我国页岩气藏直井压裂开发可行性分析

Feasibility Study of Development of Shale Gas Reservoirs by Vertical Well Fracturing in China

摘要: 国内已开发页岩气藏产能表现出与国外页岩气藏产能的巨大差异，涪陵页岩气藏个别水平井多级分段压裂试气无阻流量可达百万立方米/天，远远高于国外同类气藏产能，比大多数常规气藏产能高。通过对国内外页岩气藏地质特征进行了详细分析对比，发现国内页岩气藏十分发育的裂缝系统是页岩气井高产的决定因素。鉴于国内外页岩气藏地质特征的差异性，水平井多级分段压裂或许并不适用于我国页岩气藏的开发。本文利用压裂模拟和数值模拟方法，对相同压裂排量下的水平井多级分段压裂和直井压裂方式下的页岩气井压裂规模及产量进行了模拟，模拟结果表明，相同页岩参数和储量下，运用直井压裂开发我国页岩气藏能够取得更好的开发效益。

Abstract: There existed great difference in the productivity of shale gas reservoir development between China and the foreign countries. The test open flow capacity of individual horizontal wells with multilevel segment fracturing could be 1 × 106 m3/d, which was much higher than that of the same reservoir aboard and it was also higher than that of the most of conventional gas reservoirs. By detail analysis and contrast of geological features of shale gas reservoirs both at home and abroad, it was discovered that the well developed fracture system of shale gas reservoirs in China was the decisive factor of higher gas production. In consideration of the geological difference of shale gas reservoirs, horizontal wells with multilevel segment fracturing were not suitable for the devel-opment of shale gas reservoirs in China. In this paper, fracturing simulation and numerical simu-lation methods are used to simulate the fracturing scale and production of horizontal wells with multilevel segment fractured and fractured vertical wells with same volume fracturing fluid. The simulation results show that with same shale parameters and reserves, better economic benefit can be achieved by using vertical fractured wells in shale gas reservoirs in our country.