Field test and study for near bit torque pulse drilling speed enhancement tool

When deals with PDC bit stick-slip issues, the traditional torsion impact technology can only provide the bit with circumferential impact torque, but cannot provide the axial impact oscillation, so it is unable to deepen cutting teeth's penetration and has limited speed increase effect. To address this issue, a near-bit torsional pulse drilling speed enhancement tool was developed. Driven by mud, the tool provides the bits with both circumferential and axial impacts, realizing the increase of cutting formation and reduction and elimination of stick-slip vibration. The difficult-to-drill formation in Hainan's Wenchang block was selected as test sections. Compared with the two offset wells, the average penetration rate in the 8-1/2" section of Well Wenchang X-X-5 using the tool increased by 60.43% and 75.96%, the average top drive torque value and increase was minimal with smoother changes, and the PDC bit's cutter wear was slight. The results show that the tool can increase the drill bit penetration depth, reduce the tool and top drive torque, slow down or eliminate stick-slip, and is effective in improving the speed and protecting the bit in poor drillability formations.