Zhang Shaohe, Yang Xian
(School of Geoscience Environment Engineering, Central South University, 410083)
Abstract A kind of special bit used in high geo-stress stratum is instructed. Weak combined technology and stagger exterior are used in the design of the bit to solve the difficult drilling problem in high geo-stress stratum. The Φ75/54.5 new bit shows good performance in factual application, and its efficiency and life are improved over 42% and 28% than ordinary bits. The performance of the new bit is analyzed abstractly, and the superiorities of weak combined technology and stagger exterior are expatiated.
Keywords high geo-stress; weak combined technology; stagger exterior; bit