Subsea Fault-Finding2022-06-30T14:41:17+00:00

Subsea Fault-Finding

Find Faults Fast

C-Kore subsea measurement tools find faults and prove the health of umbilicals, jumpers, control modules, down-hole sensors (or anything else) without using downlines. The tools save days of vessel time allowing more to be achieved in every offshore campaign.

Mobilisation and deployment is simple. The measurement program is automated, dramatically speeding up the testing process and reducing the risk of human error. The tools are not much larger than standard dummy plugs, allowing simple hand-carried mobilisation and easy handling for divers and ROV.

  • Save vessel time and cost, get more done in every campaign

  • Eliminate the delays and uncertainties of downlines and platform-led testing

  • Diver safe, simple to use and automated

C-Kore tools are designed specifically to speed up and simplify subsea testing and in the process give far more accurate measurement data.  They save days of vessel time and more faults are found in each intervention campaign.


What our customers say

“Using C-Kore delivered value to Shell in several ways. Firstly, there was a tangible vessel time saving of approximately 2 days. We requested an engineer for the first deployment, but later were happy operating the equipment ourselves, so there was a personnel saving as well. Secondly, C-Kore gave us an improved diagnostic capability, allowing us to discover additional faults in the field, that would have been masked by the primary fault if traditional diagnostic methods were used. We were also able to gather timestamped diagnostic reports for all the branches and many individual components of the subsea infrastructure, allowing us to identify marginal components for the future IR surveillance and/or proactive maintenance.”
Alex Joseph, Shell UK

C-Kore Experience

C-Kore Applications

Electrical fault-finding

When low insulation resistance is reported on the LIM or communication is lost with the subsea asset, the faulty component needs to be identified so it can be repaired or replaced. Use the C-Kore Cable Monitor to test insulation resistance, continuity and capacitance of the subsea network to locate the faulty component.

  • Low Insulation Resistance

  • Communications Failure

  • C-Kore Cable Monitor

  • Finds faults down to component level

  • Umbilicals

  • Electrical jumpers and flying leads (EFL)

  • Subsea Distribution Units (SDU)

  • Subsea Control Modules (SCM)

Locating a fault within a cable (electrical or optical)

Once the Cable Monitor has narrowed down the location of an electrical fault, or fibre optics need to be investigated, a C-Kore Subsea TDR (either electrical or optical) is used to precisely locate any discontinuity along the cable’s length. The C-Kore TDR data can be used to characterise the type of fault and its precise location, allowing cable repair to be considered.

  • Location of damage

  • Type of discontinuity

  • C-Kore Subsea TDR

  • C-Kore Optical TDR

  • Locates faults within cables

  • Umbilicals

  • Jumpers and flying leads (EFL)

  • Down hole cables (DHPT)

Testing a sensor

If feedback from a sensor is lost, unreliable or not available, the C-Kore Sensor Monitor can be used to directly read a sensor output. This allows faults to be traced to either the controls, jumper cables or sensor. By knowing which component is faulty, time and money are saved when repairing the asset.

  • Sensor function

  • Sensor reading

  • C-Kore Sensor Monitor

  • Measures sensor outputs

  • Well-head sensors

  • Subsea instrumentation

Tools for Fault-Finding

C-Kore Teledyne ODI Nautilus ROV
CKore Siemens Tronic DigiTRON ROV

C-Kore vs. Traditional Methods

C-Kore tools overcome the issues of traditional testing. They remove the problems that plague downline based testing, from the slow deployment and dubious reliability of the downlines themselves to the effects of inclement weather on deck-based reading accuracy. Likewise, as C-Kore units are deployed directly by the intervention vessel there is no longer a need to use slow and cumbersome platform-led testing, where intervention vessels are left waiting for a busy platform to find time for their tests. Both approaches can easily add many hours to every test, adding up to days of vessel time.

By removing the need to use downlines or platform-led testing, C-Kore tools significantly speed up fault-finding operations and reduce downtime required for fault investigation. When deployed by ROV, C-Kore units easily fit in the tooling tray for extremely fast deployment. For divers, C-Kore is lightweight and easy to handle. We use an innovative low-voltage testing technique, so divers do not have to retreat during testing and SCMs are safe from damage. Testing itself is also faster than with traditional methods thanks to test automation and data logging.

C-Kore and Diver

Deploy with diver or ROV


  • Can be configured in advance and used by general personnel

  • Deploy in ROV tooling tray, diver cage or basket

  • Hand carry for mobilisation, no deck space required

  • Not affected by adverse weather or environmental factors


  • Specialist operator required to run test equipment on back-deck

  • Extra time required for deployment and recovery, including vessel step-off

  • Haulage, deck-space and sea fastening required for mobilisation

  • Humidity and weather affect readings, downlines susceptible to damage



  • Testing by the intervention vessel, results within minutes

  • Field or channel only has to be isolated once

  • Safe for divers, no retreating, no on-deck testing and permits

  • All data displayed and logged, automatic reports generated

Platform-Led Testing

  • Reliant on platform time for testing, potentially hours of delays per test

  • Repeated permits/paperwork delays for field isolation and reconnection

  • Divers must clear work site while field is tested from platform

  • Reliant on second-hand data reported from test personnel on platform

The C-Kore Rental Service


The first step is to talk to us. We have helped many customers configure C-Kore units for their applications and have a wealth of experience to draw on.

Commonly, after discussing the field layout and fault-finding strategy we pre-configure the C-Kore units before they leave the factory so all the end user has to do is remove them from the box and deploy. Configuration can still be changed later in the field if needed.

We can help you decide:

  • When should a test routine start
    This could be a light or proximity sensor activation from ROV lamp or diver contact

  • Which lines should be tested
    Multiple combinations of inputs and seawater can be tested with any kind of measurement (IR, CR, TDR, etc)

  • What should be displayed
    All results or just a summary can be shown on the built-in display after each test

Every unit is electrically and hyperbaric tested before dispatch and pre-loaded with configuration data if required.


The C-Kore units arrive in small pelican cases, which can be easily hand carried onto the vessel and take very little storage space.

Once the fault-finding scope of work is reached it is simple to deploy and use C-Kore tools:

  • Fit activation plug
    Fit the activation plug to take the units out of transport mode and enable sensors

  • Deploy units subsea
    Place units in ROV tooling tray (scoop), diver basket or work basket to get to the worksite fast

  • Connect and test
    Plug a C-Kore unit into the subsea infrastructure and use the light or proximity sensor to start measurement

  • Results displayed
    Instant feedback on built-in OLED display to see measurement results subsea

Every result is datalogged and the units do not need to be recovered between tests. Continue testing subsea until all faults have been found and there is a convenient point to recover the units.

CKore Fault Finding


When the fault has been found and subsea measurement is complete it is easy to recover and return the units:

  • Recover to deck
    Bring the units back the same way they were deployed, with the ROV or in a basket/cage

  • Download Data
    Connect via USB and use a built-in wizard to download full test reports

Once all scopes involving C-Kore are complete it’s simple to demob the units. Just place them back in their cases and dispatch via a normal parcel courier, no cranes or haulage required.

C-Kore Transit

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