Optimisation of offshore oilfield development including the risk of failure of subsea manifolds

A technical, economic and safety optimisation model is provided in this paper. The robust approach integrates the risk of the subsea manifold and pipelines, considering the manifold slot size and pipeline structural material, with the surface and subsea production system requirements and investment planning. A worst-case scenario has been identified and incorporated to deal with the system's intrinsic unpredictability, allowing a more tractable formulation for robust optimisation. A model verification process and a case study based on empirical data drawn from a real-world industry context are described to verify and evaluate the system's solution. The most significant managerial insight offered by the novel model is that the manifold and its corresponding slot size can directly influence the search for the most viable production system from a technical, economic, and safety perspective. This information may be considered a high asset during the offshore production system's development because the adoption of the manifold has a direct impact on the subsea layout design. • A technical, economic and safety optimisation model is provided in this paper. • The approach integrates the risk of subsea manifold and pipelines, considering the manifold slot size and pipeline material. • The worst-case scenario is used for the system uncertainty allowing a more tractable formulation for the robust optimisation. • A model verification process and a realistic case study scenario are presented to validate the solution. • The manifold, and its corresponding slot size, can directly influence the search for the most viable production system.