Chemical modification method of lamprophyre in thick coal seam by horizontal segmental hydraulic fracturing

Abstract

The invention discloses a horizontal fragmentation hydrofracturing chemical modification method for lamprophyres in a thick coal seam. According to the method, the existence state of the lamprophyres is detected in the thick coal seam; due to water injection and drilling of the coal seam in lamprophyre-containing regions of two roadways, horizontal fragmentation pre-fracturing is realized; in a drilling process, a plurality of V-shaped slots are formed in a hole through a slotting drill, and then high-pressure water injection is carried out for pre-fracturing; finally, a chemical solution is injected for fracturing. Under the actions of the chemical solution and the lamprophyres, the mechanical strength of the lamprophyres is reduced, so that the lamprophyres can be softened; a proper coal mining cyclic progress is selected, so that a coal mining machine can directly cut the lamprophyres during perforation and chemical reaction; mechanical wear and dust generation of the coal mining machine are reduced; furthermore, the horizontal fragmentation hydrofracturing chemical modification method is easy to operate, high in practicability, economic and reasonable, and is higher in popularization and practical application value.

Description

technical field [0001] The invention relates to a treatment method for large-scale lamprophyre intrusion in thick coal seams, in particular to a technical scheme for chemical modification of lamprophyre in thick coal seams by horizontal segmental hydraulic fracturing. Background technique [0002] The parent rock material in the lower part of the coal seam undergoes a lot of geological movement, and the molten magma after remelting moves upward. Because the strength of the coal is relatively weak, it directly intrudes into the coal seam on a large scale, cools and solidifies to form lamprophyre, and lamprophyre invades the coal seam and destroys the coal seam The integrity of the coal mine seriously affects the normal production and economic benefits of the coal mine. The lamprophyre in the coal seam has the remarkable characteristics of large area, continuity, high strength and weak hydrophilicity. A large amount of dust, dust is very harmful to mechanical equipment and und...

AI Technical Summary

Problems solved by technology

However, the above several methods have problems such as low production efficiency, high production cost, and waste of a large amount of coal resources. In addition, the more important thing is that the rock after blasting is large, and still needs to be cut by a shearer. Fundamentally, the problem has not been solved, and blasting has a considerable impact on the roadway and working face, which is likely to cause roof accidents or even ground pressure disasters, posing a great safety hazard

[0003] In view of the above problems, there is no better solution in the existing technology. At the same time, in the process of thick coal seam mining, coal seam water injection is the most effective dust removal measure in the mining face. With the growth of the coal mining face, generally adopted It is a deep hole water injection, the hole depth is more than half the length of the working face, the purpose of drilling is relatively single, and the maximum utilization rate cannot be achieved

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