Dem Simulation Of Enhancing Drilling Penetration Using Vibration And Experimental Validation

This paper details a study of Discrete Element Method (DEM) simulation of drilling penetration and is part of a broader investigation of the influence of bit vibration and rock-cutter compliance on enhancing drilling performance. It has been shown from laboratory experiments and field drilling trials that axial bit vibration (induced by modulated bit-rock compliance) can play a positive role in improving drilling rate of penetration (ROP), and the Drilling Technology Laboratory (DTL) at Memorial University of Newfoundland has incorporated this into passive Vibration Assisted Rotational Drilling (pVARD) technology and drilling tools. This paper focuses on DEM simulation of polycrystalline diamond compact (PDC) bit penetration and experimental validation of drilling with and without the pVARD technology, all other factors being equal, as a means of both evaluating the pVARD technology and understanding the basis of enhancing drilling performance. Simulated axial vibration properties such as amplitude and frequency were adjusted with different settings of spring compliance and dampening layers, simulating the physical configuration of the pVARD tool used for laboratory experiments. Analysis of Mechanic Specific Energy (MSE), Material Removal Rate (MRR) and Depth of Cut (DOC) are calculated to evaluate drilling performance and efficiency, and are used to compare the pVARD and non pVARD drilling results. In general, the DEM simulations agree with the experimental drilling results, and both indicate improved drilling performance using the pVARD technology.