Shell lifted the last of three force majeures on its Nigerian oil and gas exports on Thursday, declaring production restored for Forcados crude grades, after output was hit by flooding and theft.

But force majeures by ExxonMobil and ENI on Qua Iboe and Brass River grades, respectively, remain in force.

Oil output has started returning to normal in Africa's top producer, after a sharp fall owing to multiple production snags.

Nigeria is among the world's top 10 crude oil exporters and usually ships more than two million barrels per day (bpd), but a litany of problems, including a major fire caused by oil theft on a Shell pipeline, an offshore spill by Exxon and severe flooding have cut output.

A force majeure means an oil company will not be able to meet contractual obligations on output owing to circumstances beyond its control.

Shell lifted force majeures on its Bonny Light crude and supplies to a liquefied natural gas terminal earlier this month. Forcados was the last crude grade unable to meet the Anglo-Dutch major's production target.

"I've just been told the FM (force majeure) on Forcados has been lifted today," Shell spokesman Jonathan French said by telephone from London.

"There were three in place so now they've all been lifted."

ExxonMobil last week became the fourth oil major in a month to warn customers over delays to Nigerian exports because of an oil spill in a shallow water offshore facility that hurt Qua Iboe production.

Between them, Forcados and Bonny Light represented 17.2 percent of crude oil exports in November compared to 18.8 percent for Qua Iboe.

As well as Exxon's force majeure, another by ENI declared earlier this month on Brass River oil loadings due to floods that caused cargo delays of eight to 10 days remains on.

Shell's outages were caused by a fire on an oil tanker being used to steal oil last month. Oil theft is a major problem in the swampy Niger Delta, where it is easy to hide boats and makeshift refineries in thick mangroves. Nigeria estimates around 150,000 bpd is stolen, much of it shipped abroad.

Total last week restarted production from its 90,000 bpd OML 58 block, which was shut down a month ago due to severe flooding in the Delta swamplands.

Nigerian exports of Bonny light crude oil will be lower in January than December, while Forcados are set to be higher according to loading programmes.

(Reuters, edited by Topco)