Breakover (static) torque after connections can be a reliable indicator that the drill string is getting differential stuck. While drilling, connection practices should be tailored to capture the relevant data:
- Rotate FIRST after a connection (no up-down movement of the string)
- Record peak torque (i.e. breakover) values
- Compare to the dynamic off bottom torque
In this example, there was little difference between the breakover and the off-bottom torque in the Claystone section. There was a significant increase in breakover torque from 13,250’ (Friction Factor > 0.25) in a clean sand with permeability. On the last two connections at 14,060’ and 14,157’, the static Friction Factor increased to 0.33 indicating increasing differential sticking while the pipe was stationary. Although collecting the breakover torque data unfortunately the wellsite team did not respond to the increasing divergence between static and dynamic friction. While circulating the hole clean at TD, the pipe became stuck after being stationary for ±12 mins while making a connection backreaming stands. Unfortunately, the pipe could not be freed resulting in a costly unplanned sidetrack.