Imaging tight gas sandstones in the East Texas Basin

Low porosity (tight) gas sands contain important commercial reserves but, unfortunately, are difficult to image seismically with the quality needed to drive an effective drilling programme. These reservoirs typically have a small contrast in acoustic impedance relative to the encasing shales which results in a subtle seismic signature. This signature becomes even more difficult to identify in the presence of intra-bed multiples and other undesired seismic energy. Since this resource is predominantly exploited in the onshore arena, seismic imaging is also subject to the many cultural and near surface factors that affect land seismic data quality.