Hybrid Bit Technology: Transforming Tricone-Bit Drilling to New Levels

This paper describes the step performance improvement of a 16’’ section in a UAE offshore application. Through close collaboration between directional drilling services, drill bits and operator, a 44% improvement in the section ROP from the field average was achieved. The novel solutions of bit and drive system and drilling practices which allowed for this improvement will be detailed in this paper. A key contributor to this achievement was utilizing a new hybrid bit technology platform which incorporates the dual cutting mechanisms of both polycrystalline Diamond Compact (PDC) and tricone bits. This allows for more efficient drilling through bringing together the improved ROP performance of a PDC bit and the reduced torque fluctuations of a tricone bit. Where initially drilled by tricone bits, the application posed potential for performance improvement, which was to be explored with this bit and BHA solution. Continuous optimization of drilling parameters was essential to minimizing the vibrations and improving the overall drilling efficiency. As a result of the proposed bit and drive system solution and the considerations in execution, the 4900ft long section was drilled in a shoe to shoe run, from surface to Fiqa formation. The unique compatibility between the bit design and the drilling motor allowed for exceeding the intended performance KPI set by the operator. The directional objectives were met as the well was precisely steered between offset wells with critical proximity, where the minimum ellipse separation expected was as low as 1.2ft. The new bit design was seen to not compromise the directional steerability as may be of concern with a PDC bit with a motor. The ROP achieved on the section was a 44% improvement from the field average. Given this being the first run from this new hybrid bit platform, this application still holds potential for further improvements upon design changes based on learnings from the first run. The outcome ultimately would be to take the conventional tricone drilling of this 16’’ section to a complete other performance level.