将整个研究区域分成两个区域:油井区和油藏区.在油井区采用径向网格,可以在充分把握油井附近流动状态的同时实现网格体积由小到大的快速变化;在油藏区采用PEBI网格,可以很好地逼近复杂油藏形态.混合PEBI网格具有计算效率高、稳定性好、运用灵活等特点,能适应精细油藏数值模拟的需要.用2个三维、多相数值试井计算实例对混合网格的优良性能进行了验证.

Usage of hybrid PEBI grid in fine reservoir simulation

In order to solve the problems in usage of PEBI grid for fine reservoir simulation,the combination of PBEI grid with radial grid, namely,hybrid PEBI grid method, was put forward.The area of interest was divided into two parts of well region and reservoir region with hybrid PEBI method.When the radial grid was used for the well region,the pressure behavior near the well bore could be described clearly, and the grid volumes became larger quickly.While the PEBI method was used for reservoir region,the geometry of complex reservoir could be well approximated.The hybrid PEBI grid is so efficient,stable and flexible as to meet the demand of fine reservoir simulation.Two cases of 3-D multi-phase well-testing problems verified the high quality of the hybrid grid.