Effect of Back Rake Angle and Shape on Wear Rate of PDC Cutter in Hard Formation

Polycrystalline Diamond Compact (PDC) bits are widely used to drill soft formations in exploration and production due to their excellent Rate of Penetration (ROP). This project aimed to investigate the effect of cutter back rake angle and the cutter shape on PDC cutter wear rate in hard formation. Conventional PDC bits often failed in hard formations due to the formation abrasiveness and impact load damage causing excessive wear to the cutter. The study is focused on the single cutter test using 16mm PDC cutter to study the effect of back rake angle and cutter shape on hard formation (granite). The drilling operation is simulated under constant applied force and velocity. The theoretical basis of the PDC cutter is studied using the cutter-rock interaction model and Merchant's orthogonal cutting model. A 3D simulation model of rock breaking using a single PDC cutter is carried out using ABAQUS based on elastoplastic mechanics and rock mechanics to analyze the stress beneath the cutter. Effect of back rake angle and shape of PDC cutter on the cutter wear rate were analyzed using the wear model. Result showed that 30 degrees back rake angled cutter and beveled-shaped cutter are the best design to minimize the cutter wear rate in hard formation.