INTEGRATED RESERVOIR CHARACTERIZATION - BEYOND TOMOGRAPHY

In 1992, there was a collaborative effort in reservoir geophysics invo lving Amoco, Conoco, Schlumberger, and Stanford University in an attem pt to delineate variations in reservoir properties of the Grayburg uni t in a West Texas CO2 pilot at North Cowden Field. Our objective was t o go beyond traveltime tomography in characterizing reservoir heteroge neity and flow anisotropy. This effort involved a comprehensive set of measurements to do traveltime tomography, to image reflectors, to ana lyze channel waves for reservoir continuity, to study shear-wave split ting for borehole stress-pattern estimation, and to do seismic anisotr opy analysis. All these studies were combined with 3-D surface seismic data and with sonic log interpretation. The results are to be validat ed in the future with cores and engineering data by history matching o f primary, water, and CO2 injection performance. The implementation of these procedures should provide critical information on reservoir het erogeneities and preferential flow direction. Geophysical methods gene rally indicated a continuous reservoir zone between wells.