Abstract:

The distribution of remaining oil in high water cut period has the very scattered characteristics in space. The calculation of the coarse grid can not meet the requirement of analogy precision at this stage, while the calculation of the fine grid will consume much memory storage of computer and calculation time, or even worse calculation can not be processed because of dispersion. In order to define the oil-displacing front of water and further quantify the remaining oil distribution at high water cut period, the dynamic local grid refinement (DLGR) technology was developed,which take water cut and saturation as the calculation standard. The DLGR technology enables the local refinement gird change with time, which can track the oil-displacing front of water. The calculation case using the coarse grid, fine grid and DLGR technology showed that the DLGR technology could achieve the similar result with the fine gird and reduce the calculation time by 80%. This technology could realize the same analogy precision of the fine gird and greatly increase the simulation speed while shorten the simulation cycle and save the calculation cost.

Key words: high water cut reservoir, dynamic local grid refinement technology, oil-displacing front, numerical simulation, remaining oil distribution

摘要：

高含水期油田剩余油在空间分布上具有高度零散的特点,粗网格计算已无法满足该阶段的模拟精度要求，细网格计算将消耗大量的计算机内存及CPU时间，甚至由于数值弥散导致计算结果失真。为准确确定油水驱替前缘，进一步量化高含水期的剩余油分布，建立了以含水率及含水饱和度为计算标准的动态局部网格加密技术（DLGR）。该技术能实现局部加密区域随时间改变从而更好地追踪油水驱替前缘。通过粗网格、细网格及动态加密网格实例计算对比，动态局部网格加密的模拟结果与细网格的模拟结果接近，而CPU运算时间减少80%。该技术实现了细网格的模拟精度，极大地提高了模拟速度,缩短了模拟周期，节约了计算成本。

关键词: 高含水油藏, 动态局部网格加密技术, 驱替前缘, 数值模拟, 剩余油分布