Feasibility of Borehole Radar Measurements to Monitor Water/Steam Fronts in EOR Applications

A technique capable of capturing the dynamic of the reservoir fluids in the proximity of production wells would provide enormous benefit to the reservoir management; in fact, monitoring can be used to develop a feedback loop between measurements and control technologies to optimize the 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 where the radar borehole system lies. Another constraint is given by the operating frequency of the system. Too low frequencies would compromise the electromagnetic wave propagation in favor of diffusion phenomena and too high frequencies would 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 in the order of tens of meters. 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 imaging depth necessary for these environments.