Effect of Thermal Shock Treatments on Permeability and Dynamic Elastic Properties of Wolfcamp Formation - An Experimental Study

Thermal shock is a stimulation treatment that involves injecting cold fluids into hot rocks to create new cracks and to connect the existing fracture network. A few studies have been conducted to evaluate the effects of thermal shock treatments on unconventional rock properties, while they have been extensively studied in geothermal projects. In this research, four Wolfcamp reservoir-depth core samples were used to investigate the effects of two thermal shock cycles on their permeability and dynamic elastic properties using cold and liquid nitrogen. The mineralogical compositions of the core samples were determined using X-ray powder diffraction (XRD) analysis. The permeability and dynamic elastic properties of the core samples were measured prior to and after conducting each cycle of the thermal shock treatment. The results demonstrated that implementing the thermal shock treatments on the core samples increased their permeability owing to forming new fracture and/or extending existing ones. The results also showed that implementing the thermal shock technique on the core samples significantly reduced the compressional and shear velocities, resulting in alterations in the core samples' dynamic elastic properties.