Using unconventional oil sources like bitumen is really important for keeping our energy supplies steady in the future. But itʹs not easy—these fluids are super thick, with viscosities that can go over five million centipoises when theyʹre first extracted, making the process quite tricky. In this study, we looked at how well the Steam-Assisted Gravity Drainage (SAGD) method works in a reservoir that isn’t uniform. We also did a detailed sensitivity analysis on multiple factors to figure out the best way to operate the system an‎d get the most oil out of it over time. The study used a numerical simulation approach with the Computer Modelling Group (CMG) software. They built a 2D static model that reflected the uneven nature of a real bitumen reservoir, with different porosity an‎d permeability zones. To do this, they used the CMG STARS thermal simulator. They compared a simple "Natural Depletion" scenario with various SAGD injection cases. Additionally, they employed CMG CMOST to run a Design of Experiments (DoE), helping them understan‎d how different factors interact with each other. The simulation results showed that primary production just doesn’t work here—it ends up with no recoveries at all because the bitumen just won’t move. But when we used SAGD, things improved. It created a gravity-driven flow that kept a steady water cut of around 70-75% after the initial startup phase. The sensitivity tests pointed out that the pressure in Injector BHP is the most important factor for recovery. When we increased it, oil production went up in a straight-line way, mainly because higher pressure helped raise the saturation temperature, making it easier to extract the bitumen. Surprisingly, the study showed that just having higher steam quality doesn’t always mean better results. Instead, they found a "5-Star" setup that really boosts recovery up to 9,000 cubic meters by using high pressure (4,650 kPa), injecting a lot of steam (455 m3 per day), an‎d keeping the steam quality at a moderate level of 0.73. This tells us that in uneven, tricky environments, itʹs more about using a good amount of fluid to transfer heat effectively an‎d controlling how the water moves, especially with what’s called "wet steam.

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حميدرضا شاه وردي , محسن محمدي