Mechanistic Simulation of Solvent-aided Gravity Drainage of Bitumen
Abstract
The injection of solvent is an alternative method for recovering heavy oil and bitumen to reduce the viscosity and density of the bitumen. In this study, solvent assisted thermal gravity drainage is modelled in CMG STARS using propane as the solvent. First, the modeling of thermosphysical properties of bitumen and propane mixture was performed. Then, a highly refined and simple mechanistic model was constructed and validated. The parameters of the model were defined to enable the numerical model for pure mass and heat transfer as well as coupled heat and mass transfer processes.
Three mechanistic cases were studied including isothermal gravity drainage, non-isothermal gravity drainage, and solvent-aided non-isothermal gravity drainage. Also, three groups were defined to obtain a better understanding of the effect of the bitumen properties and the relative permeability curves on the drainage process. Group 1 with low initial bitumen viscosity, Group 2 with high initial bitumen viscosity, and for Group 3 with different relative permeability models were studied. Fine grid numerical simulations demonstrated extensive fingering during the drainage process and the need for fine grid numerical simulations to ensure accurate capturing the physics of gravity drainage. Scaling relations were developed to describe the rate of oil drainage as a function governing dimensionless groups. For the isothermal gravity drainage, the presence of the solvent (propane) and its molecular diffusion into bitumen was found to play a critical role in reducing the viscosity and density of the bitumen leading to gravity drainage of bitumen.
Description
Keywords
Engineering--Chemical, Engineering--Petroleum
Citation
Salas Santa, M. L. (2017). Mechanistic Simulation of Solvent-aided Gravity Drainage of Bitumen (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26870