This extended abstract describes the field development concept selection process for Karoon Gas Australia, as part of the appraisal and commercialisation of an oil resource in offshore Brazil.
From an engineering design perspective, the concept selection phase offers the greatest opportunity to create project value. Options must be carefully considered before rigorous investigation to provide a firm foundation for key decisions.
The concept selection study and option consideration began with a two-day framing and option identification workshop. Nine key decisions were identified as having significant impact on the feasibility and cost of the development. These included the wellhead type, hydrate management strategy, floating production storage and offloading vessel (FPSO) capacity, FPSO location, mooring type, subsea architecture, product export and expansion provisions. Assessment criteria were agreed on for each of the key technical decisions; these were applied in the evaluation of options defined. This workshop facilitated definition and agreement for the technical study scope.
The subsequent investigation and selection process focused on the key development decisions that needed to be made immediately, compared to those that could be made at a later stage of the development. These decisions encompassed technical viability, dry trees versus wet trees, flow assurance, mooring type and processing capacity. A geologically complex reservoir drove many elements of the development selection process.
This extended abstract highlights that the final solution balances risk management with maximising project value. The recommended base development concept is analogous to many developments already implemented in Brazil and is flexible enough to accommodate a realistic range of outcomes from future appraisal wells.
Draugen Field Development: The Role of Gravity Drainage and Horizontal Wells