Modelling of Non-Equilibrium Heavy Oil-Solvent Behaviour
Date
2021-12-17
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A multi-component kinetic model is proposed to simulate non-equilibrium solvent ex-solution and back dissolution processes in the heavy oil bulk environment. The model consists of micro bubbles, which inherit physical properties from the solution gas and is treated as a gas-like liquid, to simulate foamy oil behavior during volume expansion processes. Free gas is considered as being able to transfer directly to solution gas to simulate the hysteresis which happens in the dissolution process when volume pressure increases. The kinetic model comprises three pseudo-chemical reactions with seven parameters which were calibrated against experimental data. The model was validated by using a thermal reservoir simulator and the results were capable of predicting the oil-gas system volume changes for two different solvent-heavy oil systems accurately under various pressure variation rates at both 15 and 75°C. Four reaction orders and three reaction frequency factors were tuned and it indicated that in a solvent-heavy oil system with solvent CH4 or C2H6: (1) stronger foamy oil behavior exists with solvent of C2H6 instead of CH4 during pressure depletion processes for heavy oil with the similar solvent concentration; (2) for both solvents, micro bubble release rates are larger at higher temperature and the rates tend to increase with pressure decline regardless of temperature; and (3) in the solvent dissolution process, for both CH4 and C2H6, relatively high pressure and temperature are both significant elements for promoting solvent dissolution back into heavy oil.
Description
Keywords
Citation
Tai, N. (2021). Modelling of Non-Equilibrium Heavy Oil-Solvent Behaviour (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.