Norwegian offshore safety watchdog, the Petroleum Safety Authority Norway (PSA), has begun an investigation of the incident on the West Bollsta rig when a length of riser fell from the handling equipment during lifting.
The incident happened on 17 October 2020, the PSA said on Tuesday.
Operated by Seadrill Europe Management, this drilling rig received an acknowledgement of compliance (AoC) from the PSA in October 2020.
When the incident occurred, it was under contract to operator company Lundin.
The incident happened on West Bollsta’s drill floor when a length of the riser was being lifted from a horizontal position to the vertical with the aid of hydraulic handling equipment.
Said to measure 22.9 metres long, the pipe weighs 26.5 tonnes. It had almost reached vertical when it became detached from the handling equipment, skidded and fell to the drill floor.
The area was reportedly cordoned off, and no personal injury has been reported as a consequence of the incident.
The PSA regards the incident as serious, and an investigation team drawn from its specialist staff is now starting the work.
The main objective of the investigation is to identify the causes of the incident and possible lessons to be learnt and to share this information with the industry.
In conducting its investigation, the PSA will clarify the course of events and the scope of the incident, assess the actual and potential consequences of the incident, identify direct and underlying causes, identify nonconformities and improvement points related to the regulations, apply necessary enforcement powers to correct possible regulatory breaches, make public its findings, and contribute to experience transfer to and learning by other players in the petroleum sector.
As previously reported, the West Bollsta rig is being used by Lundin to drill the Polmak well in the Barents Sea offshore Norway. The well was spud on 10 October 2020.
The spud date came only four days after the West Bollsta semi-sub was given an AoC by the Petroleum Safety Authority.
The Polmak well is the first of three high-impact exploration prospects to be drilled by the company in the Barents Sea until the end of 2020.
In addition to Polmak, the West Bollsta is scheduled to drill the nearby Bask and Spissa wells. The gross unrisked prospective resources of the three wells are estimated to be at over 800 million barrels of oil equivalents.
As for the rig, the West Bollsta semi-submersible drilling rig is capable of operating in harsh environment areas and ultra-deep waters of up to 10,000 feet.