Correlating Wave Velocities of Some Basement Complex Rock Types With Their In Situ and Laboratory Determined Penetration Rates In North Central Nigeria

Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 9(6):271-274
© Scholarlink Research Institute Journals, 2018 (ISSN: 2141-7016)
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¹Adeyemo, A.T., ²Olaleye, B.M. and ³Saliu M.A. ¹Julius Berger Nigeria PLC, Abuja, Nigeria ^2,3Department of Mining Engineering, The Federal University of Technology, Akure, Nigeria.

Corresponding Author: Adeyemo, A.T

Abstract
Drilling performance is a critical factor for the sustainability and profitability of mining projects. The work correlated the wave velocities of some basement complex rocks types on their in situ and laboratory determined penetration rates in north central Nigeria. Rock samples were collected from five locations each of the four different rocks types, namely Karmo (Granite Gnesis); Lugbe (Granodiorite); Keffi (Granodiorite Gneiss); and Kwata (Porphyroblastic Granite Gneiss). The wave velocities (Compressional VP and Shear VS) and penetration rates (In situ and laboratory) were determined using the appropriate standards. The results of the research showed that wave velocities of the rocks correlate well with the penetration rates. It was found out that Lugbe (Granodiorite) which has the lowest wave velocities of 2641m/s and 1637m/s of VP and VS respectively was observed to have the highest penetration rate values of 3.43cm/min and 20.1cm/min for both in situ and laboratory respectively. Conversely, Keffi (Granodiorite Gneiss) that has the highest wave velocities of 5045m/s and 2618m/s of VP and VS respectively has the lowest penetration rate values of 1.88cm/min and 7.14cm/min for both in situ and laboratory respectively. The results of the same tests conducted on the rock types from Karmo and Kwata also show the same trend. It was observed that the higher the wave velocities of rocks, the lower the penetration rates. The correlation between wave velocities and penetration rates were found to be strong and their relationships were established mathematically and this will serve as a guide for investors on drill bit performance in quarrying operations.