4D Seismic Monitoring Technologies, and their Application to the Eugene Island 330 Field of Offshore Louisiana

Roger N. Anderson, A. Boulanger, Wei He, and Liqing Xu

We have developed 4D volume processing and attribute analysis algorithms to identify significant seismic changes over time that result from drainage of oil and gas within reservoirs. The 4D seismic monitoring methodology merges the computational simulation of expected changes in acoustic reflectivity from drainage with the observed snapshots of the real reservoir impedance changes. We demonstrate its utility in the Eugene Island 330 field of offshore I-ouisiana, where 4 generations of 3D seismic surveys have been acquired first in 1985. then in 1988, 1992 and again in 1994. These datasets contain seismic snapshots of the field as it has been drained of more than 100 million barrels of oil equivalents. Dim-outs were detected where production depleted oil and gas, and ampli ude increases were observed where secondary gas caps formed. The "oil/water contact" movement was also detected by the 4D technique. When combined with active pressure and temperature monitoring, production history matching, and Sw changes detected in cased-hole pulsed-neutron logs, 4D seismic imaging of producing fields promises to allow real-time production control in the future.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California