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Microwave measurements of slabbed, whole core surfaces from calcite-rich shales are correlated to mineralogy quantified from elemental maps measured using micro X-ray Fluorescence (µXRF) across those same surfaces. The nondestructive microwave measurements were performed using a spot-probe reflectometer antenna with a 30 mm-diameter illumination area using frequencies between 2.5 and 20 GHz. The broadband dielectric results show a strong correlation between the dielectric constant and the kerogen/pyrite content in the calcite-dominated intervals where different types of organic and/or pyrite inclusions are easily identified. This novel non-destructive method of analysis can measure the dielectric effects caused by mineral substrates that influence borehole resistivity measurements. These effects often cause erroneous computation of water and hydrocarbon saturations in unconventional reservoirs.

Using the dielectric/permittivity spectra from liquid hydrocarbons to characterize their composition requires knowledge of their geochemistry and the geological processes that formed them. Complex permittivity measurements of two crude oils and gas condensate at 25°C were conducted using two state of the art multipoint resonant cavities. High accuracy permittivity values were obtained for nine different frequencies between 170MHz and 8.6GHz. Geochemical analyses were performed and the main components of the hydrocarbons were identified. Results show that permittivity spectra can be related back to the asphaltene and aromatic content of the oil. The former of which is a function of the maturity of the source rock from where it originated and the latter a possible alteration due to either thermochemical sulfate reduction or evaporative fractionation. In addition, at higher frequencies, the permittivity spectra correlates with the m-xylene and toluene content of the produced fluids.