Within a decommissioning programme there are various disciplines and sometimes terminology and language don’t match. For example, when a pipe or tank has been cleaned by an offshore contractor to ‘hydrocarbon free’ it does not necessarily mean it is ‘clean’ for dismantling purposes if hot cutting is being used. Also there can be a gap in the actions undertaken offshore and how that is communicated to the onshore disposal contractor.
There have been several cases in 2019 where fires started at the onshore disposal yards due to remaining hydrocarbons in pipes and voids which should have been cleaned out.
On one 2019 D3 project we found high levels of a hazardous substance within a vessel that had been certified as ‘cleaned’ offshore.

Lesson Learned: Be vigilant in understanding the condition of the asset when passed on into the supply chain and ensure there is a transparent chain of cleaning certificates and cleaning procedures for the various pipes, vessels, tanks etc for decommissioning.