Modeling of desiccated zone development during electromagnetic heating of oil sands

Steam Assisted Gravity Drainage (SAGD) is the most common technique for bitumen extraction from oil sands. The main problems with SAGD and other conventional thermal recovery methods are high energy consumption, environmental impacts, and large capital costs associated with steam generation and water treatment surface facilities. Use of electromagnetic waves, as an alternative method for in-situ heating of oil sands, along with a carrier fluid such as a solvent has potential to provide a low capital cost and energy efficient technique with less environmental impact for bitumen production. In this study, for the first time, we model the physics of the formation of desiccated zone around an electromagnetic antenna installed in a SAGD-type well pair. An analytical model is proposed based on transient temperature distribution ahead of the interface incorporating both conduction and radiation terms. This model is capable of handling both infinite period of chamber development and pseudo-steady state following the coalescence of the steam chambers. The developed technique provides a straightforward approach to predict the oil production, energy consumption, and energy efficiency during the entire economic life of oil production. It can also be utilized as a sensitivity analysis tool to optimize the well-pair spacing in electromagnetic heating process of oil sands.