Reservoir Evaluation and Development ›› 2019, Vol. 9 ›› Issue (2): 71-74.

• Non-conventional Reservoir • Previous Articles     Next Articles

Mechanism and numerical simulation of CBM extraction by pulsed discharge fracturing in water

Bao Xiankai1,2,Cao Jiaxing1,Duan Dongming1,Zhao Jinchang2,Wu Jinwen3   

  1. 1. School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia 014010, China
    2. School of Mining Technology, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China
    3. School of Science, North University of China, Taiyuan, Shanxi 030051, China
  • Received:2018-05-30 Online:2019-05-07 Published:2019-04-26

Abstract:

In order to improve the production efficiency of coal-bed methane with low permeability, we proposed the CBM fracturing and recovery technique with pulsed discharge in water, studied the mechanism of high-voltage electrical pulse discharge in water and the fracture mechanism of coal fractures, and calculated the numerical simulation of energy by RFPA-Dynamic. The results showed that under the same hydrostatic pressure, and with the increase of discharge energy, the fissures increased, the fissure length got longer, the width got wider, and the fissure density around the borehole got larger. The tip stress of the fissure increased with the loading time and the discharge energy, so that the fissures expanded more easily. The research results could provide certain theoretical basis for the exploitation of CBM.

Key words: high-voltage electrical pulse, discharge in water, crack, break energy, RFPA-Dynamic

CLC Number: 

  • TE19