Case Study

Concept Design - Offshore Ghana

offshore rig at sunset

Remote, ultra-deep water (1,600-2,900 m) license block located ~70 km offshore Ghana. Over an 18 month period, INTECSEA assisted Hess through its stage gate processes that culminated in the recommendation of a single field development scheme.

The scope covered Assess (Identify) and Select (Evaluate) phase techno-economic evaluations of the subsea facilities, floating systems and topside facilities.


  • To fully consider reservoir uncertainties in the design and technology selection of the flow assurance, subsea and surface facilities.
  • Owing to only rudimentary reservoir modelling, many sensitivities on reservoir data were necessary.
  • To recommend a level of subsea, marine and topside pre-investment to enable future expansion or ullage fill campaigns.
  • To ensure the recommended floating architecture (risers, structure and mooring) were fully compatible and robust with only preliminary met ocean data and very limited technology analogues.


INTECSEA successfully supported Hess through its stage gate processes, we successfully recommended a single field development concept fully considering and documenting technical and economic aspects of subsea, floating systems and topside facility design, as well as non-economic risks.

We were able to ensure the:

  • Technical assurance of deepwater technologies and of the integration/interfacing of subsea, floating systems and topside facilities.
  • Latest fabrication and installation costs, with due consideration of appropriate contingencies given project uncertainties.
  • In line with the business plan, Hess successfully farmed-out 50% license ownership; INTECSEA technical and commercial assurance was key to the farm-out process.
  • The follow-on SURF Pre-FEED was awarded to the INTECSEA Houston office. Continuing the strong INTECSEA-Hess relationship


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