Closed coring device for testing coal bed methane and rock formation gas contents in surface well drilling

Abstract

The invention discloses a closed coring device for testing coal bed methane and rock formation gas contents in surface well drilling. The closed coring device comprises a coring inner barrel, a coring drill bit, an outer barrel, a power mechanism and a startup mechanism, wherein the outer barrel sleeves the coring inner barrel; a drill rod joint is arranged at one end of the outer barrel; the coring drill bit is arranged at the other end of the outer barrel; the power mechanism and the startup mechanism are arranged inside the outer barrel. The closed coring device can take a coal (rock) core sample in a fixed-point and closed way, effectively solves the technical problems that after the existing coring equipment takes a coal core, the exposure time of the sample is long, escape of lost gas is serious, content determination on gas (coal bed methane) is not accurate and the like, and further, provides more reliable basic data for coal mine gas disaster control, exploration and exploitation of coal bed methane resources, and the like.

Description

technical field [0001] The invention belongs to the technical fields of coal mine safety and coal bed gas exploration and development, and specifically relates to a sealed coring device for testing the content of coal bed gas and rock bed gas in ground drilling. Background technique [0002] Coalbed methane (gas) content is an important parameter to characterize coal reservoirs, and is an important basis for surface coalbed methane (gas) resource exploration, productivity prediction and well pattern layout design; It is an important basis for output prediction, coal seam gas occurrence law research and coal seam outburst risk prediction, mine ventilation design and equipment selection, and gas drainage engineering design. Therefore, research on coring equipment for accurate determination of coalbed methane (gas) content has important practical significance in the exploration and development of coalbed methane resources and the management of underground gas disasters in coal ...

AI Technical Summary

Problems solved by technology

In the process of coalfield geological exploration and coalbed methane resource exploration, core tubes are generally used to collect samples for coalbed methane (gas) content determination. During the process of sample collection, sample lifting and ground leakage, the coal core samples are in an unsealed state. A large amount of gas is lost in this process, resulting in inaccurate determination of coalbed methane (gas) content

There are currently three ways to collect samples in the determination of coalbed methane (gas) content in underground coal mines: one is the twist drill, which cannot extract the complete coal core, but can only extract the pulverized coal that is ground during the drilling process at the orifice. Solve the problem of gas loss in the process of sample collection, and the fixed-point collection of samples cannot be realized; the second is a single-tube or double-tube coring tube, this equipment still cannot solve the problem of gas loss in the process of sample collection, drill withdrawal and coal core removal; The third is that there is a closed coring equipment in the underground, which can realize closed coring, but the complexity of the operation process and applicable conditions of the equipment are subject to certain restrictions, and the field promotion and application are subject to certain restrictions

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