页岩气储层水力压裂物理模拟试验研究

为了给彭水地区页岩气开发提供技术支持,进行了页岩储层水力压裂物理模拟试验研究,建立了一套页岩储层水力压裂大型物理模拟试验方法。利用声发射监测系统实时监测了页岩压裂裂缝的产生与扩展演化过程,观察了水力压裂裂缝形态,并探讨了压裂液黏度、地应力差异系数、压裂液泵注排量等因素对水力裂缝形态及其扩展的影响。试验结果表明,随着压裂液黏度降低、地应力差异系数减小,水力裂缝沿着天然裂缝方向延伸,将原有天然裂缝沟通并形成网络裂缝。根据泵压曲线变化结果,提出在实际压裂施工过程中采用变排量的方式提高压裂改造体积,这可为页岩气压裂优化设计提供依据。 

Physical Simulation of Hydraulic Fracturing of Shale Gas Reservoir

In order to provide technical support to shale gas development in Pengshui Area,physical simulation of hydraulic fracturing of the shale reservoir was carried out and a set of experimental methods was established.The initiation and growth of fractures in shale was monitored on real-time,and the fracture morphology observed by acoustic emission system.In addition,this paper discussed the effect of fluid viscosity,in-situ stress difference and pumping rate of fracturing fluid on the geometrical shape and growth of hydraulic fractures.Experimental results showed that hydraulic fractures might extend along natural fractures and natural fracture might be communicated to form fracture network as the viscosity of fracturing fluid and in-situ stress difference drops.According to the pump pressure curve,this paper put forward a variable pumping rate method to improve simulated reservoir volume(SRV),which provides technical basis for fracturing optimization of shale gas.