Over the winter a light has been shining on the South Eastern horizon, far out to sea off Flamborough Head. During the day three tall slender fingers appear, almost imperceptible to the naked eye. What are these nautical towers on the horizon?

It is the Dundee-based drilling rig, Valaris 123, crewed by up to 145 people, it is exploring the Tolmount East gas field. The rig is what is termed a ‘Jack Up’. It stands on 540 feet legs on the sea floor, elevating the living quarters, drilling rig and helicopter pad above the waves on connected leg supports. The rig can drill down to 40,000 feet.

Valaris 123 was built in Singapore in 2019. It cost $285m and is contracted to oil and gas companies at a daily rate of $105,000. Although the rig is based in Dundee, due to the strange nature of the maritime world, she flies the flag of Liberia. The jack-up rigs are towed from Dundee to wherever they are required to work, they then secure themselves to the seabed with their legs and begin work.

Valaris 123 being towed at the port of Dundee

The rig is working on the Tolmount East gas field, the main Toulmont field is two and a half miles further south and over the horizon. The Tolmount field is being exploited by Premier Oil and has the potential to reach a peak production rate of around 250 million cubic feet a day. The Tolmount East field is a more recent discovery. It is thought that there is 220 billion cubic feet of gas in the new field. The gas will be pumped via a twenty-nine mile pipeline to Easington in East Yorkshire.

Location of the Tolmount Gas Field, Valaris 123 is to the north and east of the field shown on the map.