Geomechanical Characterisation of Posidonia Shale Using Nanomechanical Testing

Summary The effective exploitation of unconventional shale hydrocarbon resources requires the robust geomechanical characterisation of the reservoir. However, there is still a paucity of mechanical data on well-characterised shale, partly due to the technical and economic difficulties in obtaining high quality core for laboratory testing. Here, we present the results of a study which combines PeakForce Quantitative Nanomechanical Mapping and nanoidentation testing on three shales from the Posidonia of NW Germany, covering a range of thermal maturities. PF-QNM is used to determine the mechanical properties of individual organic, clay mineral and other phases, including their anisotropy. Estimates of bulk elastic and viscoelastic parameters are determined through use of high load instrumented indentation testing. These data form the building blocks for the estimation of the geomechanical properties of shales at larger scales, as a function of mineralogy and organic matter type and content.