煤层气体积压裂水平井产能分析

Analysis of Productivity of Network Fracturing Horizontal Well in CBM

由于煤储层地质特征和割理发育,压裂形成的人工裂缝多为缝网结构,常规的产能方程不适合煤层气体积压裂水平井产能分析,因此将煤层水平井增产改造物理模型假设为两区复合模型:裂缝波及区考虑为一个渗透率显著改善等效区域,裂缝未波及区渗透率极低;从渗流力学基本原理出发,利用儒柯夫斯基变换,借鉴Joshi对水平井产量公式研究思路,推导出煤层气体积压裂井产能公式,分析影响煤层气体积压裂水平井产能的主控因素,为准确预测煤层气体积压裂水平井产能提供技术指导。

Because of the high brittleness index and a lot of micro-fractures in CBM,it leads more artificial fractures and artificial fractures distribution is more complex,so that CBM were transformed into network structure. So it is not effective to use conventional productivity equation analyze productivity of network fracturing horizontal well. Therefore the physical model of network fracturing horizontal is supposed to be two-area composite gas reservoirs, which permeability is significantly improved by Network in swept area while the permeability is every low in un-swept area. Based on principle of seepage and conformal transformation, the productivity equation of network fracturing horizontal well in CBM, absorbing Joshi's research about productivity equation of horizontal well. At the same time, has analyzed the main controlling factor of productivity of network fracturing horizontal well in CBM, providing technical direction for accurately predicting productivity of network fracturing horizontal well in CBM.