Geoscience Reference
In-Depth Information
Fig. 5.16
Alternative reservoir architectures (Images courtesy of Simon Smith) (Redrawn from Bentley and Smith
2008, The Geological Society, London, Special Publications 309
Geological Society of London [2008])
#
Realisation
Structure
Quality
Contacts
Architecture
Thin beds
Orientation
Response
1
-1
1
1
1
-1
1
1178
2
-1
-1
1
1
1
-1
380
3
-1
-1
-1
-1
-1
-1
109
4
1
-1
1
1
-1
1
1105
5
-1
-1
-1
1
1
1
402
6
1
-1
1
-1
-1
-1
1078
7
1
1
-1
1
1
-1
1176
8
1
-1
-1
-1
1
1
1090
9
-1
1
-1
-1
-1
1
870
0
-1
1
1
-1
1
-1
932
11
1
1
-1
1
-1
-1
1201
12
1
1
1
-1
1
1
1245
13
0
0
0
0
0
0
956
14
1
1
1
1
1
1
1656
Fig. 5.17
Plackett-Burmann matrix showing high/low combinations of model uncertainties and the resulting response
(resource volumes in Bscf)
1.
Top reservoir structure;
caused by poor qual-
ity seismic and ambiguous depth conversion.
This was modelled using alternative structural
cases capturing plausible end-members.
2.
Thin-beds;
the contribution of intervals of
thin-bedded heterolithics was uncertain as
these intervals had not been produced or tested
in isolation. This uncertainty was modelled by
generating alternative net-to-gross logs.
3.
Reservoir architecture;
uncertainty in the
interpretation of the depositional model was
expressed using three conceptual models: tidal
estuarine, proximal tidal-influenced delta and
distal tidal-influenced delta models (Fig.
5.16
).
A model was built for each, with no preferred
case.
4.
Sand quality;
this is an uncertainty simply
because of the limited number of wells and
was handled by defining alternative cases for
facies proportions, the range guided by the
best and worst sand quality seen in wells.
5.
Reservoir orientation;
modelled using alter-
native orientations of the palaeodip.
6.
Fluid contacts;
modelled using plausible end-
members for fluid contacts.
These six uncertainties were combined using
a 12-run Plackett-Burmann design. The way in
which the uncertainties were combined is shown
