A Large Temperature Difference Freeze-Thaw Circulation System for Improving the Effect of Ground Drilling Gas Drainage

Abstract

The invention discloses a large temperature difference freeze-thaw circulation system for improving a gas extraction effect of surface well drilling. The large temperature difference freeze-thaw circulation system comprises a first pipeline, a first low temperature resistant pipeline, a laser rangefinder, a well drilling sealing cover, a first tee joint, a second pipeline, a pulsating pump, a third pipeline, a magnetized water generator, a fourth pipeline, a nitrogen pressurizing device, a second tee joint, a fifth pipeline, a third tee joint, a sixth pipeline, a nitrogen making machine, a seventh pipeline, a nitrogen temperature rising device, an eighth pipeline, a ninth pipeline, a fourth tee joint, a tenth pipeline, an eleventh pipeline, a liquid nitrogen tee joint, a second low temperature resistant pipeline, a liquid nitrogen pulsating pump, a third low temperature resistant pipeline and a liquid nitrogen tank. Through the interaction of high-temperature and high-pressure nitrogen, liquid nitrogen and magnetized water, an ultra-large temperature difference effect is formed, and a fracturing effect of a coal body is performed, finally, the fracturing effect of the coal body canbe improved effectively, and an expanding range of the coal body can be expanded effectively, and the permeability of the coal body is increased, and thus the surface well drilling for gas extractionwith large flow, high concentration and long time is realized.

Description

technical field [0001] The invention relates to a large temperature difference freeze-thaw circulation system for improving the gas drainage effect of surface drilling, and belongs to the technical field of gas drainage. Background technique [0002] The generally low permeability of coal seams in my country is the main reason for limiting the effectiveness of ground drilling for gas extraction. In order to improve the permeability of coal seams, hydraulic fracturing technology is generally used for coal seam anti-permeability treatment, but related research results show that: the cracks produced by hydraulic fracturing mainly expand along the direction perpendicular to the minimum principal stress, and the number of cracks produced is small, making it difficult to form relatively large fractures. Long fractures fail to produce bulk fracture effects on coal seam storage, and there are also disadvantages of high fracturing fluid pressure. At present, the application effect o...

AI Technical Summary

Problems solved by technology

In order to improve the permeability of coal seams, hydraulic fracturing technology is generally used for coal seam anti-permeability treatment, but related research results show that: the cracks produced by hydraulic fracturing mainly expand along the direction perpendicular to the minimum principal stress, and the number of cracks produced is small, making it difficult to form relatively large fractures. Long fractures, failed to produce bulk fracture effect on coal seam storage, and also have the disadvantage of high fracturing fluid pressure

At present, the application effect of this technology in most mining areas in my country is not ideal, and the relevant technical process needs to be further studied

In addition, the application number is 201410507011.9, and the Chinese invention patent titled "A Cooling and Heating Alternating System for Increasing Coal Seam Gas Drainage" proposes a system for increasing gas drainage drilling output by alternately injecting cold and hot, but the system can realize The lowest temperature is only -50°C, and the highest temperature is 200°C, but in this temperature range, the expansion range of cracks is limited, and the gas drainage effect is restricted

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