Shell Monday said it wouldn't be able to honor all its export contracts from Forcados for the rest of January and February because of the incident.
Precious Okolobo, a company spokesman in Lagos, said vandals in Forcados damaged the oil export and water discharge pipelines on Jan. 9.
"We have not been able to repair the sabotaged lines because the host communities are preventing us. This is why a force majeure has to be applied," he said.
A force majeure allows companies to suspend contractual obligations such as deliveries of oil and gas following unforeseen events without incurring penalties.
Okolobo said oil lifting will resume at the 380,000-barrel export facility as soon as repairs are carried out.
Shell is Nigeria's largest oil operator, accounting for around half of the country's daily output of 2.6 million barrels at peak production, but unrest in the Niger Delta have cut back production by a quarter since January 2006.