A massive environmental disaster appears to have been narrowly averted in Gabon after 300,000 barrels of crude leaked from a storage tank operated by Anglo-French independent Perenco.

Instead of the oil at the Cap Lopez terminal entering the sensitive coastal ecosystem, the crude leaked into retention tanks on 28 April, Perenco said in a statement.

“A situation of force majeure has been declared in order to secure the facilities and prevent any environmental damage,” statement Perenco, adding that, as of two days ago, no marine pollution had been detected.

The cause of the spill was not yet clear and Perenco has opened an investigation, according to a statement emailed to Upstream.

The statement said floating booms were being installed around the terminal to reduce the risk of marine pollution.

“To date, the teams are hard at work installing floating booms as a preventive measure, pumping the hydrocarbons in the retention tanks and bringing the terminal back into service.”

“Perenco … is working closely with the competent authorities to ensure a quick and safe resolution of the situation,” said the company, with “a full investigation into the cause of the storage tank failure will be conducted as soon as possible.”

A local news service, Gabon Review, cited the country’s oil and gas minister Vincent de Paul Massassa as confirming Perenco’s statement.

Perenco said that immediately on discovery of the leak, pumping was initiated, but "the leak became larger and the oil spilled into the retention tanks, specifically designed for this eventuality."

It added that "all of the oil was contained within the retention tanks, with no marine pollution observed at this stage."

Cap Lopez is Gabon’s key export terminal and is used by many oil companies, including Paris-based Maurel & Prom (M&P), to export their production.

M&P said Monday the facility’s reception and export activities have been suspended due to the incident, and that it has been forced to gradually reduce production from its Ezanga permit onshore Gabon to 4000 barrels per day.

M&P said Perenco “is currently working on restarting its facilities,” adding that a resumption of production from Ezanga “could take place in the coming days.”

However, the operator added that alternative export solutions are also already being reviewed if this proves to be impossible.

H2O Gabon, a local non-government environmental campaign group, said the incident comes at a time when Perenco – which acquired the Cap Lopez facility from TotalEnergies last year – is being prosecuted in Port Gentil court ROLBG, a network of civil society organisations in Gabon, over "multiple environmental" issues.

* Article updated to reflect copy of Perenco statement sent to Upstream