Energetic Optimization to Heavy Oil Recovery by Electromagnetic Resistive Heating (ERH)

Abstract

AbstractElectromagnetic resistive heating (ERH) is a thermal stimulation technique in which the electrical current passes through formation increasing the original temperature by Joule effect. Thus, greater is the electrical current intensity, highest reservoir temperatures are reached. This method is much influenced by electrical conductivity of the interested zone mainly due to electrical conductivity of connate water. So, water is directly heated by Joule effect and oil is heated by both conduction and convection heat transfer. In this work, it was studied a combination of time heating without production and heating with concomitant production, which provides a greater economic advantage depending on energy price used and oil price produced, since oil production is increased due to heating provided by ERH.This method is suitable for use in wide kinds of reservoirs, with different characteristics of reservoir thickness, injectivity, formation permeability, formation porosity, pressure, depth, temperature, oil saturation and oil viscosity. Depending on the energy magnitude delivered to reservoir and formation pressure, this method can be an alternative to in situ steam generation. For offshore productions systems, where the platform surface is limited, the ERH becomes a quite attractive thermal method, been an alternative to steam flooding avoiding heat losses in pipes.A good strategy for ERH process is, first of all, to choose an electrodes configuration, and after, to control the energy delivered to reservoir, by electrodes voltages, depending of desirable oil rate and temperature obtained in electrodes zones. Electromagnetic resistive heating may produce even better results with water flooding to displace the mobile oil bank after electrical heating, regulating the reservoir pressure and adjusting the electrical conductivity of the system. So, it was possible to optimize the operational parameters to maximize the oil recovery with minimal energy requirement, resulting in an economic advantage.In this work, it was studied an application of Electromagnetic Resistive Heating in a reservoir with similar characteristics of those found in Brazilian Northeast Basin. The obtained results can be extrapolated to others important applications, for example, offshore heavy oil reservoirs, where, actually, there is no available technology to exploit them.