Author's reply to discussion of interrelationship of temperature and wettability on the relative permeability of heavy oil in diatomaceous rocks

Abstract

Dietrich's discussion is wide ranging. We agree that oil recovery from diatomite rocks is influenced by a variety of mechanisms, that compaction plays a role, and that more work in the area of recovery mechanisms and their representation within a reservoirs simulator is warranted. His critique of our work, however, incorrectly summarizes our experimental procedures and it misrepresents the importance that we attribute to hot-water imbibition in relation to the other mechanisms that contribute to thermal oil recovery. His discussion of the simulation of field-scale recovery processes does not appear to acknowledge the need for upscaling or the inherent nonuniqueness present in history-match results. Our work highlights the role of fines detachment as well as silica and mineral dissolution combined with compressive stress (Schembre et al. 2006; Ikeda et al. 2007; Ross et al. 2008). We have found that rock wettability evolves favorably to a more water-wet state with elevated temperature. This change in wettability contributes positively to recovery.