Shahrood University of Technology Journal of Mining and Environment 2251-8592 15 2 2024 04 01 Studying Effects of Cooling/Lubricating Fluids, Machining Parameters, and Rock Mechanical Properties on Specific Energy in Rock Drilling Process 613 636 3003 10.22044/jme.2023.13478.2491 EN Shahrokh Khosravimanesh Department of mining engineering, Isfahan University of Technology (IUT), Isfahan, Iran Masoud Cheraghi Seifabad Department of mining engineering, Isfahan University of Technology (IUT), Isfahan, Iran Reza Mikaeil Department of Mining Engineering, Environment Faculty, Urmia University of Technology, Urmia, Iran Raheb Bagherpour Department of mining engineering, Isfahan University of Technology (IUT), Isfahan, Iran Journal Article 2023 08 15 Specific energy is a key indicator of drilling performance to consider in the feasibility and economic analyses of drilling projects. Any improvement in the specific energy of a drilling operation may reflect an improvement in the overall efficiency of drilling operations. This improvement can be achieved by delivering a suitable cooling lubricant into the drilling environment. The present study examines the mechanical characteristics of the drilled rock, the physical qualities of the cooling lubricant employed, and the drilling rig operational parameters related to the drilling-specific energy (DSE). To this end, seven rock samples (granite, marble, and travertine) were drilled using water and five other fluids as the cooling lubricants. A total of 492 drilling experiments were conducted with a custom-designed and built laboratory-scale drilling rig on cuboid rock specimens. The univariate linear regression analysis of experimental results revealed a significant drop in DSE after using cooling lubricants instead of conventional cooling fluid (i.e. water). Under constant conditions in terms of mechanical properties of the rock, using Syncool with a concentration of 1:100 and soap water with a concentration of 1:120 instead of water led to 34% and 43% DSE reductions in the granite samples, 48% and 54% in the marble samples, and 41% and 50% in the travertine samples, respectively. These variations in specific energy suggest that the drilling efficiency and performance can be augmented using properly selected cooling lubricants. https://jme.shahroodut.ac.ir/article_3003_e9a793da309ada37bd59bd67a57d25bc.pdf