Practicality of Tricone Bit Wear Condition Assessment

Hamed Rafezi,Ferri Hassani,Guney Guven Yapici

doi:10.1017/exp.2020.42

Abstract

AbstractA practical bit condition monitoring system is a necessary component of autonomous drilling. Tricone bits are widely used in blasthole drilling in mining. Bits experience a variety of wear mechanisms during the operation and rolling element failure is the dominant catastrophic failure mode of tricone bits. Bit lifetime and performance significantly vary based on the working condition and the critical components of the bit i.e. rolling elements, are invisible to the direct condition monitoring systems. At McGill University, extensive research work is conducted to develop an indirect bit condition monitoring and failure prediction approach relying on the vibration signals and the technology is currently patent pending. This article presents real-world experimental evidence to show the unreliability of conservative bit changing strategy based on the bit operation life or drop in the rate of penetration (ROP) and ineffectiveness of direct wear monitoring techniques to cover the dominant failure mode.ObjectiveTo demonstrate the unreliability of tricone bit replacement relying on bit operation life or ROP measurement and ineffectiveness of vision-based monitoring techniques for autonomous drilling.

Highlights

Blasthole drilling is a preliminary step in surface mining, delays caused by bit failure could impose significant losses on the production
Some research works are conducted on wear detection of tricone bits employing a variety of techniques including drilling performance measurement, study of load distribution, vibration analysis and image processing approaches (Cooper, 2002; Ghosh et al, 2016; Naganawa, 2012; Rafezi & Hassani, 2017; 2018; Saeidi et al, 2014; Sheppard & Lesage, 1988)
The effectiveness of rate of penetration (ROP) monitoring and vision-based assessments for automated tricone bit condition monitoring was investigated in fieldworks

Summary

Introduction

Blasthole drilling is a preliminary step in surface mining, delays caused by bit failure could impose significant losses on the production. Tricone bit design is relatively complex (Figure 1). Cones are connected to the bit body by bearings elements. Progressive bit wear results in failure of rolling elements which is known as the dominant catastrophic failure of tricone bits and usually happens as locked or detached cones. Some research works are conducted on wear detection of tricone bits employing a variety of techniques including drilling performance measurement, study of load distribution, vibration analysis and image processing approaches (Cooper, 2002; Ghosh et al, 2016; Naganawa, 2012; Rafezi & Hassani, 2017; 2018; Saeidi et al, 2014; Sheppard & Lesage, 1988). This article discusses the effectiveness of ROP monitoring and image processing methods for the purpose of tricone wear monitoring based on realworld drilling data and feasibility restrictions

Objectives

Results

Discussion

Conclusion