SCA2013-042 1/6 ADVANCED CHARACTERIZATION OF SHALE GAS ROCKS USING DUAL RANGE FTIR AND DIELECTRIC DISPERSION A. Marzoug 1 , T. AlGhamdi 1 , K. H. Sassi 2 , and M. Badri 2 1 Saudi Aramco 2 Sclumberger Dhahran Research Center This paper was prepared for presentation at the International Symposium of the Society of Core Analysts held in Napa Valley, California, USA, 16-19 September, 2013 ABSTRACT Dielectric properties were measured on a suite of shale gas rock samples selected from several wells across the Silurian source rock formation. The dependence of minerals in the shale-gas rocks on the interpretation of the dielectric response was studied. The dual- range Fourier transform infrared (FTIR) technique was used to accurately quantify the mineralogical composition of the studied samples, including pyrite. Pyrite has a significant effect on the dielectric responses, and an accurate estimation of its volume is crucial for an enhanced interpretation of the dielectric response. A workflow was developed to accurately estimate the effective permittivity of the rock matrix to enhance the estimate of water volume from the dielectric response. The high-resolution retort was also used for the quantification of water content, and the results were compared to the water saturations from dielectric dispersion. NMR T 2 was also measured on the selected shale gas rock samples using very short echo spacing and showed that the most abundant pore-body size is in the range of 0.2 to 0.3 μm in diameter. INTRODUCTION Extensive shale gas reservoir characterization is essential for accurate estimates of the original gas-in-place (OGIP), the production rates, and the storage capacity of depleted reservoirs. Shale gas systems are relatively low porosity and ultra-low permeability, and comprise wide ranges of pore sizes. The latter is associated with the diversity of minerals that make up shale, such as clays, carbonates, and organic material (i.e., kerogen). The complexity in mineral content leads to fundamental questions, and often uncertainties, related to the calculation of the petrophysical properties: the total amounts and spatial distribution of original fluids in the reservoir, their thermodynamic states (i.e., adsorbed or free). The industry requires new techniques to be developed that would assist in accurate predictions of the rock and fluid properties, leading to much better description of the reservoir properties of the shale plays. The dielectric dispersion along with the dual- range Fourier transform infrared (FTIR) method, are the main focus in this study to