Gas has started flowing through the Troll A platform in the North Sea from the Troll Phase 3 stage 2 subsea project.

Operator Equinor says the facilities will help accelerate production of 55 Bcm of gas from the Troll West reservoir for export to the onshore processing plant at Kollsnes, western Norway.

Troll Phase 3 produces the gas cap overlying the oil column in Troll West.

Other partners in the project are TotalEnergies, ConocoPhillips and Petoro.

Startup of Phase 3 Stage 2 came a few months ahead of schedule, and the final cost was below the original estimate of NOK12.3 billion ($1.31 billion).

“The main reasons are efficient marine operations and a highly efficient drilling campaign, which was completed 25% faster than planned," said Trond Bokn, Equinor’s SVP for project development in Equinor.

Odfjell Drillling’s Deepsea Aberdeen semisubmersible rig completed the eight-well program in five and a half months, with support from SLB and Baker Hughes.

Aker Solutions fabricated the subsea templates and manifolds for main supplier OneSubsea, with Ocean Installer performing the installations.

The umbilical, provided by OneSubsea in Moss, and the MEG line have been extended from the existing facilities, Equinor added. Allseas’ Pioneering Spirit vessel laid the 28-km, 36-inch pipeline, with the line pipe stored at Stord. 

Randaberg Industries supplied spools and pipeline end terminations, and Aker Solutions conducted associated modifications on Troll A.

Earlier this year, the Troll partners also sanctioned the next phase of the development, named TWIN (Troll West Increased gas recovery North).