China Safety Science Journal ›› 2025, Vol. 35 ›› Issue (8): 118-128.doi: 10.16265/j.cnki.issn1003-3033.2025.08.1440

• Safety engineering technology • Previous Articles     Next Articles

Development and coupling relationship analysis of downhole real-time identification experimental device for coal-rock drilling parameters under load

FAN Chaojun1,2(), SUN Qiwang1,2, LUO Mingkun3, ZHANG Jiaji1,2, LAI Xinfeng1,2   

  1. 1 Ordos Research Institute, Liaoning Technical University, Ordos Inner Mongolia 017004, China
    2 College of Mining, Liaoning Technical University, Fuxin Liaoning 123000, China
    3 Ventilation Division, Shanxi Lu'an Environmental Protection and Energy Development Co., Ltd., Changzhi Shanxi 046031, China
  • Received:2025-03-29 Revised:2025-06-06 Online:2025-08-28 Published:2026-02-28

Abstract:

Aiming at the problem of non-homogeneity and difficulty in obtaining the mechanical parameters of surrounding rock in the process of coal mining, the experimental device for determining the parameters of loaded coal rock with drilling was developed independently to realize the real-time perception of strength and structure of rock layer. The effects of circumferential pressure, drilling speed, rotational speed and rotational torque on strength of simulated rock specimens were investigated and analyzed by coupling the gray correlation of collected parameters with drilling. Under loaded conditions, stratified specimens of different combinations of types were drilled in order to restore the actual effect of drilling into coal and rock seams in real environments, and to verify the accuracy of identification of compressive strength of specimens by the following drilling parameters. It was shown that the strength of the specimens was positively correlated with the circumferential pressure, rotating torque and drilling speed. The strength of the specimen remained almost constant when the rotational speed varied. The correlations between rotational torque, circumferential pressure, drilling speed, and rotational speed and compressive strength were 0.996, 0.831, 0.739, and 0.347, respectively. The strength of the specimen was linearly related to the rotational torque. By analyzing the features of change in the rotating torque curve, the strength of the rock formation can be identified and thus the location of the stratum boundary can be located.

Key words: composite coal-rock, drilling parameters, test device, gray correlation degree, layered specimen, interface

CLC Number: