Dielectric Measurement Method for Dynamic Monitoring of Water-Saturated Sand Pack with and without Evaporation

Abstract

AbstractThermal-based recovery techniques will continue to be used in bitumen and heavy oil recovery. Among them, electromagnetic (EM) heating is promising, especially in situations in which there are technical and environmental issues with steam-based methods. To design the EM process, precise knowledge of the dielectric properties of the target formation is of great importance. To achieve the research goals, a new patented impedance spectroscopy setup is used. An alternating electric field is applied to the sample using an impedance analyzer. The impedance measurements of the clean sand sample, which is pre-saturated with deionized water or brine, are measured at an elevated temperature and pressure to mimic reservoir conditions. There are two successive cycles of heating up to 170 °C. The first heating cycle is followed by a cool-off period, while the second heating cycle culminates with evaporation. The impedance was dynamically measured during each heating cycle. In addition, the dielectric properties of fresh water-gas and brine saturated sands were demonstrated. Results show that the electrical conductivity and dielectric constant of the samples are significantly influenced when the NaCl solution is the saturating fluid. Downward trends in both the electrical conductivity and relative dielectric constant were observed as the steam quality improved, which indicates the creation of a desiccated zone.