Productivity characteristics and controlling factors of coalbed methane vertical well in a coal block of Qinshui Basin

Abstract

Although a coal block in the Qinshui Basin is a key location for coalbed methane (CBM) exploration and development, the productivity of various vertical wells varies significantly. The productivity characteristics of 636 vertical wells were analyzed better to understand the effects of different variables on CBM productivity. Grey correlation analysis was used to identify the key determinants of CBM well productivity. The findings indicate that vertical well production is below average, with more than 50% serving as water wells. The production of the central well area is high in the west and south. Highly productive wells are significantly influenced by geological conditions, primarily located in areas with high gas content, moderate cover depth, high permeability, and elevated water head. The engineering factor that exerts the most significant influence on productivity is the rate of liquid level drop. Based on grey correlation analysis, the primary determinants of CBM vertical well production are permeability and cover depth.