Cichowski, Leonard1, Roel Garcia1, Robert James2,
David Paddock2, Dan Shan2
(1) Seneca Resources Corporation, Houston, TX
(2) Schlumberger, Houston, TX
ABSTRACT: Redevelopment of a Mature Field in the Face of Seismic Uncertainty: Vermilion 252 Field, Gulf of Mexico
Vermilion 252 field was discovered in 1994 as a result of drilling well-defined
amplitude anomalies on two reservoir horizons. However, after several years of production
from both reservoirs it became clear that both reservoirs contained more oil than could be
accommodated in rock volumes based on amplitude-derived net sand thickness. This
presentation describes a method to resolve this discrepancy and to determine whether the
additional oil volume represented an opportunity for further development of the field.
After phase-matching of the near-offset seismic cube an empirical relationship was
developed between amplitude and net pay thickness, constrained by the maximum thickness of
pay based on structural considerations. The resulting net pay predictions were then used
to constrain a geocellular model, which was built using Sequential Indicator Simulation
(SIS) to distribute reservoir facies. The model was then upscaled and subjected to flow
simulation. However, no history match was possible for the initial model. The problem was
solved by developing an SIS protocol to populate the reservoir by small shale bodies that
were oriented parallel to some possible channel features seen on seismic horizon slices.
Running the final history-matched simulation model in predictive mode then allowed
development options to be evaluated. Both infill drilling and re-completion opportunities
were identified.
Vermilion 252 is an example of a field in which subsurface uncertainty cannot be
adequately constrained using the available seismic data alone. Only full integration of
seismic modeling with stratigraphic analysis and reservoir simulation could provide a
sound basis for defining redevelopment options.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.