Norway's Petroleum Safety Authority (PSA) has told Transocean, Maersk Drilling and Odfjell Drilling to beef up emergency evacuation equipment and procedures on 22 offshore oil rigs, it said on Wednesday.
Drilling rigs are equipped with enclosed lifeboats that can be dropped into the ocean in an emergency and owners must meet a series of technical and operational requirements for how to plan and carry out evacuations.
"All the audits identified a non-conformity from the regulations. This was the same for Maersk, Transocean and Odfjell," PSA said, adding the firms had been asked to explain how they would fix the shortcomings.
"The PSA has now received a response from (each) company, but this does not describe how the breach of the regulations is to be corrected," it said in a statement.
The audits comprised nine rigs each at Maersk and Transocean and four at Odfjell.
Maersk Drilling, a subsidiary of the A.P. Moller-Maersk Group, said it needed more consultations with the PSA before deciding on the measures, which might require additional investments.
"We are going to continue the dialogue to understand their reasoning… and to clarify what solutions have to be implemented," Jakob Korsgaard, head of Maersk Drilling operations in Norway, told Reuters.
"Depending on the outcome, it might require modifications or upgrades of our rigs, but it's too early to say," he added.
Odfjell Drilling said they disagreed with the PSA's conclusion.
"Our opinion has been that we operate in accordance with current regulations," Eirik Knudsen, the company's vice president for corporate finance and investor relations, said in an email to Reuters.
"We are now working to understand PSA's basis for notification of order," he added.
To operate on the Norwegian continental shelf, each drilling rig must have so-called Acknowledgement of Compliance (AoC), which is awarded by the PSA.
While the regulator could ultimately revoke an AoC if technical conditions and safety management systems don't meet requirements, it was premature to discuss such measures, a PSA spokesman said.
Transocean did not immediately respond to Reuters requests by phone and email for comment.
The PSA gave the companies a March 31 deadline to fix the shortcomings.
(Reporting by Terje Solsvik and Nerijus Adomaitis; Editing by Edmund Blair, Kirsten Donovan and Mark Potter)