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Study On Hydraulic Flushing In A1Coal Seam Of NO.2Mine Xinji

Posted on:2016-11-16Degree:MasterType:Thesis
Country:ChinaCandidate:Y J LiuFull Text:PDF
GTID:2181330467490923Subject:Safety science and engineering
Abstract/Summary:PDF Full Text Request
In this paper, due to the low permeability of coal seam and gangue seam of Al coal seam NO.2coal mine Xinji, combined theoretical analysis, numerical simulation and field test, study on hydraulic flushing tehnology. The correlated basic parameters of the A1coal seam were calculated. The5main theories of high-pressure water jet breaking coal and the3process of hydraulic flushing process of water jet breaking coal were introduced, the mechanism of permeation improvement and pressure release with hydraulic flushing measure was put forward and analyzed, results indicate that hydraulic flushing changed the stress state of the coal seam, and increased gas permeability, had a permeation improvement and pressure release effect on coal seam with gangue; With RFPA numerical simulation software, different hydraulic flushing numerical simulation models were established, under different factors of vertical pressure, pore size, strength of coal body, thickness of gangue seam to simulation analysis, results indicate that different influence factors have different influence on hydraulic punching; Hydraulic flushing numerical simulation model was established, which take A1coal seam as the research object, results show that the pressure relief range was about6m, which was study in the field test that both are basically the same. In the experimental study of hydraulic flushing technology in coal seam Al, illustrated the arrangement of hydraulic flushing drills, recorded the process of hydraulic flushing in detail, Investigated and analyzed of the effect of the measure implemented. Results indicate that after the implementation of hydraulic flushing measures, original hole diameter expanded to814mm, an increase of7.20times, concentration of gas extraction increased by11.85times, scalar increased by24.1times, influence radius extended to5-7m, residual gas content reduced to1.94m3/t,3.24m3/t, coal seam permeability coefficient increased by30to43times.In conclusion, hydraulic flushing measure can be used to reduce the gas pressure and gas content, lower coal and gas outburst hazard effectively, improve the drilling efficiency of gas extraction, play a good role in permeation improvement and pressure release.
Keywords/Search Tags:Hydraulic flushing, Permeation improvement and pressure release, Numerical simulation, Gas extraction, Water jet, Gangue seam
PDF Full Text Request
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