Discussions on paper - A new model for evaluating rock drillability considering the rock plasticity and chip hold down effect caused by hydrostatic column pressure under high confining pressure

Abstract

We discussed multiple issues in a published paper Guan, 2023. The issues are summarized as follows: (1) Dimensional theory is NOT capable of identifying quantities that have major impacts over rock drillability; (2) The applications and results of dimensional analysis in this paper is problematic; (3) Multiple wrong citations are very misleading. (4) derivations before Eq.30 can actually be ignored, the final correlations can be directly found in Eq.30. In other words, the only work in this paper is a data correlation of Eq.30. Instead, Principal Component Analysis (PCA) is recommended. (5) Misuse of pictures Fig. 12 in the discussed paper, which was originally published by Dr. Richard and Dr. Detournay at the University of Minnesota. (6) No relations are found between the theory and the PDC bit field application.