The case for depth imaging all 3D data

Structural complexity in time-imaged seismic data is often due, not to geology, but to lateral-velocity variations that have not been properly addressed. Numerous data examples show the improved imaging and phase stability that depth migration provides when compared with time migration. Gridded cell tomography is the enabling technology that allows the development of geologically-consistent velocity models suitable for use with prestack depth migration. The incorporation of VTI or TTI parameterization in the imaging process can also provide benefits, especially if well calibration is invoked, since this will improve the structural response and form “true-depth” 3-D seismic volumes.

Improving the integrity of seismic data through depth imaging has the potential to reduce the exploration cycle time, allow for improved horizontal well-planning; and reduce the uncertainty involved when fault avoidance is critical.