分段压裂水平井压力动态影响因素分析

建立了分段压裂水平井不稳定渗流数学模型,利用有限元方法求得井底压力,绘制出压力动态曲线,对压力动态的影响因素进行了分析。研究结果表明:该模型的压力动态曲线分为井筒储集阶段、双线性流、裂缝附近径向流、地层线性流、拟径向流和拟稳态流等6个阶段。裂缝导流能力越强,双线性流持续的时间越短,裂缝附近径向流出现的时间越早;压裂裂缝半长越长,压裂裂缝附近的径向流出现的越早且持续时间越长;随着裂缝间距的增大,裂缝附近径向流越明显,且持续时间越长。该研究成果可为分段压裂水平井的压力动态分析和试井解释提供依据。

Analysis on Influencing Factors of Pressure Transient Curves of Multi-Fracturing Horizontal Wells

The unsteady seepage mathematical model of multi-fractured horizontal well established, the bottomhole pressure was obtained by using the finite element method, the pressure transient curve was drawn, and influence factors of the pressure transient curve were analyzed. The research results showed that the pressure transient curve model was divided into 6 stages of wellbore reservoir, bilinear flow, fracture radial flow, formation linear flow, pseudo radial flow and pseudo steady flow. The stronger the fracture conductivity was, the shorter the bilinear flow lasted, and the earlier the radial flow near the fracture appeared. The longer the fracture length was, the longer the radial flow near the fracture lasted. With the increase of the fracture distance, the radial flow near the fracture was more obvious. The research results can provide the basis for the transient analysis of pressure test and horizontal well fracturing explanation.