In-Line Inspection (ILI) Verification

Subsea Pipeline: Confidence Through Accurate ILI Validation.

TSC Subsea conducts in-line inspection (ILI) verification on subsea and offshore pipelines from the external surface, even at depths of 3000 meters (10,000 feet). Our suite of NDT technologies includes our proprietary Acoustic Resonance Technology (ART), which is preferred by many major operators globally for ILI verification assessments.

ART stands out as the sole high-resolution technology capable of penetrating thick attenuative subsea coatings, performing precise wall thickness measurements, and corrosion mapping with a depth sizing accuracy of ± 0.2mm. This makes it an ideal choice for ILI validation, providing pipeline operators with peace of mind.

ILI Verification Technologies

TSC Subsea offers ILI verification assessments, providing operators with a cost-effective solution to validate ILI inspection results. By enhancing confidence in decision-making, our assessments contribute to safeguarding the integrity of subsea pipelines. Our team of application specialists is available to advise on the most suitable non-destructive testing (NDT) technology, considering various factors such as defect types, pipeline coatings, and water depths.

Acoustic Resonance Technology (ART):

  • Quantitative through coatings wall thickness measurement with a depth sizing accuracy of ± 0.2mm.
  • Penetrates thick attenuative coatings over 100 mm (4 in).
  • Approved by many major operators for subsea pipeline inspections.
  • Demonstrated outstanding performance with over 200 inspections on pipelines, flowlines, and flexible risers.
ART Data Wall Thickness Measurements

C-Scan from a blind trial of a coated pipe simulating channeling and pitting corrosion; all defects were measured with ± 0.2mm accuracy.

Subsea Phased Array (SPA™)

  • Quantitative wall thickness measurements and corrosion mapping.
  • Accurately detect cracks, measuring their length and depth.
  • Advanced high-resolution imaging with Total Focusing Method (TFM).
  • Collect A-Scan information every 0.5mm, ensuring 100% coverage of the inspection area.
ILI verification with Phased Array (PAUT)

ILI verification with Phased Array (PAUT) detailing corrosion pitting.

Subsea Pulsed Eddy Current Testing Array (SPECTA™)

  • Semi-quantitative screening method.
  • Scan through marine growth or coatings, including concrete and polypropylene.
  • Accurate measurements of remaining wall thickness, even on concrete weighted coated (CWC) pipes.
  • Scan in ‘screening mode’ for greater efficiency.
ILI validation of Concrete Weighed Pipe

SPECTA data through concrete weighed coated (CWC) pipe.

External Subsea Pipeline Scanners for ILI Verification

TSC Subsea’s remote inspection robotics provide efficient and cost-effective monitoring of subsea assets. Our field-proven robotic delivery systems ensure high-quality NDT inspection data, empowering clients to make informed operational decisions. This approach minimises unscheduled stoppages, incidents, and environmental leaks, ensuring smoother and more sustainable operations.

ILI Verification with Artemis

ARTEMIS™ equipped with ARTor SPECTA™

  • Remotely deployed by inspection or WROV.
  • Provides direct quantitative wall thickness measurement with highly accurate depth sizing (± 0.2mm).
  • High coverage – 700mm by 360-degree per placement.
  • Accommodates Piggyback lines.
  • Versatile design for axial and circumferential measurements.
  • Real-time live topside feed for audit and comparison purposes.
  • Only 300 mm dredging requirement.
  • Minimal vessel time is required.
  • Enhances life extension of the equipment.

vCompact™ equipped with ART, SPA™ or SPECTA

  • The robust and compact design facilitates easy handling on deck and seamless integration with ROV systems.
  • Versatile design for axial and circumferential measurements.
  • Diameters range 89 mm (3 in) to 3000 mm (118 in).
  • Magnetic or clamp versions for ferrous and non-ferrous materials.
  • Multiple NDT technology options, including ART, SPA or SPECTA
  • Provides direct quantitative wall thickness measurement with highly accurate depth sizing (± 0.2mm).
  • The low-profile design lends itself to tight access applications.
  • Instant data capture for audit and comparison.

Advantages of Undertaking ILI Verification Services

Enhanced Data Accuracy: ILI verification assessments provide an additional layer of assurance regarding the accuracy of inspection data, especially critical parameters such as wall thickness measurements and corrosion mapping.

Confident Decision: By leveraging advanced NDT technology such as ART, ILI verification assessments can offer more precise measurements and detailed insights into pipeline conditions, enabling operators to make more informed decisions about maintenance and integrity management.

Risk Mitigation: Verifying the integrity of subsea pipelines through ILI verification helps mitigate the risk of incorrect data, reducing the likelihood of costly repairs, environmental incidents, and production downtime.

ART Data Corrosion Mapping

ART corrosion mapping detailing wall thickness measurement as captured by ARTEMIS, on a subsea pipeline.

Cost-Effective: ILI verification assessments offer a cost-effective means to monitor previously ILI identified defects. By strategically scheduling inspection campaigns to focus solely on the areas of interest, pipeline operators can accurately calculate corrosion rates and make informed decisions regarding maintenance strategies.

 ILI Verification on Subsea Pipelines

Pipeline operators often rely on intelligent internal pigging tools for subsea pipeline in-line inspections (ILI). These tools play a crucial role in generating detailed ILI data necessary for assessing pipeline integrity and calculating remaining life.

However, despite their advanced capabilities, decisions based solely on this data can carry significant financial implications and pose risks of production loss, especially in subsea and offshore environments.

Subsea pipelines pose a significant challenge to the accuracy of ILI tools. These tools encounter harsh conditions, such as high pressures and corrosive environments, that can impact their reliability and performance. As a result, there is a risk that the inspection data provided by these tools may be inaccurate.

Subsea Pipeline Inspection with TSC Subsea ARTEMIS
ILI Validation of Subsea Pipe with vCompact

Inaccurate data could result in incorrect pipeline condition assessments, leading to misinformed maintenance, repair, or replacement decisions.

Pipeline operators often choose ILI verification or validation assessments to address accuracy concerns and mitigate risks. These assessments involve conducting a secondary inspection using an external method to validate the findings of the initial inspection performed by internal pigging tools.

By comparing the results from both inspections, operators can gain confidence in the accuracy and reliability of the data, thus enhancing their decision-making process.


Case Studies

Through Coating Wall Thickness Inspection for ILI Verification

Beach Energy Ltd contracted TSC Subsea to carry out a wall thickness inspection through coating on the 20 in pipeline. The inspection was to determine the size and depth of corrosion which had been identified during a previous In-Line Inspection (ILI).

4” of Coating no Match for ART and ARTEMIS

The purpose of the inspection was to measure effective steel thickness through 4 inches of pipeline insulations made of Glass syntactic polypropylene and injection moulded polypropylene. Scanning operations were carried out at 2000 meters water depth.

Inspecting Concrete Weighed Pipes with SPECTA

TSC Subsea was contracted by a client to carry out wall thickness assessment of Condensate Export Pipeline (CEP) and Pipeline End Manifold (PLEM) without removing the protective concrete weight coat (CWC).

See all case studies

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