West Mira rig - Wintershall Dea

Drilling stops on Wintershall Dea field after serious rig incident

Drilling operations have been stopped and an investigation has been launched following a serious incident on the West Mira rig. At the time of the incident, the rig was working for Wintershall Dea on the Nova field in the North Sea.

West Mira rig; Credit: Seadrill

According to an update by Wintershall Dea on Tuesday, there was an incident on Friday, 19 March during a lifting operation on the Seadrill-operated rig West Mira, located on the Nova field.

No personnel were injured and the well is secure, the company added.

Wintershall Dea mobilised its emergency response organisation and notified relevant authorities. The drilling operation has been stopped until further notice.

An investigation into the incident, which is considered serious, has been initiated.

Wintershall Dea said that, while lowering a x-mas tree from the West Mira, the winch wire snapped when the tree was five metres below the sea surface. The x-mas tree sunk to the seafloor 368 metres below water level.

Eight people were working in the area of the rig where the incident occurred in safe distance from moving equipment.

A Remote Operated Vehicle (ROV) was sent to the seafloor to assess the situation. The ROV survey showed no risk of discharge of well fluids or hydrocarbons and the x-mas tree has been localised on the template. The well is under control and secured with three barriers.

Further incident details will be available once the investigation is finalised, Wintershall Dea concluded.

When it comes to the rig and its current job, Wintershall Dea started drilling the first of six wells on the operated Nova field in late October 2020, using the West Mira rig.

In February 2021, the rig completed the top hole drilling campaign on the Nova field.

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The campaign involved drilling some 3,400 metres of top holes for the six Nova production and water injection wells on two different templates.

The Nova field drilling is expected to last throughout most of 2021. When it comes on stream in 2022, Nova will be the fourth subsea field in production for Wintershall Dea.

West Mira is a sixth-generation semi-submersible drilling rig built to the Moss Maritime CS60 design. Operated by Seadrill Europe Management, it received an acknowledgement of compliance (AoC) from the PSA in 2019.

This is not the first safety incident on the West Mira rig. About a year ago, the lower marine riser package (LMRP) on the rig was unintentionally disconnected.

This incident also happened while the rig was working for Wintershall Dea, this time on the Maria field in the Norwegian Sea.

In September 2020, the Norwegian offshore safety regulator completed its investigation of the incident on the West Mira rig. The regulator found serious breaches of regulations and Seadrill, as the rig operator, was given a safety order.