We report here some work on the modeling of oil shale retorts for electromagnetic sensing techniques. The aim is to obtain useful information about the contents of the retort by means of electromagnetic probes. In this work, the retort is modeled by a spheroid with an average dielectric constant which depends on the void ratio. The near field due to a radiating dipole source in the vicinity of a spheroidal retort is computed using the Extended Boundary Condition Method due to Waterman, Barber and Yeh. Numerical results are given at 4 MHz for a retort with major axis 45.7 m, minor axis 25.1 m, bulk dielectric constant 3.8 3.7 j, and various void ratios. The results indicate feasibility of determining the void ratio by remote electromagnetic measurements. It is also believed that this work may be of interest beyond the immediate context of oil shale retort modeling.
MODELLING OF OIL SHALE RETORTS FOR ELECTROMAGNETIC SENSING TECHNIQUES