PSI - Issue 68

Sair Kahraman et al. / Procedia Structural Integrity 68 (2025) 722–726 Sair Kahraman and Abdalrahim A.M. Malakni / Structural Integrity Procedia 00 (2025) 000–000

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Where, PR is penetration rate (cm/min), W is thrust (kN), N is rotational speed (rpm), V p is P-wave velocity (km/s). Eq. (1) includes both operational parameters and rock properties. As stated above, the P-wave velocity of rocks is a measure of microfractures and microfissures. P-wave velocity is also correlated to rock strength. Therefore, it can be said that Eq. (1) is also cover the strength of rock. 4. Conclusions The drillability of igneous rocks were investigated using an instrumented diamond core drilling machine in the laboratory. A penetration rate model including both operational parameters and P-wave velocity was derived. It was concluded that P-wave velocity measurement, which is one of the non-destructive testing methods and a measure of microfractures, can be used for the predictions of diamond drilling penetration rate. The derived equation can be used to estimate the penetration rate of a diamond core bit when drilling igneous rocks. Acknowledgements We would like to thank the Hacettepe University-Scientific Research Projects Coordination Unit (BAP) for funding (Project no. FHD-2024-21169). References Akün, E., Karpuz, C., 1990. Improvement of the penetration rates with respect to some operational and formation properties in exploration drilling in Turkey. International Journal of Surface Mining and Reclamation 4, 101-106. Akün, M.E., Karpuz, C., 2005. Drillability studies of surface-set diamond drilling in Zonguldak region sandstones from Turkey. International Journal of Rock Mechanics Mining Sciences 42: 473–479. Chenga, W., Ba, J., Fu, L-Y., Lebedev, M., 2019. Wave-velocity dispersion and rock microstructure. Journal of Petroleum Science and Engineering 183, 106466. Ersoy, A., Waller, M.D., 1995. Prediciton of drill-bit performance using multivariable linear regression analysis. Transactions Institution of Mining and Metallurgy (Section A: Min. Industry) 104, A101-A114. Zinke, J.C., 1999. The relationship between open, dry microcracks and P wave velocity of crystalline rocks: Application to in situ stress estimates on KTB drill cores after stress relaxation. Journal of Geophysical Research 104 (B5), 10863-10881. Wang, H., Pana, J., Wang, S., Zhua, H., 2015. Relationship between macro-fracture density, P-wave velocity, and permeability of coal. Journal of Applied Geophysics 117, 111–117.