MONDAY, MARCH 10, 2014
An X-ray machine used to detect fractured bones is being souped up to give the same treatment to fractured pipelines in the crushing depths of the ocean.
Engineers from General Electric's Healthcare and Oil & Gas divisions are teaming up with Oceaneering International and BP to develop an X-ray machine that can check for cracks and corrosion in underwater pipelines.
The goal is to meet new challenges for assessing pipeline integrity, as oil and gas exploration pushes deeper into the ocean.
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This video from GE explains how engineers are adapting an X-ray detector to withstand the ocean's depths. |
"I think about preventative healthcare—seeing cancer before it's Stage Four," said Karen Southwick, a mechanical engineer for GE Healthcare. "With this, we're seeing pipe corrosion before it's pipe breakage."
Subsea pipelines are often situated 10,000 feet deep, with pressure reaching more than 4,400 pounds per square inch (or 300 atmospheres) and the temperature staying around 40°F.
Oh yeah, and it's pitch black down there.
The X-ray could also be used to detect foreign objects, pipeline blockages and valve operational issues, the team says.
Squish-proof Electronics
The team took apart GE's medical X-ray detector and put it back together inside a high-tech, durable case designed to protect it from water and pressure.
"You've got to protect the electronics," said Dan Scoville of Oceaneering. "Anything with air in it would be squished."
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| GE |
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"You don't know something's wrong, and then you see it," said a GE mechanical engineer. "Whether it's a small spill or a catastrophic one, this is hopefully preventing that." |
The detector was then put inside a larger machine that attaches to a deep-sea submersible rig. The rig latches around the pipeline, taking incremental images as it slides down the length of the pipeline.
Testing 10K Feet Deep
The equipment includes a Digital Detector Array (DDA), a delicate glass the size of a computer screen that produces the radiographic image, and fragile electronics.
Radiography is a powerful non-destructive testing technique that enhances the contrast, measurement and magnification in instant radiographic images, according to Oceaneering.
"People didn't really think that radiography would work subsea," said Scoville.
Using the DDA allows for live data collection and analysis, covering multiple thicknesses and pipe sizes in a single exposure without the need to remove coatings. The images can be relayed instantly using a fiber-optic link to a topside monitoring and data collection system.
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| Oceaneering International |
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Radiography is a powerful tool for non-destructive testing, says Oceaneering.   |
The subsea X-ray detector could soon be sent deep into the ocean, as it has performed well in lab tests using a pressure chamber that simulated 10,000 feet of pressure.
"This is not what we normally do. X-rays are giving us insight," Southwick said. "You don't know something's wrong, and then you see it. Whether it's a small spill or a catastrophic one, this is hopefully preventing that. Ideally, we will be able to have data for every pipeline that's in the water."
Scoville added: "It's all an adventure. We are going somewhere we don't go every day."
Tagged categories: BP; Coating failure; Coating inspection; Corrosion; Laboratory testing; Oil and Gas; Performance testing; Pipelines; Quality Control; Research
