Subsea processing systems are designed with service and repair in mind
A definition of Maintainability… Characteristic of design and installation which determines the probability that failed equipment will be restored to its normal operable state within a given timeframe, using the prescribed practices and procedures. Its two main components are serviceability and reparability.
FMC considers maintainability to be a primary design parameter for its subsea processing technologies. Whether an outage is planned or unplanned, the relative ease, speed and resource requirements to return a piece of equipment to a specific condition are of paramount importance and are addressed during the FEED stage of a project. Therefore, paramount in the subsea system design is an analysis of what failure modes can occur and with what frequency. The design of the retrievable module, for example, is such that it can be rapidly replaced. In-situ repair and vessel deck repair have not been employed to date but highly modular sub-systems within a given retrievable system may be considered in the future. FMC already combines sensors on its retrievable modules, such that when a module requires replacement, sensors can also be replaced.
Based on successful subsea experiences, FMC has adopted a modular approach to equipment design. Modular components can be retrieved without pulling the entire system out. Additionally, many components are designed to allow installation and replacement by a remotely operated vehicle (ROV). This can significantly reduce the cost of installation, maintenance and repair of subsea systems.
An integrity management program based on FMC’s Condition and Performance Monitoring (CPM) software that incorporates monitoring, testing and inspection is also used to capture data for risk analysis. This information can be used for integrity monitoring. For example, wall thickness loss estimations can be deduced from pressure measurements, sand level (eg. from acoustic sand detector), compositions, and velocity. Another use for the software is monitoring component health where specific sensors and algorithms can be used to estimate time to failure of a component with single mode failure including large systems like pumps. Decision support software can also be utilized to process data, model forward behavior and train personnel on the recommended operation of equipment to assure flow.
A maintenance strategy is a central element in FMC Technologies’ design and engineering process for complex subsea processing systems. FMC has a global presence of service centers located near to the operational fields in each of the major hydrocarbon producing regions of the world. These service centers provide assurance to operators that the right support is at hand throughout the operating lifetime of subsea processing systems.