Conoco and Hitech collaborate on a cheaper offshore loading solution.

Conoco's desire to simplify offshore loading in its worldwide operations has resulted in a partnership with Norway's Hitech Marine to develop HiLoad, an active offloading buoy that the two organizations believe can save up to 30% on the cost of offshore loading operations.

The partnership was arranged prior to the recent merger between Conoco Inc. and Phillips Petroleum Co.
Designed to use a number of existing pieces of offshore equipment, the buoy can directly dock on to any tanker, floating storage offloading (FSO) vessel or floating production storage and offloading (FPSO) vessel. It is equipped with dynamic positioning and propellers to provide maneuverability and suction equipment below the surface. It attaches to the hull of a flat-bottomed tanker with a 75-ton grip and allows a tanker to be moored and loaded without any tug assistance.

The buoy is controlled from a "cyber-station" - a virtual workstation - on the FSO or FPSO, where all the navigation and control equipment is based.

Ole Lindefjeld, head of research at Norske Conoco, said the company has a commercial arrangement with Hitech. Conoco has been paying Hitech to develop the system over the past 21/2 years, with a letter of intent to make it commercial, Lindefjeld said.

He said the concept was developed because Conoco wanted to simplify offshore loading; current thinking is that the best application for the concept is offshore West Africa where there is little or no infrastructure for deep offshore developments.

Capital expenditure savings of up to 30% are possible, Lindefjeld suggests, compared to a conventional loading buoy where a shuttle tanker would need tugs to remain on station during an oil offloading operation to avoid any undue stress to offloading hoses.

Conoco and Hitech's design is a system that does not need tugs, and it is intended for operation in remote areas, or to be used as an oil terminal loading point.

HiLoad is capable of operation with up to a 14.7-ft (4.5-m) significant wave height and, Lindefjeld says, it offers a much bigger operating envelope than a conventional offshore loading buoy.

All of the buoy's components are well known and used. Suction pads on the bottom use the same seals as those found in dykes in Holland, explains Lars Ødeskaug, president of Remora Technology, the company formed by HiTech Marine to develop the concept further and market it from Houston.
Dynamic positioning and joystick control allows the unit to be maneuvered below a tanker. De-ballasting is then used to physically "mate" the unit with the hull of the tanker. Thrusters on the HiLoad keep the two at the desired position, then offloading hoses can be connected for the discharge of cargo.
"It is completely new," says Ødeskaug. "We have spent between 2 and 5 years developing the technology. We have done a lot of model testing at Marintek in Trondheim in Norway."

HiLoad requires up to 2 hours for connection or disconnection. It provides a soft impact with a tanker hull; the unit is de-ballasted onto the bottom of the tanker so that seawater provides a cushioning effect as HiLoad connects with the tanker hull bottom.

Featured on the unit are six large suction pads, which effectively grip the tanker hull. Once connected, these are almost watertight, says Ødeskaug. "There is a force of 4,000 tonnes of friction. The HiLoad and the vessel become one unit."

As part of the concept, Remora is offering its patented Bottom Attached Mooring System (BAMS), designed to attach to the bottom of a ship hull. It can accommodate several production risers, which hook up to a submersible multi-path swivel. In the event of an emergency, it disconnects within minutes.
BAMS features ballasting that allows the unit to be brought to the surface for inspection and maintenance.
And in an effort to convince the industry of the value of this whole concept, Ødeskaug points out that on one deepwater West African project, three mooring lines broke on a conventional offloading buoy.

Commonly, he says, two or three tugs are needed to keep a shuttle tanker on station during an offloading operation; with tug day rates between US $12,000 and $15,000 per tug, offloading is a costly exercise.
"The operational cost of HiLoad is $5,000, so the saving is in the region of $20,000 to $25,000," he says.
To get a HiLoad installed on a deepwater West African field could be between $34 million and $40 million, he suggests. That compares with $50 million to $100 million for an "average" deepwater loading system.

Now that it is based in Houston, Remora Technology will operate as an equally owned joint venture between Conoco and HiTech to sell the concept.

May Roesand, project coordinator for research and development at Conoco Norway, adds, "Traditionally, an offloading system requires special design or major modifications to the tanker. The HiLoad system, however, does not require any anchors and can be used with different sizes of tankers. "That's what sets this offloading system apart from others - its adaptability in a number of deepwater environments and in different offloading scenarios."

Further applications for the concept are under consideration, too, as a potential oil terminal and for liquefied natural gas and liquefied petroleum gas applications. With the number of deep fields to be exploited off West Africa, it might not be long before HiLoad makes its debut there.

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