用边界元法分析复杂形状油藏不稳定压力动态

油藏的形态对井底压力动态响应有着显著的影响,常规的解析方法只能计算规则形状油藏的井底压力响应。首先依据边界元理论推导了任意形状外边界地层以及任意形状外边界地层中含多个任意形状局部不渗透团块的复杂形状油藏的井底不稳定压力响应的计算方法,应用杜哈美原理考虑了井筒储集效应和表皮效应对井底压力动态的影响,然后将边界元方法计算的结果与常规解析方法求解的结果进行了比较,并分析了任意形状油藏的井底不稳定压力动态特征。

ANALYSIS OF PRESSURE TRANSIENT BEHAVIORS IN ARBITRARILY SHAPED RESERVOIRS BY THE BOUNDARY ELEMENT METHOD

The effect of the shape of reservoir boundaries on the well-bore pressure response is evident. The conventional analytical methods can only be used to calculate wellbore pressure responsein regularly shaped reservoirs. In this paper, according to the theory of Boundary-Element Method (BEM), pressure transient solution in an arbitrarily shaped reservoir with any numberof irregularly shaped impermeable sub-regions is proposed by Laplace domain BEM. By using Duhamel theorem, the influence of wellbore storage and skin effect on pressure transient response is considered. Then the BEM results are compared to that of analytical methods. And pressure transient behaviorcharacters in arbitrary reservoir shaped are analyzed.