Grant: Discovery Grants Program - Individual

This research addresses a critical societal question of our time: Does unconventional fuel development come at a greenhouse cost? Proponents of unconventionals frequently cite the reduced greenhouse footprint of the fuels as an advantage (gas in particular). However, recent high profile studies have shown that extraction and processing sites are heavy emitters of methane, due to leaks from aboveground infrastructure. Or, from wells. All unconventionals share the characteristic of being drilling-intensive, and wells are thought to be common failure points both during and after completion (cementing), and even after abandonment, and there is some concern that well failures may contribute heavily to overall site emissions. In particular, there is concern around wells that develop Gas Migration (GM), where gases flow up the well bore, along cement imperfections at the contact between cement and formation, to the surface. Up to 30% of wells may leak via GM, at rates as high as 200 cubic meters of methane. Some wells are known to allow GM from gas-bearing formations over 1000 m deep. Surprisingly, the contribution of GM to overall site emissions is unknown, in part because regulated GM tests do not measure release rate. Many provinces do not require GM testing of any sort, and even if they did, the testing methods are too coarse to identify anything less than moderate to severe cases. These coarse tests have generally shaped our understanding of GM, and our understanding about the geochemical and transport elements of this problem is proportionately coarse. Too little is known about: the pattern of GM expression at the surface (footprint of disturbance at surface, symmetry, transport pathways, geochemistry); the variability across different types of wells or soils; the degree to which natural methane production confounds detection (or creates false positives); or the fractional contribution of GM to overall site emissions. The proposed research takes on these questions. Addressing this leakage problem is important, as methane's greenhouse potential is 20 times that of CO2, and widespread development of unconventionals could significantly increase overall human methane emissions. This research will be done at abandoned and suspended well sites in Nova Scotia, and an active unconventional site in Saskatchewan. The initial two years of research will involve surveys to identify GM and understand its incidence. In subsequent years, the research involves in-depth study of wells with GM, establishment of sound accounting GM practices, and lastly building estimates of cumulative GM emissions to compare against known whole-site emission footprints recorded by my group. It is unlikely that energy companies will sponsor this research, but they will tolerate it being done onsite, so long as trusted researchers with an established track record of constructive collaboration are doing the work in a self-funded manner. My group is positioned well in this regard. There is a strong role for HQP in this project, and good possibilities for expansion of the research and HQP footprint via collaborations, which could expand its conceptual scope and/or geographic coverage. This work will build important knowledge related to environmental impacts and estimates of cumulative GM emission to the atmosphere, and will incorporate significant scientific challenge for student projects. The likelihood of societal impact from this project is strong. The results could alter the course of unconventional fuels development, could impact regulatory regimes, and could spur a pursuit of new technological solutions to GM in the energy industry, on GM or other leakage sources.