Abstract: 4-D Seismic Interpretation Technologies, and Their Application to the Eugene Island 330 Field, Offshore Louisiana

R. N. Anderson

Within the Global Basins Research Network, we have developed 4-D volume processing and attribute analysis algorithms to identify significant seismic amplitude interconnectivity and changes over time that result from active fluid migration. To accomplish this 4-D imaging, we use multiple 3-D seismic surveys done several years apart over the same blocks.

We have applied these 4-D analysis techniques to known production from the most prolific Pleistocene oil field in the world, the Eugene Island 330 field of offshore Louisiana, central Gulf of Mexico. Three main producing reservoirs were examined at 4500, 5400, and 7200 ft. Dim-outs were detected where production depleted oil and gas during the interval of investigation, and amplitude increases were observed where gas/oil ratios increased during production. The "oil/water contact" movement was detected by the 4-D technique. When combined with active pressure and temperature monitoring, repeated 3-D seismic imaging of producing fields promises to identify missed hydrocarbon zones, and to provide the critical production management information of the future.

In addition, we have imaged fluid flow pathways that are actively recharging shallower reservoirs in the field from fluid sources that appear to be turbidite stacks within salt withdrawal mini-basins buried deep within geopressure. Fault zone conduits provide the migration pathways out of geopressure. If correct, large reserves remain untapped within the deep shelf of the northern Gulf of Mexico.

AAPG Search and Discovery Article #90953©1995-1996 AAPG Distinguished Lecturers