Technology and practice for deep CBM fracturing in eastern Ordos basin

The resources of deep coalbed methane buried at depth of more than 1 200 m in the eastern Ordos basin are rich and the key point for further exploration and development of CBM in the future. Compared with shallow CBM fracturing, there are many challenges in deep CBM fracturing such as with high situ stress, high closure stress, breakdown pressure as well as complex mechanical parameters of rock. Combined with the existing practice of CBM fracturing, taking the deep CBM buried at depth of about 2 000 m in the eastern Ordos basin as an example, tubing+ circulating SSD +packer +tubing shoes were used as operation string and low concentration linear gel as fracturing fluid system. Through on-site operation in 2 wells, the construction is relatively smooth, gas production is quite satisfactory(the output is above 800 m³/d). It proves that the process is simple and easy and provides reference technology for deep CBM fracturing.