Mærsk Contractors is building a new breed of semisubmersible designed specifically to operate in the Caspian Sea for ExxonMobil and ChevronTexaco.

Marine Structure Consultants of the Netherlands and Keppel Far East Levington Shipyards designed the four-column, double pontoon unit.
Parts of the new unit - the pontoons and four-column hull - are under construction in Singapore and due to be sailed out in April. The Caspian Shipyard Co. (CSC) will complete the rig in Baku, where the drill floor and topsides will be added. Input on the design has been provided by Exxon Azerbaijan and Chevron, which will be leading a new rig club for drilling commitments on exploration acreage in the region. Exxon already has drilled the Nachivan region using the Istiglal upgraded semisubmersible, but when the new Mærsk becomes available in 2003, it will be deployed on other Azerbaijan sectors of the Caspian Sea.
Distinguishing this rig from any other design is the high level of environmental protection put into the operational case. The Mærsk Caspian semisubmersible new-build, dubbed DSS 20 CAS M, is designed for maximum up time, despite the environmental sensitivities of the region in which it will be operating. That means avoiding harmful emissions as much as possible.
Kaj Kristensen, construction project manager for the rig, said, "It is tailor-made.
"We have considered the waves and wind in the Caspian Sea to make sure it has an up time as high as possible. This is a remote area where the rig will be operating, and we have added manual controls to override functions."
But he stressed the new unit is by no means a low-technology rig, describing it instead as "state of the art."
"Everything can be run in the old-fashioned ways without compromising on safety. This comes from the input from Exxon. You do not need to get anyone out on the drill floor," Kristensen said. Pipe feed and stabbing is automated, as are the pipe-handling functions.
Only cooling water will be dumped over the side of the rig once it becomes operational.
Even rainwater can be contained in tanks. "We have clean areas and dirty areas. Everything can be collected and put in a process system for cleaning," Kristensen said.
Of particular interest in the design is the mooring spread. Mærsk has designed the unit with eight-point wire rope mooring capable of self-contained operation in up to 1,640 ft (500 m) of water. But the unit will be able to anchor beyond that depth with preset systems up to 3,280 ft (1,000 m).
The centrifuge system is "the most modern in the world," Kristensen said. One is not inclined to doubt these claims because the adverse impact on any rig operator or oil company for polluting the Caspian Sea and its prized sturgeon breeding grounds is too severe to contemplate. Exxon knows only too well the harm that can be done to its corporate identity by oil spills. The Exxon Valdez incident in Alaska was an unfortunate accident, and any pollution of the Caspian Sea could just as easily harm the operator's image.
With a displacement of 30,000 tonnes, the rig bears favorable comparison with any other semisubmersible, but it represents a huge technological step forward compared with two other semisubmersibles already operating in the Caspian, the Dada Gorgud and the Istiglal. These former Russian units were upgraded to provide drilling capacity in the region.
Mærsk's new semisubmersible opens a new chapter for drilling in the Caspian. It will be the first modern rig constructed elsewhere and transhipped into the sea. Keppel is due to sail the hull to CSC in April, and it will be transported via the Don and Volga canal and river system to Baku for outfitting. It has been a year since Mærsk signed the construction deal on the back of a long-term contract with Exxon Azerbaijan, and when the hull arrives in Baku, final outfitting should be completed for delivery in September 2003.
Then it can start paying back Mærsk's construction investment - believed to be near US $300 million.
Mærsk also has moved to strengthen its jackup fleet. Hyundai Heavy Industries in Korea is constructing two new heavy-duty, harsh-environment jackup units.
Designs for these units were on display at the 2001 Offshore Technology Conference in Houston, Texas. They won the Woelfel Best Mechanical Engineering Achievement Award for Mærsk with input from Marine Structure Consultants of the Netherlands, Hyundai and Varco.
These units are due for delivery midyear, and will be rated for operating in water depths to 492 ft (150 m) and have a maximum drilling depth of 30,000 ft (9,144 m). In addition, they will have a variable deck load, including the hook load, of 10,000 tonnes. Each will have a cantilever rig with a reach of 90.2 ft (27.5 m).

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