Dynamic characteristics and parameter analysis of drill string system with sliding drilling controller

Abstract

In the deviating section of horizontal well, a greater length of horizontal section leads to a more severe friction and a smaller weight on bit transmitted to bit, which affects the rock breaking power. To address this issue, this paper introduces a novel tool termed the Sliding Drilling Controller (SDC). Subsequently, the modal analysis of axial-torsional coupled vibration is carried out. Then, the dynamic model of the horizontal drill string system is established during sliding drilling and compound drilling to obtain the corresponding dynamic response characteristics of axial torsional coupled dynamic response. The results show that the rig speed and external load should be increased as appropriate when the SDC is connected to the drill string system, which prevents resonance. A judicious increase of weight on bit can enhance the effectiveness of reducing friction and drag. In contrast, increasing rotary torque has minor impact on the reduction of friction and drag. The research offers valuable insights for the practical application and structural enhancement of SDC.