oa The Role of Mineralogy (QEMSCAN) in the Facies Heterogeneity Characterization of Organic Rich Shale

Due to the increased complexity of unconventional plays, existing workflows, developed for more conventional reservoirs, are not always applicable. A better understanding of the rock matrix is critical for the development of improved models for the exploration and exploitation of these resources. As minerals control fundamental parameters such as grain density and directly or indirectly influence many of the wireline responses e.g. density, resistivity, spontaneous potential, gamma ray etc, accurate determination of the mineralogy is a vital input to petrophysical models. In addition, the composition and fabric of the reservoir rocks control geomechanical properties such as well bore stability and fracking potential. Therefore, accurate and reproducible quantification of the mineralogy and texture of the rock matrix is a particularly important factor in exploitation and development workflows for tight and / or unconventional resources. QEMSCAN analyses on the COUY-1 well cores and cuttings (Toarcian Shale, Paris Basin, France) provide quantitative mineralogical data, textural data and mineral maps of each cutting/core sample, thereby allowing for the detailed characterisation and determination of the nature and distribution of the inorganic sample components. The particles are lithotyped in order to quantify the variations between the samples and brittleness indices were calculated from the modal mineralogy.