Statoil is facing a safety order from Norway’s Petroleum Safety Authority (PSA) for regulatory violations over an oil leak that led to a nearly four-day shutdown of its Statfjord C platform.
The state-owned operator has calculated that as much as 42 cubic metres (264 barrels) of crude leaked for a period of 37 minutes at a rate of 28 kilograms per second, of which 37 cubic metres (233) barrels was discharged into the sea, in the incident earlier this year.
The leak occurred during the transfer of stabilised oil between the Statfjord A and C platforms and was traced to a fire seal under the cellar deck of the platform.
In its investigation report, the PSA revealed that an isolation valve in a loading pump under maintenance housed in one of the platform’s shafts started leaking, filling the pump house with oil that then leaked into a sump tank at the base of the shaft.
When the level reached 70% in the sump tank, a pump started transferring the liquids to another tank for oily water under the cellar deck and another valve failure then resulted in the oil leaking onto the deck.
The agency warned there was a risk of spray fire or that dripping oil could have been ignited in the January incident, which occurred while 270 personnel were onboard the facility.
“In addition, there was a high probability for the repetition of a similar leakage just after the incident,” the PSA stated.
The agency identified six regulatory non-conformities committed by Statoil related to, among other things, the original and modified design solutions for the drainage system and preparatory work for maintenance.
The PSA also criticised the operator’s own investigation procedure, claiming the causes of the leak were not properly clarified and potential consequences were not adequately considered.
Statoil has now been warned by the agency that it will face a safety order over the incident requiring it to assess its own follow-up system and to identify the technical, operational and organisation factors that led to the leak, with a 1 October deadline for compliance.
Such a warning is given by the agency to allow the operator to assess the facts of the incident before a final ruling is made.