Acoustic fingerprinting for rock identification during drilling
During the process of mining, it is imperative to know the type and properties of the rocks being handled. The current technology for this involves core drilling, and subsequently subjecting the drilled cores to various tests in the laboratory, to identify the rocks and establish their properties. In many cases, obtaining a sample may be cumbersome and/or non–profitable. This paper presents a novel method to monitor and evaluate the sounds produced as undesirable by–products, at the drill–bit and rock interface, to predict the type of rock being drilled. A rotary drill was fabricated in the laboratory and vertical drilling was carried out on cubical rock samples, keeping various drilling parameters constant. The results obtained are promising and reinforce that it may be possible to extend the proposed methodology in the field as well, with appropriate modifications. This method may be extrapolated further in the estimation of rock properties as well.
Keywords: drilling, FFT, fast Fourier transform, frequency analysis, mining, igneous rocks, rock identification, acoustic fingerprinting, rock properties