Detecting and pinpointing small leaks from problems such as corrosion or insecure flanges has remained difficult for the industry, because the leaks are not big enough to create the kind of events associated with larger leaks – orifice noise, temperature change and negative pressure waves – that are usually picked up by leak detection technology, including DAS. That is where Fotech’s research into ground displacement comes in.
“Over the course of time, as a leak remains undetected, it would soak the surrounding soil, and that soil will start swelling and increase in volume and size,” Peter explains. The hypothesis was that as the soil starts to expand it well bend or deform the fibre cable, creating strain, which can be detected by DAS. “Our research that formed the basis of our presentation shows very positive results that say yes, it can, and it can do it very accurately. “Our presentation was really quite novel for the audience and is very new and promising,” Peter continues.
“For the first time, we showed that DAS technology can also identify very small, very low rates of soil expansion that would be associated with very, very small and low rates of liquid leaking from the pipeline.”
Following the presentation, Fotech’s presence in the exhibition hall of Europe’s leading pipeline conference allowed industry leaders to follow up and find out more about how DAS technology can be applied to their assets.
Another theme that emerged from the PTC was industry-wide concern about illegal tapping and product theft from pipelines. The statistics are staggering. In Nigeria alone, 150,000-200,000 barrels of oil are lost to hot tapping per day. With barrels worth over $50 each or more, the losses are huge. Illegal tapping is also a problem across Europe, including over 100 hot taps in England in the last few years.
“The feeling was that everyone should be focusing on finding solutions,” says Peter. “And the technology that wins out will need to be a preventative technology rather than a reactionary technology.”
While the act of tapping from the pipeline itself takes a matter of minutes, the whole sequence of events leading up to a tap – approaching the pipeline, digging, and fitting tapping equipment – can be hours or days in the build up.Peter hopes that he can present at next year’s conference to show how DAS works to detect the events leading up to a tapping attempt.
“The earlier in that sequence of events you can detect this pattern of activity occurring, the more preventative you can be in your response,” Peter continues. “DAS is the perfect technology for this.”
In the meantime, Peter is already back in Fotech’s lab to continue ground displacement testing with non-linear models, which will more accurately depict real-life conditions. He aims to present the results of this second round of research in Cyprus at the European Workshop for Optical Fibre Sensors later this year.
Peter is also excited by the potential this application of DAS has outside the oil and gas industry. “The benefit of what we’ve shown is not just for leak detection in pipelines: if we can detect very small ground movements, it can ultimately be developed for avalanche detection, detection of geo-hazards such as landslides, earthslips, or for dam breaks. The technology has greater benefits for the safety of the human race, long term.”