Title: Study of rock drillability evaluation based on drilling parameters of cutting rig

Authors: Xiaolei Yue; Zhongwen Yue; Yang Li; Yifei Yan; Xu Wang

Addresses: BGRIMM Technology Group, Beijing 100160, China; School of Mechanics and Civil Engineering, China University of Mining & Technology, Beijing 100083, China ' School of Mechanics and Civil Engineering, China University of Mining & Technology, Beijing 100083, China ' School of Mechanics and Civil Engineering, China University of Mining & Technology, Beijing 100083, China ' School of Mechanics and Civil Engineering, China University of Mining & Technology, Beijing 100083, China ' School of Mechanics and Civil Engineering, China University of Mining & Technology, Beijing 100083, China

Abstract: Accurate assessment of mechanical properties and interface information in layered rock formations is crucial for informed decision-making in geotechnical engineering. In this study, we investigated the rock drillability distribution to determine interface information in layered rock masses. Using a self-developed digital rotary drilling system, we conducted indoor experiments on layered rock masses with varying strength grades. We proposed a rock drillability index (L_d) based on the correlation between drilling specific energy and penetration rate, and analysed its variation within the rock mass. Our results demonstrate significant fluctuations in L_d across rock strata, particularly at interfaces, indicating high sensitivity to interface recognition. Additionally, we found that L_d has a positive relationship with penetration rate and a negative correlation with rock strength, reflecting both the rock's resistance to drilling damage and the interaction between the rock formation and drilling rig. In conclusion, L_d accurately identifies layered rock mass interfaces and establishes the relationship between drillability and rock strength. This study provides a theoretical framework and methodology for the application of digital drilling technology in engineering rock masses. [Received: March 20, 2023; Accepted: January 10, 2024]

Keywords: interface identification; drillability index; layered rock mass; measurement while drilling rock.

DOI: 10.1504/IJOGCT.2025.147304

International Journal of Oil, Gas and Coal Technology, 2025 Vol.38 No.1, pp.50 - 69

Received: 07 Mar 2023
Accepted: 10 Jan 2024
Published online: 14 Jul 2025 *

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