Anisotropic rock physics and AVO modelling for the Bowland shale

Seismic anisotropy is often observed in organic-rich shales due to the presence of bedding-parallel organics, pores and fractures. Anisotropic rock physics models provide a crucial tool to link sub-seismic geological variations to seismic-scale elastic parameters; and this approach is of particular importance to complex shales such as the Bowland Shale; a prospective shale-gas target in England. In this study, we use rock physics models, combined with synthetic trace and AVO models to study the impact of kerogen, porosity and fractures at a discrete impedance boundary within the Bowland Shale. Our work demonstrates the effect these anisotropic features have on seismic-scale synthetic traces across the boundary, and how the AVO signature is modified; particularly the switch from Class 3 to Class 4 at high concentrations.