Subsalt Image Improvements in GOM using Shale and Salt Discrimination through PSDM Velocity Model Building

Muskaj, Shkelqim¹, David Quintanilla², Hector Sepulveda² (1) Veritas Humpson Russell, Houston, TX (2) Veritas Humpson Russell, Houston,

Shale and salt generally have the same seismic chaotic facies. Further more, shales, like salt can be movable under sedimentary load. Because of these similarities it is difficult to separate them from each other. Having different velocity from salt will deteriorate the subsalt image if they are interpreted to be salt instead of shale. Through iteration of velocity model building for PSDM in Keathley Canyon, Walker Ridge of GOM we have separated the shale and salt bodies and by doing that the subsalt image has been improved significantly. Reflection strength, wavelet polarity, as well as gather, base salt and subsalt reflection behavior on different iteration of velocity model building process have been very helpful in differentiation of shale and salt.