A high-temperature and high-pressure steam secondary fracturing device and method for coal seam drilling

Abstract

The invention discloses a coal seam drilling high-temperature high-pressure steam secondary pressing crack device and method. The device comprises a high-temperature high-pressure steam proportioningdevice used for proportioning mixed gas according to the proportion, a third-level temperature rise pressurizing system, a secondary pressing crack pipeline for injecting gas into a failure pressing crack drill hole or extraction drill hole, a pressure and temperature sensor arranged on a pressing crack steel pipe and a pressure and temperature data analysis terminal. The method comprises the steps that a failure drill hole is cleaned, and a hole protection casing pipe, a pressing crack steel pipe and a dual-way hole sealing device are fed into the drill hole through a tunnel drill machine; before secondary pressing crack, a dual-way hole packer is used for hole packing; and after the steam is subjected to proportioning and third-level temperature rise pressurizing, high-temperature high-pressure mixed steam is injected into the pressing crack steel pipe to carry out secondary pressing crack and temperature rise treatment on a coal seam, and according to the pressure and temperature real-time monitoring data, the secondary pressing crack finishing and water and gas draining time is precisely determined. A large amount of existing failure drill holes are effectively used, methane desorption is promoted from pressure relief and temperature rise, and the coal seam methane extraction efficiency is greatly improved.

Description

technical field [0001] The invention relates to a coal seam drilling and fracturing device and method, in particular to a coal seam drilling high temperature and high pressure steam secondary fracturing device and method. Background technique [0002] In my country, high-gas mines account for about 70% of the total number of mines, and coal and gas outburst mines have reached 1192 pairs, and accidents caused by gas account for 27% of the total accidents in coal mines. And gas (coal bed methane) is a kind of clean energy. Therefore, it is imminent to increase the extraction rate of coal mine gas and increase the intensity of coal mine gas extraction, no matter from the perspective of safety or energy. [0003] In view of the characteristics of traditional gas extraction such as large drilling volume, low extraction efficiency, and high cost, various measures have been taken to improve the efficiency of gas extraction in the industry. Gas drainage efficiency is significantly...

AI Technical Summary

Problems solved by technology

However, the method or device disclosed in this patent is not suitable for the drilled holes that have been broken at the borehole or the shallow position, and cannot be used for secondary drilling for the drilled holes that have failed in fracturing or the drilled holes that have lost the value of gas drainage. Secondary fracturing; the water vapor pressure injected by this patent is far less than the magnitude of fracturing, and it is impossible to generate a large-scale fracturing fracture network in the coal seam, and the range of effect on the coal seam is much smaller than the impact of fracturing

This patent needs to inject a large amount of water vapor into the coal seam, and it is difficult to produce a large amount of high-temperature and high-pressure water vapor in a short period of time underground in the coal mine; moreover, this patent only uses a single component of water vapor, and does not start from the perspective of solving different engineering and implementation problems. Reasonably mix steam components; at the same time, the temperature and pressure of the patented fracturing water steam can be formed at one time, and high-temperature and high-pressure mixed steam with different temperatures and pressures cannot be produced according to different needs

This patent requires the construction of new boreholes into the coal seam. Since the method has a small range of action on the coal seam and cannot use a large number of existing invalid or abandoned boreholes, it is necessary to drill holes for multiple constructions, which increases the cost of the method.

The above reasons have greatly restricted the scope of application and actual effects of this patent.

Images