Refraction seismic survey recorded in a wellbore on the flank of a salt dome.  A seismic source is positioned aboev the shallowes portion of the salt. Tota travel time along the refracted raypath is recorded in the wellbore. The depth to the top salt has to be known (a disposable well as to be drilled). From the top-salt depth, and the interval velocities of the salt, the overburden and the sediment on the flank, a salt profile can be computed. The resulting salt image is represented as a series of points in XYZ space (salt-exit points) positioned relative to the wellbore in which it was acquired ("salt-proximity survey")..  Results of several salt-proximity surveys (colored octagons) were used in conjunction with wellbore penetrations (yellow spheres) to grid the salt-sediment interface. Discovering the overhanging salt shown on this visualization was responsible for assing 20% reserves to an onshore Louisiana field.