Analysis of the heat losses associated with the SAGD visualization experiments

Abstract

Dealing with the heat losses associated with steam-assisted gravity drainage (SAGD) experiments has been an issue for which different heat loss prevention techniques have been developed and utilized in the literature. The aim is to minimize the amount of heat losses from the porous medium to the surrounding environment. Excessive heat losses negatively affect quantifying the energy requirements of the SAGD experiments. In this study, an inverted-bell vacuum chamber was employed to minimize the excessive heat losses while steam was injected under different superheating levels. Local temperatures along the glass micromodels’ height and width were recorded on a real time basis. Details of the heat losses associated with our pore-scale SAGD visualization experiments are described in this paper. According to the results presented, employing extremely low vacuum conditions resulted in effective heat loss prevention in a sense that the convective element of heat loss could be neglected. As a result, radiation heat transfer was the only mechanism of heat transfer that contributed to the heat loss from the micromodels’ surfaces. In each pore-level SAGD experiment, the overall steam consumption to produce one unit of the mobile oil was corrected based on the heat loss analysis of the process to account for the additional volume of steam which was condensed because of the heat loss. The net cumulative steam consumed, corrected for the heat losses, was in very good agreement with the predictions made based on the theory of gravity drainage and its application in performance analysis of the SAGD process.