Siesmic imaging of Cotton Valley hydraulic fractures

Summary Seismic events recorded during the hydrofrac of three zones of a deep gas well in the Cotton Valley formation are reported upon. Several thousand events were detected from three production fracs and a subset of these were located in the field. Induced fractures were observed to be longer than the predicted 750’-850’, with most of that length occuring early in the treatment. Asymmetric growth along the predicted fracture direction was documented, with one of the fracs appearing to have broken through a shale above the perforated interval.