The incident occurred last Friday during preparations for a well operation from theDeepsea Bergensemisubmersible.
Gas reportedly escaped from the seabed manifold to the sea and, according to operatorStatoil, the leak continued for 20 minutes.
While gas was observed on the sea surface, it was not detected on theDeepsea Bergen.
PSA intends to clarify the course of events and identify the direct and underlying causes in order to contribute to lessons learned and experience transfer.
One of its main areas of scrutiny will be the planning for and risk assessment of the operation.