Darius Snieckus
OGJ Online
LONDON, Feb. 6�Extreme winter weather conditions across the UK and Norwegian sectors of the North Sea have disrupted production, forcing Norsk Hydro AS, Statoil AS, Shell Exploration & Production PLC, Norske Shell AS, and other operators to reduce or shut in flows from platforms.
Norway's Norsk Hydro said production from its Snorre and Vigdis fields had to be "cut to a minimum" last night as a result of frost problems on Statoil's Statfjord A platform, which receives output from the two fields for processing.
The Snorre tension leg platform, and Vigdis subsea installation tied back to Snorre, were together producing 45,000 b/d to Statoil's Gullfaks C platform instead of Statfjord A, a Hydro spokesman said. That was down from an average combined total of 250,000 b/d, made up of 170,000 b/d from Snorre, and 80,000 b/d from Vigdis.
On Snorre, two drilling rigs�the West Alpha and Bideford Dolphin�were idled due to snow and ice, according to Hydro. Routine checks were being carried out "to ensure all safety systems are functioning effectively."
A drastic production slowdown at its Oseberg field center, where "persistent frost problems" slashed output from 200,000 b/d to 50,000 b/d, was compounded Tuesday by the fact that the wet gas facility at the onshore Sture oil terminal, which received Oseberg production, was closed by the deep freeze.
Hydro said production from its Oseberg Øst platform�affected by the slowdown at the field center�was back up to 70,000 b/d, some 100,000 bbl of output having been lost since Saturday.
At the Norwegian operator's Njord field, where production is usually 75,000 b/d, output was cut to 7,000 b/d because the installation's gas compressors "cannot function properly." At Hydro's Troll B platform, production was 137,000 b/d, down from 195,000 b/d last Saturday.
Gas transportation was also affected by the cold, said Hydro, with exports from the Oseberg D unit via the Heimdal riser platform shut down Sunday night because of "problems operating valves on the gas pipeline at Heimdal." Hydro could not say when gas exports�normally 5-7 million cu m/day�would resume.
So far, a Hydro spokesman said, "as a ballpark figure," the operator has lost some 600,000 bbl of production due to the weather-related slowdowns.
Statoil AS, meanwhile, said only one of its nine main offshore developments, Yme field, fell prey to the freezing conditions.
"We were able to cope with the various problems (presented by the adverse weather) until Sunday, when we had some problems due to ice on a pipe and had to shut in Yme," said Statoil spokesman Kristofer Hetland.
Yme is the smallest field in the company's Norwegian portfolio, producing only 10,000 b/d.
Hetland said Statoil had been able to prevent some "minor problems related to the freeze" at its 10 million tonne/year Mongstad refinery near Bergen by manning up over the weekend.
UK operator Shell Exploration & Production brought giant Brent field back on stream and up to full production of 64,000 b/d after blizzards disrupted output over the weekend.
Across the North Sea, Norske Shell said it had not yet succeeded in bringing Draugen field back on flow after processing equipment succumbed to temperatures as low as -46� C last Friday. A spokesman said steaming equipment had been sent to Draugen and that Shell hoped to have the 220,000-b/d field back on flow by Friday, when weather was due to moderate.
Contact Darius Snieckus at [email protected]