Rock Customized Shaped Cutters Improve Rock Cutting Efficiency

Abstract

Abstract Failing the rock and removal of failed rock are the two primary actions that control drill bit efficiency. A proper design must address both primary actions while focusing on the major efficiency driver. This has been the basis for development of shaped cutter technology where the geometry of polycrystalline diamond compact (PDC) cutter is designed according to the rock type. Using the learnings from advanced modeling techniques on cutter-rock interaction, more than three dozen new geometries for PDC cutters were designed, manufactured, and tested. Based on the performance and application needs, three shapes were selected for further development: geometry A designed for shale applications focusing on efficient cuttings removal, geometry B for proper fracture initiation and propagation, and geometry C combines the features from the other two geometries to improve both creation and removal of cuttings. The geometries were optimized for maximum rock cutting efficiency while maintaining the cutter durability via analytical and numerical modeling, and pressurized drilling tests, which are the focus of this paper. The cutters were then successfully tested in field applications with consistent good performance resulting in several performance records including in North America and the Middle East.