Optimisation & Reliability of Equipment

Drill pipe has a finite life that is typically governed by three main criteria; the length of the tool joints, the OD of the box tool joint and the wall thickness of the tube.

Periodic visual and dimensional inspection is required to ensure that wear or damage is identified and when possible, repaired. Damaged seals and threads, worn hardband and slip cuts are all things that may be spotted by an alert crew and the joints returned for repair.

A more complex, less visible type of damage that needs to be found before it develops into a leak or a failure is the fatigue crack. A propagating crack cannot be spotted by the naked eye so the pipe needs to be laid out and sent to a specialist facility for inspection. This is usually costly in dedicated rig and logistics time as well as the expense of the work itself. There are therefore drivers to optimise inspection intervals.

The speed at which a fatigue crack develops is dependent on the material that the component is made from, the intensity of the loads it see’s and the number of times it sees them.  These variables can all be defined in their worst case, which then means that the length of time that it takes for the crack to develop can be predicted.

NS Inspect is a proprietary programme in which data can be input (RPM, ROP, Dogleg Severity, Rotating hours etc) to enable calculations to be performed that then predict the amount of Inspection Life that has been used up.

This output is very useful in assisting Operators to optimise operations to enable non-productive time to be minimised.

With the vast experience we have in the investigation of tool & equipment failures, we can assist in the development of detailed Failure Mode Effect Analysis (FMEA) worksheets. This helps in the identification of potential failure modes, and alternative solutions or mitigations which reduce the risk or consequence of scenarios.