Investigating Three-Phase Flow of Steam-Water-Oil in Porous Media for Maximizing SAGD Potential: A New Measurement Technique

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The proposed research program develops a novel laboratory technique and procedure for fundamental study of three-phase flow in porous media. The measured data will be used for prediction and optimization of in-situ thermal recovery methods for oil production from Canada's heavy oil and bitumen resources. More than 300 billion cubic meters of viscous bitumen exist in Alberta and Saskatchewan. Only one-third of this huge resource is enough to meet the hydrocarbon requirements of all of North America for more than 100 years. However, only 20% of this resource is accessible through surface mining. The other 80% requires in-situ methods such as Steam Assisted Gravity Drainage (SAGD). SAGD has been proved to be the most successful in-situ recovery method for heavy oil and bitumen recovery in Canada. In SAGD, steam, steam-condensate, and oil simultaneously flow through the rock pore space. Mathematical modelling and optimizing such processes require careful measurement of flow conductance (relative permeability) and residual saturation of each phase in the laboratory. However, laboratory determination of relative permeability curves for steam, oil, and water is very challenging due to difficulties in phase saturation (i.e., volumetric fraction) measurement. The main challenge is to distinguish between the water and oil phases, which have similar densities. Phase A of this research develops a novel non-destructive method for measuring the saturation of oil, water and steam simultaneously flowing through a porous medium confined inside a core holder. In this method, the total oil and water saturation (So + Sw) is measured by a x-ray based technique, and water saturation (Sw) is measured by a capacitance (described by dielectric constant) based technique. The dielectric constant of water is several times higher than that of oil, which allows computing the fraction of each phase. The three-phase saturations measured in time and space will be interpreted and modelled to obtain three-phase relative permeabilities for each point in the saturation space. Phase B of the research develops mathematical techniques to use the measured data to evaluate, predict and optimize the performance of field-scale SAGD projects. The existing models for steam chamber development rate will be improved to account for the physics of three-phase flow, which is an inevitable phenomenon during steam-based in-stue recovery processes. The results of this study, which will be conducted by two PhD and two MSc students is anticipated to develop an improved understanding of complex dynamic phenomena occurring during simultaneous flow of steam, water, and oil in porous media. Modelling three-phase oil relative permeability in the presence of steam condensation phenomenon is a challenging problem, which will be studied by conducting careful laboratory measurements in the proposed research program. In addition to the scientific impacts, this research will help the oil industry to estimate the amount of oil remaining in the reservoir after the operations and to develop complementary techniques for recovering the remaining oil. Predicting and extending the economic life SAGD projects are important strategically since there are many mature SAGD steam chambers in Canada containing a significant amount of oil and heat energy. Therefore, the outcomes of this research will help the industry indirectly to 1) reduce the cost and environmental impacts per barrel of oil produced.