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Inline Inspection (ILI)

Inline Inspection Pigging and Data Analysis Services for Pipeline Integrity

Geometric Defect Location Screenshot
Technicians Performing ILI
Streamview Software Screenshot

MISTRAS’ free swimming and tethered combination inspection tools and high-resolution sensors help to ensure cost-efficient pipeline integrity through pigging and precise data management.

After being in operation for years, many pipelines undergo damages that cannot be detected from the outside, but these damages must be diagnosed to prevent further damages, potential revenue loss, and environmental concerns. Even if a pipeline shows no signs of damage, governmental and pipeline industry regulatory bodies often require inspections after certain years of operations.

In addition to our expansive asset protection solutions for newly-constructed pipelines, we also excel in offering solutions to ensure pipeline integrity. Our innovative inline inspection (ILI) tools and software improve how clients obtain and review essential pipeline integrity data, and have helped top energy companies save time and money while enhancing safety.  

Our systems identify and record all pertinent pipeline data, including:

  • Hardware
  • Girth Welds
  • Bends
  • Cracks
  • Metal Loss Defects, including Corrosion and gouging
  • Pipeline-Specific Geometric Features: Ovality, Dents, Body Wall Changes, etc.

Inline Inspection (ILI) Pigging Services

Inline inspections (ILI) evaluate pipelines internally for damages. MISTRAS performs ILIs using smart inspection tools called “pigs,” which move through a pipeline in free-swimming or tethered deployments. Smart pigs gather information on pipeline geometry, metal loss, bending, and cracking. After the inspection is completed, our pipeline integrity experts review and analyze ILI data with pipeline operators.

The MISTRAS team handles the inspection completely, from providing and executing the pigging process, to managing and analyzing the data the pig records. Inline inspection is a form of non-destructive testing (NDT), as pipelines are unaffected from the procedure. Free swimming and tethered inspections are used for different types of pipes, but produce the same quality results. Our inline inspection services include:

  • New Construction Caliper
  • Stand-Alone Geometry
  • Magnetic Flux Leakage (MFL) Metal Loss
  • Inertial Mapping Unit (IMU) for GPS
  • Combined Geometry, MFL, and IMU

Free Swimming Inline Pipeline Inspection

Free swimming inline inspection (ILI) tools are implemented for pipelines that flow and have launch and receive facilities. The pig utilized is not attached to an anchored source and moves independently within the line, among the commodity being transported.

Our single combination inspection tool combines all necessary recording instruments into the shortest body in the industry. With a compact yet effective design, only one run is necessary when collecting data during a free swim inspection. The Inertial Mapping Unit (IMU) supplies center-line mapping and 3-dimensional coordinates for features within a pipeline.

Another innovative aspect of our free swimming inspection is the Intelligent Gauge tool. This device identifies, quantifies and records any spots in the pipeline that could restrict an inline inspection tool. Our free swimming tools have inspected lines up to 300 miles in length.

Bi-Directional Tethered Inline Pipeline Inspection

Bi-directional tethered pigs are used for inline inspections (ILis) of pipelines that have no flow or lack launch and receive facilities, which are typically older generation pipelines. The tool is tethered to a nearby truck and enters and exits the pipeline at the same location.

The pig utilized in tethered inspections is our bi-directional Caliper tool, designed to inspect pipes that are incompatible with free swim techniques. The Caliper tool features on board transmitters and an inertial mapping unit, which communicate with Above Ground Markers (AGMs) and improve tool accuracy. High resolution calipers and odometers measure deformations within a pipeline and distance. Hall effect sensors provide a faster logging speed and increased accuracy for more precise data reporting.

By integrating multiple inspection and recording instruments into bi-directional combination tools, we can gather all relevant inspection data in a single run, compared to the multiple runs completed by multiple contractors that is common throughout the industry.

Wireline solutions are necessary for pipes with no launch facilities or have flow problems, but a multitude of other factors could qualify a pipeline for tethered inspection. Temperature limitations of the line and economic considerations could be responsible. Bends and un-passable tees that restrict free swimming tools may also determine the necessity of a tethered inspection.

Our bi-directional tethered inspection tools have inspected a daily average of 3,000 meters but have reached up to 6,000 meters in a single day.

Tethered Inspection services include:

  • Geometry
  • Magnetic Flux Leakage (MFL) Metal Loss
  • Inertial Mapping Unit (IMU) for GPS
  • Combined Geometry, MFL and IMU

Inline Inspection Data Management and Analytics

Once the pigging is complete, our work does not stop there. Our Data Analysis group analyzes inspection data using proprietary algorithms within purpose-developed data management software and from the inspection tools’ tri-axial sensors and geometry functions.

The inspection software was designed with operators in mind and serves as a second set of “eyes” within a pipeline. It performs bending strain analysis, run-to-run comparison, and real time dent strain circulation. Defect visibility is enhanced, as it displays and analyzes the whole line in both directions. It has easy identification of the turnaround point and can reload and flip the run. The software also aligns data and demonstrates faster reporting. It is designed to accommodate larger diameter tools and works compatibly with all of our free swimming and tethered pigs.

Once the findings are reviewed, MISTRAS’ pipeline integrity experts work with our clients to determine the appropriate course of action to remedy any damages or potential issues that were found.

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