Editor’s Note: Opinions expressed by the author are his own.

My Hart Energy colleague Len Vermillion recently wrote about the historical importance of technology as the backbone of the oil and gas industry. I can relate to that, having spent several months writing a series of articles focused on the role that technology plays in the midstream pipeline sector.

I shouldn’t have been, but I was shocked by the strong responses I received from research centers, associations, operators, service companies and consultants alike. What’s not surprising is the tremendous amount of research and development attention centered on integrity management. It’s today’s buzzword for pipeline maintenance as we deal with an aging infrastructure and a rapidly expanding pipeline network that now stretches into more populated regions eager to take advantage of abundant low-priced supplies of petroleum products.

Pipelines remain the safest way to transport hazardous materials, but several deadly incidents have led to much greater scrutiny from the government, environmental groups and the public. As a result, operators and service providers have launched an intensive effort aimed at a zero-tolerance policy in maintaining safe systems.

To maintain the integrity, safety and efficiency of those extensive systems, operators increasingly partner with vendors that specialize in the inline inspection of pipelines, commonly referred to as pigging. Through the years, I learned many of the intricacies concerning “smart” pigging, including the benefits of ultrasonic testing, magnetic flux leakage (MFL) and other sophisticated procedures to inspect pipelines.

Every February, the Pipeline Pigging & Integrity Management (PPIM) conference is held in Houston. The event—now in its 31st year—had to be switched from a hotel to the George R. Brown Convention Center to accommodate its growing global audience of vendors and operators eager to display the latest inspection tools and learn how to deploy them. This year, a record of 3,100 came to the three-day event.

Considerable attention was directed at the introduction of the Evo Eclipse, a new tool designed and developed by NDT Global. It is being trial-tested by Marathon Pipe Line Co. in partnership with Kiefner & Associates of Columbus, Ohio. By successfully combining some previous technologies, the makers hope to be able to circumvent hydrostatic testing, the heretofore traditional protocol used to confirm safe operating parameters of pipelines. Hydrostatic testing is the historical go-to process to confirm these parameters, either for new pipelines to be put in-service or certifying pipeline safety for existing lines.

However, the benefits of hydrostatic testing stay in stark contrast with some of the concerns voiced by industry experts, including:

  • ·       Environmental impact due to the excessive amount of wastewater produced;
  • ·      Significant product loss during hydrostatic test operations;
  • ·       Concerns that the test might initialize new cracks or interconnecting existing cracks;
  • ·       Successful test parameters are confirmed only during the moment of the test, i.e. “snapshot,” and;
  • ·       Providing no information/location of existing cracks or anomalies for analysis and/or projection of integrity management programs.

Historically, MFL has been one of the primary methods utilized to detect corrosion, surface pitting, cracks and possible weld defects in steel (liquid) pipelines. Caliper pigs contain sensors able to locate potentially critical deformations along the pipe wall.  The new generation of “intelligent” pigs employ ultrasonic crack (UTC) and wall-thickness (UWT) technology using piezoelectric transducers to locate pipe defects. It’s the ability to combine some of these technologies into one device that can make a significant difference, experts say. 

In their Evo Eclipse white paper titled, “Measuring Crack Defects with Sub-Millimeter Accuracy,” NDT Global authors Dr. Thomas Hennig, technology advisor; Rogelio Jesus Guajardo, global manager of data analysis; and Dr. Michael Haas, physicist; assert that “Over the past 20 years, only minor developments and improvements in this area were offered to pipeline operators. The most significant enhancement was a move from bucket sizing to absolute depth sizing. After two decades of incremental improvements, technology-related limitations still prevent accurate sizing of defects.”

What Evo Eclipse claims to do is combine ultrasonic technology to inspect the pipeline and high-resolution crack robots (UCx) that measure the inside pipe wall thickness, particularly along the seam welds where most cracks are likely to occur.

“Higher-resolution tools, specialized sensors and measurement configurations address major flaw-measurement challenges: accurate depth-sizing, extended maximum crack depth sizing beyond the formerly known maximum crack depth of typically 4 mm (0.16 in.), through wall defects and measurement capabilities less susceptible to skew and tilt.”

The developers tout their technology, which started in 2016, as a combination of UCx and new analysis methodologies that together, provide for new inline inspection robots with a circumferential resolution of 5.0 mm (0.2 in.).

High-resolution robots, they said, offer increased crack depth-sizing accuracy and repeatability, enabling operators to judge where problems may occur later. “More importantly, they are an enabler for Enhanced Sizing methodology, allowing new ways to analyze data, which successfully overcomes existing depth-sizing limitations.”

Evo Eclipse sizing technology is said to result in accurate depth values for many flaws, typically below 0.88 mm (31 mil) tolerance. “A combination of different datasets, characteristics, and sizing methodologies allows highly accurate inspection with greatly reduced tolerances. Sub-millimeter accuracy for the entire range of flaws, including hook cracks, is now possible,” NDT Global suggests.

The company cites four areas of significant improvement that have led to “the technical evolution leading to the development of Evo Eclipse technology:

  • ·         Greater sensor density (with more channels);
  • ·         Greater onboard processing power;
  • ·         Greater onboard data storage capacity, and;
  • ·         Improvements in analysis methodologies, partly as the result of more and better data produced by the high-resolution robots.

One challenge the industry still must contend with is the difficulty to accurately measure tilted cracks. Detecting the types of crack is possible with today’s technology, but they can’t size them accurately. NDT Global said that it has overcome these remaining challenges in liquid crack-detection technologies.

“Instead of arranging clockwise and counter-clockwise sensors independently from each another, the new arrangement always combines a clockwise and counter-clockwise sensor as a pair. This allows recording a third type of signal, in addition to the conventional pulse echo and Enhanced Sizing information.”

What their new technology leads to the opportunity is that “Pipeline operators can now get a far more accurate understanding of their pipeline condition, without assuming the costs and risks of hydrostatic test inspection.”

However, there have been many times that the inline inspection (ILI) industry claimed that intelligent pigs could deliver, and as such eliminate the environmental impact of hydrostatic testing, with its assumed negative effect on pipeline integrity. But so far, the ILI technology presented has never been convincing enough to replace hydrostatic testing, with operators continuing to use hydrostatic testing in their inspection portfolio, and so does the governing agency, PHMSA (Pipeline and Hazardous Materials Safety Administration).

This time the results might be different. Marathon is a major pipeline operator, together with Kiefner & Associates, and has engaged in a series of tests which, if successful, could well deliver the proof that the Eclipse tool could be the answer. A series of tests, hydrostatic testing alternating with UTC and Evo Eclipse runs, might provide detailed information on the impact of hydrostatic testing, and at the same time deliver on a new and alternative inspection method which could provide the needed crucial data without the environmental impact while significantly reducing production loss.

The author would like to thank Dietmar Neidhart, former GM of Tuboscope for help with this article.