Norwegian oil company Aker BP has restored production at Alvheim field, causing an oil spill during the process of starting up the production vessel located in the central North Sea.
The downtime resulted from a malfunction in new equipment installed during maintenance activities in the previous quarter, causing a deferral of approximately one month in the production from the Alvheim area, Aker BP said.
The oil spill from the Alvheim production vessel on November 29 occurred in connection with starting up the field following an unplanned production shutdown, where one well was producing.
A preliminary estimate indicated a discharge of 51 cubic meters of oil through the produced water outlet, which leaked to sea.
The incident was reported to the authorities, and Aker BP’s emergency response organization mobilized alongside the Norwegian Clean Seas Association for Operating Companies (NOFO) and the Norwegian Coastal Administration to deal with the oil on the sea surface.
NOFO and the Norwegian Coastal Administration chose to use the oil spill response measure known as mechanical degradation, where the propellers on the standby vessel Esvagt Stavanger mixed the oil down into the water column until it dissolved.
Satellite and aerial surveillance measures were also initiated, in addition to the standby vessel’s oil radar. According to Aker BP, the oil spill response measure proved to be highly effective and the oil slick was significantly reduced in size as early as the next day.
The Norwegian Coastal Administration, in consultation with NOFO and Aker BP, decided to end the operation the next day, on December 1.
Ine Dolve, Aker BP’s SVP Alvheim, said: “This oil spill response operation has been effective and was characterised by very good teamwork between the involved contributors. We’ve started an investigation of the incident aimed at learning and strengthening our barriers to avoid any similar incidents in the future.”
At this point, no oil was visible on the sea surface in satellite images and flyovers, Aker BP confirmed. The Norwegian Coastal Administration and NOFO have not reported that any harm has been caused to the environment.