CO₂-injection parameters in horizontal well of deep coalbed in north Shizhuang block of Qinshui basin

Based on the principle that CO₂ adsorption capacity is greater than CH₄ adsorption capacity, CO₂ is injected and stored in deep coal seams, CO₂ replaces CH₄ to increase CBM production, having environmental and economical benefits. By using dual-porosity, two-phase model was established with the help of CBM reservoir simulation method, then the time of CO₂-injection with different pressures was studied. Injection pressure needs fracturing pressure lower than 10 MPa, and the injection rate is less than 47 L/min. Numerical simulation results are in good agreement with the experimental data given in this paper, show that the method is effective.