The Hibiscus and Ruche oil fields are located in the Dussafu Marin permit offshore Gabon. Source: BW Group.
The Hibiscus Alpha jack-up rig is being converted into an offshore production unit to serve the Hibiscus and Ruche development. Credit: julesromero70/Pixabay.
Borr Drilling’s Norve jack-up drilling rig will drill four wells at the Hibiscus and Ruche fields. Image courtesy of Borr Drilling/Cision.

Hibiscus and Ruche are two co-located oil fields being developed in the Dussafu Marin permit off the coast of Gabon in West-Central Africa. First oil from the development is expected in the fourth quarter of 2022.

BW Energy Gabon, a subsidiary of BW Energy, is the operator holding 73.5% interest in the Dussafu Marin permit. The other partners include UK-based Panoro Energy (17.5%) and state-owned Gabon Oil Company (9%).

BW Energy Gabon became the operator of the Dussafu licence by acquiring Harvest Dussafu, a subsidiary of Harvest Natural Resources, in 2017. Panoro Energy acquired an additional 10% working interest in the Dussafu licence from Tullow Oil to increase its stake to 17.5% in June 2021.

The Hibiscus and Ruche fields are planned to be developed in two phases with an estimated investment of $560m.

Final investment decision on the Hibiscus and Ruche development was made in the fourth quarter of 2019. The project was initially estimated to cost $660m, which was reduced by $100m due to a change in the development plan in the second half of 2020 to use a converted jack-up drilling rig instead of installing a new wellhead platform.

The Hibiscus and Ruche phase one development is estimated to cost $393m. It is expected to produce up to 30,000 barrels of oil a day (bpd) by 2023. Phase two is expected to come on stream in 2024 and increase the gross production to more than 40,000bpd.

Location and greater Ruche area details

The Hibiscus and Ruche fields are located in the Dussafu Marin permit in the Southern Gabon Basin, 50km off the coast of Gabon.

Gabon issued the Ruche exclusive exploitation authorisation (EEA) to develop oil discoveries within the Dussafu Marin permit in July 2014. The Ruche EEA covers a total area of 850km2 with water depth ranging from 70m to 650m. It includes the Tortue, Hibiscus, Ruche, Ruche North East, Moubenga and Walt Whitman fields.

The Tortue, Hibiscus, Ruche and Ruche North East fields are located in the central part of the Ruche EEA in 116m-deep waters.

Operational since September 2018, the Tortue field, located 15km-20km south-east of the Hibiscus and Ruche fields, is the first field to commence production in the Dussafu Marin permit.

Hibiscus and Ruche discovery and reservoir details

Discovered in August 2019, the Hibiscus field is estimated to contain 46.1 million barrels (Mbl) of oil in gross proven and probable (2P) reserves.

The Ruche field was discovered by Harvest Dussafu in 2011, while the Ruche North East field was discovered by BW Offshore in 2018. Ruche and Ruche North East are estimated to contain 24.1Mbl of gross 2P oil reserves.

Recent exploration activity

BW Energy announced oil discovery in the Hibiscus North exploration well DHBNM-1 in August 2021. Drilled to a total depth of 3,336m, the DHBNM-1 well encountered an oil-bearing reservoir in the Upper Gamba and the deeper Dentale sandstone formations.

However, the Hibiscus Extension appraisal well DHIBM-2, drilled in May 2021, did not encounter hydrocarbons.

Hibiscus and Ruche fields development details

Phase one of the Hibiscus and Ruche field development involves drilling six horizontal production wells, of which four wells will be drilled in the Hibiscus field and the remaining two in the Ruche field.

The production wells will be tied back to the Hibiscus Alpha production facility, which will be installed in the Hibiscus field. A jack-up drilling rig is being converted into the Hibiscus Alpha offshore production unit with an operating life of 20 years.

Hibiscus Alpha will be connected through a 20km-long subsea pipeline to the BW Adolo FPSO operating in the Tortue field.

Six additional production wells are planned to be drilled in the Hibiscus, Ruche, and Ruche North East fields as part of phase two development of the project.

Phase one targets 48Mbl of gross 2P oil reserves in the Gamba reservoir, while phase two targets 22.2Mbl in the Gamba and Dentale reservoirs.

BW Adolo FPSO details

The 311.8m-long, 56m-wide and 29.5m-tall BW Adolo FPSO commenced production in the Dussafu license in September 2018. It has an oil production capacity of 40,000bpd and a crude oil storage capacity of 1.35Mbl. Oil tankers transport crude from the FPSO to the shore.

The FPSO also has a gas compression capacity of 18 million cubic feet a day (Mcfd) and a water injection capacity of 60,000bpd.

Contractors involved

Borr Drilling, a drilling contractor based in Bermuda, received a contract to drill four production wells at the Hibiscus and Ruche fields using its jack-up drilling rig Norve in December 2021.

TechnipFMC was contracted to manufacture and install an infield pipeline for the Hibiscus and Ruche development.

Lamprell’s oil and gas business unit bagged a contract to convert the Hibiscus Alpha jack-up rig to an offshore production facility in October 2021. The value of the contract ranges between £4.36m ($6m) and £36.3m ($50m). The rig is being converted at Lamprell shipyard in Dubai, UAE, and is expected to be ready in 2022.

BW Energy acquired the jack-up drilling rig Atla from Borr Drilling in 2020 and renamed it as Hibiscus Alpha.

Zentech, a  marine engineering, project and construction management company based in the US, received a contract from BW Energy to prepare shipyard construction specifications for the jack-up rig conversion in March 2021.

Zentech also performed the front-end engineering and design (FEED) study and was contracted to provide structural engineering services for the Hibiscus Alpha jack-up rig conversion in November 2020.

Aquaterra Energy, an offshore energy engineering solutions company based in the UK, received a contract worth $4.4m from BW Energy to supply multiple conductor tensioning units for the Hibiscus Alpha offshore production facility in November 2021.