Application of Nitrogen Vibration Fracturing and Plugging Removal Technology in Reservoir Reconstruction of Coalbed Methane Well

Considered about the water sensitivity, water locking damage and the blockage of pore throat and cracks caused by the water in the fracturing fluid of conventional hydraulic fracturing process, this paper proposes a method of coalbed methane reservoir reformation with nitrogen as fracturing medium. It develops a construction tool string of nitrogen vibration fracturing and plugging removal technology, evaluates the application effect of nitrogen vibration fracturing and plugging removal technique through crack monitoring and post production tracking. The research results show that the tool string for nitrogen vibration fracturing can achieve three main contents of vibration, release and pressure monitoring, which can well meet the needs of process; looking from the effect of blocking capacity before and after fracturing solution, the productivity of two unfractured coalbed methane wells is similar to its adjacent hydraulic fracture coalbed methane wells, but its production cycle is shortened. Therefore, both of the productivity of two fractured wells have improved after unplugging, and the reservoir reconstruction effect is good.