U.S.-SOVIET JOINT VENTURE TO PRESS SEISMIC PRESTACK INTERPRETATION

Geophysical companies are seeking new ways to extract information from seismic reflection data lost or hidden by common depth point (CDP) stacking, a standard processing technique. A new U.S.-Soviet joint venture that will specialize in prestack interpretation cites two problems with conventional CDP stacking: CDP assumptions aren't valid in areas of complicated structure and in the presence of velocity anomalies. The stacking process tends to remove or smear important characteristics of

May 27, 1991

2 min read

Geophysical companies are seeking new ways to extract information from seismic reflection data lost or hidden by common depth point (CDP) stacking, a standard processing technique.

A new U.S.-Soviet joint venture that will specialize in prestack interpretation cites two problems with conventional CDP stacking:

CDP assumptions aren't valid in areas of complicated structure and in the presence of velocity anomalies.
The stacking process tends to remove or smear important characteristics of the data, such as amplitude, velocity, and phase information. Smearing often reduces data resolution.

With modern computers and new processing techniques, seismic interpreters can make use of information hidden or destroyed in the stacking process, says the venture, Earth Modeling Systems (EMS), Houston.

Three U.S. firms and a Soviet research center formed the venture to develop and market software for interactive analysis and specialized interpretation of prestack seismic data.

Participants are Interactive Network Technologies, Minneapolis; Radix Inc. and Resource Technologies, Houston; and Geophysical Informatics Research Center/Siberian Division of the U.S.S.R. Academy of Sciences.

SPECIALTIES

Technologies employed by EMS will reflect the specialties of its participants.

Resource Technologies works in prestack analysis. Central to the technique 'is the relationship between high resolution stacking velocities, surface-associated time distortions (statics), and buried time distortions (velocity effects).

Resource Technologies says properly trained interpreters can use refraction statics, horizon velocity analysis, surface consistent statics analysis, and linearized inversion to identify and correct for velocity gradients, which distort the relationship between time and depth.

The Soviet research center has been conducting theoretical and computational studies in the area of advanced algorithms of digital signal processing, forward seismic modeling, and linearized inversion.

It has worked in 2D and 3D prestack depth migration, 1D and 2D inversion, and wave-equation and ray-tracing forward modeling. Comparison of wave-equation and ray-tracing forward solutions can help geophysicists relate seismic anomalies with specific components of the full wave field.

Radix specializes in the mathematical aspects of digital signal analysis and processing.

The company has worked on handling of mathematical operators via a discrete approach that eliminates noise problems introduced through the conventional, sampled approach.

Interactive Network Technologies specializes in data analysis and visualization tools.