Gas turbines on Phillips's two Eldfisk platforms are being replaced by vastly more energy-efficient Hedemora diesel engines. Hedemora's engines, which have an output range of 1,100-2,300kW, are also designed to allow full power take-off at both ends of the crankshaft and have the ability to operate at 35! inclination.
Furthermore, they have the dual advantage of reducing fuel consumption by some 60% over old gas turbines and limiting NOx emissions to values lower than the proposed IMO regulations. Payback is therefore achieved in very short timespans.
Eldfisk is the second largest field in the greater Ekofisk area. For the Eldfisk Alpha platform, Hedemora is replacing two existing gas turbines with one diesel engine to produce a power generation base load of 2,150kW. The Alpha diesel will be built and tested at Hedemora, Sweden and shipped in three sections on special beams to enable them to be slid into place on the platform.
With very narrow corridors to pass through, installation presents particular problems, so Hedemora has been working closely with Phillips' consultants to ensure that the engine will slot into place. The existing gas turbines will continue to produce power until the 18-cylinder Hedemora unit is installed and commissioned so that the platform can remain in production.
The Eldfisk Bravo platform will receive a 1,400kW, 12-cylinder engine which, being smaller, will be lifted into position by crane. Both engines will be delivered to a base outside Stavanger in mid-June, with Hedemora personnel supervising the installation and hook-up on their arrival at the platforms.
Lower maintenance
The Hedemora engines are supplied with PLC computer-based programming systems which are hooked into the platforms' own computer systems.
Maintenance requirements are much lower than for traditional gas turbines with a major overhaul every 8,000 hours, once a year, lasting only 200 man-hours. Inspections are also performed every 4,000 hours to check the fuel equipment.
"We see the Phillips contract as a trend-setting exercise, particularly with the onset of the Article 21 regulations in Norway," says Nordstrom. "We had a low NOx system built in to our engines before other companies even started to think about it, so we already have a lot of experience in this area."
Another contract received late last year illustrates a further application for the high power to weight ratio of the Hedemora diesel. The contract, from Saipem, is to replace a diesel-driven fire fighting pump on an ex-flotel which is being converted into a semisubmersible drilling rig, the Scarabeo VII. Hedemora will rebuild the diesel engine to provide an emergency power generation set using the existing engine which has only undergone 60 hours' operation.
"The Hedemora option was attractive to Saipem as we are one of the few companies that can modfiy or build a diesel engine capable of operating at a 35! incline," says Nordstrom.
For more information contact Lars Nordstrom, Hedemora Diesel: telephone +46 225 15540 or fax +46 225 15440.
