Using the direct seismic responses of fractures and fracture zones in productive formations to obtain information about their locations and characteristics is an essentially new and promising direction of investigation. Given the growing production of hydrocarbons from unconventional reservoirs, the basic understanding of seismic wave responses of natural and hydraulic fractures is urgently needed, and the ability to model those waves is a necessary first step toward detection and more accurate characterization of fractured reservoirs and through this process toward improved oil production. This book addresses the properties of seismic waves of fractured media by describing, modeling, and analyzing the various seismic wave responses from discrete fractured media, and it proposes a methodology for the direct detection of fractured reservoirs based on these analyses. Use of the grid-characteristic method to numerically model the waves allows for the inclusion of fundamental properties of real fractured reservoirs and fractured features in the analysis. Importantly, this method facilitates a highly accurate computation of wave propagation that accounts for the multiple discreteness of the medium. Of use to oil company geophysicists and geologists directly involved in interpretation of seismic data acquired from prospects of fractured reservoir development, this book also will be of interest to scientific workers in universities (particularly postgraduate students) and R&D departments of geophysical and oil companies.