Temperature Perturbation with Depth and Induced Pressure in Vicinity of Wellbore During Supercritical CO2/CH4/H2 Injection for Gas Storage Design and Evaluations

CO2/H2/CH4 are injected into subsurface for sequestration and storage purposes. The properties of gases are sensitive to the pressure and temperature, particularly when the supercritical condition is surpassed. Both density and viscosity change are critically dominating the pressure profile and stress induced in vicinity of a wellbore, These induced stresses and pressure must be calculated accurately for safety, injectivity and storage efficiency design. To calculate fluid pressure and induced stresses under different THM environments, a fully coupled THM model with mutiphase fluid may be used. Analytical solution is highly desirable as an efficient engineering tool, but difficult to be achieved. Thus numerical methods are normally utilized. To avoid resorting the complex numerical methods in this study, an coupled THM borehole solution is developed by considering thermal gradient, but the temperature change for a given depth is neglected. Pressure and density profiles in vicinity of a wellbore are studied and implications to field wellbore integrity subject to different injecting flux with perturbated temperature.