Most traditional polycrystalline diamond compact (PDC) cutting elements have a flat polycrystalline diamond table at the end of cylindrically shaped tungsten carbide body. During drilling, the flat diamond table engages the formation and shears the rock layer by layer. A new ridge-shaped diamond cutting element (RDE) has a similar cylindrical tungsten carbide base; however, the diamond table is shaped like a saddle with an elongated ridge running through the center of the diamond table and normal to the cutter axis. The intended cutting portion, the "ridge," engages the formation to fracture and shear the rock at the same time. The design intent was to create a unique cutting element that could combine the crush action of a traditional roller cone insert and the shearing action of a conventional PDC cutter. The new cutting elements were tested in the laboratory against standard flat PDC cutters in a rock-cutting evaluation, and later the new elements were applied to PDC bits and run under real drilling conditions. The laboratory rock-scrape tests indicated that the new cutting element not only enables the cutter to efficiently shear formation in the same way as a conventional PDC cutter, but also delivers a crushing action similar to a roller cone insert. Preliminary results indicated a reduction of roughly 40% in both cutting force and vertical force on the new ridged diamond element cutters (RDE) over a conventional PDC cutter. Similar findings were also observed during the rock-shearing test on a vertical turret lathe (VTL). Subsequent field tests in multiple areas in North America have produced faster rates of penetration (ROP) in most of the cases. The trials indicate that the new cutting element is efficient at removing rock, and a bit equipped with these elements requires less mechanical specific energy (MSE) during drilling than does a bit with a conventional PDC cutter. In addition, the reduced cutting forces reduces bit torque and thus improves the drilling tools’ life and the bit directional performance. Field data has proven this technology improves drilling performance in terms of ROP and footage over the current PDC bits fitted with traditional flat PDC cutters.

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The most traditional polycrystalline diamond compact (PDC) cutter technology is composed of a flat surface that contacts the rock to be sheared and removed throughout the drilling process. The necessity to overcome engineering limitations related to PDC capability drove the industry to innovate cutter shapes and 3D surfaces to interact with the rock. A new hyperbolic diamond element (HDE) bit has been developed to improve drilling efficiency in soft formations compared with conventional polycrystalline diamond compact (PDC) cutters. The design concept and bit utilization theory, laboratory validation, including full-scale drilling simulator testing, implementation of the time-based dynamic bit and drillstring modeling system, as well as the operator's field drilling results from the Niobrara shale play of the DJ Basin, Colorado, USA are presented. The HDE development, from concept to validation and field deployment, consisted of a multidisciplinary approach that combined proprietary knowledge, manufacturing, and computational analysis. Creating the HDE concept required an overall understanding of shaped diamond elements (SDEs), their applicability, field results, and mechanical properties and outputs. After creating the concept, proprietary manufacturing processes, single cutter-rock experiments, and full-scale bit-rock testing were used to validate the innovative new SDE. Based on success with the baseline drill bit design—a PDC bit with a different SDE—as well as results from implementing HDEs into a time-based dynamic modeling system used to predict field performance improvements, a DJ Basin operator agreed to test the new HDE bit. After the first 10 field tests, the HDE bit resulted in a 20% improvement in overall ROP compared with the baseline PDC bit design. The HDE drill bit improved drilling efficiency and lowered mechanical specific energy (MSE) in both the rotating and sliding drilling modes. These results were in line with full-scale bit-rock testing, which indicated a 10 to 20% ROP improvement for the same weight-on-bit (WOB) in various formation types. Furthermore, the results were obtained without increasing bit torque, which is a performance parameter important for positive displacement motor (PDM) -driven bottomhole assemblies (BHAs). Field testing also indicated that the cutting structure durability was improved, which increased drilling system reliability for the operator. Insignificant or no damage was observed over the HDE bit cutting structure after field tests. The new HDE drill bit efficiently transfers drilling system energy into formation removal without increasing reactive torque to uncontrollable or catastrophic levels. Due to rock-cutting efficiency and cutter durability improvements, SDEs are quickly replacing PDC cutters in various drilling applications worldwide. The concept and laboratory validation delivered a unique and innovative cutting technology for soft formations. Field experience and software modeling combined BHA and nonbit factors during the HDE bit design process to achieve the field performance using the new technology.