The invention relates to a multi-pulse combined fracturing device for perforation of
coalbed methane reservoir, comprising a percussion initiator; the lower part of the percussion initiator is connected with a perforating
barrel; the perforating
barrel is internally provided with a frame type ammunition rack, and perforating bullets are loaded on the frame type ammunition rack; the perforating bullets are isolated from low-explosive-velocity liquid explosive by means of capsules, so that the low-explosive-velocity liquid explosive can be safely detonated; the lower part of the composite perforator is connected with a
detonation convertor, the lower part of the
detonation convertor is connected with a first-stage propulsion device, a central aluminum
pipe is positioned in the center of thefirst-stage propulsion device, the lower part of the central aluminum
pipe is connected with a
delay ignition device, and the lower part of the
delay ignition device is connected with a second-stage propulsion device; when the temperature of the outer wall of the central aluminum
pipe reaches the
ignition point of a
propellant, a great deal of high-temperature and high-pressure gas produced by thepropellant acts on the coalbeds in a pulse loading way, thus enabling cracks to rapidly extend; the lower part of the second-stage propulsion device is connected with a connecting rod, a detonating cord is arranged in the connecting rod, the lower part of the connecting rod is connected with a perforator, and the perforator is connected with a
pressure measurement tail plug, so that the
deflagration pressure change of
gunpowder in a fracturing process is reflected; the multi-pulse combined fracturing device has the advantages of treating the multiple coalbeds at a time, and being high in energy
utilization rate and cost-saving.