Dunlin Offshore Oil Rig
A&A were contracted to provide a specialist offshore decontamination clean up team to remove oil spillage from an offshore oil rig platform leg. The rig was sited off the North Scotland Coast in the North Sea and had an historical problem of crude oil leaking from the subsea cells under the rig onto the leg. The cells were previously used to store oil, but were no longer in use.
After client meetings in Aberdeen a methodology and Safe System of Work was developed to deal with the platform leg oil contamination. The leg contained 100m3 of oil. This had to be pumped 150 metres up the rig leg to the rig holding tank. Following the removal of oil the leg had to be cleaned using high pressure water jetting equipment. Our client provided all support offshore.
Air operated diaphragm pumps were installed on the platform level 75 metres above the oil contamination with air supplied from topside. The oil was then pumped topside and, once removed, the leg wash pressure jetted down at pond level to remove any further contamination from the area. Waste was pumped topside as well.
The diaphragm pumps, air-driven high pressure jetting units and additional equipment were lowered to the required leg level by crane. A change in the connections and positioning of the equipment meant that a change in the method statement and approval had to be sought at this point from the client and OIM before proceeding. Work continued and the oil was successfully removed and the area was cleaned down using high pressure water jetting equipment.
In June 2012 the works were successfully completed to the full satisfaction of our client.