Using
Outcrop-Based 3D Geocellular Model as Seismic
Benchmark: Prestack Seismic Modeling of Grainstones in
Janson, Xavier1, Hongliu Zeng1, Charles Kerans1, Fred
Wang1, Sergey Fomel1 (1) The
Three dimension seismic data have become
a primary tool for building reservoir models and forecasting reservoir volumes
at all stages of the reservoir's life. In particular, one of the important
issues in the characterization and modeling of carbonate reservoir strata that
remains to be effectively addressed is the seismic characterization of
touching-vug pore systems and the integration of
seismic information into fluid-flow models. To address this problem, we built poststack and prestack synthetic
seismogram from accurate outcrop-based 3-D geological models. The geological
model is built for a Permian (lower San Andres) carbonate sequence exposed in
the Lawyer Canyon outcrop, New Mexico, that provides an excellent analog of
ramp-crest grainstones having both interparticle porosity and touching-vug
porosity. Post-stack seismogram calculated by 3-D exploding reflectors methods
are initially used to calibrate the sensitivity of the seismic methods to
velocity changes due to moldic pore and to assess the
mapability of these two pore type system using
acoustic inversion. Using the assumption that the effect of moldic
pore compared to inter-particle pore on seismic velocity primarily affects compressional velocity, we investigate the sensitivity of
the AVO response of these grainstone bodies using
pre-stack synthetic modeling. Because of the different Vp/Vs
between the grainstone with moldic
pores and the grainstone with interparticle
pores, we can map the two grainstone 3D bodies
directly from the synthetic pre-stack seismic volume.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California