【摘要】 在油藏数值模拟中 ,利用任意三角网格来剖分渗流区域 ,可以方便灵活地加密重点研究区结点 ,特别在处理渗流区的内外边界及断层方面有很大的拟合性。以二维三相黑油模型为例 ,提出用于油藏数值模拟的三角网格差分方法。首先建立以剖分结点为中心的均衡单元 ,再以均衡单元为单位 ,根据质量守恒原理 (均衡原理 )和能量守恒与转换定律 (达西定律 ) ,考虑单元侧向流量、源汇项及其内部储存量的变化量 ,建立了物理概念清楚的油、气、水渗流的三角网格差分方程 ,可用求解矩形网格差分方程的方法求解。介绍了三类渗流区域边界条件 (给定压力边界 ,给定流量边界 ,封闭边界 )应用方法 ;在处理断层时 ,将断层结点视为两个结点 ,在两侧分别编号 ,二者用达西定律产生水力联系的方法处理。对面积为 7.8km2 、有 5条断层的某油藏渗流区 ,应用三角网格差分方法仅剖分 2 90个结点、442个三角形面元 ,就很好地处理了非均质分区和断层问题 ,使所有采液井、注液井和探井均落在结点上 ,从而使计算精度得以提高 ,并很容易地进行了生产史匹配。图 3参 3 (王孝陵摘 )更多还原

【Abstract】 By using a random triangular grid system to study the region of seepage flow in an oil reservoir in numerical reservoir simulation, the grid nodes in the studying region can be refined easily and flexibly, especially at the inner and outer boundaries of this region and at the faults occurred in the region studied. Taking 2 dimensional 3 phase black oil model as an example, a finite difference method with triangular grid system is formulated. The balanced element as a central grid node is established first. With this element as a unit, based upon law of conservation of mater (balanced principle) and law of conservation of energy and energy interchange (Darcy’s law), taking lateral fluid flow, source and sink terms and the change of reserves included into consideration, a set of difference equations with very clear physical meaning are established. These difference equations can be solved by a technique similar to that used to solve the difference equations with rectangular grid system. 3 typical kinds of boundary conditions (given boundary pressure, given boundary flow velocity, and closed boundary) are assumed and solved. In the treatment of a fault, fault node can be treated as 2 nodes located at each side of the fault, and the two nodes are treated as being hydraulic connected by Darcy’s law. A seepage flowing area of 7.8km 2 in an oil reservoir with 5 faults is studied: this area is divided into 290 nodes and 442 triangular surface elements, and the problem of regional heterogeneity and faults are better solved easily. All production and injection wells are located on grid nodes, so that the accuracy of calculation is improved and the production history is easily matched.更多还原