Controlled sinking of an oil rig. Commissioning and decommissioning a rig is a major issue. solarnavigator.net

BBC
5 October 2010 The cost of dismantling North Sea oil and gas platforms is forecast to reach £19bn over the next 30 years. A new report by industry specialists said there were about 260 platforms to be decommissioned. Consultants Deloittes and Douglas-Westwood said the work presented “big opportunities” for those in the industry. They estimate the value of contracts to process the aged structures could be worth $1bn (£630m) a year. The projected workload is expected to exceed the capacities of the existing heavy lift vessel fleet and onshore deconstruction facilities. …

£19bn to dismantle North Sea rigs