3-D seismic surveys in particular are helping in the imaging of subsalt exploration plays. Confirm salt shape with Gravity. Reiterate interactive seismic processing. Seismic Methods Imaging subsalt is a critical challenge . Salt, with a velocity of 14,000 feet per second, is significantly faster than surrounding sediments with typical velocities of 7,000 - 10,000 feet per second.
Much energy is lost in passing through the salt, requiring a strong seismic source for subsalt work.
Also, accurate stacking and migration velocities are necessary to get good results. Multiples present a major problem subsalt, and stacking the data with multiple velocities will only enhance the multiples further. A Tau-p or Radon Transform demultiple program can do wonders at repressing multiples. Depth Conversion is another critical skill in successful subsalt exploration. Since salt is faster than the sediments above or below it, unequal thicknesses of salt result in varying amounts of velocity pull-up over the area.