iTOUGH2-EOS7C model used to analyze multiphase flow and underpressured shale at the Bruce Nuclear Site, Ontario, Canada

Hydraulic testing has revealed dramatic underpressures in Paleozoic shales and carbonates at the Bruce nuclear site in Ontario. Although evidence from both laboratory and field studies suggests that a small amount of gas phase methane could be present in the shale, previous studies examining causal linkages between gas phase and the underpressure have been inconclusive. To better elucidate processes in such a system, we used a highly simplified 1-D representation of the site to test, using iTOUGH2-EOS7C, the effects of various factors on the evolution of gas phase methane and pressures within the system. Heterogeneity was represented using three stratigraphic regions with distinctly different capillary pressure characteristics and, [...]