用边界元法分析油藏不稳定渗流问题

Application of boundary element in unsteady state flow

油藏几何形状对井底压力动态响应有显著的影响。常规的解析方法却只能解决一些简单、规则形状的问题。对于非规则形状的问题,边界元法是有效手段之一。它具有降维、计算速度快、精度高以及求解内点方便等特点。根据边界元理论推导了任意形状油藏不稳定渗流的计算方法,并将其计算结果与常规解析方法求解结果相比较。边界元法在油藏数值模拟和试井领域有广阔的应用前景。

Reservoir geometry significantly influences the flow field and consequently the pressure transient response in underground reservoir fluid flow. The conventional analytical methods are limited to simple and regular geometries. The Boundary Element Method ( BEM ) is one of the effective methods which can handle the complex reservoir geometries. It has the characteristics of reducing dimension, calculating fast, high precision and giving the interior point solution easy, only dividing the reservoir area boundaries. According to the BEM theory, this paper obtains the calculation method to solve unsteady state flow problem of odd shaped reservoirs and compares the results with the ones resulted from the conventional analytical method. It should be widely used in reservoir numerical simulation and well testing.