Computational Fluid Dynamics Analysis of Polycrystalline Diamond Compact Drill Bit Nozzle Efficiency Designed for Interbedded Formation Drilling

The drilling industry faces challenges related to bit balling, where cuttings stick to the drill bit’s cutting structure, causing inefficiencies in drilling and overheating. This ultimately limits advancements in drilling in Malaysia and its surrounding region. The root cause lies in the design of Polycrystalline Diamond Compact (PDC) drill bits, specifically the nozzle geometry, which influences the fluid flow and cutting behaviour. This study aims to improve a Computer Aided Design (CAD) of a 5-bladed PDC Drill Bit that adheres to American Petroleum Institute (API) standards to determine the ideal angle, number, and drilling fluid flowrate of the nozzle for optimal cleaning of the cutting structure and drill cuttings removal, by analysing the Computational Fluid Dynamics (CFD) data. The objectives will be completed by utilising ANSYS Space Claim to develop improved PDC Drill bit designs with varying design specifications, utilising Boolean operation to create a borehole model of the design, and using ANSYS Fluent to simulate the flow of non-Newtonian drilling fluid and cuttings removal via Discrete Phase Modelling (DPM). Parametric study and simulation utilising the K-Epsilon Viscous Model and Herschel-Bulkley Rheological Model conducted on the nozzle inclination angle of 20, 30, and 40°, nozzle number of 3, 5 and 7 and drilling fluid flow rate of 300, 400, 500, and 600 Gallon per Minute (GPM). These parameters are then utilised to find the optimum results in the parameters of average drilling fluid velocity, average cuttings particle velocity, and cuttings transport ratio (Ct). Findings from the study show that the drilling fluid of 500 GPM, a secondary nozzle inclination angle of 20°, and a 5-nozzle count have resulted in optimal Transport Ratio (Ct) values, ranging from values of 0.8913 to 0.9779.