Coal seam ultrasonic activation staged fracturing device

Abstract

The invention relates to the technical field of coal seam gas extraction, in particular to an ultrasonic activation staged fracturing device for a super coal seam. The coal seam ultrasonic activation staged fracturing device comprises a pipe fitting, one part of the pipe fitting extends into a coal seam drill hole, and the end, extending into the coal seam drill hole, of the pipe fitting is connected with at least two ball injection sliding sleeves in series; the ball throwing sliding sleeve is provided with a first liquid passing channel, a second liquid passing channel, an ultrasonic vibrator and a power supply, and the ball throwing sliding sleeve has an original state and a matched state; each ball injection sliding sleeve is provided with a fracturing ball, and the fracturing balls enter the matched ball injection sliding sleeves to block the first liquid passing channels; the ball injection sliding sleeve is provided with a limiting piece in a matched mode, the limiting piece limits the ball injection sliding sleeve in an original state, after the first liquid passing channel is blocked, the limiting piece loses efficacy, and the ball injection sliding sleeve is switched into a matched state from the original state. When the ball injection sliding sleeve is in an original state, the first liquid passing channel is used for circulating fracturing liquid and allowing a fracturing ball matched with the downstream ball injection sliding sleeve to penetrate through; and when the ball throwing sliding sleeve is in the matched state, the fracturing fluid flows through the second fluid passing channel.

Description

technical field [0001] The present application relates to the technical field of coal seam gas drainage, in particular to an ultrasonic activation staged fracturing device for ultra-coal seams. Background technique [0002] Coal seam gas, also known as coalbed methane, is a catastrophic gas that causes coal mine gas disasters, and is also a clean energy that occurs in coal seams and is associated with coal. As the mining depth increases year by year, the coal seam gas pressure continues to increase, the ground stress conditions become more complex, the coal seam permeability continues to decrease, and gas desorption is difficult during the extraction process, which seriously affects the normal continuous production of coal mines and personnel safety. In order to improve the effect of gas drainage, it is necessary to improve the permeability of the coal seam (increase in permeability). For this purpose, an underground multistage fracturing technology based on directional long...

AI Technical Summary

Problems solved by technology

[0004] However, when staged fracturing is combined with ultrasonic-assisted anti-reflection technology, due to the limitations of staged fracturing technology, it is impossible to install ultrasonic transducers, and it is also impossible to power the ultrasonic transducers through cables, so they can only be installed in the fracturing casing The ultrasonic vibrator is installed, resulting in low ultrasonic power, which cannot better achieve the purpose of enhancing the fracturing effect

Images