heavy-oil seismic monitoring at pikes peak, sk i.a. watson*, l.r. lines and k.f. brittle november...
TRANSCRIPT
HEAVY-OIL SEISMIC MONITORINGat PIKES PEAK, SK
I.A. Watson*, L.R. Lines and K.F. BrittleI.A. Watson*, L.R. Lines and K.F. Brittle
November 20, 2001November 20, 2001
Combined two CREWES papersCombined two CREWES papers– ““Heavy-oil time-lapse seismic monitoring Heavy-oil time-lapse seismic monitoring
at Pikes Peak, Saskatchewan”at Pikes Peak, Saskatchewan”– ““Heavy-oil reservoir characterization Heavy-oil reservoir characterization
using elastic wave properties”using elastic wave properties”
Outline
IntroductionIntroductionGeologyGeologyAnalysis 1: Section DifferencingAnalysis 1: Section DifferencingAnalysis 2: Isochron RatioAnalysis 2: Isochron RatioAnalysis 3: Vp/Vs RatioAnalysis 3: Vp/Vs RatioConclusionsConclusions
Pikes Peak Time-lapse
Injected steamInjected steam– Reduces reservoir impedanceReduces reservoir impedance– Causes increased compressional wave Causes increased compressional wave
traveltimetraveltimeTwo (time-lapse) seismic lines Two (time-lapse) seismic lines
– 2-D lines in co-incident locations2-D lines in co-incident locations 1991 (swath)1991 (swath) 2000 (multi-component)2000 (multi-component)
Pikes Peak
Heavy-oil fieldHeavy-oil fieldOperated by Husky EnergyOperated by Husky Energy40 km east of Lloydminster40 km east of LloydminsterOver 40 million bbls producedOver 40 million bbls producedSteam injection operationSteam injection operation
DATA
• 200+ wells 200+ wells
• 1991 2D swath 1991 2D swath
• 2000 4C-2D 2000 4C-2D
• 2000 VSP2000 VSP
Pikes Peak Field Map
R.23W3 R.24W3
T.49
T.50
1 km H1991 and H2000
3C8-6
D15-6
1A15-6
D2-6
Data Comparison
H1991H1991February 1991
6 sec6 sec8-110 Hz non-linear
3 vibrators over 20 m3 vibrators over 20 m4 sweeps/vp4 sweeps/vp
10 m drag length10 m drag length40 m40 m source interval source interval20 m20 m group interval group interval
9 geophones over 20 m9 geophones over 20 m3030 CDP fold CDP fold
Bandwidth 14 – 110 Hz
H2000March 2000
16 sec8-150 Hz non-linear
22 vibrators over 20 m vibrators over 20 m4 sweeps/vp4 sweeps/vp
NoNo drag drag220 m0 m source interval source interval20 m20 m group interval group interval
66 geophones over geophones over 110 m0 m66 CDP fold66 CDP fold
Bandwidth 14 – 150 Hz
Data Comparison
Pikes Peak Geology
Waseca Trend in Pikes Peak AreaWaseca Trend in Pikes Peak Area
Van Hulten, 1984
Pikes Peak Geology
• Incised valleyIncised valley• Estuarine -point barsEstuarine -point bars• N-S N-S • ~500 m depth~500 m depth
• Salt dissolution structure Salt dissolution structure and stratigraphic trapand stratigraphic trap• 80-90% oil saturation80-90% oil saturation• 5-30 m net pay5-30 m net pay• 32-36% porosity32-36% porosity• 1-10 darcies perm. 1-10 darcies perm. • 1212° API° API
Van Hulten, 1984
Analysis 1: Section Differencing
Time-lapse differences ofTime-lapse differences of– Reflectivity Reflectivity – Acoustic Impedance (AI)Acoustic Impedance (AI)
Calibration
Required prior to differencing Required prior to differencing Hampson-Russell’s Pro4DHampson-Russell’s Pro4DAdjustments for:Adjustments for:
TimeTimeAmplitude Amplitude PhasePhase
Time window above zone of interestTime window above zone of interestTrace-by-trace gave best resultsTrace-by-trace gave best results
Refectivity Differencing
Applied a wavelet-shaping filter to H2000Applied a wavelet-shaping filter to H2000Differences seen below reservoir Differences seen below reservoir Increase in traveltime caused by Increase in traveltime caused by
presence of injected steampresence of injected steamDoes not allow signal to cancelDoes not allow signal to cancel
Other differencesOther differencesNoiseNoiseAcquisition parametersAcquisition parameters
H1991 Reflectivity Section
N S
H2000 Reflectivity Section
Reflectivity Difference Section
Impedance Differencing
Applied a band-pass filter, wavelet Applied a band-pass filter, wavelet shaping and time and phase matching to shaping and time and phase matching to H2000H2000
Significant differences seen within Significant differences seen within reservoir zone – lower impedancereservoir zone – lower impedance
Lower AI extends further than expectedLower AI extends further than expectedHas the steam reached further?Has the steam reached further?Limited by 2-D sectionLimited by 2-D section
H1991 AI Section
H2000 AI Section
AI Difference Section
Analysis 2: Isochron Ratio
Interpretation basedInterpretation based– H1991 and H2000H1991 and H2000– Waseca-Sparky intervalWaseca-Sparky interval
Isochron ratioAddition of steamAddition of steam
– Vp decreaseVp decrease– Increase in 2000/1991 isochron ratioIncrease in 2000/1991 isochron ratio
Position of steam zone predicted on linePosition of steam zone predicted on line
Seismic lineSeismic line
Steam zone Steam zone on lineon line
Steam zoneSteam zoneradiusradiusHusky, 2000
D2-6 Waseca Core Analysis
0
500
1000
1500
2000
2500
0 20 40 60 80 100 120 140 160 180
Temperature (°C)
Vel
oci
ty (
m/s
)
Compressional
Source: Core Laboratories
H1991 Reflectivity Section
H2000 Reflectivity Section
2000/1991 P-P Isochron Ratio (Waseca-Sparky)
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1 51 101 151 201 251
CDP #
inte
rva
l ra
tio
3B1-61D2-6
3C1-63B8-62B9-61D10-6
Waseca thickest sands
N S
Analysis 3: Vp/Vs Ratio
Interpretation based Interpretation based – H2000 multi-component onlyH2000 multi-component only– PP and PS sectionsPP and PS sections– 2 intervals2 intervals
Vp/Vs ratioAddition of steamAddition of steam
– Vs decrease < Vp decreaseVs decrease < Vp decrease Vp/Vs decrease = steamed zoneVp/Vs decrease = steamed zone
Vp/Vs ratio derived from P-P and P-S interpretationsVp/Vs ratio derived from P-P and P-S interpretations
pp
ppps
s
p
t
tt
V
V
2
pp
ppps
s
p
t
tt
V
V
2
Margrave et al., 1998
D2-6 Waseca Core Analysis
0
500
1000
1500
2000
2500
0 20 40 60 80 100 120 140 160 180
Temperature (°C)
Vel
oci
ty (
m/s
)
Shear
Compressional
Source: Core Laboratories
H2000 P-P (Vertical Component)
H2000 P-S (Radial Component)
Vp/Vs Isochron Ratio (Waseca-Sparky)
1.0
1.5
2.0
2.5
3.0
3.5
1 101 201 301 401 501 601 701
CDP #
Vp
/Vs
ra
tio
3B1-61D2-6
3C1-63B8-62B9-61D10-6
Waseca thickest sands
N S
Vp/Vs Isochron Ratio (Mnvl to L.Mnvl)
1.0
1.5
2.0
2.5
3.0
3.5
1 101 201 301 401 501 601 701
CDP #
Vp
/Vs
ra
tio
3B1-61D2-6
3C1-63B8-62B9-61D10-6
Waseca thickest sands
Injection during2000 acquisition
N S
Conclusions
Anomalies are generally located where Anomalies are generally located where expectedexpected
Inferred steam response on both the time-Inferred steam response on both the time-lapse and the Vp/Vs ratio plotslapse and the Vp/Vs ratio plots
Difficult interpretation on converted wave data Difficult interpretation on converted wave data Potential lateral lithology changes identifiedPotential lateral lithology changes identified Minimize all variables external to the reservoir Minimize all variables external to the reservoir 3-D seismic data is recommended3-D seismic data is recommended
Acknowledgements
• Husky EnergyHusky Energy
• AOSTRA (COURSE)AOSTRA (COURSE)
• Jason Geosystems Jason Geosystems
• Hampson-RussellHampson-Russell
• CREWESCREWES
• NSERC and Imperial OilNSERC and Imperial Oil
PS synthetic: GMA
Acoustic Impedance ( AI )
• AI obtained through inversionAI obtained through inversion• Band limited resultBand limited result• Trace-based vs. model-basedTrace-based vs. model-based• Post-stack interpretation techniquePost-stack interpretation technique
i
iii
ii
iii
ii
R
RZZ
ZZ
ZZR
VZ
1
1 Thus,
tyReflectivi
Impedance
1
1
1
i
McQuillin 1984
iZ
1iZ
AI Inversion
Reduces effect of wavelet sidelopes and Reduces effect of wavelet sidelopes and tuningtuning
Interpret boundaries and evaluate internal Interpret boundaries and evaluate internal propertiesproperties
Allows direct comparison of time-lapse Allows direct comparison of time-lapse surveyssurveys
Inversion performed using Jason Inversion performed using Jason GeoscienceGeoscience
WellWell Months Months before H91before H91
Months Months before H00before H00
3B1-63B1-6 00 1414
1D2-61D2-6 3838 2525
3C1-63C1-6 6767 8989
3B8-63B8-6 n/an/a 00
2B9-62B9-6 n/an/a 2626
1D10-61D10-6 n/an/a 1212
Injection Information
PS synthetic: matlab
0 300