Evaluation of Stratigraphic Elements on Fluid Flow – An Experiment Based
on Deep-Water Slope Channels in the Capistrano Formation (Miocene),
Stewart, Jonathan1, Ben
Fischer1, Colin Lyttle1, Kirt
Campion1, Anthony Sprague1 (1) ExxonMobil
Upstream Research Company,
Accurate predictions of flow rates,
timing of water and gas breakthrough, and hydrocarbon recovery are necessary to
assess the economic viability of deep-water reservoir developments. Typically,
this is achieved by constructing a geologic model, up-scaling,
and performing flow simulation. However, the replication of organized stratigraphic architectural elements in geological models
and the preservation of these elements in up-scaled reservoir simulation models
are difficult, often resulting in poor predictions of reservoir performance.
To examine the effects of stratigraphy on fluid flow, fine-scale 3D geologic models,
based on descriptions and measurements of deep-water channel remnants in the
Miocene Capistrano Formation, were constructed. This well-exposed formation
contains a variety of deep-water architectural elements including storeys, channels and channel complexes. The lithofacies within the Capistrano Formation include
gravel-rich turbidites, sandy turbidites,
and thin-bedded muddy turbidites.
Without up-scaling the geologic model, a
number of flow simulation experiments were carried out to test the impact of
gravel beds and shale drapes at the margins of channels on reservoir
performance. The presence of these heterogeneities had a significant negative
impact on recovery efficiency and timing of water breakthrough. The results
from these simple simulation experiments compared favorably with behavior
observed in subsurface reservoirs based on production and 4D seismic data. A
remaining challenge is to preserve the effect of these stratigraphic
details in coarser-scale simulation models, and we suggest one such method.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California