Spar platform technology moves forward in the Gulf of Mexico with Kerr McGee's new gas development.

Using a proprietary Technip-Coflexip design, development of Red Hawk will see the first use of a cell spar in the Gulf of Mexico.

Red Hawk, estimated to contain 250 Bcf of gas, also will become the deepest deployment of a spar so far by Kerr-McGee in a water depth of 5,300 ft (1,615 m).

The cell spar, the first of its type, was designed to be used on medium-size fields. "The other spars are adapted to larger capacities and mainly consist in [of] a wide cylinder," said a spokeswoman for Technip-Coflexip. " The cell spar consists of a series of tubes attached together surrounding a central core tube. It can be used for a number of purposes related to both production (wet and dry trees) and drilling systems. It's cheaper, and can be built on any yard without specific infrastructures."

This design also can be used for shallower water applications.

Partner Ocean Energy describes the Red Hawk platform as a "state-of-the-art mini-floating production facility." The unit will be installed in Garden Banks Block 877.

Gulf Marine Fabricators in Corpus Christi, Texas, will build the new cell spar, which will have a displacement of 15,200 tonnes and measure 480 ft (146 m) tall, with a 64-ft (19.5-m) diameter hull. Construction should commence before the end of the year and should be well under way by the turn of the year.

Kerr-McGee describes the cell as a third-generation spar. It will feature six "tubes," each 20 ft (6.09 m) in diameter, arranged around a seventh 20-ft (6-m) tubular central column, all connected by structural steel. A top deck will measure 132 ft (40 m) by 110 ft (33.5 m).

Kerr McGee's Chairman and Chief Executive Luke Corbett said the cell spar was chosen primarily because of the lower cost base required to exploit Red Hawk reserves. "This new cell spar technology will allow us to capitalize on our deepwater prospects by reducing the reserve threshold needed for an economical platform development in deep waters," Corbett said.

Process topsides on board will have initial handling capacity for 120 MMcf/d of gas, and ultimately for 300 MMcf/d of gas. First production from Red Hawk is due in the second quarter of 2004.

In November last year, Technip-Coflexip won a previous contract from Kerr-McGee to supply a truss spar for the Gunnison field, spanning three Garden Banks blocks, 667, 668 and 669 in a water depth of 3,122 ft (950 m).

That deal through CSO Aker Maritime - the deepwater division

of Aker bought by Coflexip - gave the contractor turnkey responsibility for engineering, procurement, fabrication and delivery of the completed spar hull, moorings and risers. CSO Aker Engineering in Houston is performing engineering on that spar, as well as procurement of the riser system. But the hull is being built at CSO Aker Rauma's Mäntyluoto fabrication facility in Finland, which is also working on the mooring system. Delivery of the Gunnison spar hull is due for July 2003. It will measure 549 ft (167 m) tall and has a hull diameter of 98 ft (29.8 m); it will have a displacement of 38,000 metric tonnes, and a steel weight of around 14,000 tonnes.

"The Truss Spar was designed to improve efficiency and reduce the operators' level of investment," said Tom Ehret, president of Technip-Coflexip's Offshore Branch.

BP and partner Vaster Resources previously ordered another spar from the same Mäntyluoto facility for the Horn Mountain project, also in the Gulf of Mexico. This unit was slightly larger at 557 ft (170 m) tall and with a hull diameter of 105 ft (32 m).