A NEW WELLBORE SEISMIC PROSPECTING TECHNOLOGY

Seismic while drilling is a new wellbore seismic technology. It uses the vibrations produced by a drill bit while drilling as a downhole seismic energy source, and the continuous signals generated by the drill bit are recorded by a pilot sensor attached to the top of the drill string and by receivers located at selected positions around the borehole. The signals are processed by ways of crosscorrelation and deconvolution. Subsurface conditions (layer velocity, depth of reflected-interface, etc.) ahead of the drill bit can be predicted at any time during drilling without tripping out of the hole, and the seismic data are available at the well site for real-time drilling decisions.