Monitoring Pipeline Movement & Bending Strain: Fiberbuilt’s IMU Pigs

Pipeline geohazards are naturally occurring, human-triggered, or construction-related threats heavily influenced by weather, outside forces, and the earth’s movements. The increase in extreme weather events in recent years—and the related landslides, subsidence, and floods—has created mounting challenges for pipeline operators and regulators alike. Over the past few years, the Pipeline and Hazardous Materials Safety Administration (PHMSA) has increased its focus on managing geohazards for pipeline operators, resulting in several advisory bulletins. These bulletins suggest pipeline operators incorporate geohazard risk assessments into their integrity management programs. The increase in geohazard-related incidents has also led PHMSA to identify several pipeline failures related to geohazards.

One notable incident involved a hazardous liquid pipeline near Houston, Texas, which experienced a significant loss of containment in May of 2021.  An estimated 640 barrels of gasoline spilled into the nearby Green Bayou, causing significant disruption to nearby metropolitan areas. After investigations were conducted, the operator determined that earth movement and progressive ground shifting had contributed to the break [Source: PHMSA].

This incident, and others like it, highlight the need for more frequent IMU (Inertial Measurement Unit)- equipped inspection and analysis of pipeline movement and bending strain. ILI tools are known by pipeline integrity and geohazard professionals as the go-to source for measuring pipeline bending strain and are critical inputs for determining pipeline movement over time. However, conventional ILI methods are expensive, infrequent, and operationally complex to execute, limiting their frequency. The extended intervals between full-scale ILI combo tool inspections (five years for liquid pipelines and seven years for natural gas pipelines) result in inevitable knowledge gaps, leading operators to make decisions based on past rather than current data. Prioritizing decisions based on past data may not effectively keep pace with the rate of ground movement around active pipelines—and the potential issues that could arise from earth shifts.

Current Gaps IMU Inspection Using ILI Combo Tool Platforms

IMU data has historically been incorporated into ILI combo tool platforms to map important pipeline trajectory data, such as bending strain and pipeline movement. IMU data inputs deliver critical insights for monitoring geohazard threats. However, the high cost and infrequency of in-line inspections using these advanced combo tools limit the use of IMU inspections for more frequent geohazard monitoring.

Expense

Operators hire third parties to conduct ILI combo tool runs and interpret the data collected. The degree of specialization of ILI tools prevents operators from executing these runs themselves. Additionally, to prepare for ILI tool runs, pipelines require thorough cleaning to remove paraffins and other debris buildup that could interfere with the ILI tool’s sensitive equipment. Cleaning regimens are usually carried out in stages, requiring substantial time and operational investment from the operator and potentially third-party cleaning crews. When the pipeline has completed pre-inspection cleaning and is ready to undergo an ILI run, operators often adjust the flow rate of the line to ensure a specific speed window for accurate data collection, sacrificing productivity. Finally, additional investment is required to interpret the post-run data before actionable insights can be collected. While operators would benefit from IMU inspections at more frequent intervals to monitor changes in their pipeline’s profile, frequent data collection via combo tools can quickly become cost-prohibitive.

Infrequency

Inspections with ILI combo tools are typically conducted every five years for liquid transmission pipelines and every seven years for gas transmission pipelines. These inspections provide valuable insights for metal loss and crack detection; their high cost and complexity limit the frequency of IMU data runs, leaving operators with long gaps between inspections. This is problematic for geohazard monitoring, where more frequent data collection is potentially important to address risks such as ground movement and positional shifts of the pipeline.

Operational Complexity

Running ILI combo tools requires significant resource allocation. AGMs (above-ground markers) must be deployed, which require costly land surveys to be conducted. The operator must coordinate with third-party crews for cleaning, inspection, and data collection and interpretation, adding substantial time, cost, and effort.

Fiberbuilt addresses the pain points of significant cost, infrequency, and operational complexity through the introduction of its innovative IMU Inspection services. This platform is a cost-effective solution for geohazard monitoring, enabling easy, frequent, and low-cost inspections with minimal disruption to operations.

What is the Fiberbuilt IMU Inspection Mapping Pig?

The Fiberbuilt IMU Inspection Mapping Pig is an easy-to-use, single-body inspection pig that launches and receives like a standard cleaning pig. It collects precise data to calculate bending strain and track pipeline movement. Unlike complex ILI combo tools, the Fiberbuilt IMU Pig’s simple approach enables it to be self-deployed by the operator.

The tool’s modest configuration allows pipeline operators to gather IMU data easily and efficiently without the need for third-party crews, AGMs, or pre-inspection preparation.

The Fiberbuilt IMU Pig can travel through pipelines at speeds of up to 40 feet per second without the need for flow adjustments or even pre-inspection cleaning. It effectively operates across a variety of pipeline mediums, including steel, poly, and fiberglass compositions, and can easily navigate diameter changes.

One of the standout features of IMU Pig is its precise detection of pipe welds and joints. Its advanced sensors can detect the location of pipe joints without odometer wheels, gathering reliable positional data that facilitates run-over-run comparisons. The accuracy of Fiberbuilt’s run-over-run analysis allows operators to observe changes over time in the profile of their pipeline, such as movement or shifts, with extreme accuracy.

Exploring the Value & Benefits of Fiberbuilt’s IMU Platform 

The Fiberbuilt IMU Pig also collects crucial in-service operating data, including temperature, velocity, and pressure profiles, establishing a solid foundation for future comparisons. Its ability to mimic the ambient flow speed conditions of the pipeline ensures accurate results while minimizing downtime. Because the tool requires no pre-inspection preparation, it can operate and collect data in dirty pipelines.

By making IMU inspections more accessible and affordable, the Fiberbuilt IMU Inspection Mapping Pig empowers operators to increase inspection frequency and affordably monitor timely geohazard risks.

Case Study: Upstream Pipeline IMU Inspection Successfully Navigates Extreme Liquids Accumulation

An upstream operator managing an 8-inch natural gas pipeline encountered difficulties monitoring for geohazards due to expensive ILI combo Tools. To further complicate inspections, extreme liquid loading, and elevation changes were present. The line, situated in a valley, required daily pigging to remove liquids. The presence of multiple ditch features in the terrain created many opportunities for both ground and pipeline movement, as well as liquid accumulation in the pipeline.

Fiberbuilt’s IMU Pig successfully navigated through the pipeline, even with extensive liquid buildup. The Fiberbuilt IMU Pig delivered critical insights on pipeline bending strain despite the challenging conditions. As a result, the operator has asked for more IMU inspections from Fiberbuilt.

Case Study: IMU Inspection Helps Operator Defer Costly Integrity Site Visit

A different upstream operator faced challenges inspecting a 3-inch natural gas pipeline prone to geohazards. Hydrate accumulations and other debris buildup further complicated inspections in this pipeline. Because of the pipeline’s small diameter, traditional ILI methods were too expensive relative to its revenue potential, making it economically unfeasible to inspect for pipeline movement.

Fiberbuilt’s IMU Pig provided an affordable solution for the operator that delivered critical, yet economical, insights. The tool, which successfully operated at flow speeds of around 30 ft per second, identified strain-related features to monitor, and allowed the operator to continue safe operation of the pipeline.

The data collected from the IMU inspection avoided the necessity of a full-scale field visit from a geohazard professional, which would have introduced significant expense and complexity by requiring a ground survey. Instead, the IMU inspection provided direct measurements of pipeline bending strain. The success of the project has led to several more IMU inspections in critical geohazard locations.

Integrating IMU Inspections Into Your Pipeline Integrity Management Program 

Fiberbuilt’s IMU Inspection Mapping Pig alleviates many of the challenges present with traditional IMU pipeline inspections using ILI combo tools, offering a cost-effective, practical geohazard monitoring solution that operators can self-deploy with no line preparation. It contains none of the cost or logistical limitations associated with conventional ILI combo technologies and requires no specialized equipment, services, or additional personnel. In fact, as easily as an operator can deploy a standard cleaning pig, they can deploy Fiberbuilt’s highly accurate, single-body IMU platform.

While advanced ILI combo tools, such as MFL tools, can effectively measure pipeline movement through integrated IMU capabilities, the focus of these runs is primarily for anomaly detection, such as metal loss or crack features. These complex tools can require flow adjustments to perform effectively. Alternatively, the Fiberbuilt IMU Pig travels through dirty pipelines without adjusting the existing flow. The tool is purpose-built for highly accurate IMU inspections and precise run-over-run comparisons that allow operators to observe changes over time in the position of the pipeline—something that ILI combo tools cannot do economically.

Through this valuable inspection platform, operators can proactively monitor pipeline movement and bending strain, an important variable within a comprehensive geohazard management program. The actionable data allows operators to make more informed decisions and effectively deploy their integrity budget.

Fiberbuilt Pipeline has completed numerous successful field runs that demonstrate the widespread benefits of its IMU Inspection Mapping Pig services. Get in touch today and learn how this valuable service benefits your existing geohazard management program.