Detection technique and application of transmitted in-seam wave in thin coal seam

YANG Hui1

(1.Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an, Shaanxi Province, China 710077)

【Abstract】Aiming at the problem of serious attenuation of in-seam waves in thin seam and its limited distance of propagation, a method of restricted CT imaging was proposed with the furthest in-seam wave propagation distance. Firstly, the variation of in-seam wave frequency with different thickness of coal seams was studied by theoretical derivation. With a 1.5 m thin seam as the main research object, the attenuation characteristics of in-seam waves were simulated by forward modeling, and the effective propagation distance of in-seam waves was determined. The actual data of No. 15 coal seam in a coal mine in Shandong Province shows that the in-seam wave propagation distance is about 300 m. For the in-seam wave data of Seam 15 in a coal mine in Shandong Province, the fault position interpreted from CT imaging with the technology coincided basically with that exposed by roadway. When processing the in-seam wave data of 1.5 m thick coal seam, with 300 m of propagation distance as the constraint to conduct the energy attenuation imaging on actual data, the in-seam wave CT imaging quality and interpretation accuracy were improved. This method takes into account the propagation characteristics of in-seam waves in thin coal seams, reduces the influence of attenuation, and highlights the anomalies caused by structural factors. It is useful for the development and application of in-seam wave detection technology in thin seams.

【Keywords】 thin coal seam; transmitted in-seam wave; energy attenuation; velocity filtering; fault; CT imaging;

【DOI】

【Funds】 National Key R&D Program of China (2018YFC0807804) Science and Technology Innovation Fund of Xi’an Research Institute of CCTEG (2019XAYMS28, 2019XAYMS29)

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(Translated by ZHANG XY)

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This Article

ISSN:1001-1986

CN: 61-1155/P

Vol 48, No. 03, Pages 176-181+187

June 2020

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Article Outline

Abstract

  • 1 Detection technology of transmitted in-seam waves in thin coal seams
  • 2 Application case
  • 3 Conclusion
  • References