1. A method of characterizing a fractured reservoir in a field, comprising: measuring seismic reflection coefficient of the fractured reservoir as a function of angle of incidence and azimuth; predicting seismic reflection coefficient of the fractured reservoir as a function of angle of incidence and azimuth using an elastic stiffness tensor and an elastic compliance tensor of the fractured reservoir; determining components of an excess compliance tensor due to the presence of fractures in the fractured reservoir by matching the predicted seismic reflection coefficient to the measured seismic reflection coefficient; and characterizing one or more properties of the fractured reservoir using the excess compliance tensor.