Petroleum coke is a byproduct of oil sands upgrading which can be utilized as a low-cost feedstock for further value-added operations such as gasification. The design and scale up of gasifiers for oil sands coke demands reliable data on the intrinsic reaction rates, which are currently missing from the literature. The intrinsic gasification rates for char-CO2, and char-H2O reactions were determined for Canadian oil sands fluid coke. Four different specific surface area measurement techniques were used to normalize the specific reaction rate calculated from the weight loss profiles of TGA: N-2-BET surface area, two micro-porosity measurement techniques based on Density Functional Theory (DFT) and Dubinin-Radushkevich (DR) models, and finally active surface area (ASA) measured by CO2 chemisorption at different levels of conversion (char conversion). The specific reaction rates, calculated at different levels of conversion were divided by different surface areas, in order to find the specific surface area that results in the best reduction in the variability of reaction rate, r(X), by using surface area as a regressor variable. Overall, ASA was found to be the best regressor for deriving the intrinsic rates. Surface areas based on the N-2-BET technique were also proven to be a better choice for normalizing the specific rates compared to the ones based on DFT and DR models.