The worst oil spill off the coast of Nigeria in more than a decade has been contained before reaching the West African nation’s coast, officials with Royal Dutch Shell PLC said on Monday, less than a week after one of its lines bled crude into the Atlantic Ocean.
An investigation into how the spill of less than 40,000 barrels happened remains ongoing, though company officials acknowledged workers only discovered the leak after seeing a sheen of crude in water surrounding its Bonga offshore oil field.
Meanwhile, Shell officials say the company will clean up another spill it discovered while containing its own — highlighting how prevalent pollution remains in oil-stained Nigeria after more than 50 years of production.
“We can undeniably say we traced our oil ... and stopped it,” said Cliff Pain, who manages the Bonga operation for a Shell subsidiary.
Shell organized a helicopter flight on Monday for journalists to see the Bonga field — controlled from a large ship as opposed to a stationary rig — about 120km off Nigeria’s coast.
There, waters appeared free of the oil sheen as ships continued to patrol along the underwater lines linking the vessel to oil fields and transfer buoys for filling tankers.
The leak discovered on Dec. 20 came from a break in a flexible line about 360m out from the vessel that sends oil to tankers, Pain said. While the vessel has a variety of gauges to check pressure on the line, it wasn’t until daylight broke that workers noticed a sheen surrounding the Bonga vessel, he said.
It takes about 25 hours to fill a waiting tanker with 1 million barrels of oil from the vessel, Pain said. That means the leak could have spewed for hours before being noticed.
At its height, Shell statistics show the sheen spread across about 900km2, matching an estimate earlier issued by an independent watchdog group called SkyTruth. Nigerian government officials previously said the spill only affected an area a third that size.
The Nigerian group Environmental Rights Action, which monitors spills around Nigeria’s oil-rich southern delta, has blamed Shell for the new spill. Nnimmo Bassey, the group’s executive director, could not be immediately reached for comment on Monday night.
Shell operates the Bonga field in partnership with Italy’s Eni SpA, Exxon Mobil Corp, France’s Total SA and the state-run Nigerian National Petroleum Corp. It produces about 200,000 barrels of oil a day — about 10 percent of production in Africa’s most populous nation.
The field remains shut down and Shell officials offered no estimate on Monday of when production could resume at a field vital to Nigeria’s government finances.
Some environmentalists say as much as 550 million gallons of oil poured into the delta during Shell’s roughly 50 years of production in Nigeria — a rate roughly comparable to one Exxon Valdez disaster per year. Many blame Shell and foreign companies working in Nigeria for the pollution.
However, Shell in recent years has blamed most of its spills on militant attacks or thieves tapping into pipelines to steal crude oil, which ends up sold on the black market or cooked into a crude diesel or kerosene.