LUTON, LARRY C. and CORINE PRIETO , Integrated Geophysics Corp., Houston, Texas

Accurate depth conversions reduce risk is not a new concept. The challenge lies in the proper selection of velocity data and model types that will generate accurate depths for the prospective area.

Velocity information is available from a number of different sources. Well velocity data is available from checkshots, vertical seismic profiles, sonic logs and geological tops. Seismic imaging velocities (stacking and migration) are interpreted from various seismic processes (2D/3D DMO, 2D/3D Prestack Time and Depth Migration).

There are many velocity model types. They range from a single function to detailed 3D model and can be average velocity, interval velocity, root mean square velocity or depth. The type of model and procedure selected is influenced by available data, lithology and geophysical acquisition and processing parameters.

Our Gulf of Mexico example will illustrate the gains in prospect resolution by using the correct data set and the benefits to calibrating well and imaging data sets for that area. We will also show the refinement gained from the integration with interpretations such as seismic derived fault interpretation and/or salt geometry from a 3D-gravity model.

AAPG Search and Discovery Article #90908©2000 GCAGS, Houston, Texas