* Full production expected in second half January
* Leaky pipe repaired, lengthy restart procedure begun
(Adds background, detail)
OSLO, Jan 4 (Reuters) - Norwegian oil firm Statoil (STL.OL) said on Tuesday that its idle Snoehvit gas field in the Barents Sea will resume production in late January after an onshore processing facility returns to service following repairs.
Snoehvit, which produced some 80,000 barrels of oil equivalent per day in the third quarter of 2010, shut down on Dec. 20 after a malfunction at the onshore plant where gas from the field is liquefied for ship transport.
"We have found the error, and we have repaired it," said Ola Anders Skauby, a spokesman for Statoil, which operates Snoehvit on behalf of fellow licensees that include Total (TOTF.PA), GDF-Suez GSZ.PA and Petoro.
He said maintenance crews "have now started the quite extensive set of procedures to start up the plant again. That will go on for some weeks and we expect to have full production during the second half of January."
The problem, he said, was a leaky pipe in the system that cools and pressurises gas arriving by subsea pipeline from wells off Norway's northern coast.
"They had to examine 1,600 pipes, and found one leakage causing water to come into the system, which caused a sort of ice plug because it's so cold in the system," said Skauby.
The Snoehvit LNG facility was also down for repairs between August and December 2009, and had frequent start-up problems after entering service in September 2007.
(Reporting by Walter Gibbs; editing by Keiron Henderson)