The challenges of offshore decommissioningby Georgina Enzer on Apr 16, 2014
There are more than 7,000 offshore oil and gas structures around the world. As these platforms mature, operators aim to extend their economic and productive lives either through the introduction of new technologies, expertise with asset integrity and production optimisation, or the development of marginal and remote satellite reservoirs.
Despite these advances, it is now recognised that a growing number of offshore assets have either reached, or are approaching, the end of their economic lives.
In accordance with a number of regional and international regulations, these structures will have to be decommissioned and removed. Over the next 10-20 years, an average of 15-25 installations are expected to be abandoned annually.
In addition, several thousands of kilometres of pipelines will have to be removed, trenched or covered. This presents critical challenges for the owners and operators of mature assets in terms of engineering capability, safety and, significantly, costs.
Offshore decommissioning is a complex series of activities, each with its own level of skill and expertise. From operations to communications, engineering to legislation, each strand is vital. Understanding how a platform was installed, how it was operated, and the expectations for when it reaches the end of its life is a collaborative process which requires a transparent sharing of knowledge.
Decom North Sea (DNS) is the industry body that facilitates this in the North Sea. Since its inception in 2010, DNS has grown to have more than 230 members drawn from operators, major contractors, service specialists and technology developers. The aim of the group is to bring people from all over the industry together in an open environment to discuss opportunities and, above all, to learn from one another.
“In the North Sea many assets are over 30 years old. Minimal consideration was given during the design phase as to how these structures would be removed and disposed of in the future.
As a result, operators now face a number of challenges, including whether to attempt to remove vast concrete structures from the sea bed, not to mention hidden dangers, such as asbestos, as the approaches required to meet these challenges have yet to evolve.
The majority of operators gearing up to undertake their first decommissioning programme are taking time to develop their own approach and strategy.
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