Navigating Pipeline Integrity: CMI vs. ILI in Comparative Case Study

Integrity Assessment with CMI Technology

In the rapidly evolving field of pipeline integrity assessment, the Current Magnetometry Inspection (CMI) method has emerged as a revolutionary technology, distinguishing itself from traditional In-Line Inspection (ILI) tools. Developed through extensive collaboration with industry leaders, CMI has successfully inspected thousands of kilometers of pipelines worldwide, setting new benchmarks for efficiency, safety, and cost-effectiveness in pipeline surveillance, especially for unpiggable pipelines.

Unlike conventional methods that often require operational interruptions and extensive preparations, CMI offers an innovative approach by allowing in-service inspections of buried pipelines without soil removal, operational disruptions, or the need for making pipelines piggable. This method is particularly advantageous for inspecting pipelines that are traditionally considered unpiggable due to their inaccessible locations or complex geometries. With CMI, operators can perform comprehensive assessments over vast areas, covering an average of up to ten kilometers daily.

CMI's non-invasive technology works remotely from the earth's surface, leveraging advanced electromagnetic survey techniques to detect anomalies in the pipeline wall. These anomalies result in measurable changes in the magnetic field, which CMI's high-tech equipment and sophisticated algorithms can accurately interpret to provide valuable insights for integrity and mapping assessments.

One of the key benefits of CMI is its ability to detect metal loss in the pipe wall, offering a "no-dig" solution that operates without the need for pipeline shutdown during inspection. This aspect alone makes it a cost-effective and reliable choice for challenging pipeline diagnostics from above ground. Additionally, CMI is known for its flexibility, capable of inspecting all types of buried pipelines made of ferromagnetic material, regardless of the transported product.

The development and application of CMI represent a significant leap forward in the domain of pipeline inspection, providing a unique, patented, and globally recognized solution. By overcoming the limitations faced by modern ILI tools, CMI is paving the way for safer, more efficient, and environmentally friendly pipeline management practices.

For more detailed insights into the innovative world of CMI and its broad spectrum of applications, especially exploring the technical background, click


  • CMI uses electromagnetic fields to detect anomalies in pipelines from above ground, making it non-invasive. It's particularly effective for assessing pipelines that cannot be inspected by traditional methods due to accessibility issues or operational constraints.
  • ILI involves inserting inspection devices (commonly referred to as "pigs") into the pipeline. These devices travel with the flow of the product, using technologies like magnetic flux leakage (MFL) or ultrasonic testing (UT) to inspect the internal condition of the pipeline.


  • CMI is suited for inspecting pipelines that are difficult or impossible to pig, such as those lacking pigging infrastructure, in inaccessible locations, or with complex geometries.
  • ILI is widely used for routine maintenance inspections and is applicable to pipelines that can accommodate pigging devices, offering detailed internal diagnostics.


To provide a comprehensive understanding of the benefits associated with Current Magnetometry Inspection (CMI) and In-Line Inspection (ILI) technologies, here's an overview of their key advantages in enhancing pipeline integrity management.


  • Non-invasive and does not require operational shutdown.
  • Capable of inspecting unpiggable pipelines.
  • Provides a quick overview of pipeline integrity with the ability to cover large distances quickly.


  • Offers detailed information on the internal condition of the pipeline, including precise measurements of corrosion, wall thickness, and cracks.
  • Technologically diverse, with various tools available for different inspection needs.


While both Current Magnetometry Inspection (CMI) and In-Line Inspection (ILI) offer significant advantages in pipeline integrity management, each method comes with its own set of limitations that are important to consider for optimal application.


  • May not provide as detailed data on internal conditions as ILI.
  • Effectiveness can vary based on the complexity of the network and depth of the pipeline.


  • May require pipeline shutdown and preparation for pig launching and receiving.
  • Not applicable to unpiggable pipelines or those with severe restrictions.

Key Considerations

  • Choosing between CMI and ILI depends on the specific needs of the pipeline system, including its accessibility, the level of detail required in the inspection, and operational considerations.
  • Integrating both methods can provide a comprehensive assessment by utilizing CMI for quick, extensive coverage, and ILI for in-depth analysis of identified anomalies.

Corrosion Assessment: Elevating Precision with CMI

The capability of Current Magnetometry Inspection (CMI) to deliver a comprehensive corrosion analysis marks a significant advancement in pipeline health diagnostics. Unlike conventional In-Line Inspection (ILI) methods, which primarily identify the presence of corrosion anomalies, CMI delves deeper, offering a nuanced understanding of these defects. This refined analysis is pivotal in distinguishing between static and active corrosion issues, revolutionizing how operators approach pipeline maintenance and budget allocation.

Unveiling Electrochemical Activity:

  • ILI identifies severe anomalies but lacks depth in understanding the nature of defects.
  • CMI extends investigations to assess if anomalies indicate ongoing electrochemical processes, determining active corrosion.
  • This analysis is vital for distinguishing between passive corrosion controlled by cathodic protection (CP) and active threats to pipeline integrity.

Strategic Pipeline Management:

  • CMI differentiates between active and passive corrosion, enabling informed prioritization of repairs.
  • Identifies defects requiring immediate attention, directing efforts and budgets towards mitigating critical issues.
  • Evaluates the effectiveness of CP measures with precision, highlighting areas needing corrective action.

Optimizing Budget Allocations:

  • CMI’s detailed corrosion analysis surpasses traditional inspection methods, informing strategic maintenance planning.
  • By understanding corrosion dynamics, operators can optimize budget allocations, focusing on actively deteriorating defects.
  • Resources are allocated to interventions with the highest impact on pipeline integrity and safety.

Comparative Analysis: Elevating Pipeline Integrity with CMI on a 90 km Pipeline

This case study of a 90 km pipeline underscores the technological distinctions and operational advantages of Current Magnetometry Inspection (CMI) over traditional In-Line Inspection (ILI). Through detailed examination, we reveal how CMI's superior methodologies offer more reliable, accurate, and comprehensive pipeline integrity assessments.

Spatial Accuracy and Feature Assessment

  • Spatial Accuracy Challenges with ILI: Throughout the 90 km span, ILI demonstrated spatial inaccuracies, with discrepancies reaching up to 20 meters from the actual pipeline position. Such variances introduce significant challenges in accurately pinpointing anomalies, complicating maintenance strategies and potentially leading to ineffective repairs.
  • CMI's Precision Mapping: Contrary to ILI, CMI showcased unparalleled precision in mapping the pipeline's course. This advanced accuracy enabled exact localization of anomalies, streamlining maintenance efforts by targeting specific sections in need of intervention without the ambiguity presented by ILI data.

Bend Angle and Radius Determination

  • ILI Limitations: A critical limitation observed with ILI across the 90 km inspection was its inability to accurately determine bend angles and radii. This shortfall restricts comprehensive understanding of pipeline geometry, which is essential for assessing structural integrity and planning corrective measures.
  • CMI's Comprehensive Geometric Insights: CMI, with its refined data collection techniques, accurately captured detailed information on bend angles and radii along the entire pipeline. This capability facilitates a deeper understanding of the pipeline's structural nuances, aiding in the precise planning of maintenance and reinforcing pipeline safety.

Corrosion Analysis and CP Efficacy

  • Electrochemical Activity Assessment with CMI: In instances where ILI flagged severe anomalies, CMI was deployed to delve deeper into the electrochemical nature of these defects. CMI's advanced diagnostics distinguished between active corrosion processes leading to metal loss and areas where corrosion had been effectively mitigated by cathodic protection (CP). This differentiation is crucial for prioritizing repairs based on the immediacy of the threat posed by active corrosion.
  • Strategic Pipeline Management: By leveraging CMI's nuanced corrosion analysis, operators gained insights enabling them to prioritize critical repairs and allocate resources effectively across the 90 km pipeline. This strategic approach ensures that maintenance efforts are concentrated on sections where active corrosion poses a real threat, enhancing the pipeline's overall safety and longevity.

The comprehensive evaluation of a 90 km pipeline utilizing both CMI and ILI technologies highlights CMI's superiority in spatial accuracy, geometric assessment, and detailed corrosion analysis. CMI's ability to provide precise location data, accurate geometric details, and in-depth corrosion activity insights presents a significant leap forward in pipeline integrity management. By enabling more informed decision-making, CMI supports optimized maintenance planning and resource allocation, affirming its invaluable role in the future of pipeline inspections.


As our comprehensive case study demonstrates, Current Magnetometry Inspection (CMI) technology stands at the forefront of pipeline integrity assessment, eclipsing traditional In-Line Inspection (ILI) methods in adaptability. Through detailed analyses and real-world application on a 90 km pipeline, CMI has proven its unmatched capability to offer deeper insights into pipeline health, especially for those deemed unpiggable due to their challenging locations or complex geometries.

CMI's advanced electromagnetic survey techniques have opened new doors for pipeline operators, allowing for in-service inspections that do not disrupt operations or compromise safety. By providing a non-invasive, accurate, and comprehensive approach to detecting anomalies and assessing corrosion, CMI empowers stakeholders to make informed decisions, prioritize maintenance, and allocate resources effectively, ensuring the longevity and reliability of their infrastructure.

The future of pipeline inspection lies in technologies that can adapt to the evolving demands of the industry while offering solutions that are both economically viable and environmentally responsible. CMI represents a significant leap toward achieving these goals, setting new benchmarks for what is possible in pipeline integrity management.

Take the Next Step with EMPIT

If your operations involve pipelines considered challenging or impossible to inspect with traditional methods, it's time to explore what CMI can do for you. Don't let the term 'unpiggable' limit your maintenance strategies or compromise your pipeline's safety and efficiency. Reach out to our EMPIT experts today, and let us show you how our cutting-edge CMI technology can secure your unpiggable pipelines, enhance your operational safety, and optimize your maintenance budgets.

Discover the full potential of your pipeline assets and take a proactive stance towards their integrity and safety. Contact EMPIT now to schedule a consultation and see firsthand how our innovative solutions can transform your pipeline inspections.

Empower your pipeline management with EMPIT's expertise and ensure your infrastructure's safety, reliability, and longevity. Reach out to us, and together, let's redefine the standards of pipeline integrity assessment for a safer, more efficient future.

Frequently Asked Questions (FAQ)


What is Current Magnetometry Inspection (CMI)?

CMI is a non-invasive pipeline inspection technology that uses advanced electromagnetic survey techniques from the earth's surface to detect anomalies in pipeline walls. It is especially beneficial for inspecting unpiggable pipelines without the need for operational disruptions or soil excavation.

How does CMI differ from In-Line Inspection (ILI)?

While ILI requires inserting a device inside the pipeline to gather data, CMI operates from above ground, using electromagnetic fields to detect pipeline anomalies. This fundamental difference makes CMI more adaptable for pipelines that cannot be inspected using traditional pigging methods.

What are the main advantages of using CMI?

CMI offers several advantages, including its non-invasive nature, the ability to inspect unpiggable pipelines, rapid coverage of extensive pipeline lengths, and operational efficiency as it doesn't require pipeline shutdown during inspection.

Can CMI detect all types of pipeline anomalies?

CMI is proficient in detecting corrosion and identifying areas of potential concern related to pipeline integrity. However, its ability to provide detailed data on internal conditions is not as extensive as that of ILI.

Is CMI technology applicable to all types of pipelines?

CMI is applicable to buried pipelines made of ferromagnetic materials, regardless of the product being transported. It is particularly useful for pipelines in inaccessible locations or with complex geometries that make traditional pigging methods impractical.

How does CMI contribute to strategic pipeline management?

By differentiating between active and passive corrosion, CMI allows operators to prioritize maintenance tasks effectively. It aids in identifying critical areas that require immediate attention, optimizing budget allocations, and enhancing pipeline safety and longevity.

What limitations does CMI have compared to ILI?

While CMI offers a broad overview and is efficient for rapid assessments, it may not provide the same level of detailed internal diagnostics as ILI. Its effectiveness can also vary based on the complexity of the pipeline network and the depth of the pipelines.

How can operators choose between CMI and ILI?

The choice between CMI and ILI depends on various factors, including the pipeline's accessibility, the level of detail required for the inspection, and operational considerations. Often, integrating both methods can provide a comprehensive assessment, leveraging CMI for extensive coverage and ILI for detailed analysis of identified anomalies.

What developments have been made in CMI technology?

CMI has seen significant advancements in electromagnetic survey techniques, allowing for more accurate anomaly detection and integrity assessments. Its application in pipeline inspections worldwide has set new benchmarks for efficiency, safety, and cost-effectiveness.

How does CMI impact environmental and operational safety?

CMI's non-invasive "no-dig" approach minimizes environmental impact and operational risks by allowing for in-service inspections. This ensures that pipeline integrity can be assessed without compromising safety or requiring extensive land disturbances.

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