An experimental investigation into the borehole drilling and strata characteristics

PLoS One. 2021 Jul 20;16(7):e0253663. doi: 10.1371/journal.pone.0253663. eCollection 2021.

Abstract

Measurement while drilling is an important part of the intelligent development of coal mines. The main purpose of this paper is to comprehensively analyze the response characteristics of borehole drilling parameters and find a better method to predict rock mechanical properties based on drilling parameters. Firstly, six concrete blocks and multiple specimens were prepared with different material ratios. Next, the concrete specimens were tested for mechanical properties in the laboratory. Meanwhile, the displacement, rotation speed, torque, and sound pressure level (SPL) were observed during the drilling of the concrete blocks. Finally, the response characteristics of drilling parameters such as rotation speed, rate of penetration (ROP), torque, and SPL were analyzed. Besides, multiple prediction models of rock mechanical parameters were obtained by data analysis. The research results indicate that the drilling process can be classified into the initial stage of drilling (fast speed) and the steady stage of drilling (slow speed). The torque work ratio accounts for more than 99%, which increases with the increase in rock strength. The penetration depth per revolution and torque work ratio are significantly related to rock uniaxial compressive strength, Brazilian tensile strength, cohesion, and elastic modulus. The ROP is the best choice for estimating rock mechanical parameters. This research provides an important reference for laboratory rock mechanics parameter testing and geological features detection based on drilling parameters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brazil
  • Coal Mining / standards*
  • Coal*
  • Compressive Strength
  • Forecasting
  • Humans
  • Rotation*
  • Tensile Strength
  • Torque
  • Vibration

Substances

  • Coal

Grants and funding

The research was supported by the Science and Technology Innovation Project of Guizhou Province (Qiankehe Platform Talent [2019] 5620 to XZ). No additional external funding was received for this study.