Another look at the question of azimuth

The question of azimuth seems to be an emotional issue in 3-D seismic exploration. Some people believe that 3-D surveys should contain a wide range of source‐receiver azimuths so that the subsurface is sampled from all directions and the acquisition is closer to a “true” 3-D survey. Others, on the other hand, argue the case for narrow azimuth acquisition. A few years ago, Malcolm Lansley, then with Halliburton Geophysical, gave an excellent presentation regarding the question of azimuth at an SEG summer workshop. In this talk (which was recently presented to the Houston Geophysical Society), Lansley provided an extensive summary of the advantages and disadvantages of wide azimuth surveying, and listed many aspects that one should consider when deciding between narrow and wide azimuth acquisition.