Integrated optimization of the thermal processes in heavy oil recovery

Three activities of research are deemed necessary to provide the industry with technology and method to optimize the thermal process for heavy oil reservoirs:
 
(1)    Modeling the Thermodynamics of Heavy Oil. We are challenged by the thermodynamic modeling of complex hydrocarbon mixtures experiencing a wide range of temperatures and pressures -- from in-situ conditions to thermally-induced heating, potential chemical transformation. Modeling of phase behavior of thermal process in heavy oil requires detailed information of heavy-end fractions. However, significant amount of heavy oil can not be distilled and remains as an undistillable solid. Our goal is to develop thermodynamic models which are internally consistent and have basic thermodynamic properties and component descriptions that are applicable throughout the production system.
 
(2)   Optimization of thermal methods in heavy oil recovery. Recently, we developed a new approach to model a thermal process steam-assisted gravity drainage (SAGD) using an isothermal black-oil (BO) reservoir simulator. The oil viscosity reduction caused by heating in the actual SAGD process is emulated by a tuned saturated pseudo-oil viscosity relation where solution gas-oil ratio is used as an "equivalent temperature variable". The proxy model saturated pseudo-oil viscosity relation used is found by history matching a full-physics thermal model performance prediction of oil rate, BHFP, and cumulative oil for a 2D homogeneous model. We also see the potential of using the black-oil proxy model for solvent-based SAGD. We are also planning to optimize the solvent co-injected steam for a SAGD process using the thermodynamic model from step one. Full field optimization study for using Black-Oil proxy versus thermal model will be the last part of the study.