Characterization of complex permittivity for consolidated core samples by utilization of mixing rules

Candidacy of any reservoir as a microwave absorber is predicated on the complex permittivity of the sample. Modeling both the penetration and absorption dynamics of the electromagnetic wave in the reservoir is dependent on realistic estimation of this parameter. Therefore, it becomes necessary to understand the inherent intricacies of complex permittivity in the reservoir. Reservoirs are comprised of both a void space represented by the porosity parameter as well as the rock matrix and can be treated as a binary mixture of the two. Mixing rules can then be introduced and have been shown to be a viable means of estimating the dielectric response. The behavior of the bulk material is considered to be an extension of the isolated contribution of the separate parts. Therefore, by characterizing the response of the individual components of the mixture, the overall response can be estimated. Utilization of mixing rules enables efficient estimation of the dielectric properties anywhere in the reservoir as a function of the rock matrix, fluid saturation, and porosity. The absorptive capacity of the reservoir can then be described which is used to screen the efficacy of the material for microwave introduction. Both the real and imaginary components of complex permittivity are measured on nine consolidated core samples of varying lithology and fluid saturation over the frequency range of 400 MHz to 6 GHz. Experimental data is compared to various mixing rules commonly implemented to determine validity and viability of the estimation of complex permittivity for consolidated samples.