Condition monitoring of hydraulic- and subsea machinery

The reliability, availability and safety of installations are particularly significant challenges for subsea applications. Subsea installations have traditionally been designed to be maintenance-free for 20 to 30 years due to the fact that the equipment i s usually not accessible for inspection, maintenance or repair. But machinery outages and deviations can still occur for subsea installations on the seabed. The costs for repair and maintenance of subsea installations are usually very expensive due to use of costly equipment. In addition, operators are facing long delivery time of spare parts, production shutdown, and large impact of bad weather. With condition monitoring it is possible to detect at an early stage many cases of wear-related damage, and ap propriate maintenance can be scheduled in accordance with equipment requirements. Currently, subsea operators are using sensor technology to measure process parameters (temperature, pressure, sand production, flow-rate, etc.) in order to monitor changes in the production process over time, which may provide limited information about the condition of the installation, mainly based on the operator?s experiences. Today, there is not any available Online Condition Monitoring (OCM) system for subsea installat ions that is capable of utilising these data to pick up faults, wear and tear or the development of mechanical or material weaknesses. An OCM system can provide warning signals, which can be used to safely inform about failure in the system before signifi cant damage occurs. This can lead to synchronized repairs or replacements on the same installation, hence decreasing the maintenance cost. A reliable condition monitoring system will make the production process more predictable and may also prevent enviro nmental impact by reducing major oil and gas leakages. There is an increasing demand from subsea industry to develop online condition monitoring systems for subsea applications.