3D Geometrical
Simulations of LOSCs (Laterally Offset Stacked Channels)
Labourdette, Richard1 (1)
Total S.A,
Reservoir modeling commonly requires a
description of sedimentary heterogeneity on a scale smaller than that given by
seismic resolution. In particular, complexes of Laterally Offset Stacked
turbidite Channels (LOSCs) require a description at the scale of individual
channel bodies, while seismic data only displays the outside geometry of their
lateral stack, i.e. a turbidite fairway. The most common representation of
channels in a fairway is by stochastic object modeling; i.e., populating the
observed fairway by realistic shapes representing individual channels, but
without ensuring a consistency between the individual channels. On the other
hand, one essential characteristic of LOSCs is to evolve by progressive
migration laterally and/or downdip. Stochastic object modeling fails to
adequately represent this progressive evolution, and therefore provides a poor
rendering of the distribution of heterogeneity in the reservoir. The method we
propose consists in defining a realistic succession of individual channels that
can build the fairway observed on seismic. “Realism” is defined using criteria
on the shape of individual channels, and on the amount of displacement that is
allowed between successive episodes. Depending on seismic resolution, the
system can be constrained by one or several positions of individual channels
(the last position of the channel is often filled by shale, therefore visible
on seismic and usable as a control point). The final result is a deterministic
succession of channels laterally stacked to build the seismically observed
envelope. Even in the absence of any calibration, the resulting architecture
will honor the general “texture” of the complex, and provides a better
simulation of flow pathways than random object modeling.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California