Paper Summary
Prestack depth imaging—consisting of both velocity/depth model building and prestack depth migration (PSDM)—is increasingly becoming the rule rather than the exception when the goal is to more clearly reveal a subsurface complicated by structure or velocity.
The growth of depth imaging was initially fueled and cost-justified by the extreme risk presented by subsalt exploration targets such as those found in the deep water Gulf of Mexico. Depth imaging is now being applied around the world, both onshore and offshore and during both exploration and production phases, to remove obscuring effects produced by a diverse range of geologic and geophysical conditions. Recent case studies illustrate that salt, reefs, thrusts, normal faults, low signal-to-noise ratio, gas clouds, slump zones, shale, and basalt can all result in velocity complexity and imaging challenges that only prestack depth imaging can address effectively.