Mitigating Hydrogen Blistering in Sour Gas Pipeline through Inline Inspection

Project overview

Our client wanted to increase the maximum operating pressure (MOP) of its pipeline to meet market demand. They also had a secondary goal of expanding into new markets, only made possible by boosting throughput. Given that this pipeline transported highly corrosive sour natural gas, a comprehensive inspection was essential to ensure integrity and safety before increasing the flow.

Inline Inspection

This free-swim pipeline was situated in the Grande Prairie region, approximately 10 kms long and 6” in diameter. UPP used our 6” UXD Inline Inspection Tool to get the job done efficiently and safely. All of our small multi-tools include MFL (Magnetic Flux Leakage), CAL (Caliper), and IMU (Inertial Measurement Unit) capabilities, typically reducing inspection costs by about 30%.

Analysis results

The inspection revealed over 6000 metal loss features, with strong signals indicating hydrogen blistering. Standard MFL-A tools have a hard time detecting Hydrogen blistering, so our client sought further clarification on our findings. They simply were not expecting that one little tool could do so much. A third party verified our our results, confirming the presence of hydrogen blistering. 

Client result

Thanks to our client’s smart decision to analyze the pipe, they could address the blistering issues and ultimately avoided a potential explosion or rupture when they finally did increase MOP on the pipeline.