Drillstring vibration is a leading cause of downhole-tool failure and premature wear of downhole equipment. The main challenges faced during drilling include performing rapid analyses to determine the root cause of the vibration, clear identification of the active mechanism, and implementation of the appropriate corrective action quickly enough to prevent failure. This paper describes a comprehensive methodology created to identify root causes, vibration mechanisms, and methods to reduce or eliminate drillstring vibration.
Introduction
A bottomhole assembly (BHA) and drillstring have six degrees of freedom and three dominant modes of vibration: axial, lateral, and torsional. This movement is used to describe the different vibration mechanisms such as stick/slip; bit bounce; bit whirl; BHA whirl, both forward and backward; torsional resonance; bit chatter; modal coupling; and lateral shocks.
