"It is anticipated that the work may need to continue towards the summer of 2014," the company said in a statement Friday.
The platform operating at the Njord field in the Norwegian Sea was emptied and inspected in July. Statoil said it determined the platform needed major reinforcements before production can resume.
Last year, Statoil said it planned to invest $310 million to develop a section of the Njord license area.
The company said the development in the northwest flank of the Njord license area would extend the life of the field by two years and increase recoverable reserves to 18.6 million barrels of oil.
Faroe Petroleum, focused on the Atlantic region, said in a statement Statoil's decision meant a lower production forecast from the Norwegian Sea. It said it expected it would produce no more than 6,500 barrels of oil per day from the region this year, compared with its earlier high-end estimate of 9,000 barrels per day.