Mathematical Modeling of Heavy Oil Recovery Using Electromagnetic Heating Combined with Solvent Injection
Date
2019-01-11
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Abstract
Efficient heating of oil sands is a challenge in thermal recovery of bitumen. Currently, a standard computational platform for modeling electromagnetic heating combined with solvent injection is lacking and a coupled approach is used. In this approach, a thermal reservoir simulator and an electromagnetic (EM) simulator are coupled to model electromagnetic heating (EMH) combined with solvent injection. This study presents first effort to model the recovery process by developing a standalone electromagnetic heating thermal simulator to simulate the recovery process. The work described in this thesis has two main contributions including development of analytical and numerical models. The analytical contribution includes development of solutions for electromagnetic heating of lossy geological media with applications to bitumen extraction from oil sands. Analytical models are presented for the start-up period of a SAGD-type well-pair for three different scenarios including steam circulation, electrical heating (EH), and EMH-EH. These analytical solutions are then combined with the Duhamel’s theorem to predict the temperature distribution around the horizontal wellbores. The energy efficiency of each scenario is evaluated. The results show that EMH-EH results in a shorter preheating period and is more energy efficient than the current practice of steam circulation. A semi-analytical model was also developed to predict the bitumen production rate, steam chamber growth, and energy efficiency of the process during the vapor chamber development period. The results showed that electromagnetic assisted gravity drainage is less energy intensive than the SAGD. The numerical contribution includes development of standalone two-dimensional, multi-component and multi-phase thermal simulator with an integrated electromagnetic EM component to simulate EM-based bitumen recovery processes. This numerical model integrates full Maxwell’s equation in the frequency domain with variable electrical properties based on temperature and water saturation, coupled with heat and mass transfer in the reservoir. Coupled equations are solved in a fully implicit scheme. The aim of developing a numerical model was to investigate the applicability of high-frequency waves coupled with the solvent as a viable method for bitumen extraction at the field scale. A case study demonstrates the physics of the various phases of the recovery process. The results of the EM-solvent process are compared with the commonly-used conventional thermal recovery method (SAGD) to assess production performance of the two processes in terms of energy efficiency, solvent usage and oil rate. The results reveal that EM-solvent recovery process has potential to eliminate water usage, reduce energy intensity, while recover more oil. These findings reveal that electromagnetic heating is a promising water-free recovery technology for future developments of oil sands resources.
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Sadeghi, A. (2019). Mathematical Modeling of Heavy Oil Recovery Using Electromagnetic Heating Combined with Solvent Injection (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.