The Fortuna FLNG is touted to be the first FLNG project in West Africa. Credit: Ophir Energy.
The development of Fortuna field envisions the initial tie back of seven wells to the FLSO vessel. Credit: Ophir Energy.
As of November 2014, seven wells were discovered at Block R. Credit: Ophir Energy.
The Fortuna field is estimated to hold 1.3 trillion cubic feet (TCF) of gas from the overall estimated recoverable reserves of about 3.4TCF at Block R. Credit: Ophir Energy.


Fortuna floating liquefied natural gas (FLNG) project includes the development of the Fortuna field using a leased floating liquefaction storage and offloading (FLSO) vessel. It forms the first phase of the proposed four-phased development of the fields discovered within Block R, offshore Equatorial Guinea.

Covering an area of approximately 2,450km², Block R is located in Distal Niger Delta, approximately 140km off the coast of Bioko Island, in water depths ranging from 600m to 1,950m.

Ophir Energy holds an 80% interest in Block R, while the remaining 20% is held by GEPetrol. The production sharing contract (PSC) for the block was signed by the Equatorial Guinea Government with the two partners in April 2006. Seven discoveries were made at the block by November 2014.

The front end engineering and design (FEED) contract for the project is expected to be awarded in early 2015. The final investment decision (FID) is expected to be made in 2016 and first gas is expected in 2019.

Fortuna FLNG project agreements

The partners also signed a non-binding letter of intent with Petrofac in February 2014 to provide services for the project up to the FID stage, which also includes preparing and issuing the field development plan (FDP).

The gas fiscal terms for the PSC and a financial framework for the FLNG project were agreed upon by the partners with the Ministry of Mines, Industry and Energy (MMIE) in November 2014.

During the same month, Exelerate Energy entered into an agreement to head a consortium, which would involve other partners such as Samsung Heavy Industries and Black & Veatch, to build, own and operate the new-build FLSO vessel.

Discovery and drilling at Fortuna

The Fortuna field was discovered in November 2008 by drilling the Fortuna-1 well at a water depth of 1,691m and to a total depth of 3,400m. A 3D seismic survey data covering an area of 1,000km² was acquired in 2009.

The Fortuna East-1 (R5) well was drilled in August 2012 using the Eirik Raude semi-submersible rig at a water depth of 1,853m and to a total depth of 3,465m. The well encountered a 55m gas-bearing column with 40m of net pay in the Late Miocene sands in the eastern part of the Fortuna Complex.

The Fortuna West-1 (R6) well was drilled in September 2012 at a water depth of 1,758m and to a total depth of 3,178m. The well encountered a 72m gas-bearing column with 60m of net pay in the Late Miocene sands in the western part of the Fortuna Complex.

The drilling of the Fortuna-2 well was completed in 2014 using the Vantage Titanium Explorer drillship to appraise the existing wells. The drill stem test (DST) of the appraisal well achieved a sustained flow rate of 60 million standard cubic feet of gas per day (MMscfd) and estimated a deliverable production rate of 180MMscfd via a five inch diameter drill pipe that was used for the DST.

Reserves of Block R

The Block R is estimated to hold 3.4 trillion cubic feet (TCF) of recoverable gas reserves, of which the Fortuna field accounts for approximately 1.3TCF, the Silenus Complex holds approximately 1.2TCF, the Tonal discovery holds about 0.5TCF and the other smaller discoveries together hold 0.4TCF.

Fortuna FLNG development

The current proposal for the development of the Fortuna field involves the initial drilling of up to seven development wells to be tied back to the FLSO vessel via a dual 12in diameter and a single 16in diameter flowlines. Up to 13 additional development wells will be drilled over a period of 15 years from the start of production.

The Fortuna FLSO is proposed to have an overall length of 357m, a breadth of 60m and an LNG storage capacity of 230,000m³ and will be provided with a turret mooring system.

The FLSO will liquefy natural gas into LNG onboard and convey it to LNG carriers for supply. It is expected to produce approximately three million tonnes of LNG a year at the rate of 440MMscfd for approximately 20 years.