局部网格粗化与加密技术在大底水油藏数值模拟中的应用

大型底水油藏数值模拟模型的网格数量庞大,其中底水区域的网格数目占绝大部分,占用很大数值计算量。同时,对于储层较厚的底水油藏,常规的网格系统通常无法准确描述油水分布及开发动态。针对大型底水油藏数值模拟中存在的问题,提出了底水区域实施适当网格粗化,生产井附近区域适当加密的处理方法。采用此方法既能保证计算精度,同时减少了模型网格数,大幅提高模拟计算效率,同时为该类油藏生产井的射孔位置、厚度等指标的设计优化提供了技术保障。

Local Grid Coarsening and Refinement Technique in the Numerical Simulation of Large Bottom-water Reservoirs

The simulation models of reservoirs with huge bottom water often have a large number of grids, most of which belong to the bottom water zone, and will cost much computation time. Because accuracy is unimportant in this region of the reservoir, grid coarsening may be used to amalgamate cells and increase the simulation efficiency. Otherwise the distribution and movement of oil and water cannot be described clearly in thick reservoirs, in which grid refinement can be used to enhance grid definition, especially the near well bore zone. In this paper local grid coarsening and refinement are used in the numerical simulation of reservoir with large bottom-water, which help to increase the computation efficiency and accuracy, and provide a foundation for optimization of perforation interval and thickness of producers.