Multi-pump coordinated fracturing method for long-drilling and multi-pump coordinated fracturing in bedding rock on soft coal seam roof

Abstract

The invention relates to a soft coal seam roof bedding rock long drilling hole and multi-pump coordination fracturing permeation increasing method and belongs to the technical field of coal mines. By adoption of the soft coal seam roof bedding rock long drilling hole and multi-pump coordination fracturing permeation increasing method, construction is convenient, construction cost is low, gas treatment efficiency is effectively improved, and the engineering quantity of strip-shaped gas treatment roadways is decreased. By adoption of the technical scheme, operation is conducted according to the following steps that a, geological fine exploration is conducted, specifically, a detection hole is constructed along the roof of a target coal seam through a one thousand meter drilling machine and is subjected to full-hole sealing through cement mortar; b, positioning drilling is conducted through the one thousand meter drilling machine; c, drilling hole blocking is conducted, specifically, a fracturing hole is blocked through a seamless steel pipe and cement mortar; d, the drilling hole is subjected to a hydraulic fracturing test; and e, fracturing effect inspection is conducted, specifically, a fracturing range is verified through a transient electromagnetic geophysical exploration method and a drilling exploration method, and after verification, the fracturing radius is 40-50. The soft coal seam roof bedding rock long drilling hole and multi-pump coordination fracturing permeation increasing method is widely applied to coal mine gas extraction.

Description

technical field [0001] The invention relates to a multi-pump coordinated fracturing anti-permeability method for long drilling holes in bedding rock on the roof of a soft coal seam, and belongs to the technical field of coal mines. Background technique [0002] my country's coal geological occurrence conditions are poor, low hardness, high gas content and low gas permeability, and with the increase of coal mining depth, the gas permeability of coal seams will be lower, most of which are difficult to extract coal seams; at the same time, due to the soft coal seams , When constructing gas drainage boreholes in coal seams, problems such as hole collapse, injection holes, and drill sticking are prone to occur, making it difficult to form gas drainage boreholes and meet the design requirements of drainage boreholes. [0003] With the research on pressure relief and permeability enhancement technology for high-gassy and low-permeability coal seams and the development of science and...

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Problems solved by technology

[0002] my country's coal geological occurrence conditions are poor, low hardness, high gas content and low gas permeability, and with the increase of coal mining depth, the gas permeability of coal seams will be lower, most of which are difficult to extract coal seams; at the same time, due to the soft coal seams When constructing gas drainage boreholes in coal seams, problems such as hole collapse, injection holes, and drill sticking are prone to occur, making it difficult to form gas drainage boreholes and meet the design requirements of drainage boreholes

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