Ocean GreatWhite semi-submersible rig; Source: Kishorn Port

One of world’s largest semi-sub rigs comes back to UK port ahead of resuming drilling gig with BP

A giant semi-submersible rig, which is considered to be one of the largest ones ever built, has gone back to the UK’s Kishorn Port (KPL), a 50/50 joint venture between Ferguson Transport (Spean Bridge) and Leiths (Scotland), to prepare for its return to the drilling campaign with Britain’s energy giant BP in the UK sector of the North Sea.

Ocean GreatWhite semi-submersible rig; Source: Kishorn Port

Diamond Offshore’s Ocean GreatWhite semi-submersible drilling rig previously reached the Kishorn Port in the UK in October 2022 for its second visit to KPL, following a ten-week stay in early 2019. The rig began drilling in the North Sea in 1Q 2023 and was slated to finish the assignment in 300 days.

During an equipment incident on February 1, 2024, west of the Shetland Islands, the semi-sub’s lower marine riser package (LMRP) was disconnected from the rig’s BOP on the well while waiting in harsh weather. As a result, the LMRP and the deployed riser string unintentionally separated from the rig and dropped to the seabed.

Due to the incident, the rig was expected to be out of service for 90-100 days. The Kishorn Port team has confirmed the arrival of the Ocean GreatWhite rig back to the port where it will get ready for its return to drilling activities with BP, which are slated to resume by the end of April or early May. The rig is expected to remain under contract until at least late November or early December 2024.

Delivered by Hyundai Heavy in Ulsan, South Korea, and classed by DNV, the Ocean GreatWhite is a sixth-generation MOSS CS60E harsh environment rig capable of drilling down to 10,000 m in 3,000 m of water. With a draft of over 23 meters, the 123-meter-long and 78-meter-wide rig weighs 60,800 tons.

The total contract value of the committed scope of work with BP is approximately $80 million and it also includes priced options for up to eight additional wells. Recently, Diamond Offshore tucked a contract extension under its belt with the same oil major for one of its drillships working in the U.S. Gulf of Mexico.