Heat exchanger cleaning, Aberdeen

In-place circulation is done offshore routinely, where the unit can be isolated against a spare and the deposit is one that circulation will shift. It avoids the cost and the lifting of bringing anything back.

Anything needing the unit opened generally comes ashore. Deck space, lifting capacity, bed availability and waste handling all argue against opening equipment offshore, and a plate pack or bundle is far cheaper to deal with at a facility than on a platform.

Naturally occurring radioactive material. Radium-bearing scale that deposits from produced water in some fields. It is not present everywhere, and where it is present it changes the handling, the monitoring and the disposal route entirely.

Establishing is before anyone opens a unit, not after. Where NORM is suspected, the work runs under a radiation protection arrangement and the waste is consigned accordingly, which is a materially different scope from ordinary hydrocarbon cleaning.

Removing and neutralising whatever the equipment held so that it can be safely dismantled, recycled or disposed of. Hydrocarbon, hydrogen sulphide, pyrophoric iron sulphide, mercury on some assets and NORM scale on others.

The deliverable is documentary. What was found, what was removed, what monitoring was done and to what standard, so the receiving facility can accept the material. That evidence and not restored heat transfer, is the point of the job.

More than most onshore work. Personnel need offshore survival and medical certification, beds have to be available, equipment has to be certified for lifting and containerised, and the weather has to cooperate.

Scope precision matters more than usual as a result. A vague brief that turns out to need different equipment cannot be corrected the way it can onshore, so the survey and the specification carry more weight.

Both, and they run alongside each other. Producing assets still need their coolers and condensers cleaned, and an ageing asset arguably needs it more carefully because the margin for unplanned downtime is smaller.

Decommissioning is the growth area rather than the whole picture, and the NSTA's projections cover a multi-decade programme, never a short one.

Anything that can be transported. Plate packs, bundles, coolers and modules returned from offshore are cleaned at facilities served by the harbour, which is much of the reason the supply base exists.

Terminal and gas plant onshore is cleaned in place like any other process site, on a conventional turnaround programme with the usual permit, isolation and decontamination requirements.