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Development of torque clutch drilling tool and evaluation of drag reduction performance

Horizontal well is one of the important methods of unconventional oil and gas resource development. As increasing length of horizontal section, there is a serious problem that axial force cannot transfer to bit. The drilling field needs a low-friction and low-cost drag reduction tool. This article summarized existing technologies of drag reduction in the horizontal and inclined well and proposes an integrated design of torque clutch. Detailed design of tool sub-systems is introduced. The tool includes three sub-systems: clutch, hydraulic system, and monitoring system. The clutch is consisted of multiple clutch units mounted in a parallel arrangement. Power of hydraulic control system adopts difference in pressure between inside and outside of drill pipes. It can efficiently reduce power consumption. The design function and minimum working pressure are validated and obtained by indoor test. According to theoretical calculation, reasonable distance from tool to bit can be obtained for an actual drilled well. During directional drilling mode, the tool can reduce more than 30% axial drag of drill string according to theoretical calculation. The tool can effectively improve the capacity of transfer weight to bit and overcome the excessive drag in horizontal drilling. No similar tools are reported in the current field.