Oil and Gas Decommissioning

Offshore decommissioning of oil and gas facilitiesthis, in particular, companies with speciality skills in
becomes necessary when the useful life of thewater jetting, cleaning, waste management, asbestos
structures, or when the fields that they tap into,removal and so on. All the waste from such an
have reached their limits. Oil and gas offshoreoperation has to be removed and disposed of and
platforms can be a considerable distance from thethis is strictly regulated. They provide project
nearest onshore facilities equipped to deal with themanagement and technical support, cleaning and/or
task of decommissioning, so the task can be adecontamination consultation, hazard identification,
difficult one.waste management (identification, removal,
In the North Sea, most of the oil and gas offshoretreatment, handling and disposal), asbestos
installations have been in place for many decades.management (identification, removal, handling and
This means many of the structures are nearing thedisposal), cold cutting of steel, concrete and other
end of their useful lives and will need to undergocomposite materials using water jetting, wire and
offshore decommissioning.mechanical methods. Upon CoP (cessation of
Offshore decommissioning is not a particularly easyproduction) they may carry out preparation for
task. In the North Sea this is especially so. The harshtopsides removal and NUI (normally unattended
conditions faced there raise their own specialinstallation). All the waste from such an operation has
problems that have to be overcome. Removing hugeto be removed and disposed of and this is strictly
installations from the sea bed where they have lainregulated.
for several decades requires a lot of careful planning.Despite human ingenuity in getting rigs up and running
This activity may also have an impact on thein the North Sea, it must not be assumed that any
environment and the health and safety aspect fordifficulties encountered in decommissioning them can
workers is another factor to be taken intoeasily be overcome. New technologies are emerging
consideration; while the cost of it all is likely to beall the time to deal with problems that seemed
enormous.insurmountable just a short time ago. Many of the
What happens when decommissioning takes place?structures can be floated away to a mainland base
A plan of action is first put forward by the Operatorwhere decommissioning can be undertaken more
who will carry out the dismantling of the structure.easily. Those structures that cannot be floated away
This needs to be approved by the governmentcan, in most cases, be cut into smaller sections. The
before any action can be taken. Once approval issections can be placed on barges and towed to land
given, the job can start. It will take a number ofwhere possible. Where this is not possible, offshore
years and will involve many different organisations,decommissioning takes place where the installations
each one responsible for a part of the whole.lie.
Many service providers get involved in a project like