页岩气藏超临界CO_2致裂增渗实验装置研制

A New Experimental Apparatus for Fracturing Shale Gas Reservoir to Enhance Permeability with Supercritical Carbon Dioxide

页岩气储层水力压裂过程会消耗大量的水资源，超临界CO2由于其兼具气体的流动性和液体的高密度特性，能够代替清水实施压裂，展示了非常好的应用前景。基于此，提出了超临界CO2致裂页岩增加储层渗透性的思路，并自主研制了相应的实验装置。该装置主要由CO2增压系统、三轴加载与控制系统、油浴温度控制系统、声发射监测系统等6部分组成，其轴压控制范围为0～100 MPa，围压控制范围为0～15 MPa，最高加热稳定温度为100？C ，试件尺寸为100 mm＆#215;200 mm。该装置能够对CO2相态进行精确控制，并对页岩破裂过程应力应变关系、压力、温度、声发射信号等数据进行实时采集，获取多场（地应力、温度、压力）耦合条件下超临界CO2致裂过程页岩气储层渗透率动态变化规律，为超临界CO2致裂增加页岩气储层渗透率机理的研究提供实验平台。

The process of hydraulic fracturing of shale gas reservoir will consume large amounts of water. Duo to the high den-sity and diffusivity of gas,supercritical CO2 can replace water as fracturing fluid,showing a very good application prospects. Based on this,we proposed increasing the permeability of shale gas reservoir with supercritical CO2 fracturing and indepen-dently developed experimental device. The device is mainly composed of the CO2 booster system,triaxial loading and control system,oil bath temperature control system,acoustic emission system,and its axial pressure control range is 0～100 MPa, confining pressure control range is 0～25 MPa,maximum heating temperature is 100℃ ,specimen size is 100 mm×200 mm. The apparatus can precisely control CO2 phase and acquire data of shale rupture stress-strain,pressure,temperature,acoustic emission signals,and can get supercritical CO2-induced shale gas reservoir permeability dynamics of cracking shale process in multi-field（stress,temperature,pressure）coupling conditions,providing experimental platform for supercritical CO2 fractur-ing increasing shale gas reservoir permeability mechanism study.