Microseismic monitoring of hydraulic well treatments is one of the most useful seismic techniques that can aid the development of tight-gas and shale-gas fields. The main challenge in these fields is an extremely low formation permeability, which lies in the microdarcy or even nanodarcy range and requires thousands of closely spaced wells to drain the reservoir. For example, the Barnett Field in Texas, USA, has more than 12,000 producing wells. Depending on the specifics of a given reservoir, it might be developed via vertical, or slanted, or horizontal wells, or any combination thereof. Such varied well geometries and relatively small well spacing provide ample opportunities for microseismic surveys.