Assessing the Reliability and Availability of Offshore Subsea Production Systems: A Comparative Analysis Using ESDs and FTA

As the demand for oil and gas production from offshore fields grows, the complexity and scale of subsea systems continue to increase. Ensuring the reliability and availability of these systems is critical to minimizing operational risks and maximizing productivity. The layout of subsea production systems plays an important role in achieving these goals, but determining the most efficient configuration remains challenging. This paper discusses four distinct subsea production systems: Satellite, Manifold, Trunkline, and Production loop. To assess the reliability of these configurations, we modeled the systems using a combination of Event Sequence Diagrams (ESDs) and Fault Tree Analysis (FTA), allowing us to capture both the dynamic sequences of events and the potential failure modes within each system. We also considered repair and mobility times for the equipment and pipes, treating these times as exponentially distributed random variables to model downtime and repair logistics uncertainties realistically. By comparing the reliability and availability of each system, we provide a comprehensive evaluation of the trade-offs between design complexity and system performance. The insights gained are expected to guide engineers and decision-makers in selecting subsea production system designs.

Keywords: Subsea reliability analysis, Availability modeling, Subsea production layouts. Oil and gas industry.