Analytical and numerical modeling of the Cyclic ES-SAGD process

Date
2019-04-25
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The world is still highly dependable on the energy that comes from oil. The current demand for energy has given importance to oil reservoirs that were normally overlooked in the past due to its properties. One example is found in the Canadian heavy oil sands. The amount of oil that is accumulated in these reservoirs represents the third largest accumulation of oil in the world. In these reservoirs, thermal processes such as Steam Assisted Gravity Drainage (SAGD), are used extensively as a production method. In SAGD, the injection of the steam into the reservoir reduces the viscosity of the oil, which moves downward by the effect of gravity until it reaches a production well. This research presents an alternative way of using SAGD in an efficient and profitable manner. One of the possible variations of SAGD that has shown positive results is the co-injection of a solvent in the injected stream. The idea behind this is to improve the effect of the reduction in the oil viscosity by the diffusion of this solvent in the oil. The amount and type of solvent injected as well as the amount that is recovered are key parameters in the performance of this process, particularly because these solvents are generally more expensive than oil. This work studied the co-injection of the solvent with the steam periodically. This means that in this case the solvent is co-injected through cycles instead of continuously. Some of the aspects that were evaluated are the type of solvent, its concentration and the duration of each of the solvent injection cycles. This study includes the derivation of an analytical model that is able to estimate the oil rate than comes from a cyclic solvent co-injection SAGD process and the use of numerical reservoir simulation to determine the principal recovery mechanisms of the process. One of the principal conclusions is that a similar positive result of the solvent co-injection could be achieved with less amount of solvent usage. This would considerably benefit the profitability of the process and the general performance of SAGD.
Description
Keywords
SAGD, ES-SAGD, Reservoir Engineering, Numerical simulation, Thermal Recovery Methods
Citation
Manfre Jaimes, D. (2019). Analytical and numerical modeling of the Cyclic ES-SAGD process (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.