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The multi-year aerial survey improves the British Columbia Energy Regulator’s (BCER) understanding of the potential for abandoned well leaks and the long-term risk of methane leaks at decommissioned wellsites, while providing well integrity oversight.

DATE ISSUED: May 27, 2024

EFFECTIVE DATE: May 27, 2024

A multi-year aerial survey of 1,221 decommissioned wells in northeast B.C. between 2017 and 2023 found less than one per cent had a confirmed methane leak. The aerial surveys were conducted using a methane detector mounted on the underside of a helicopter, flying at 90–150 metres (300-500 feet) above ground level. The methane detector uses lasers directed downwards to illuminate an area on the ground and is reflected back to the detector. Where methane is present in the path of the beam, the reflection is weaker due to absorption of the laser. This survey method allows easier access to sites in very difficult and inaccessible terrain. It’s fast, cost-effective and can detect very low concentrations of methane.

Wells were selected for inspection using a variety of measures, including legacy wells, wells with a known surface casing vent flow or wellbore integrity history, over-pressured zones, sour gas (H2S) content, surface casing set depth or the presence of an open hole abandonment plug. Of the 1,221 aerial surveyed wells, 25 had initial indications of methane leaks. Subsequent investigations of the indicated sites, through ground inspections, confirmed six abandoned well leaks – or less than one per cent - 10 with no methane leaks with nine currently under further investigation. Through this work, the BCER continues to explore emerging technologies and utilize the latest science to effectively manage energy resource activities including well integrity oversight.

More information on the aerial methane survey, including a map and details of each annual survey, can be found in the summary report (pdf). The BCER intends to continue its aerial survey program in 2024.

If you have any questions regarding this Information Update or the report, please contact:

Dave Fukumoto
Engineer, Drilling and Production
BC Energy Regulator