Abstract

Approximately a quarter of a century ago, Eivind Berg, James Martin and Bjørnar Svenning “took land seismic to the seabed.” Their pioneer acquisition and processing work, which was supported by Statoil (now Equinor) provided a new tool to the seismic exploration community to address the well known issue of imaging reservoirs located underneath gas charged sediments. The early successes on the application of shear waves recorded at the seabed sparked an explosion of interest and activity. Theoretical seismologists, who studied the potential applications of this new type of seismic acquisition, came up with a long list that included: imaging reservoirs with weak acoustic impedance contrasts, fracture characterization, distinction of lithology and fluid effects, pore pressure prediction, high resolution imaging of shallow reservoirs, imaging underneath formations with high P impedance contrasts and discrimination between saturation and pressure changes in reservoir monitoring. Arguably, only imaging underneath gas charged sediments has so far been a widely employed success of shear waves recorded at the seabed.