Thermal methods for heavy oil and bitumen recovery include the injection of steam in the form of SAGD (Steam Assisted Gravity Drainage), CSS (Cyclic Steam Stimulation), and steam flooding, whereby thermal energy is given to the oil, reduces its viscosity and allows it to flow towards a production spot. Latent heat from the condensing steam carries considerable amounts of energy into the bitumen and helps in heating it up. In novel electrothermal processes, it is proposed that all the latent heat of this steam is to be replaced by electrical resistive heating (ERH) and boiling of the water in-situ, provides displacement pressure and voidage replacement. In ERH, the formation water acts as an electrical circuit so electrical energy is dissipated into the reservoir. During this process, the formation water can be vaporized due to the overheating of the near well bore area and heterogeneities of the electrical conductivity. This could result in cutting off the electrical circuit and process termination. Therefore water vaporization is often considered as a catastrophic phenomenon for electrical heating processes. On the other hand, additional oil production can be expected by converting some water into steam.

In this study, the effect of in-situ water vaporization on the bitumen production is evaluated and water injection strategies are investigated. CMG StarsÔ (2006.13) is used as the simulation tool. 3-block conceptual and 3-D Cartesian models are set up with properties that simulate the conditions of the Athabasca oil sand deposits of Northern Alberta, Canada. The 3-block model is used to demonstrate the incremental oil brought by the formation water vaporization. A field scale model - an array of electrodes and production wells in triangular pattern is set up to evaluate how water injection can be incorporated and how the amount of water injected affect the ultimate bitumen recovery at field scale level.

The simulation results of 3-block conceptual model showed that a significant bitumen recovery can be obtained by vaporizing the formation water. The water injection can be used to maintain a continuous water and electrical path. At the same time, the water injection can improve the ultimate bitumen recovery. Within the range (amount) of water injected, the higher the water injection rate, the higher the ultimate bitumen recovery.