Field Development

Vaalco revives Gabon plan to deal with hydrogen sulphide

If successful, company's reserves would receive a welcome fillip

George Maxwell, chief executive of Vaalco Energy.
George Maxwell, chief executive of Vaalco Energy.Photo: VAALCO ENERGY
Africa CorrespondentLondon

New York-listed independent Vaalco Energy is taking a fresh look at whether resources discovered offshore Gabon that are contaminated with hydrogen sulphide can once again be added to its proven reserves base.

In 2012, when drilling development wells on the shallow water Ebouri field, two wells had to be shut-in after the surprise discovery of H2S in the reservoir fluids. Two years later, H2S also flowed from a development well drilled at the company's nearby, and bigger, Etame field.
Vaalco had planned to install a dedicated platform hosting amine sweetening equipment to strip out the H2S from well streams so production could continue, but, in 2017, that project was dropped due to costs, leading Vaalco to reclassify 1.9 million barrels of net oil reserves as contingent instead of proven.
The company is now eyeing plans to reverse this classification and in the first quarter of 2025, conducted an extended flow test on the Ebouri 4-H well to gather information on the H2S concentrations to aid in equipment design and to evaluate Vaalco's chemical crude sweetening process.
In its first-quarter results statement published on Thursday evening, the operator said this well has flowed for over four months, with "the H2S concentration within modeling expectations, demonstrating Vaalco's ability to treat the oil."

Vaalco added that this well has provided additional oil production, with some extra operating costs associated with chemical treatment.

In the third quarter of this year, the operator will bring Borr Drilling's jack-up rig Norve to Gabon to drill multiple wells — a mixture of development, appraisal and exploration — and perform workovers.

Some of these wells, said the company, will be re-drills and workovers at the Ebouri field to access production and reserves that were previously shut in and removed from proven reserves due to the presence of H2S.

Meanwhile, Vaalco reported that the Baobab floating production, storage and offloading vessel has left Ivory Coast and is on route to Dubai to be refurbished.

The FPSO ceased hydrocarbon at Canadian Natural Resources' Baobab field on 31 January, departed from the field in late March 2025 and "is now currently under tow to the shipyard in Dubai for the refurbishment."

Significant development drilling is expected to begin in 2026 after the FPSO returns to service, said Baobab partner Vaalco, with potential "meaningful additions" to production from the main field, plus a potential future development of the Kossipo discovery, probably as a subsea tieback to the vessel.

Vaalco reported net income of $7.7 million in the first quarter of 2025, unchanged from a year earlier.

Production averaged 17,764 barrels of oil equivalent in the last quarter, up from the 16,848 boepd reported in early 2024, mainly due to Vaalco's Ivory Coast acquisition of a Baobab stake.

(Copyright)

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Published 9 May 2025, 10:02Updated 9 May 2025, 10:02
Vaalco EnergyGabonIvory CoastEtameBaobab