Geoscience Reference
In-Depth Information
Fig. 2.3
Capturing the reservoir concept in a simple sketch showing shapes and stacking patterns of reservoir sand
bodies and shales (From: van de Leemput et al.
1996
)
the absence of new seismic, a fault model may be
passed on between users and adopted simply to
avoid the inefficiency of repeating the manual
fault-building.
Such an inherited fault framework therefore
requires quality control (QC). The principal
question is whether the fault model reflects the
seismic interpretation directly, or whether it has
been modified by a
2.3
The Structural
and Stratigraphic Framework
The structural framework for all reservoir models
is defined by a combination of structural inputs
(faults and surfaces from seismic to impart gross
geometry) and stratigraphic inputs (to define
internal layering).
The main point we wish to consider here is
what
are the structural and stratigraphic issues that a
modeller should be aware of when thinking through
a model design
?Thesearediscussedbelow.
conceptual
structural
interpretation.
A direct expression of a seismic interpretation
will tend to be a conservative representation of
the fault architecture, because it will directly
reflect the resolution of the data. Facets of such
data are:
Fault networks tend to be incomplete, e.g. faults
may bemissing in areas of poor seismic quality;
Faults may not be joined (under-linked) due to
seismic noise in areas of fault intersections;
Horizon interpretations may stop short of faults
due to seismic noise around the fault zone;
2.3.1 Structural Data
Building a fault model tends to be one of the more
time-consuming and manual steps in a modelling
workflow, and is therefore commonly done with
each new generation of seismic interpretation. In
