“Triggered lightning” has left staff unable to leave platforms near Denmark since November.
Image source, TotalEnergiesHundreds of offshore workers could spend Christmas in the North Sea after weather conditions cancelled more than 50 helicopter flights.
About 300 staff, many of whom are Scottish, have been unable to leave platforms off Denmark as scheduled.
French firm TotalEnergies said a phenomenon called “triggered lightning” was responsible for the disruption.
The company said it would never compromise with the safety of employees.
It also denied reports it was refusing to reschedule cancelled flights and put extra transport on to get workers home for Christmas.
A spokeswoman said: “Helicopter transports during wintertime around the North Sea are always challenging due to ice, fog, wind speeds and other factors.
“This year has been particularly impacted by so-called “triggered lightning” which is caused by polar air passing over a warmer sea surface.
“This phenomenon has led to the cancellation so far of 52 flights in November and December 2022 which can be compared to zero cancellations caused by triggered lightning during the same period in 2021.
“Unfortunately, the phenomenon cannot be eliminated with de-icing systems, as has been mentioned in the media.”
The company, which runs the Tyra Redevelopment Project, said manned offshore installations were normally serviced by helicopters.
They usually transports 130 people back and forth every weekday out of a total offshore staff of about 1,250.
“Since the flights have not been able to take place to the required extent, there are approximately 300 people who should have left and are now awaiting transport to shore,” the spokeswoman said.
“We never compromise with the safety of our employees, neither on the platforms offshore nor during the transport back and forth between Esbjerg [Denmark] and the fields 250km out in the North Sea.
“We are in close dialogue with our supplier of flights, Offshore Helicopter Services Denmark, and other parties, so that we can best keep our employees informed and restore flights when it is safe. “
TotalEnergies has also called in helicopters from another supplier to increase the number of flights when weather allows them to resume.
The spokeswoman added: “In addition, we have committed three boats at short notice, which can dock close to the platforms and establish a safe footbridge if the wave height is not too great. The first one left Esbjerg harbour the night between Saturday and Sunday, and new boat trips are planned for this week.
“We will do our outmost to bring all stranded people back before Christmas.”