Deepwater is where much of modern subsea technology is being bought and used as companies seek to improve their offshore performance parameters.

From field sensing to flow solutions, key contractors are cashing in on the technologies that they can bring to the market.

Major developments in the Gulf of Mexico, offshore Angola and in deep, freezing waters offshore Norway are providing market opportunities for deployment of state of the art subsea systems.

Norsk Hydro contracted Aker Kværner to clean and recycle glycol to enhance gas flow as part of the deepwater US $9.016 billion Ormen Lange gas development offshore Norway. Here, the company has won a $7.04 million deal for design engineering, procurement and construction of a glycol process system that will be used to remove salt entrained in the monoethyleneglycol (MEG) circulated within field flowlines from subsea wells. The wells are located in a water depth of 2,624 ft to 3,608 ft (800 m to 1,100 m), 125 miles (200 km) back via two 30-in. high pressure and low temperature pipelines to the onshore processing center at Nyhamna. Glycol circulation is being used to avoid the formation of hydrate plugs.
Kværner Process Systems will be the key contractor within the Norwegian group to supply the MEG for Ormen Lange, using patented technology first developed for Norway's Åsgard project to provide flow assurance.

Still in deepwater, the potential for pipeline corrosion is being taken so seriously by BP that it has decided to reuse technology first deployed on its Thunder Horse project in the Gulf of Mexico.
A non-intrusive and specialized field signature method (FSM) that electrically measures pipeline thickness and reacts to pipeline thickness changes in real time is to be deployed by the operator on its forthcoming Greater Plutino project in Block 18.

"It measures changes in the resistivity in steel pipe," explained Svein Ove Eimhjellen, business manager for CorrOcean's FSM unit in Trondheim, Norway, which is supplying the FSM technology.

He said the system relies on inducing a current through a steel pipeline to determine its resistivity which is based on the thickness of steel linepipe. This resistivity measurement is taken on a pipeline before installation offshore, and provides the baseline signature resistivity. That measurement is then used to provide a reference point as both the resistivity and voltage induced in the pipeline changes over time. More resistance means that the pipewall is becoming thinner and, therefore, corroding internally.
Because of this the electrical signature provides a reliable method for measuring pipeline integrity in real time, and it can assist with pipeline corrosion control.

CorrOcean, which also supplied four FSM packages for Thunder Horse, is contracted to supply another four units for Greater Plutino under a $1.80 million sub-contract from FMC Kongsberg - which itself is already supplying up to 45 subsea trees, manifolds and production control systems to BP for Plutino under successive 2004 deals totaling $382 million. Delivery of the equipment is due to start early this year.

Water depth at Greater Plutino ranges between 1,640 ft and 5,248 ft (500 m and 1,600 m). Accordingly, BP requires robust systems to withstand that depth. Eimhjellen said his company has spent 2 years on research and development, concentrating on re-design and qualification of its FSM subsea systems for this type of application, for depths up to 9,840 ft (3,000 m) and higher operational temperatures up to 282?F (140?C). "It is rewarding to see that hard work paying off," Eimhjellen said. "We are pleased that our proven non-intrusive FSM technology has gained acceptance."

Still offshore West Africa, after hybrid riser towers were first used by Total for its award-winning Girassol project in Angola's Block 17, another novel system is being considered for a stepout development there where the water depth extends to 4,592 ft (1,400 m).

A phase-change material, a gel that can absorb and retain heat for crucial subsurface equipment, is under consideration for deployment at the Rosa development which is being tied back to the Girassol floating production, storage and offloading vessel.

FMC Kongsberg won a $120 million deal to provide subsea systems for Rosa involving 18 subsea trees, manifolds, production controls and related systems. Equipment delivery was scheduled to commence early 2005.

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