Vibration minimisation for conventional Slim Hole Drilling
Minimizing Vibration - Specialy for slim hole drilling with downsized conventional or retrofit equipment, the larger relative annular clearances required to facilitate kick detection and control, low ECDs with adequate flow rate, drillpipe flexibility for directional drilling requirements etc., increase the potential for vibrations.
As the hole size decreases loads due to vibrations become more significant and the relationships between exciting forces, the coupling between different modes of vibrations, stiffness and damping change.
Torsional and bending stiffness decrease the most and hence vibrations in these modes become more important . . .