Investigation of the Ultrasonic Stimulation Performance on Permeability Enhancement in Coal Seam: Field Tests and In Situ Permeability Evaluation

Power ultrasonic-assisted reservoir modification is a promising technique for enhanced coalbed methane recovery. However, the in-site performance of ultrasound-assisted CBM production has not yet been revealed. In current study, in situ antireflection test was conducted with high-power ultrasound ~18 kW underground coal seam, and investigated by measuring borehole drainage gas data field zone, then, permeability change target seam evaluated numerically. The result shows that, within 40 days’ after ultrasonic average concentration single experimental group increased 81.4 %~227.3% than that control group, flowrate 20%~106% improvement over pure about 3.83 times. inversion indicates at least 2.36 times stimulation range 8 m from source.