BOW ISLAND, AB – With the help of some innovative technology, supplied by Tecvalco Ltd., ATCO helped a land owner find an elusive source of methane detected on their property. The technology, a Vapour Extraction Unit (VEU), is manufactured by MBW Inc., but sold by Tecvalco in Canada.
ATCO discovered methane during a standard line walk near Bow Island. They were checking the service line to a farmhouse built in 2012, and survey equipment detected methane readings of 30 to 50 LEL around the perimeter of the garage.
ATCO alerted the homeowners and began the process of identifying the source of gas. The first step was exposing their own service line from the main line to the house. After isolating and pressure testing the line, ATCO ruled out their service as the methane source.
Working with the homeowner, they exposed an old exploration well on the property which was located roughly 500 metres from the house. Again, they found no evidence of methane escaping from the exploration well.
At this point, a third-party testing company was brought in to perform isotopic identification on the gas coming out of the ground. The analysis revealed the gas was thermogenic or formation gas, but showed no markers for manmade or line gas. Extensive testing, sampling, digging, backfilling, and hard work had turned up nothing conclusive for the homeowners.
A magnetometer sweep of the area around the house (to see if there were any other unknown pipelines) had some minor hits and possible anomalies, but no pipelines were found.
Incidental evidence pointed towards an anomaly in the driveway, but not enough to justify a hydrovac excavation. As it happened, an ATCO representative had spotted the VEU equipment at the American Gas Association show the previous year. Determined to help the homeowner isolate the problem, the company contacted Tecvalco to investigate the technology, and Tecvalco had a unit brought in.
The VEU arrived on location in October 2017 and went to work drilling 25 bar holes around the site and then extracting gas. The process allowed the team to narrow down the leak location to a five-foot by five-foot area. In the area, the VEU was getting consistent levels of 40 ppm methane. The methane levels did not drop over the six-hour period that the unit was extracting gas from the area.
Confident that the source of the problem had been located, a hydrovac truck was brought in. Excavation revealed the top of a 40-year-old water well that had tapped into the Medicine Hat formation, but had never been properly capped off. Once exposed, the top of the well pipe showed 90 per cent methane in the air.
Amazingly, the location of the well pipe was within two feet of the area the VEU had identified as the “centre” of the leak.
Tecvalco Ltd. is a premier distribution and manufacturing company, with staff across Canada. Incorporated in 1980, the company has a history of being integral in the development of the energy industry in Canada. Recently, the company acquired key assets from Grit Industries Inc., including the 93,000 square foot manufacturing facility in North Battleford, Saskatchewan. Tecvalco also operates offices out of: Lloydminster, Saskatchewan; Rockledge, Florida; and has their head office in Niagara Falls, Ontario.
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