Depth Imaging
PGS has been an industry leader in depth imaging since 1992, when we were the first to implement the vertical update procedure for Kirchhoff prestack depth migration commercially. Our depth imaging professionals at PGS centers worldwide have processed large volumes of prestack depth migration from a diversity of geological settings, and covering a full spectrum of imaging challenges and processing objectives. PGS continues its leadership position in depth imaging with new technologies including an efficient wave equation depth migration, and velocity model building and tomography in the context of our 3D visualization technology, holoSeis. Our philosophy is to work closely with our clients to better understand the characteristics of their data and the velocity regime, as well as their expectations in depth domain processing. We can then recommend a velocity model building and depth imaging strategy best suited to the specific requirements of their project.
Kirchhoff PSDM Wave Equation PSDM Velocity-Depth model
Example comparison of standard Kirchhoff vs. PGS wave equation pre-stack depth migration results.
The PGS holoSeisTM visualization technology provides an excellent interface between velocity model building and QC.
An example of pre-stack depth migration (PSDM) in combination with 4D and 4C began in 2003. PGS provided on-site dedicated services to process the industry’s first Life of Field Study (LoFS) over the Valhall field in the North Sea. This permanent installation, time-lapse (4D) study is comprised of a baseline survey and multiple repeat surveys at regular time intervals. Processing encompassed the preprocessing of 4C data, anisotropic velocity model building and updating for p-wave and converted wave volumes, and pre-stack depth migration (PSDM) of the P-wave and C-wave volumes, all in the perspective of 4D processing of the Baseline and Monitor surveys.
