Dependence of Drillability Parameters on Engineering Properties of Selected Rocks from Pakistan
M. Z. Abu Bakar, Y. Majeed
University of Engineering and Technology, Lahore, Pakistan
Keywords: Sievers’ J-value, brittleness value, drilling rate index, Schimazek’s F-value, rock abrasivity index, Vickers rock hardness number, quartz content, equivalent quartz content
Abstract
In this study, the rock drillability tests, as well as a comprehensive set of physical and mechanical rock property tests were performed on rock units selected from various localities of Pakistan. Petrography of included rock samples was also conducted for the computation of geotechnical wear indices including Schimazek’s F-value, rock abrasivity index and the Vickers hardness number for rocks. Initially, univariate regression analysis was performed to check the dependence of drillability parameters on physico-mechanical properties and rock wear indices. Significant correlations of drillability parameters with uniaxial compressive strength were found. Similarly, Sievers’ J-value and drilling rate index showed considerable dependence on Schimazek’s F-value. In the next step, multivariate linear regression models of Sievers’ J-value, brittleness value and drilling rate index, based on physical, mechanical and petrographical rock parameters were developed. Finally, the predictability of proposed multiple regression models was validated by employing the statistical performance indices.
|
