Experimental Study on the Interaction Between CO2 and Rock During CO2 Pre-pad Energized Fracturing Operation in Thin Interbedded Shale

To investigate the impact of CO 2 on rocks during whole period pre-pad energized fracturing operation for thin interbedded shale reservoir, including and well shut-in, a series laboratory triaxial experiments soaking were conducted (from Jimsar formations). In these experiments, combined with computed tomography (CT), effect fluid, horizontal principal stress difference, vertical stress, natural fractures fracture morphology studied respectively. And based X-ray diffraction (XRD) scanning electron microscopy (SEM) dissolution minerals changes pore structure before after analyzed. The results experiment show that bedding planes are easy to be opened by low viscosity longitudinal intersect build complex network. During shale, difference is no longer crucial factor form network, but play important roles. indicate main dissolved mineral carbonate whose ratio can reach 45.2% 5 days, leading expansion original pores or exposure new pores.