Subsea Pipeline Inspection Technology To Quickly Locate And Identify Suspected Blockages
Accurately detecting the location of blockages caused by a build-up of deposits is an on-going issue for the oil industry. Deposits in subsea pipelines such as flexible risers can cause major problems including lost or delayed production, increased pressure, structural damage, safety hazards, and environmental risks.
Being able to screen flexible riser blockages quickly and accurately can save valuable operational and unplanned maintenance costs. Explorer™ from Tracerco provides fast and accurate screening for content and deposit build-up at typical speeds of up to 100 metres per hour, meaning many kilometres can be surveyed per day.
A North Sea operator had a suspected blockage in a 6-inch flexible riser to a semi-submersible production platform and wanted information on the location and type of material that was causing it. After evaluating a variety of subsea pipeline inspection technologies, the operator chose non-intrusive fast screening technology – Tracerco Explorer™.
Rapidly locating the problem
Up to 80% of remediation attempts fail first time. This is largely due to limited knowledge of exactly where, what and how much material is causing a blockage. Attempting remediation more than once doubles the cost, and if there is a lack of information on what the blockage is, or the actual amount of material, the second, third or fourth remediation can still fail.
Each failed remediation attempt extends lost production time and is costly. The operator also runs the risk of compounding the original issue, which can lead to unrecoverable pipelines.
Tracerco Explorer™ subsea inspection technology for flow assurance
Explorer™ works by scanning pipelines through any type of coating, to obtain a mean density profile along the pipeline. By comparing the known material flowing, Explorer™ can identify variances that indicate a buildup of deposits. This allows operators to screen pipelines quickly and determine the location of any deposits.
Deployed by an ROV, the North Sea riser was scanned using Explorer™ and a significant high-density area was found leading up to the mid-water arch. Due to its high density, it was suspected that the deposit was NORM (Naturally Occurring Radioactive Material) scale. To prove this, background scans were performed at the previous inspection locations to account for the radiation signature from the NORM. By comparing the mean density scans and the NORM background data, it was possible to accurately calculate deposit depth.
Combining convenience and confidence in a low-risk solution
The results confirmed a full-bore blockage of NORM scale in the loop, leading up the mid-water arch. This provided the operator with the required information to begin remediation activities with confidence.
Explorer™ can operate at depths of up to 3,000m (~10,000ft) and can cover pipe diameters from 2 to 60 inches. It can screen a variety of different piping systems: standard rigid pipe (coated or uncoated), pipe-in-pipe, bundle systems and flexibles. It’s a cost-effective solution to your flow assurance problems.
To learn how Explorer™ can provide you with critical information about the condition of your subsea pipeline, contact:
+44 (0) 1642 375500
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