Novel applications of ground-penetrating radar in oil fields

Ground-penetrating radar (GPR), usually working in the frequency from tens of megahertz to several gigahertz, is widely applied in mapping near-surface applications. In recent decades, GPR is frequently utilized for fluid-related applications, such as groundwater assessment, contaminant monitoring, and water-filled fracture detection, based on the principle that at these radar frequencies, electromagnetic (EM) waves are sensitive to water content. When operated from the surface, ground-penetrating radars are limited to a survey depth up to tens of meters in most soils. To further extend the detection range, borehole radar is developed by placing the GPR antennas in boreholes close to the underground targets. Different downhole survey modes, e.g. single-hole, cross-hole, and vertical radar profiling measurements, have demonstrated applicabilities for fracture detection, metal ore exploration, or water content prediction, up to a depth of a few hundred meters from the ground. Deeper GPR measurements in hydrocarbon reservoirs have been proposed. Some theoretical studies have shown that a borehole radar is expected to have the capability of mapping structures in the range of a few decimeters to ten meters away from the borehole in most reservoir environments, filling in the gap of the conventional electrical, sonic and nuclear logging methods. More attractively, GPR has a relatively high radial resolution and suits best for the downhole structure and fluid imaging. This thesis aims to explore the potential applications of GPR and assess their values in these oil industry applications. Applicability studies are carried out in the fields of well logging and monitoring of oil production. Numerical simulations are carried out, where joint multiphase flow and borehole radar modelling is established.