Experimental Study on Relative Permeability Characteristics for CO2 in Sandstone under High Temperature and Overburden Pressure

In this study, CO2 seepage of sandstone samples from the Taiyuan-Shanxi Formation coal seam roof in Ordos Basin, China, under temperature-stress coupling was studied with aid TAWD-2000 rock mechanics-seepage test system. Furthermore, evolution law and influencing factors on permeability for temperature axial pressure were systematically analyzed. The results disclose that decreases increase stress. lower stress is, more sensitive is to variation. High a decrease permeability, when sample about fail, surges. falls first then rises rise temperature, which caused by among thermal expansion sandstone, desorption CO2, evaporation residual water fractures. Finally, quadratic function mathematical model fitting degree 98.2% constructed between effect sandstone. provides necessary data support subsequent numerical calculation practical engineering application. experimental study characteristics high overburden crucial evaluating storage potential predicting migration underground gasification projects.