Sampling device and sampling method for accurate determination of coal seam gas content

Abstract

The invention relates to a sampling device and a sampling method for accurate determination of coal seam gas content. The device comprises a hollow drill rod and is characterized in that: the hollow drill rod is used for fixing a high energy power rod by a connection board which is placed in connection grooves and by connection groove screwed holes, and is used for fixing a sampling drill bit by the connection board which is placed in the connection grooves and by the connection groove screwed holes. The device and the combined sampling method realize instantaneous positional sampling with punching at any angles, considering of loss amount is not needed, the sampled coal sample is an original coal sample, and the sample is directly sealed in the sampling drill bit; the drill bit is taken out and directly sent to a laboratory for determination, so that sampling without gas loss amount is basically realized, and determination accuracy of the gas content is improved.

Description

technical field [0001] The invention relates to a fixed-point sampling device and a sampling method for measuring coal seam gas content, in particular to a sampling device and a sampling method for accurately measuring coal seam gas content. Background technique [0002] Coal seam gas content is the basic data for determining mine gas emission, and is one of the important parameters for mine ventilation and mine gas drainage design. Coal seam gas content is the volume of gas contained in unit mass of coal body. Measuring the gas content is one of the important tasks in gas control. The gas pressure is directly related to the gas content. However, the downhole measurement of the original gas pressure is cumbersome and difficult to measure accurately. Therefore, it is particularly important to accurately measure the gas content. [0003] At present, the accuracy of measuring underground gas content is poor. There are three main reasons. First, it is difficult to realize fixed...

AI Technical Summary

Problems solved by technology

Measuring the gas content is one of the important tasks of gas control. The gas pressure is directly related to the gas content. However, the downhole measurement of the original gas pressure is cumbersome and difficult to measure accurately. Therefore, it is particularly important to accurately measure the gas content.

[0003] At present, the accuracy of measuring underground gas content is poor. There are three main reasons. First, it is difficult to realize fixed-point sampling. If the coal samples taken are not the freshest coal samples, the measurement results will be greatly affected.

Second, sampling generally adopts compressed air sampling. Under the state of compressed air, the desorption law of coal changes, which also causes inaccurate measurement results.

Third, there is a big difference between the desorption law of underground gas and the desorption of geological exploration boreholes. Simply referring to the desorption law of ground boreholes will also cause errors

[0006] Although the DGC gas content direct measurement device has integrated supporting equipment on the basis of traditional measuring instruments, the degree of automation has been improved, and a model has been established for the loss calculation, but the sampling method uses compressed air sampling. Under the compressed air state, the coal The desorption law changes, which also causes inaccurate measurement results.

The amount of loss cannot be accurately measured, so there are obvious defects. It is necessary to develop a sampling device and sampling method for accurately measuring the gas content of coal seams, so as to realize sampling without gas loss and improve the accuracy of gas content measurement.

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