致密气藏中压裂水平井的动态分析

Performance analysis of fractured horizontal wells in tight gas reservoir.

将水平井与无限导流裂缝的物理模型相结合 ,获得了预测压裂水平井产能的简单方法 ;系统地分析了影响水平井产能的主要因素 ,其中包括水平段长度、气层厚度、地层渗透率的各向异性以及人工裂缝的裂缝半长等。研究表明 ,在渗透率低于 0 .1× 10 - 3μm2 的致密气藏中 ,压裂裂缝表现为无限导流裂缝的假设是合理的 ;对于给定的气藏 ,存在最佳的水平段长度 ;裂缝半长对产能具有较大影响 ;水平井压裂适用于气层分布稳定、厚度较小、具有一定垂向渗透率的气藏。

A simple method of predicting productivity of fractured horizontal wells is presented combining horizontal well and physical model of fractures with infinite fluid diversion. The main factors of influencing the productivity of the horizontal well are analyzed systematically, which include horizontal length of the well, thickness of gasbearing formations, permeability anisotropism and fracture halflength of artificial fracture etc. The research showed that it is reasonable to suppose artificial fracture behaving as infinite fluid diversion in tight gas reservoir with permeability lower than 0.1×10 -3 μm 2 . For given gas reservoir, there exists a optimal horizontal length, and fracture halflength has a obvious influence on the productivity. Fracturing on horizontal well is applicable in gas reservoirs with stable distributed gasbearing formation, small pay thickness and certain vertical permeability.