An incident on the BP-operated Central Area Transmission System (CATS) riser platform during a restart in the middle of December means output on the Huntington field, and others, remains restricted.
Partners in the E.ON operated Huntington field, Noreco and Iona Energy, say they have been informed that the CATS system will not resume normal operations until late February, at the earliest.
Image: The Voyageur Spirit FPSO.
The field was being brought back on stream in December, after gas export restrictions on the CATS system mean oil production had to be shut-in. The restriction on CATS "wet" gas transportation system was imposed after off-specification gas from an unknown source was delivered to the CATS gas terminal at Teeside, in northeast England, another Huntington partner Premier Oil had said last year.
The restriction meant Huntington oil production was reduced to about 40% of its capacity, because it was unable to produce gas. Before the restriction, it had been producing at full capacity, at 30,000 bbl/d and 27 MMcf/d gas. Operator E.ON had been considering gas injection, in order to allow oil production to return to normal.
Further complicating the issue was, due to the shutdown of other fields within the CATS system, resumption of gas export had to wait until other dry gas fields resumed production, to allow a blend of dry and wet gas streams.
Production from Huntington, via the Voyageur Spirit cylindrical FPSO, had originally been shut-in from 31 July to 26 August 2014 for planned maintenance on the CATS system and on the Voyageur Spirit.
But, a planned restart on 26 August was hampered by technical issues related to the low pressure compressor on board, which then meant some equipment had to be replaced.
Production had resumed to normal levels by 5 September, but then restricted from October 1.
CATS comprises a fixed riser platform linked to the Everest oil and gas platform, a 404km, 1700 Mcf/d capacity subsea pipeline and a two-train onshore gas processing terminal at Teesside, which has a capacity of 1200 Mscf/d.