考虑非均质性的分段压裂水平井压力动态分析

建立了致密油藏分段压裂水平井不稳定渗流数学模型,利用有限元法对其进行求解,分析了分段压裂水平井的流动阶段特征,对比了不同非均质情况下分段压裂水平井压力动态曲线的特征。研究表明:非均质性主要影响压力动态曲线第一径向流、第二线性流和晚期拟径向流阶段:当压裂区域与未压裂区域的基质流度之比α小于1时,α越小,压力动态曲线越向右上方移动,压力传播到油藏封闭边界的时间越晚,且压力导数曲线在晚期拟径向流阶段呈现"下凹"趋势。当α大于1时,压力动态曲线在晚期拟径向流阶段的斜率逐渐减小,且α越大,曲线越偏下。

Pressure Transient Analysis of Multi-Fractured Horizontal Wells Considering Heterogeneity

Based on the Galerkin finite element method,the unstable flow mathematical model of multi-fractured horizontal well in the heterogeneous reservoir is established. In addition,flow phase characteristics of the multi-fractured horizontal well are analyzed. And the pressure transient curve of multifractured horizontal well in the case of different heterogeneity is contrasted. Results show that the heterogeneity mainly influences the bilinear flow phase,the reservoir linear flow phase and the pseudo radial flow phase:when the mobility ratio-α between the fractured area and the non-fractured area is smaller than 1,the smaller the α,the more the pressure transient curve moves to upper right,the later the pressure moves to the closed boundary,and the pressure derivative curve shows a "concavity" trend in the pseudo radial flow phase. On the contrary,when the α is bigger than 1,the slope of the pressure transient curve decrease gradually,and the bigger the α,the more the pressure transient curve moves to below.