FOXTROT International (FOXTROT), operator of the CI27 Block Joint Venture, is committed to contributing to meeting the growing energy needs of Côte d'Ivoire. This ambition is reflected in the Management's real desire to invest to make production reliable in the long term, which is achieved by drilling exploration and development wells.

The missions of the drilling department are:

  • Well drilling
  • Well completion
  • Well interventions (workover, coiled tubing, wireline, slickline)

The operations are mainly linked to the drilling campaigns sanctioned with the partners, which generates very irregular activities over time.

FOXTROT works with a network of experts recognized in their field for their in-depth knowledge of best practices and industry rules. Through their participation in the various FOXTROT drilling campaigns, these experts have acquired a good knowledge of the CI27 block, which allows for capitalization of experiences and a fair assessment of risks.

In 2015-2016 and then in 2021-2022, FOXTROT carried out two major drilling campaigns on the PFB platform, which enabled eight additional wells to be put into production, bringing the number of wells operated to 16.

In 2024, Foxtrot drilled two exploration wells on the CI-12 block.

Technological challenges

During these drilling campaigns, the input data were particularly restrictive:

  • Exploitation of the two Marlin and Manta reservoirs by the same platform requires significant offsets and drilled lengths as well as sophisticated 3D profiles. The installation of two platforms was not economically viable.
  • The Manta reservoir is located in deep water beyond the continental slope in more fragile soils because the weight of the land decreases with distance and depth; The combination of the drilled length, the inclination (80°) and the lesser consolidation of the land becomes very delicate to manage and requires the implementation of the most recent technologies;
  • The oil ring in the Marlin reservoir is not very thick and requires very precise positioning of the drain.

The two campaigns on PFB were carried out with semi-submersible tender rigs. Surface and bottom information was transmitted in real time to the base for permanent monitoring.

For each of the two reservoirs, specific and very different issues had to be addressed.

Reaching the Mantaa reservoir required drilling two long-offset wells.

200-6400 m total length

Objectives located 5 km south of the Marlin platform, under the continental slope in deep water

Sub-horizontal inclinations (80°)

Fragile formations due to the water depth

Presence of faults

The presence of oil in the form of a thin ring in the Marlin reservoir required the realization horizontal wells. The low oil thickness requires high precision on the vertical coasts.

3,900 m total length

Unconsolidated reservoirs requiring control of sand inflows

Low oil thickness

Pilot hole for vertical recalibration then side-track in order to achieve a horizontal "landing" at a precise coast

Horizontal drains

Cutting-edge technologies used

To meet these challenges, FOXTROT implemented the latest techniques that ensured the success of these drillings. With the help of its service providers and its network of specialists, the following technologies were chosen.

"In-Field Referencing" technology

Local magnetic field measurements to improve the accuracy of the well trajectory and achieve small targets at drilled distances greater than 6000 m.

"Hole cleaning Cuttings flow meter" technology

Accurate measurement of the volume of cuttings to detect potential "hole cleaning" anomalies in an open, long and highly deviated hole

"Managed Pressure Drilling" (MPD) technologies

MPD technology uses a rotating BOP (Blow Out Preventer, surface safety valve) and a servo-controlled backpressure system to maintain the most constant bottomhole pressure possible. This prevents hole collapse or losses.

Rotary steerable downhole motor

This technology achieves high trajectory precision, remotely controlled from the surface, to optimize drain positioning in a thin oil reservoir. Combined withc the correlation of the pilot hole (the pilot well), the vertical precision achieved is of the order of 10 cm.

"Gravel pack alternative path" used in horizontal drains in unconsolidated formations

Gravel is pumped and placed between the reservoir and the screens in order to prevent sand from entering the well during the production period. This proven technology is simpler and more robust than other technologies on the market.

The use of these technologies made it possible to achieve the objectives of the eight wells while respecting the announced schedule and the budget