Analytical Modeling of Steam Injection and Steam-Solvent Co-Injection for Bitumen and Heavy Oil Recovery with Parallel Horizontal Wells
Date
2019-04-30
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Abstract
Steam-assisted gravity drainage (SAGD) is recognized as one of the most promising techniques for the commercial in situ recovery of bitumen reserves. The process, however, is energy intensive and is economically challenged in thin and low-quality reservoirs. Years of small-scale testing have shown that adding small amounts of hydrocarbon solvents to steam can yield large gains in oil output and reduced emissions over the conventional SAGD (Rassenfoss, 2012). The process has been referred to with different names in industry and academia such as expanding solvent-SAGD (ES-SAGD), solvent aided/assisted-SAGD (SA-SAGD), SAGD+TM, solvent aided process (SAP) and so on. High costs of solvents compared to bitumen requires their optimized use. The numerical simulation complexities and run times can make the filed-scale optimization exercise extremely costly. Therefore, analytical models can play an important role for such a purpose and to increase the confidence in performance forecasting. This dissertation starts with a review of the primary analytical models available for SAGD and co-injection and discussion on their limitations. Then, a new universal modelling approach is proposed that is applicable to the both processes. The breakthrough in the modelling approach is the robust coupling of mass balance, energy balance and fluid flow in porous media. This approach solves the heat and mass transfer problems at the stationary base of the steam chamber where the drainage to the producer happens. Combining material balance and Darcy’s Law, it then estimates the bitumen production rate and chamber shape. Then, energy balance is incorporated to estimate the steam requirements. In addition, the new modeling approach closes the material balance on all the components which allows for the estimation of solvent requirements for a particular set of key performance indicators. The developed model is intended to be simple enough for practical applications. After validation against numerical simulation results, its application to history-matching, forward prediction, pre-screening and uncertainty analysis is demonstrated through a number of field case studies.
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Analytical Modeling, Bitumen and Heavy Oil Recovery, Thermal and Solvent-Thermal Recovery, Steam-Assisted Gravity Drainage (SAGD), Expanding Solvent-Steam-Assisted Gravity Drainage (ES-SAGD), Solvent Aided-Steam-Assisted Gravity Drainage (SA-SAGD), Steam and Solvent Co-Injection, Thermodynamics and Phase Behavior, Numerical Simulation, Uncertainty Analysis, Decision Making under Uncertainty, Risk Quantification and Management, Technology Maturity and Pathway to Commercialization, Economic Analysis, Piloting, Discretized-Interface (DIN) Model, Prescribed-Interface (PIN) Model, Linear-Interface with Averaged Rate (LINAR) Model
Citation
Keshavarz, M. (2019). Analytical Modeling of Steam Injection and Steam-Solvent Co-Injection for Bitumen and Heavy Oil Recovery with Parallel Horizontal Wells (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.