Feasibility of borehole radar measurements to monitor water/steam fronts in enhanced oil recovery applications

A technique capable of capturing the dynamics of reservoir fluids in the proximity of production wells would provide enormous benefits to the reservoir management. In fact, monitoring can be used to develop a feedback loop between measurements and control technologies to optimize production. This paper examines the feasibility of a borehole radar tool for near-wellbore imaging. Modeling results show that the maximum imaging range depends mainly on the conductivity of the formation in which the radar borehole system lies. Another constraint is given by the operating frequency of the system. Too low frequencies compromise the electromagnetic wave propagation in favor of diffusion phenomena and too high frequencies drastically attenuate the signal. In case of a relatively low conductive reservoir and a limited band of frequencies higher than 100 MHz, we have defined the optimal imaging capacity of the radar system to be in the order of ten of meter. We suggest borehole radar measurements as a promising approach to monitor steam chamber growth in Steam Assisted Gravity Drainage (SAGD) processes and to prevent water encroachment in thin oil rims. The penetration capacity of a radar system fits the required imaging depth for these environments.