Services > Dynamics

The drillstring is a very long and flexible structure, moving in a complex environment and submitted to irregular action-effects. Thus, its movement is never uniform and regular and there are often mechanical vibrations.

Dangerous vibrations occur for certain values of RPMs, often called "critical RPMs". Our numerical modeling predicts the frequencies to avoid in order to identify safe RPM operating limits.

DrillScan offers services in Dynamic Modal Analysis. Three kinds of vibrations are taken into account:

• Axial vibrations, leading to bit-bouncing
• Torsional vibrations and stick-slip
• Lateral vibrations, snaking and, mostly, whirling

For a given well geometry we determine:

• Axial, lateral & torsional vibrations based on detailed BHA & drillstring design
• Critical zones
• Deflection shapes of the BHA
• Critical frequencies
• Critical RPM/WOB