Numerical modeling of electromagnetic-based thermal recovery techniques combined with solvent injection

Electromagnetic heating (EMH) has been the focus of ever-increasing theoretical and experimental studies to examine if it can be used to heat geomaterials at the field scale. Bitumen recovery process using EMH technique assisted by solvent injection, such as that used in Enhanced Solvent Extraction Incorporating Electromagnetic Heating (ESEIEH (R)) pilot in currently being conducted in the Athabasca oil sands, utilizes radiofrequency waves to generate a moderate amount of heat in the reservoir. In conjunction with dilution effect of solvent the generated thermal energy reduces the viscosity of highly viscous bitumen leading to its mobilization. Electromagnetic (EM) wave propagation in a reservoir is a coupled multiphysics process that involves not only the heat transfer and fluid flow, but also EM field distribution. Currently, a coupled approach is followed by industry using a commercial reservoir simulator (CMG-STARS) and another commercial software (ANSYS-HFSS) or in-house electromagnetic wave solver with different gridding system where both are linked through a property mapping interface (CEMRS or AxHeat). The coupled scheme utilizes the interface to map parameters from two different gridding structures which causes an additional computational load on the simulation process and could be a source of error. This study presents an alternative integrated compositional numerical modeling approach to explore the EM heating phenomena pertinent to fluid flow and heat generation and transfer in oil sand reservoirs in the same grid structure. Energy balance and EM wave propagation are derived using Maxwell's equations in the frequency domain. Then, the newly developed numerical simulator is validated using benchmark problems and used to demonstrate the physics of EM-induced volumetric heat generation in multi-phase oil sand reservoirs. Finally, the developed numerical model is applied in a case study of propane injection along the antenna to achieve oil recovery and the results are compared with the analogous Steam Assisted Gravity Drainage (SAGD). (C) 2020 Elsevier Ltd. All rights reserved.