V-IR monitors and locates subsea electrical faults without the need for subsea intervention


The cost of subsea electrical failures is high in terms of intervention costs, capital spares and deferred production. Water ingress to subsea electrical cables is the dominant cause of electrical faults. A costly subsea fault finding campaign and possibly a production outage is required which also carries the risk of introducing new faults in previously good connections. Even if a fault can be found and fixed, the entire process must be repeated each time a new fault occurs providing no long term added value.


V-IR brings the V-LIM and V-SLIM products together into a system that provides visibility of the subsea distribution system electrical integrity. The V-LIM unit is installed on the topsides and acts as the data gathering node for the V-SLIM units. The V-SLIM  enabled electrical flying leads are installed at strategic subsea locations. V-IR continuously monitors the subsea distribution network and provides the output via an intuitive user interface, which can be easily interrogated to identify the location of any electrical faults together with any observed degradation (pre-failure) of the network. This means that any repair or replacement effort can be directed straight to the fault location, minimising spares capital expenditure and vessel time. 

Key Benefits

  • V-IR provides high reliability integrity monitoring for brown-field and green-field systems
  • V-IR provides information to locate electrical faults without the need for an intervention
  • V-IR facilitates planned maintenance
  • V-IR minimises subsea intervention costs and mitigates unplanned production loss

Key facts

  • V-SLIM measures IR both upstream and downstream of its location
  • Also measures capacitance, voltage, current, power-factor
  • Can be used on transformer coupled and bus-bar systems (AC or DC)
  • Communicates directly back to the surface host system
  • Fail safe: designed so that V-SLIM failures do not impact on overall system integrity and reliability
  • Extensive use of digital signal processing techniques for high resolution / accuracy measurements with simple electronics
  • Typically better than 5% measurement accuracy