Coalbed Methane Company Uses Concentric Tube Hydraulic Jet Pump to “Pull out” Coal Rock Gas

China Petroleum Network News (Correspondent Liu Yinhua Zhang Kang) On October 25, the author learned that the deep coal-rock gas concentric tube hydraulic jet pump production technology optimized by the Coalbed Methane Company was successfully applied in the Jishen 6-7 Ping 01 well. The jet pump operated stably for 480 days, increasing coal-rock gas production by 4.8 million cubic meters, setting a new record for deep coal-rock gas well production in China.

Deep coal-rock gas is an unconventional natural gas hidden in deep coal and rock, with free gas and adsorbed gas coexisting. How to ensure continuous drainage and promote the full output of adsorbed gas is the key to high and stable production. The Engineering and Technology Research Institute of Coalbed Methane Company adheres to a problem-oriented approach. Aiming at the large inclination of deep coal-rock gas horizontal wells, which leads to limited depth of rod pumps and serious pipe-rod eccentric wear, through repeated discussions and multi-party comparisons, it selects concentric tube hydraulic jet pumps as the main drainage process, eliminates the influence of pipe-rod eccentric wear, deepens the pump hanger to the section near the coal seam, and effectively improves the drainage capacity of the jet pump. At the same time, in view of the high mineralization of produced water in deep coal-rock gas wells, which is easy to cause corrosion and scaling underground, the evaluation of produced water is strengthened, and more than 20 composite protection measures are formulated from the three dimensions of wellbore protection, ground matching, and management and maintenance to improve the adaptability of the jet pump process to the high-mineralization wellbore environment, effectively solving the problems of underground corrosion and scaling.

Up to now, the concentric tube hydraulic jet pump drainage technology and composite protection measures optimized by the coalbed methane company have been used as the main drainage technology in the later stage of deep coal-rock gas production. It has been promoted and applied in 24 wells in the past year, providing strong guarantee for the stable drainage of deep coal-rock gas wells.