This summer will be a busy time for StatoilHydro and the group’s suppliers off the Sogne region of western Norway, with marine operations on both Gjøa and Vega. These activities are intended to prepare the two North Sea fields to start production next year.
“We have 20 units at work and are due to perform some 1,000 vessel days,” reported Bjørn Midttun, head of subsea installations, pipelines and marine operations on Gjøa.
Roughly 200 kilometres of oil and gas pipelines will be laid, along with a 100-kilometre transmission cable from Mongstad near Bergen to supply the floating platform with power from shore.
Installing umbilicals, risers, and connection and protection structures, and making more than 60 connections, are just some of the other jobs to be done.
Vega is located 26 kilometres further out to sea, and its gas will be produced via subsea templates tied back to the Gjøa platform for processing and export.
“We also have a busy summer, because these two fields are literally close and due to be completed together,” said Tore Karlsen, manager for subsea installations and pipelines on Vega.
Ten vessels will be at work on this field during the coming season, including the Bideford Dolphin drilling rig. Karlsen expects to use about 500 vessel days.
Pipelines, glycol lines and control cables are due to be installed from Gjøa to the Vega South, Central and North discoveries. Earlier this summer, three huge seabed templates each weighing 500 tonnes were installed on these fields by the Thialf crane barge.
Ensuring that 30 vessels, including two rigs, can work in a relatively confined area without having to wait on each other calls for detailed planning and good communication.
“We have meetings with all the vessels on Gjøa every day, and have planned this for six months,” said Midttun. A representative from the Vega project also attends the daily meetings to ensure that those involved have a full overview of what has been and is due to be done.