How to Survive a Rig Inspection: Part 16

In this series, our head of Rig Inspection Services Steven Lee shares tips on how operators and owners can get through rig inspections with flying colours – and which pitfalls to avoid! Mr Lee has more than a hundred rig inspections under his belt, from all parts of the world. In this chapter, we look at how to survive rig inspection on jacking systems.

Part 16: Jacking Systems

As jacking systems have become more complex, rig inspection teams have turned their attention to them more and more.

As modern jacking systems have moved from the simplistic direct online drive systems to more complex Variable Frequency Drive (VFD) systems with complex control and monitoring systems – including remote Rack Phase Differential (RPD) Measurements – the requirement for rig inspection has increased.

The rise of modern jack-ups with higher variable deck loads means that RPD tolerances have become more critical and as such an inspection team will want to verify that any remote monitoring systems are in good working condition.

Visual inspections will take you so far in assessing the RPD monitoring system. Taking manual RPD’s and comparing against the remote monitoring and control systems will also assist in this evaluation process. But ideally, a jacking trial over a relatively short height will be requested to verify correct operation of the RPD measuring devices.

For systems built post-2012, there is also a classification requirement for Failure Mode Effect Analysis (FMEA) to have been conducted, and the rig inspection team will review this document to ensure that all the appropriate risks have been identified and assessed.

Rig inspection teams will also review logs of rig moves to note if there have been any issues recorded during rig shifts, looking particularly for any non-productive time associated with the jacking system.