Ground movement measurements and pipelines: how satellites are providing early warning

With transmission pipelines buried safely underground, they’re largely protected from potential damage. But, as we’ve seen in previous blog posts, pipeline operators still have to protect against such issues as corrosion, unauthorized digging, floods and more.

Some dangers, though, are less obvious and harder to anticipate, such as geohazards, which include gradual ground movement of slopes, subsidence and landslides.

When the ground surrounding a pipeline moves slowly but continually, it puts stress on the pipeline and, over time, increases the risk of damage to the materials. Fortunately, pipeline companies can use satellite-imaging technology to detect and monitor ground movements as small as a few millimetres per month – long before they create enough force to compromise the pipeline.

MDA is a Canadian company that uses satellite-imaging technology to help pipeline companies monitor for ground movement. To learn more, we spoke with Mauro Sartori, MDA’s Business Development Manager for Energy and Mining.

Mauro explained that each satellite image typically covers an area of about 50 kilometres by 50 kilometres, so, even though a pipeline might be thousands of kilometres long, it’s possible to monitor large portions of the right-of-way to detect and monitor problem areas.

“The satellite images can cover large areas – detect movement where you might not even know it, and also measure the amount of movement,” Mauro said. These satellite measurements, along with other measurements from ground-based instruments are analyzed by geotechnical engineers to assess the risk to the pipeline; action can then be taken to reduce the stress on the pipeline and thereby reduce risk of pipeline problems.

The technology that MDA uses is called interferometric synthetic aperture radar (InSAR) analysis. “This analysis calculates the change in distance from the satellite to each ground pixel based on the change in phase of the reflected radar signal between two images taken 24 days apart,” said Mauro.  “The radar wavelength is five point six centimetres and by measuring the phase, one can measure fractions of a wavelength.  The result provides a high density of independent measurements, over large areas, with high accuracy.  In addition, InSAR is able to provide a time series history of each point of movement over a number of months and years to show changes in motion over time.”

Satellite monitoring of ground movement

MDA’s RADARSAT-2 radar satellite can measure small amounts of ground movement over large areas to help assess pipeline risks. Measurement using InSAR analysis is one of the many tools available for the industry’s management of pipeline infrastructure. (RADARSAT is an official trademark of the Canadian Space Agency)

One more tool for safety

Pipeline companies use satellite monitoring in conjunction with other monitoring tools, such as Geographic Information Systems (GIS), borehole instrumentation, GPS systems, surveying and strain gauges. The unique power of satellite InSAR monitoring lies in the ability to measure small movement, looking over very large areas, on a regular basis, without sending personnel to the field.  MDA has been providing this service to the oil and gas, and mining industry for over 20 years, and is now gaining use in the pipeline industry as a valuable tool to help maintain the integrity of pipeline systems.

An all-Canadian solution

MDA designed and built the RADARSAT-2 satellite, which is a Synthetic Aperture Radar (SAR) satellite that uses microwaves and special processing to create high resolution images. The SAR satellite can capture images in darkness, and independently of weather events such as cloud and rain, providing a reliable source of information for monitoring the entire planet. The satellite data is being used across the world to measure ground movement, map floods, identify deforestation, track iceberg movement, map ice thickness, detect ships, map oil on water, and more.

For the pipeline industry, it is proving a valuable way to measure where the ground is moving and how much. It can even be used to identify areas where the ground is not moving, in order to find suitable areas for pipelines to be routed.

Watch for future posts as we continue to explore more of the technologies being developed to help make pipelines safer and more sustainable.

The Canadian Energy Pipeline Association represents Canada’s transmission pipeline companies who operate approximately 119,000 kilometres of pipelines in Canada. In 2015, these energy highways moved approximately 1.2 billion barrels of liquid petroleum products and 5.4 trillion cubic feet of natural gas. Our members transport 97 per cent of Canada’s daily natural gas and onshore crude oil from producing regions to markets throughout North America.