Effects of Pressurizing Cryogenic Treatments on Physical and Mechanical Properties of Shale Core Samples—An Experimental Study

The technique of cryogenic treatments requires injecting extremely cold fluids such as liquid nitrogen (LN2) into formations to create fractures in addition connecting pre-existing fracture networks. This study investigated the effects implementing and pressurizing treatment on physical (porosity permeability) mechanical properties (Young’s modulus, Poisson’s ratio, bulk compressibility) Marcellus shale samples. Ten core samples were inserted a holder heated 66 °C using an oven. Then, LN2 (?177 °C) was injected at approximately 0.14 MPa. Nitrogen used pressurize nine injection pressures 1.38, 2.76, 4.14 MPa while tenth sample not pressurized. Using pressure transducer T-type thermocouple, temperature monitored recorded during test. scanned computed tomography (CT) scanner, their porosities, permeability, ultrasonic velocities measured both before after conducting treatments. analyses CT scan results illustrated that created new cracks inside all These increased pore volume, result, porosity, compressibility increased. creations also resulted reductions compressional shear samples, decreasing Young’s modulus ratio. Moreover, revealed alterations aforementioned properties.