View
219
Download
1
Category
Preview:
Citation preview
www.oplnk.net/~glinsky
Integration of uncertain subsurface information into multiple reservoir simulation models
Michael E. Glinsky, Bruce Asher, Robin Hill, Mark Flynn, and Mark Stanley, BHP Billiton PetroleumJames Gunning, CSIRO PetroleumTroy Thompson, DownUnder GeoSolutionsJerome Kalifa, and Stephane Mallat, Ecole PolytechniqueDidier Renard, Ecole des MinesChris White, LSU
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 2
Outline
• Description of Stybarrow oil field• Use of sparse spike inversion and the correlation wavelet• Probabilistic wavelet derivation giving critical noise level• Probabilistic model based inversion with uncertainty• “Massaging” the results into the reservoir simulation model• “Decoration” and “Enforcement”
– adding the subseismic structure
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 3
Location of Stybarrow field
WESTERNAUSTRALIA
ExmouthPlateau
BarrowSub-basin
Exmou
th
Sub -ba
sin
InvestigatorSub-Basin
Cape Range Fracture Zone
NovaraArch
Reso
lution
Arc
h
Kanga
roo Syn
cline
Exm
outh
Pla
teau
Arc
h Oil Field
Gas Field
Oil & Gas Field
Jurassic to EarlyCretaceousDepocentre
Early CretaceousDepocentre
Triassic-Cored Structural Highs
Ningaloo ArchWA-255-P
50 km
Barrow Island
Scarborough
MacedonStybarrow
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 4
Structure map of Stybarrow field
Depth Structure Map of the Top Macedon Member
Stybarrow Oil Field
Laverda Oil and Gas Field
WA-271-P
WA-255-P(1)
1
2
34
N
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 5
Geologic cross section of Stybarrow
ReservoirDingo Fm Source Rock
Seal
NW SE
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 6
Seismic data and sparse spike inversion with secant amplitude extraction
soft
hard
Impedance
2.16 s
2.40 s
Stybarrow-3Stybarrow-4
Stybarrow-2 Stybarrow-1
-10%
+10%
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 7
Definition of secant amplitude and area
impedance vs. time
A
area
WP1 P3 P2
net sand = secant area * Vsand / 2 Rsand
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 8
0
5
10
15
20
25
30
35
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Net sand calculated from secant area
net sand (m)
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 9
Geometry used for inversion benchmark
400 ft
station0 200
8500 ft/s2.33 gm/cc68% N/G 9434 ft/s
2.37 gm/cc
7134 ft/s2.01 gm/cc
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 10
Inversion benchmark
0
100
200
300
400
0 50 100 150 200
station
net
san
d (
ft)
uninverted dataindustry inversion #1industry inversion #2new inversiontrue value
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 11
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Oil probability map calculated from secant amplitude
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
shale
oilgas
brine
0%
-8%
-16%
RFC
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
1.24 1.25 1.26 1.270%
-8%
-16%
secant amplitude
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 12
Tie of seismic data to synthetic seismic using probabilistic wavelet derivation
2.0 s
2.4 s
timegreen = seismicred = synthetic
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 13
Most likely probabilistic wavelet compared to correlation wavelet
probabilisticcorrelation
-60 ms
0 ms
60 ms
note: probabilistic wavelet is much shorter than correlation wavelet
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 14
Most likely probabilistic wavelet compared to ensemble of possible wavelets
-20 ms
20 ms
0 ms
note: noise is 17% size of oil reflector, SNR is 15 dB
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 15
Probabilistic model based inversion
• Layer based model built at seismic loop scale using sparse spikeinversion
• Standard rock physics correlations estimated with uncertainty• Fundamental properties of layers are:
– net-to-gross ratio (N/G)– layer top and base– fluid type
• Ensemble of models generated that are consistent with seismic towithin estimated noise level
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 16
Ensemble of models at Stybarrow-1 well location show effect of model based inversion
soft
hard
acoustic impedance
before after
realization realization
2.2 s
2.4 s
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 17
Effect of model based inversion on match of synthetic seismic to seismic data
2.24 s
2.36 s
before after seismic
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 18
Inversion tightens the range of possible net sand
before
after
well value0 m 50 m
probability of oil increased to 97% from 50% (oil in sand at this location)
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 19
Effect of inversion on estimation of N/G in main hydrocarbon (krieged to wells)
N/G0%
100%
STD N/G
before
after
after
before0%
30%
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 20
Estimation of oil probability
well control only inversion only0%
100%
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 21
Cross sections of mean model
before
after
2.40 s
2.16 s0%
100%
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 22
Net sand prediction ahead of drill bit
7.612.3 ± 4.3Stybarrow -4
29.1 ± 6.4Stybarrow-3
result (m)prediction (m)well
40% probability well values larger deviation than observed
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 23
Results of model based inversion “massaged” onto reservoir model
• Lateral correlation added• Short range noise eliminated• Put onto irregular corner point geometry• Fault blocks honored• Inter-layer and inter-property correlation honored
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 24
Difference between the seismic grid and the reservoir simulation grid
Stybarrow-1
1400
1600
1800
2000
2200
2400
2600
2800
Stybarrow-1
seismic grid reservoir simulation grid
1.2 km x 1.2 km
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 25
0
5
10
15
20
25
30
35
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Effect of massaging on mean net sand map
after
net sand (m)
7 km x 7 km
before
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 26
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Stybarrow-1
Stybarrow-2
Stybarrow-3 Stybarrow-4
Realizations of net sand generated by massager
net sand (m)
0
35
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 27
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
Cross sections through model realizations2040 m
2180 m
N/G
0%
100%
Stybarrow-1
Stybarrow-2
2.6 km
well
fault
note: models in depth
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 28
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
-2180
-2160
-2140
-2120
-2100
-2080
-2060
-2040
Reservoir simulation models are “decorated with subseismic structure
before decorationafter proportional decoration
after offlapping decoration
N/G
0%
100%
Integration of uncertain subsurface information into multiple reservoir simulation models4 April 2005Page 29
Conclusions
• Ensemble of reservoir simulation models consistent with:– Seismic data– Well information
– Geologic concepts
• Gives:– Volumetric distributions– Minimum net sand (well completion)– Etc.
• Range of production profiles– Potential production– Risks for development
Recommended