ABSTRACT
The Bruce field is a large gas condensate accumulation, which underlies blocks 9/8a, 9/9a and 9/9b in the UK sector of the North Sea. The decision to develop the Bruce field was taken by the Bruce Partners (BP Exploration, Elf UK, Total Oil Marine, Hamilton and LASMO North Sea) in 1989, and the responsibility for gas transportation was assigned to Total Oil Marine, as operator.
In November 1989, TOTAL formed a project group, which was set up to study, design, construct and install the Frigg UK Wye Project, besides other responsibilities within the Bruce Area Development Project developed by B.P. In the actual economic context calling for cost effective developments, the project group conceived, engineered, tested and deployed a new pipeline isolation philosophy: TOMSEAL, which is based on a combination of proven hot tapping and folding stopple techniques associated with the development of new remotely controlled plugs, for the tie-in of the Wye piece into the Frigg UK line. TOMSEAL makes lengthy recommissioning redundant as it avoids the need for pipeline flooding, dewatering and drying, therefore generating cost savings on the connection operations but, more importantly, shortening dramatically gas export transportation system unavailability when performing the connection.
Once the works are commissioned in 1993, gas will be exported from the Bruce field through a new 32-inch pipeline 5.8 km long which is now connected to the 32-inch Frigg UK line and on to St Fergus terminal in Scotland. The pipeline connection is through a subsea Wye component which has been tied into the Frigg UK line. The preparation works commenced in December 1991 and were completed in April 1992. The installation and isolation works were successfully performed in Summer 1992.
