Simplified Seismic Modelling of Fractured Rock: How Effective is the Localised Effective Medium Compared to Explicit Representation of Individual Fractures

Abstract Seismic waves can be an effective probe to retrieve fracture properties particularly when measurements are coupled with forward and inverse modelling. These seismic models then need appropriate representation of the fracturing. The fractures modelled either explicitly, considering zero thickness frictional slip surfaces, or by medium which incorporates effect into medium, creating anisotropy in wave velocities. In this work, we use a third approach is hybrid previous two. area surrounding predefined treated as rest made homogeneous isotropic, Localised Effective Medium (LEM). LEM accurate explicit but more efficient run-time. We have shown that model closely match reproducing waveforms recorded laboratory experiment, for propagating parallel perpendicular fractures. performs close wavelength much larger than element size spacing. By definition model, expect layer becomes coarser will start approaching result. However, what limitations there balance between stiffness, frequency thickness, where approaches model? To define limits experiment varying stiffness source frequency. compare each five different thickness. Finally, conclude thick layers lower resolution perform same thinner finer frequencies higher stiffness.