Development of a heat-penetration criterion to characterize steam chamber growth and propagation dynamics during a steam-assisted gravity drainage (SAGD) process

Abstract

Steam chamber growth and propagation dynamics dictates the success of a steam-assisted gravity drainage (SAGD) process, which is an enhanced oil recovery (EOR) method for effectively and efficiently exploiting the enormous heavy oil and bitumen reserves. To set the baseline, this work is focused on the SAGD process with pure steam. After numerous trials and errors, a heat-penetration criterion has been developed and integrated into a reservoir simulator for the first time to characterize steam chamber growth and propagation dynamics conditioned to the production profiles during a steam-assisted gravity drainage process. More specifically, based on the heat transfer principle, a pore-scale heat-penetration criterion has been developed with respect to both heat conduction and convection for calibrating the temperature distributions ahead of the steam chamber interface (SCI). Subsequently, such a heat-penetration criterion has been upscaled to a grid-scale for its integration with a commercial reservoir simulator (i.e., CMG STARS), allowing us to pragmatically and accurately quantify the dynamic temperature field during a steam-assisted gravity drainage process. Furthermore, three sets of multiphase relative permeabilities are employed to evaluate comprehensive impacts of the thermally sensitive co/counter-current flows. Finally, such a heat-penetration criterion has been verified by reproducing the experimentally measured steam chamber during a steam-assisted gravity drainage process from a large-scale 3D physical model. With such an integrated method, good agreements between the measured and simulated data including production profiles and temperature distributions have been found, whereas the dynamics of production profiles and corresponding steam chamber propagations cannot be well reproduced solely with a commercial reservoir simulator. Sensitivity analysis has been performed to examine the effects of thermal-sensitive properties, steam chamber configuration, boundary, multiphase flow behaviour (e.g., co-current and counter-current flow), and gridblock dimension. In practice, the newly developed heat-penetration criterion can be seamlessly integrated with a commercial reservoir simulator. Such an integrated method can significantly reduce the model complexities and uncertainties, providing a simple and convenient way to dynamically and accurately characterize the steam chamber growth and propagation dynamics within a unified, consistent, and efficient framework.