The researchers studied how different types of coal react to stress and water saturation, affecting coalbed methane production. They found that high-rank coal is less sensitive to stress than low-rank coal. As effective stress increases, coal permeability decreases, impacting methane output. The most significant drop in permeability occurs at stress levels below 5 MPa. Increasing water saturation enhances coal permeability sensitivity to stress. To maximize methane production, a slow depressurization and continuous production method is recommended based on these findings.