Mariner Field – Chevron
Xodus has recently completed a concept selection study for Chevron for the Mariner field development.

This involved working closely with Chevron as part of an integrated project team providing specialist input in the areas of concept selection processes, facilities definition, subsea systems definition, flow assurance and cost estimation.

There were some key challenges:

› Processing – the Mariner oil is heavier than any which has been produced in the North Sea to date (14.6°API and lower). Heavy oil is more difficult to process and to transport due to the higher viscosity and density.
› Cost estimation – the concept selection was carried out during a time of rapid escalation in equipment, materials and fabrication costs.

The initial eleven concepts identified were narrowed down based on a variety of criteria including NPV, safety, environment, technical and market risk. The two remaining options were then assessed in detail and the preferred concept selected.