In Canada, production has also been cut as wildfires forced closures of around 1 million bpd, although output is gradually returning.
Libyan output has also been hit by internal conflict.
By some estimates, these outages should undoubtedly lead to a swifter market rebalancing, but ones like in Nigeria are just the start.
"The risks are mounting and Venezuela could be the next shoe to drop," said Michael Tran, director of energy strategy at RBC Capital Markets in New York.
Other analysts, however, expect oil prices to come further off recent highs, correcting their recent upwards trend. Prices have risen for six out the last seven weeks, buoyed by the supply disruptions.
"We feel that markets have moved too high, too far, too soon," Harry Tchilinguirian, lead oil and commodities strategist at French bank BNP Paribas in London, told Reuters' Global Oil Forum.
"The combination of a stronger dollar, still excess supply over demand and ongoing overhang of inventories can be expected to put strong downward pressure on prices."
He said oil prices could fall to the mid to high $30 range.