3-D Seismic Surveys and the Data Crush

M. R. Stamatedes, E. S. Hagan

3-D seismic surveys acquired in old fields with hundreds of wells present an overwhelming volume of seismic and subsurface data, resulting in a data management "crush". Utilizing the key data elements is essential to a successful exploitation program.

A "data factor" was developed to aid in project planning. The data factor considers the number of wells, productive reservoirs, major fault planes, and the quality and size of the 3-D seismic survey.

West Cote Blanche Bay Field (WCBB) in South Louisiana exemplifies the data crush. Discovered by Texaco in 1938, the field has produced approximately 200 MMBO and 200 BCFG from 130 sands in nearly 800 wells surrounding a highly faulted salt dome. A 65 square mile 3-D seismic survey was acquired in 1992.

For the WCBB project, relevent subsurface data were loaded into a database which contains 770 well bores, 21,600 top and fault picks, 2,000 completions, 790 log shows and production tests, 660,000 curve feet of logs and 4 check shot surveys.

Subsurface data can be displayed on seismic base maps and trace data. Penetrations/production maps demonstrate decreasing penetrations and a change from oil to gas production with increasing depth. Superimposing seismic fault planes on the maps quickly reveal lead areas. High potential areas are determined and interpreted in detail using the 3-D seismic data.

The #831 well, currently producing 25 MMCFG/D and 230 BCPD from a Marg(A) sand, was suggested by production-penetration-fault plane maps and drilled based on a 3-D seismic interpretation. Additional pay zones in the #831 have been evaluated utilizing penetration/production maps in conjunction with seismic mapping.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995