THE ANALYSIS OF PDC CUTTER CHARACTERISTIC IN HARD FORMATION DRILLING RELATING TO WEAR (BACK & SIDE RAKE ANGLE)

The project focuses on the optimization of Polycrystalline Diamond Compact (PDC) cutters characteristic features relating to wear for improvement on durability in drilling of hard formation. Case history shows that conventional PDC drill bit failed to complete the section that provides troublesome hard formation. The PDC drill bit’s performance dropped and affects the rate of penetration. Therefore, and intensive study in PDC bit design characteristic would help complete the section with high ROP if the design features of PDC drill bit can be optimized. The enhancement of ROP will result in the reduction of the well costs. Design features of PDC bit can be improved with an analysis of important design parameters that can help in improving the ROP. The important design features of PDC bit include the size, shape and number of cutters used, the angle of attack between the cutter and the surface of the exposed formations and cutter orientation which consists of back rake angle and side rake angle. This project focused on back and side rake angle design features to improve PDC bit to resist wear when encounter hard formation drilling process. 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 done using Ansys based on elastoplastic mechanics and rock mechanics to analyze the stress beneath the cutter. Effect of back and side rake angle of PDC cutter on the rule of cutter wear rate were analyzed by using the wear theory. Result showed that 60 ̊ back and side rake angled cutter are the best design to minimize the cutter wear rate in hard formation