“Shell have encountered low Insulation Resistance faults on installed subsea equipment, but traditional fault identification methods are not always accurate and make finding the causes of low IR labour intensive, time consuming and thus costly. In a drive to seek alternative solutions and utilise new technology to enable cost reduction, maximise the effectiveness and minimise offshore staff and equipment requirements of fault-finding campaigns, Shell held discussions with C-Kore about the suitability of their equipment.
Our first deployment with C-Kore (of four in 2016) was on the Corrib field, we were comfortable trying the tool as it was already at TRL7 and had been used by other oil majors. Although C-Kore was previously used to monitor new umbilicals during lay, Shell saw its potential as a quick subsea fault-finding tool.
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 overcomes the issues of traditional testing
Customers have told us that C-Kore overcomes the issues of traditional testing. It removes all of the problems that plague downline based testing, from the effects of inclement weather on deck-based reading accuracy to the slow deployment and dubious reliability of the downlines themselves. C-Kore also uses an innovative low-voltage testing technique, divers do not have to retreat during testing and SCMs are safe from damage.
By removing the need to use downlines or platform-led testing, C-Kore significantly speeds up fault-finding operations and reduces any downtime required for fault investigation. When deployed by ROV, C-Kore will fit in the tooling tray for extremely fast deployment. For divers, C-Kore is lightweight and easy to handle. Testing itself is also faster than with traditional methods thanks to test automation and automatic data logging.
- Insulation Resistance
- Continuity Resistance
- Shock & Position
…all in the same unit
“We first tried C-Kore on a fault-finding campaign to compare against platform-led testing. It quickly became apparent that we got better data from C-Kore hours before the rig could respond. It was so much faster we switched to C-Kore testing with the platform just as back-up. The weather was also deteriorating. The sea height was such that we couldn’t deploy downlines for conventional testing but we could still deploy C-Kore in the ROV tooling tray. It was just good enough to get the ROV down.
We also needed to test an SCM – to rule it out as the cause of low IR in the field. C-Kore plugged into the SCM, tests were run by triggering the light sensor and everything was completed from deployment to recovery in two hours. C-Kore is very safe with low-voltage testing. Not just for divers, it’s also safe for subsea equipment. There was no chance of frying a control module.”
Client representative, field owner
Innovative low-voltage IR measurement technology
C-Kore has been designed with safety in mind. Because we use innovative low-voltage IR measurement technology, divers do not have to retreat while testing is in process. This means it is now possible to test a whole distribution unit in the time it would previously take to test a single cable. You also need not worry about sensitive subsea control module electronics being damaged with C-Kore as you would with high-voltage DC testing.
The setup and result retrieval process has been designed to be simple and intuitive, with flexibility to tailor to any job’s requirements. The conditions that trigger a test routine, the measurements that are taken and what is shown on the built-in display are all easily configurable by the user. Test results can be exported from the unit as spreadsheets or pre-formatted reports in just a few clicks.