High-Resolution
Reservoir Modeling of a Deepwater Channel Complex with Thin Beds,
Schwans, Peter1,
Marty Cohen2, Kim Zauderer2, Stephen D. Knapp2,
Ted C. Lukas3 (1) Devon Energy Company, Houston, TX (2) Devon Energy
Company, (3) Consultant,
The Zafiro
Field of Equatorial Guinea comprises stacked channel complexes of
Miocene-Pliocene clastics deposited in the mid to
lower slope position of the Niger Delta. Detailed reservoir models are being
built to better understand facies distribution and
the impact of thin beds on reservoir performance.
Models integrate 4th - 5th order seismic
surfaces, geobodies interpreted in VoxelGeo, petrofacies calibrated
to core, and thin-bed data from image logs. The channel complex consists of
three multi-stage channels with complex margins. Three reservoir facies are recognized: (1) Massive pebbly sandstones
deposited by debris flows; (2) Medium to fine grained sandstones deposited as
debris flows and turbidites; and (3) Interbedded sandstones, siltstones, and shales
deposited in the proximal overbank by turbidites. Distinct e-log facies
or petrofacies calibrated to cores were brought into
the modeling process as facies-specific probability
curves. The relationship of seismic amplitude to reservoir facies
was used to populate the model. Geobodies interpreted
in VoxelGeo allow better definition of near-channel overbank areas. The geological model captured the
connectivity between wells. The dynamic model evaluated the performance of thin
bed regions in the proximal overbank. A history match
of the production performance at all wells was achieved primarily by adjusting
net-to-gross values in the gas cap. Shut-in pressures, water cuts, and GOR data
were all matched successfully at each well.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California