There are extensive bitumen deposits in Canada that, with the development of sustainable exploitation technologies, can satisfy the energy requirements of the nation for more than a century. The currently available surface mining and in situ recovery techniques are applicable to only similar to 15% of the known in-place resources. There is an obvious need for improved technology to make more of the in-place resources exploitable. This paper is aimed at studying the macroscale performance of the steam-assisted gravity drainage (SAGD) and the solvent-aided SAGD (SA-SAGD) processes. A two-dimensional (2-D) physical model of porous media was designed and fabricated for the purpose of implementing these two processes. The physical model was packed with different sizes of glass beads to create porous media with different permeability values. Athabasca bitumen was used as the oil phase. All the SAGD and SA-SAGD experiments were performed in an isothermal jacket as the controlled-temperature environment to reduce the amount of undesired heat loss from the model to the surrounding environment. In addition., layers of insulating materials attached to wooden frames were used to cover the back and side faces of the packed model to further reduce the heat losses. All the experiments were conducted under the free uptake flow circulation methodology at atmospheric pressure. For the SAGD experiments, replicate trials were also designed and conducted in order to ensure the repeatability of the experiments. According to the SAGD experimental results, the average mobile oil production rate, as well as that of the dead oil, is constant over the course of the process. When all other experimental variables are unchanged except the porous medium permeability, the higher the permeability of the porous medium, the higher the amount of water content of the produced mobile oil, but the lower the steam-to-oil ratio. The residual oil saturation in the invaded region of the porous medium was obtained to be similar to 3%-4.6% of the total pore volume at higher and lower permeability levels, respectively. Moreover, the microstructure of the dispersed water condensate droplets in the continuum of the produced mobile oil was studied with the aid of an advanced photomicrography system integrated with image processing unit. It was determined that water condensate droplets with equivalent sizes as small as 5 mu m were dispersed in the mobile oil background. Average droplet size values were measured for both of the permeability levels used in the SAGD experiments, based on the image processing of the microscopic snapshots taken from the produced emulsion samples. One SA-SAGD trial was also conducted in order to demonstrate the enhancement made in the production performance of the SAGD process, following the coinjection of solvent with steam. It was determined that the average mobile oil and dead oil production rates of the SA-SAGD process are reasonably constant over the course of the experiment. In the SA-SAGD process, there were enhancements of similar to 18% and 20% in the mobile oil and dead oil production rates, respectively, compared to the corresponding average values in the SAGD experiments at similar permeability values. The average water production rate and the SOR values of the SA-SAGD experiment: were similar to 9% and similar to 35% less than those of the corresponding SAGD trials, respectively. The microscopic snapshots of the produced water in oil emulsion were also studied for the case of the SA-SAGD experiment and it was obtained that water condensate droplets with an equivalent size of as small as 5 mu m were dispersed in the continuum of the produced mobile oil. In addition, an average water droplet size range was determined based on the measurements using image processing techniques.