Elf abandons NE Frigg facilities

Northeast Frigg field's control tower is under tow from the field for Elf Petroleum Norge AS. The abandonment contract was carried out by an alliance of Kvaerner and Stolt Comex Seaway. Photo courtesy Elf. Elf Petroleum Norge AS has removed an articulated control tower and flare column from Northeast Frigg field off Norway and is preparing to dispose of the facilities. Elf said the flare boom arrived ashore July 12 after being towed from the field, and the control tower came shortly after

Aug. 12, 1996

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Northeast Frigg field's control tower is under tow from the field for Elf Petroleum Norge AS. The abandonment contract was carried out by an alliance of Kvaerner and Stolt Comex Seaway. Photo courtesy Elf.

Elf Petroleum Norge AS has removed an articulated control tower and flare column from Northeast Frigg field off Norway and is preparing to dispose of the facilities.

Elf said the flare boom arrived ashore July 12 after being towed from the field, and the control tower came shortly after this.

The control tower consists of a small topsides-normally unmanned but with quarters for maintenance visits-mounted on an 8 m diameter, 120 m high concrete tower that was fixed to a concrete base in 100 m of water.

Facilities status

Elf said the tower has been moored in the fjord outside Tau, near Stavanger, about 200-300 m from where the deck and tower will be re-used. Beginning July 24 the deck was to be separated from the column.

The deck will be used by North Sea Drilltrainer AS, Tau, as a training facility, while the tower will be laid on a bed of rock to form a breakwater for a new marina.

Abandonment was carried out by an alliance of Kvaerner AS of Oslo and Stolt Comex Seaway AS, Stavanger, under an 80 million kroner ($12 million) contract.

Abandonment procedure

Kvaerner Stolt Alliance said abandonment started with flushing hydraulic oil from umbilicals into tanks aboard a diving support vessel (DSV). The umbilicals were then cut at the base and hauled aboard the DSV.

A 2 in. diameter methanol pipeline was cut and the spool piece recovered to the DSV, then an electrical cable connecting the tower to Frigg field's TCP2 platform was cut and left on the seabed. The column was lifted in a vertical position by removal of ballast water and then towed inshore in a vertical position, where it was anchored for dismantling.

The topsides will be cut off and lifted onto an awaiting foundation at the training center. The column will be tilted into a horizontal position and laid in place on the breakwater.

The flare column was towed inshore and tilted into a horizontal position. It was brought onshore up a slipway for dismantling and recycling.

Northeast Frigg's six well subsea template will be removed from the field next year by Kvaerner Stolt Alliance. It will be brought onshore to be scrapped, with all metal being recycled.

Northeast Frigg yielded 11.6 billion cu m of gas in 10 years and ceased production in 1993. Dismantling of the facilities marks Norway's first major field abandonment (OGJ, June 3, p. 18).