A device and method for downhole drilling directional fracturing

Abstract

The invention discloses a directional fracturing device and method for underground drilling. The device comprises a plurality of sections of casing pipes and fracturing pipes which are connected end to end, wherein the casing pipes are provided with directional fracturing control devices, and each directional fracturing control device comprises a screw hole with an adjustable angle and a one-way destructive conical screw matched with the screw hole; and the casing pipes are connected through stroke-controllable threaded connection assemblies or flange connection assemblies, and alignment scribed lines corresponding to the positions of the directional fracturing control devices in the circumferential direction are arranged on the casing pipes, so that the alignment scribed lines and the directional fracturing devices are always aligned. The method is mainly characterized in that after a hole is drilled in a roadway, the casing pipes are sent into the drilled hole, and the annular spacebetween the casing pipes and the drilled hole is sealed by grouting; and fracturing pipes provided with front packers and rear packers are sent into the casing pipes, and after entering the casing pipes from the fracturing pipes, the pressurized fluid flushes the casing pipes to fracture the coal rock mass when the pressure reaches the maximum bearing pressure of the directional fracturing controldevices. According to the directional fracturing device and method for underground drilling, provided by the invention, the fracturing direction is controllable, and various directional expansion forms can be realized.

Description

Technical field[0001]The invention relates to an underground drilling directional fracturing device and method, and belongs to the technical field of mine rock formation pressure.Background technique[0002]The geological occurrence conditions of coal seams in my country are complex and changeable. Coal and rock dynamic disaster accidents caused by gas or gas as an inducing factor have caused serious challenges to the safe and green coal mining in my country. In order to solve this problem, experts at home and abroad proposed the pressure relief and permeability enhancement drainage for the gas-bearing coal seam and the roof and floor of the mine.[0003]For high gas mine coal seam pressure relief and drainage, there have been a variety of hydraulic measures in the industry, including: hydraulic punching, hydraulic slitting, hydraulic cavitation and hydraulic fracturing. Among them, hydraulic fracturing is widely used due to its advantages of large pressure relief range, simple engineer...

AI Technical Summary

Problems solved by technology

However, in actual operation, there are still the following problems: due to the long borehole, which can reach hundreds of meters or even kilometers, after the connection of multi-section rigid fracturing pipes, the direction of the pressure valve on the first section is prone to deviation, while the rigid fracturing pipe It is sent into the rigid casing and cannot be adjusted, and the position of the pressure valve cannot be observed, so that the direction of constant pressure fracturing is uncontrollable; not only that, the installation of the one-way valve takes up a lot of space, and it is difficult to change the direction in the narrow borehole. It can only achieve segmental fracturing of long drilling holes, and cannot realize directional fracturing such as linear directional expansion, fan-shaped directional expansion, and cross-shaped directional expansion according to the original rock stress and gas distribution of the rock formation, so that the pressure effect cannot reach the ideal state

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