Sealing core drilling device for underground coal seams and application method thereof

Abstract

The invention relates to a sealing core drilling device for underground coal seams and an application method thereof. In the core lifting process of the existing underground coal seam gas content testing and sampling device for coal mines, coal cores are exposed, thereby causing gas loss and influencing the measuring accuracy of the coal seam gas content; and a core drilling device which is used for an oil-gas field needs to be used together with a rope, thereby being not suitable for the underground coal seams. The invention provides the sealing core drilling device and the application method thereof, wherein the device comprises a core drilling bit, an outer cylinder and a drill rod joint which are sequentially connected, an inner cylinder is sleeved in the outer cylinder; the upper end of the inner cylinder is connected with a water distribution joint with a ball seat, and the lower end of the inner cylinder is connected with a reducing sleeve; a hydraulic closing mechanism is arranged between the inner cylinder and the outer cylinder and is connected with the water distribution joint with the ball seat; and an inner cylinder sealing ball valve is arranged at the lower end of the reducing sleeve. In the invention, by using the core drilling device and the matched application method, in the extraction process, the coal cores are fully in a sealing state, thereby reducing the gas loss in samples and fully meeting the underground coal seam gas content testing and sampling requirements for the coal mines.

Description

Technical field [0001] The invention belongs to the field of geological prospecting, and relates to a tool for measuring gas parameters in underground coal mines and a use method, in particular to a closed coring device for underground coal seams and a use method of the coring device. Background technique [0002] Coal mine gas accidents occur frequently in China. The combined extraction of surface and underground coalbed methane is an effective way to improve gas management in gas mines. The exploration and development of surface coalbed methane requires a large number of coalbed methane content tests to meet the requirements of coalbed methane resource evaluation and coalbed methane. Exploration needs; at the same time, the design of underground gas drainage also requires a large amount of CBM content data as guidance to improve the gas drainage rate; in addition, after the underground gas drainage is completed, a gas content test is also required to verify the gas drainage Whe...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide an underground coal seam airtight coring device and a method for using the device. The core is completely in a closed state, which effectively solves the problem that the existing coring device cannot extract a complete coal core, which affects the measurement accuracy of coalbed methane content, and then provides strong data support for underground gas drainage and surface coalbed methane development.

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