Main geological characteristics, exploration and development progress, and strategic suggestions for coalbed methane in southern China

Objective and Methods The multi-thin coalbed methane (CBM) resources in southern China are abundant and constitute an important type of CBM in China. Significant progress has been made in exploration and development in recent years, yet several challenges remain. To promote the development of the CBM industry, the main geological characteristics of southern CBM have been summarized, the current status of exploration and development has been reviewed, a nd key countermeasures have been proposed. Results The research results indicate that southern China is rich in CBM resources, characterized by "numerous but thin coal seams, large cumulative thickness, medium to high rank evolution, high gas content, high saturation and abundant free gas in deep seams, and complex geological structures and coal body textures." Exploration and development have gone through three stages: resource investigation and technology adoption (1989-2009), technological exploration (2010-2020), and technological upgrading and deep CBM research (2021-present). Currently, it is in the stage of advancing theoretical understanding of deep CBM in southern China and adapting to upgraded effective fracturing technologies, which is expected to lead to rapid development of CBM in the south. Conclusions Based on geological characteristics, four development suggestions are proposed: "selecting structurally stable areas for integrated assessment and phased development;selecting main coal seams for multi-layer and large-scale fractured combined mining; prioritizing the implementation of horizontal wells; and accelerating exploration and assessment of deep CBM." L everaging the advantage of multiple coal seams and adopting pseudo-horizontal well technology to accelerate the assessment of deep CBM is a crucial path for the large-scale development of multi-thin coal seams in southern China.