GE O&G Completing Oil Pipeline Inspection for TransCanada

GE Oil & Gas' PII Pipeline Solutions group is completing its largest pipeline inspection project by helping TransCanada evaluate the condition of an 864-kilometer (537 mile) portion of a natural gas pipeline in Canada. This part of the pipeline, which covers a span equivalent to the distance between Paris and Berlin, needed to be inspected prior to being converted to carry crude oil as part of the Keystone Oil Pipeline.

TransCanada is converting its 34-inch, Mainline gas pipeline between Burstall, Saskatchewan and Carman, Manitoba as part of TransCanada and ConocoPhillips' joint Keystone Oil Pipeline project. The initiative will allow crude oil to be transported to U.S. Midwest markets at Wood River and Patoka, Illinois and to Cushing, Oklahoma.

The converted pipeline will transport liquids at its approved operating pressure of 880psig (6,067kPa). To ensure optimal availability of the converted pipeline, TransCanada first had to make sure it was free of stress corrosion cracking (SCC) that could potentially lead to leaks.

TransCanada turned to GE Oil & Gas' PII Pipeline Solutions division, which operates the industry's most advanced ultrasonic pipeline inspection tools used for crack detection. Headquartered in Houston, GE's PII Pipeline Solutions operates an integrated engineering services center in Calgary to support TransCanada and other Canadian pipeline operators.

Between October 2008 and March 2009, GE's field team performed crack-detection inspection runs in three segments of the natural gas pipeline of 294, 315 and 255 kilometers in length, respectively.

"GE was selected by TransCanada because we were the only company with both the experience in using ultrasonic tools for crack detection and the resources to manage this critical project's scope and technical requirements, particularly the need to deploy multiple tools over such a vast distance," said John Bucci, general manager for GE Oil & Gas' PII Pipeline Solutions business.

The project's scope and schedule requirements meant that GE needed to simultaneously deploy several types of in-line inspection (ILI) tools, also known as "pigs." Prior to deployment, TransCanada had to develop a special pipeline manifold to accommodate all the tools and ensure that no air bubbles were left in the line. A total of eight tools were dispatched in section 1, and seven tools in section 2. Six of those were batching tools.

TransCanada's most serious challenge was the need to control a 3-km batch of fluid (in the winter diesel-like Frac Fluid is used) in a given pipeline segment to ensure GE's ILI tools could move at a consistent speed needed for accurate data collection.

To help TransCanada overcome this challenge, GE deployed its UltraScan™ Duo, the first ultrasonic "smart pig" to utilize phased array sensors to search for multiple types of cracks and other microscopic flaws in just one run of the line. The Duo's phased array sensor system was originally developed by GE Healthcare for use in hospital imaging systems but later adapted to evaluate the condition of pipelines.

The UltraScan Duo's increased speed, combined with its ability to detect smaller flaws than conventional crack detection tools, helped TransCanada minimize the time needed for the inspection project and will increase confidence levels once the inspection results are analyzed.

Canada's National Energy Board, which sets regulations for the country's pipeline operators, is reviewing the conversion project and the results of GE's UltraScan Duo application.