Image: Joey Podlubny/JWN This article is part of the Fall 2018 edition of the Journal of the Canadian Heavy Oil Association. The waterflooding of heavy oil reservoirs in the Western Canada Sedimentary Basin (WCSB) is challenged by adverse mobility ratios from high oil viscosities. Modification of injected water flow vectors via downspacing and/or the implementation of line drive injection patterns has resulted in strong performance in many pools (Beliveau, 2009). Lab studies with high-perm sand packs and high-viscosity oils (Bryan and Kantsos, 2009; Wu et al, 2011) have demonstrated strong performance of chemical floods following waterflooding via a flow diversion mechanism, even though the chemicals employed might classically be expected to reduce interfacial tension. Many heavy oils were created from lighter oils by microbial action (Larter et al, 2008; Wenger et al 2002). Heavy oil pools both globally and in the WCSB continue to host communities of microbes who respire anaerobically by transforming portions of oil to lighter and heavier compounds. Lab studies with reservoir fluid samples have shown that microbial communities go dormant when reservoir conditions change, often due to exhaustion of a key microbial nutrient (see also Head et al, 2006), and that the microbial community will […]
