Multi-coal-seam slide sleeve isolating and separate layer fracturing device and multi-coal-seam slide sleeve isolating and separate layer fracturing method

Abstract

The invention discloses a multi-coal-seam slide sleeve isolating and separate layer fracturing device and a multi-coal-seam slide sleeve isolating and separate layer fracturing method. The multi-coal-seam slide sleeve isolating and separate layer fracturing device comprises a casing pipe arranged in an open hole and passing through multiple coal seams, and a plurality of screen pipe segments corresponding to the multiple coal seams in position are formed on the casing pipe. Capsular bags sleeve the screen pipe segments and are used for enabling the casing pipe and rock strata on two sides of the coal seams to form a capsular bag-type well cementation structure, each two adjacent capsular bags are communicated through a communication pipe, and one of the capsular bags is connected with a grouting system through a grouting pipe. A plurality of slide sleeves, as many as the screen pipe segments, are movably arranged in the casing pipe to block screen holes of the screen pipe segments, a traction inhaul cable and a drag inhaul cable are connected at the front ends and the back ends of the slide sleeves respectively, and the traction inhaul cable passes through a reversing component at the front end of the corresponding slide sleeve to return out of a pipe orifice. The multi-coal-seam slide sleeve isolating and separate layer fracturing method is used for separate layer fracturing based on the multi-coal-seam slide sleeve isolating and separate layer fracturing device. The multi-coal-seam slide sleeve isolating and separate layer fracturing device has the advantages of simple structure, good hole blocking effect and low manufacturing cost. The multi-coal-seam slide sleeve isolating and separate layer fracturing method has the advantages of high operability, high efficiency and good coal seam permeability improvement effect.

Description

technical field [0001] The invention relates to a hydraulic fracturing anti-permeability technology before coal seam gas extraction, in particular to a multi-coal seam sliding sleeve isolation layer fracturing device and method. Background technique [0002] Coal seam gas is a kind of clean energy, but it is also a source of disaster for coal mine production. The geological conditions of coal occurrence in my country are complex, mainly relying on underground mining. With the increase of mining depth, the gas content of coal seams gradually increases, the pressure of coal seam gas increases, the risk of outburst increases, and the difficulty of outburst prevention becomes more and more difficult. The gas drainage of the existing coal mining face is carried out by drilling along the bedding in the coal seam in the transportation roadway and the air return roadway respectively. For the coal seam with poor air permeability, it is usually necessary to carry out hydraulic fractur...

AI Technical Summary

Problems solved by technology

The gas drainage of the existing coal mining face is carried out by drilling along the bedding in the coal seam in the transportation roadway and the air return roadway respectively. For the coal seam with poor air permeability, it is usually necessary to carry out hydraulic fracturing to increase the gas permeability. Existing methods are mostly suitable for single coal seam fracturing and anti-permeability

At present, although there are some anti-permeability methods for multi-coal seams, either the operation method is complicated, or the hole-sealing device or hole-sealing structure is complicated. The sealing and fracturing time is long, and the cost of coal seam anti-permeability is high.

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