Characterization of Shale Structure Subjected to Two Different Loading Rate Conditions

Hydraulic fracturing is an important technique to produce oil and gas through the stimulation of unconventional hydrocarbon reservoirs, typically shale deposits. Quantifying elastic properties of bi-modulus shale under static and dynamic loading in different orientations is consequential. The in-situ bulk modulus of Wolfcamp shale is tested at two different loading rates. First, a universal testing machine was used for a quasi-static uniaxial compression test of a Brazilian disk, and then SHPB was utilized for a dynamic compressive load. Far-field loading data and local full-field deformation are used to calculate the physical properties through the linear elastic model. Static and dynamic mechanical properties of shales, such as elastic bulk modulus, compressive and tensile strength, were analyzed in two bedding orientations. The full experimental results are shown in detail, and in general, the elastic properties of shale under parallel and normal bedding conditions are different, as well as the static and dynamic in-situ elastic modulus are different.