The final weld is complete on the separation unit for the North Sea's Tordis field. Equipment will soon be lifted onto the world's largest subsea template.
The separator is rolled out of the yard in Tønsberg. It will separate sand and water at Tordis. (Photo: Harald Pettersen)
In mid-March the Tordis improved oil recovery (IOR) project reached a milestone when the construction of three enormous subsea modules was completed. Work is now underway to fit the modules to the template.
Subsea separation allows the recovery of 35 million extra barrels of oil from Tordis. These are reserves that would remain unrecoverable without using new technology. IOR increases the level of recovery at Tordis from 49% to 55%.
"Equipment will be tested before being shipped out to Tordis, 11 kilometres south of the Gullfaks C platform," says Hans Kristiansen, Statoil's project manager for Tordis IOR.
The 19-metre-high, 40-metre-long and 25-metre-wide template is being built by the Grenland Group in Tønsberg, eastern Norway, who lack crane capacity to move it. It is therefore being rolled onto a barge outside the yard. A hired crane ship will then lift the manifold and separation modules onto the template.
The Tordis field will have the world's biggest full-scale subsea water and sand separation unit. The unit will be in place at the field in August with first oil expected in October. Mr Kristiansen will then find out whether the equipment functions as intended.
"This isn't my biggest concern," he says. "I strongly believe that the technology will work. The only thing we are unable to control on the day of installation is the weather."