V-IR provides an electrical integrity map for subsea distribution systems which gives the critical information required to execute an efficient maintenance and repair plan.


The cost of subsea electrical failures is high in terms of interventions costs, capital spares and deferred production. When failures occur it is time consuming and expensive to find the location of the fault using the existing installed technology, and in many cases problems can be exacerbated by the fault finding process itself i.e. previously good electrical connections are disconnected and faults occur when they are re-mated. 


V-IR brings the V-LIM and V-SLIM products together into a system that provides a complete subsea distribution system electrical integrity map. The V-SLIM units are installed at strategic subsea locations within the electrical distribution network. This can be through retro-fit of separate V-SLIM units at nodes for brownfield applications or through integration of the technology into the distribution hardware for greenfield usage. The V-LIM unit is installed on the topsides and acts as the data gathering module for the V-SLIM units with all inter-communications via the V-NET line to earth communications network. Once connected, the user can access a graphical 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 facilitates planned maintenance
  • V-IR mitigates repair costs and 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