Zero-offset Profile from Near-field Hydrophone Data

Subsurface reflection imaging as currently practiced in the oil industry attempts to generate an equivalent zero-offset seismic trace by combining the energy recorded at many source locations. Because of the source and receiver geometries used for marine seismic data acquisition, a seismic trace is never recorded at the zero offset. This is true for marine streamer, Ocean Bottom Cable (OBC) and Ocean Bottom Seismometer (OBS) acquisition geometries. Recording a zero offset or a very nearly zero offset seismic trace allows for more accurate trace interpolation for such processes as AVO analysis and SRME, allows the identification of near surface reflections and diffractions and possibly allows multiple generators to be identified. With appropriate processing, the near-field hydrophones that are embedded in seismic source arrays can be used to create zero and near zero 2D profiles. For 3D OBC and OBS surveys, the 2D profiles can be combined to create 3D, near-surface volumes.