Methods for Eliminating Drill Pipe Oscillations and Enhancing Drilling Efficiency under Adverse Working Conditions during Pressure Relief Drilling

Due to operating environment limitations, many pressure relief borehole drilling operations cannot employ large drilling equipment directly. Using small drilling machines with lightweight, small-diameter drill pipes for large-diameter borehole drilling is effective for drilling pressure relief boreholes in harsh environments. However, small-diameter drill pipes are prone to violent vibration, leading to drilling bending and low drilling efficiency. To address these issues, a method for eliminating drill pipe oscillation and enhancing drilling efficiency is proposed. Through theoretical analyses, numerical simulations, laboratory experiments, and other methods, the reasons for low efficiency and poor quality in large-diameter drilling operations using small-diameter drill pipes were analyzed. This study investigated the drill pipe vibration characteristics and vibration damping mechanisms during large-diameter pressure relief borehole drilling. Severe drill pipe oscillations cause borehole curvature and additional power consumption, affecting the drilling quality and efficiency. Supporting the drill pipe radially with an oscillation absorber during drilling eliminates the drill pipe oscillations. The effectiveness of the oscillation absorber becomes more pronounced as the drilling depth increases, with a significant reduction in the drill pipe amplitude of up to 80% when the borehole depth reaches 4 m. A static support oscillation absorber was developed for pressure relief borehole drilling. This device functions as both an oscillation absorber and a drill pipe connector. Field trials have demonstrated that employing this static support oscillation absorber reduces the drilling time by 28% at a depth of 4 m, which enhances the drilling efficiency and quality.