Fixed Structures Floating Structures. Decommissioning and Removal. Explore Projects. Our Fleet. Explore About us. Sitemap Phishing. Explore Contact. Leiden , The Netherlands. Charell Portier. Related Jobs Jr. Structural Engineer Do you want to work for a leading marine contractor creating sustainable value s for clients and stakeholders in the offshore industry? Read more. Engineer - Decommissioning Do you, as an engineer, drive creative solutions, are you a team player and a great networker?
HOOKS Somehow they are expected to scramble onto the boom and walk in to the deck. Thermometers Self-propelled cleaning machines Magnetic handles and suction pads Power-actuated fasteners, cutters Abrasive and mechanical cutting equipment Underwater rock drills Vacuum corer Pressure:- The increase of pressure with depth affects human sensory and reasoning powers and causes gases to be dissolved into the bloodstream. Temperature:- Low temperatures cause serious loss of body heat.
This is especially critical in deep diving and when diving in Arctic or sub-Arctic areas. Turbidity :- Especially near the bottom and around structures, turbidity impairs vision. Refraction phenomena:- Underwater refraction of light and acoustic waves is different from those in air. Waves:- Waves endanger the descent and ascent of the diver through the sea—air interface. They are gradually taking over many of the functions, such as inspection of pipelines, formerly performed by divers.
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Now customize the name of a clipboard to store your clips. Visibility Others can see my Clipboard. Recommend this site to a colleague. Highly recommended by the Offshore-Environment. Below you will find a brief overview of decommissioning, abandonment and removal off offshore oil and gas installation, including a discussion on secondary use of obsolete structures and reef effects of offshore rigs and platforms.
To learn more about Environmental Impact of the Offshore Oil and Gas Industry, click on the links at the end of the page. The extremely high cost of decommissioning and removal off offshore installations led to the need to revise some of the national and international regulations adopted about 40 years ago. Such a revision covered, in particular, the requirement set by the Convention on the Continental Shelf Geneva, and the United Nations Convention on the Law of the Sea Montego Bay, to remove abandoned offshore installations totally.
At present, a more flexible and phased approach is used. It suggests immediate and total removal of offshore structures mainly platforms weighing up to 4, tons in the areas with depths less than 75 m and after - at depths less than m.
In deeper waters, removing only the upper parts from above the sea surface to 55 m deep and leaving the remaining structure in place is allowed. The removed fragments can be either transported to the shore or buried in the sea. This approach considers the possibility of secondary use of abandoned offshore platforms for other purposes.
From the technical-economic perspective, the larger the structures are and the deeper they are located, the more appropriate it is to leave them totally or partially intact. In shallow waters, in contrast, total or partial structure removal makes more sense. The fragments can be taken to the shore, buried, or reused for some other purposes. From the fisheries perspective, any options when the structures or their fragments are left on the bottom may cause physical interference with fishing activities.
In these cases, the possibility of vessel and gear damages and corresponding losses does not disappear with termination of production activities in the area. Instead, abandoned structures pose the threat to fishing for many decades after the oil and gas operators leave the site. The obsolete pipelines left on the bottom are especially dangerous in this respect.
Their degradation and uncontrolled dissipation over wide areas may lead to the most unexpected situations occurring during bottom trawling in the most unexpected places. At the same time, national and international agreements about the decommissioning and abandonment of offshore installations refer mostly to large, fixed structures like drilling platforms.
The fate of underwater pipelines is still not affected by clear regulations. The options of reusing abandoned platforms, their foundations, and other structures that are out of service have been actively discussed for the last 10 years.
An analysis of scientific potential of research stations permanently based on abandoned oil platforms in the Gulf of Mexico revealed several promising directions of marine research at such stations [Dokken, ; Gardner, Wiebe, ].
These include studying regulation of the marine populations and coral reproduction, making underwater observations, monitoring the sea level, and collecting oceanographic and meteorological information within the framework of international projects.
These platforms also could be used as bases for search and rescue operations or centers for waste processing and disposal [Side, ]. From the fisheries perspective, the most interesting projects are the ones aimed at converting the fixed marine structures into artificial reefs.
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