Simulation Study of Warm VAPEX Process Using Water-soluble Solvent
Date
2020-04-15
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Abstract
Vapor extraction (VAPEX) is considered a promising alternative to the SAGD process to recover Alberta's heavy oil and bitumen resources. In the past, researchers have found that the main drawback of the VAPEX process is its slow oil production rate due to the inherent mechanism of relatively slower mass transfer compared to heat conduction and convection. Warm VAPEX, which combines the effect of both heating and solvent dilution, can increase the oil production rate significantly. In this study, the feasibility of injecting dimethyl ether (DME) to extract Athabasca bitumen is investigated through numerical simulations. A synthetic reservoir model with fine grids was developed to investigate the displacement mechanisms in a hot DME VAPEX process. Thermal dynamic properties of a bitumen-DME-water system were modelled and validated with experimental measurements. The performance of hot DME VAPEX is compared with a SAGD process in terms of an oil rate, cumulative oil production and energy input. Simulation results indicate that the oil rate of warm DME VAPEX is comparable to SAGD, and the energy consumption is dramatically reduced. Subsequently, a sensitivity analysis is conducted to examine the effect of various parameters on the overall performance of DME-based warm VAPEX. Injecting DME at higher temperatures is effective in reducing the solvent-oil ratio. Oil production can be significantly promoted by increasing the injection pressure. The original reservoir water saturation also has a significant impact on the performance of warm DME VAPEX. For higher water saturation reservoirs, oil production is enhanced, but more DME is trapped in the water phase.
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Keywords
VAPEX, Solvent, Dimethyl ether
Citation
Qi, R. (2020). Simulation Study of Warm VAPEX Process Using Water-soluble Solvent (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.