Predicting the penetration rate of diamond core drilling of igneous rocks using P-wave velocity

This paper investigates the predictability of the penetration rate (PR) of diamond core drilling of igneous rocks using P-wave velocity measurement which is a non-destructive testing method. For this purpose, forty-two drilling tests were conducted in the laboratory using an instrumented diamond core drilling machine. During the drilling tests, the parameters of PR, thrust (weight on bit), and rotational speed (rpm) were recorded. Then P-wave velocity measurements were performed on each core sample. After that multiple regression analysis was performed by including, thrust, rotational speed, and the P-wave velocity values to the analysis to develop an estimation equation for PR. A model with a very high correlation coefficient (r = 0.98) was derived for the PR prediction. It was concluded that the derived equation could be used to estimate the PR of a diamond core bit when drilling igneous rocks.