Rocks drillability classification based on comparison of physico-mechanical properties with drilling rate timing

The article considers various approaches to the assessment of rock drilling. Domestic classifications and methods for estimating the drillability according to physicomechanical properties are given. Based on the analysis of the results of international practice and various studies, the use of strength properties as a characteristic of drillability is justified. To determine the local productivity of drilling rigs, a video-timing of the pure drilling rate and a complex of mechanical tests are performed. Timing was carried out on various models of the Atlas Copco and Sandvik drilling rigs and various drilling diameters. The best correlation between the pure drilling rate is established with the strength of the rocks for uniaxial tension in accordance with the procedure of GOST 21153.3 paragraph 2. To account for the diameter of drilling and the power of the drummer, a transition to the conditional specific volume rate of drilling is performed. To account for the diameter of drilling and the power of the hummer, a transition to the conditional specific volume rate of drilling is performed. As a result of the generalization of the results, dependencies have been obtained that make it possible to determine the pure drilling speed of drilling rigs, depending on the power of the hummer, the drilling diameter and the tensile strength. Dependencies are presented separately for face and long-hole drilling rigs. For the long-hole, the coefficient of reducing the drilling speed from depth is given.