Status and prospect of coalbed methane drillingtechnique and equipment in China

According to the current exploration and development of coalbed methane (CBM) in China, based on the experience in CBM drilling and investigation on the recent CBM projects, the present status of CBM drilling technique and equipment was analyzed. The analysis indicates that the CBM drilling technique system has been formed, including vertical well drilling technique whose cores are air drilling and combined drilling technologies, cluster well drilling technique whose core is directional drilling, horizontal well drilling technique whose core is Geo-steering technology and the gas reservoir damage controlling technique whose cores are underbalanced drilling technology and shielding temporary plugging technology. The drilling equipment system has been formed as well, which mainly includes shallow oil and gas rigs, full-hydraulic mobile rigs, wireless measurement system while drilling and Geo-steering system. The future development direction of CBM drilling technique and equipment was then stated along which fast mobile drilling equipment, domestic Geo-steering technique and equipment, coal reservoir damage controlling technique, optimal and fast drilling technique with regional adaptability and well drilling technique associated with combined CBM drainage by both surface and underground boreholes should be studied, used and popularized to meet the goals of lowering the total cost of CBM development.