Health-Aware Operation of a Subsea Compression System Subject to Degradation

We propose an health-aware operation approach for combining short-term control objectives with long-term profit and reliability targets. In particular, we present a hierarchical approach for operating a compressor subject to degradation. We consider a case study of a subsea compressor, where the goal is to maximize the gas throughput, while ensuring that the compressor can be operated continuously until a planned maintenance stop. In the top layer, we repeatedly solve a dynamic optimization problem to find the optimal long-term operation strategy, subject to load-induced compressor degradation. The supervisory control layer below receives the computed setpoints and operational parameters, and applies them in a self-optimizing control structure to ensure nearoptimal operation in the presence of disturbances. The regulatory control layer in the bottom stabilizes operation in an otherwise unstable operating region (surge). We show the efficacy of our health-aware operation approach by comparing it to traditional control structures where the equipment health is not explicitly considered as part of the production optimization. Our approach results in higher average production, without jeopardizing the health of the system.