Concept Feasibility: Hydrocarbons

Concept Feasibility: Hydrocarbons

By: Stephen Stokes

Advisian front-end methodology was streamlined for a Subsea, Umbilicals, Risers & Flowlines (SURF) scope in order to assess potential development concepts. Determination of a single functional design suitable for efficient, economic and safe operation was achieved in less than 12 weeks.

The challenge

The Advisian upstream offshore division (INTECSEA) was engaged to provide concept selection to determine the optimum subsea infrastructure for tie back to an 800 MMscfd gas FPSO. The objective was to identify, define and evaluate potential development concepts, leading to a single recommended SURF concept for the subsequent FEED project phases.

The key challenge was to deliver a robust development concept on a tight schedule (less than 12 weeks).

Our approach

To achieve the tight timeframe, a structured process was used to initially identify all options that addressed the key development decisions and key success factors agreed for the project. Then, through a series of commercial and non-economic screening processes backed up by an appropriate level of technical definition, concept development options were reduced down to a shortlist, and ultimately one single concept for the SURF scope (Figure 1).

The application of our front-end tool kit to this SURF scope was unique. Highlights of this approach were:

  • Early Client engagement on development success factors and project drivers;
  • Continued Client engagement through multiple framing workshops;
  • A detailed project analogue review to support key decisions;
  • Integrated Production Modelling to provided direction on deliverability and phasing constraints;
  • A cost ‘building block’ approach, with use of proprietary software, enabled costing of a large number (>25) shortlisted options;
  • Our bespoke Non-Economic Screening (NES) tool was used to highlight option strengths and risks, including HSSE evaluation;

The solution

Consideration of cost, deliverability, risks and opportunities in the option ranking enabled a clear single preferred SURF reference case to be identified from an original shortlist of >200 variants. The result was a functional design that is suitable for efficient, economic and safe operation.

The structured approach gave the Client an auditable and costed decision process to progress to the next project phase, delivered within the 12 week schedule (Figure 2).