Abstract: It is not accurate to model radial fluid flow around horizontal wellbores due to the fact that the rectangular local grid refinement used the same coordinate system for arbitrary simulation region,moreover refined griding leads to grid blocks increasing and limiting simulation scale and accuracy.In this paper,the radial fluid flow is simulated around the horizontal wellbores with an efficient method of hybrid refinement around the wellbore by combining rectangular grid blocks with the radial grid blocks.Realizing different coordinate systems coupling,the hybrid grid scheme is used to simulate horizontal well performance and dramatically reduce the total number of grid blocks necessary to accurately model the fluid flow around the wellbore and overcome disadvantages of conventional rectangular grid blocks.The different equation for the hybrid grid system is derived,how to determine and order the grids is introduced.This technique is applied to a modeling program in three dimension,three phase horizontal well and good results are obtained.

Key words: hybrid, reservoir simulation, black oil model, horizontal well

摘要： 矩形局部网格加密方法,由于在模拟区域的任何地方均使用相同的坐标体系,因而反映井眼周围的径向流动特征不精细,同时细分网格后造成节点数增大,也限制了模拟的规模和精度.为此,本文采用了一种环绕井眼的混合网格加密方法来模拟水平井井区内的流体流动,即在水平井眼附近采用柱坐标网格,而在远离井眼的模拟区域采用直角坐标网格,从而在模拟上实现了多种坐标体系的结合,既能够较为准确地反映井眼周围流体流动特征,又能大大地减小网格数目、克服常规矩形网格在模拟过程中的不足.文中推导了混合网格的差分,介绍了网格划分及网格的排序,并将这种技术应用于三维三相水平井的模拟程序中,取得了良好的效果.

关键词: 混合网格, 油藏模拟, 黑油模型, 水平井