In order to accurately obtain the gas content of in-situ coal seams in coal mines, a sealed coring technology for in-situ coal seams in coal mines has been proposed. By utilizing the pressure difference generated by high-pressure water at both ends of the piston, the piston is driven to cut off the positioning pin, which in turn drives the ball valve in the coring device to rotate, achieving the goal of cutting off and sealing the in-situ coal core. Performance tests were conducted on the sealing pressure of the coring device by opening the amount of water holes on the piston and using suspension pins of different materials, verifying the working parameters of the piston opening amount and suspension pins of different materials, providing basic data for subsequent industrial underground tests. Finally, during the industrial test underground, it was found that the gas content in the coal seam measured by closed sampling was 1.9-2.5 times higher than that of the coal seam sampled by the hole, which verified the successful design of the closed sampling device.
Directional long-borehole In-situ coal seam Sealed coring Pressure difference Cutting mechanism
The authors gratefully acknowledge the support of the general project of Natural Science Foundation of Chongqing (Grant No.CSTB2023TFII-OFX0011), the Banan District Natural Science Foundation Project (Grant No. 7), the Yongchuan District Natural Science Foundation Project (Grant No. Ycstc, 2019nb0801).
Primary Language | English |
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Subjects | Coal |
Journal Section | Research Article |
Authors | |
Publication Date | September 10, 2024 |
Submission Date | January 26, 2024 |
Acceptance Date | September 10, 2024 |
Published in Issue | Year 2024 Volume: 63 Issue: 1 |