Continuous 4D Seismic for Thermal EOR Monitoring
Continuous 4D Seismic for Thermal EOR Monitoring Dave Tam, CGG
Outline Introduction to 4D or Time Lapse seismic SeisMovie – a continuous 4D seismic solution
Case Study: Monitoring a Heavy Oil field with Steam Assisted Gravity Drainage (SAGD) Conclusion
4D Seismic Basics
Base
-
Monitor
=
Difference
1. Acquire & process Base & Monitor seismic surveys 2. Measure differences in time and amplitude 3. Changes in the seismic is an indicator of fluid movement during production
Benefits of 4D
Better understanding of the reservoir during production
Ekofisk formation
Tight zone
Maximizes O&G recovery
Optimizes production prediction
Minimizes production hazards
Tor formation
Source: ConocoPhillips
4D Feasibility
Survey design -
-
compute 4-D synthetics from flow simulation model Include all relevant information (well logs, petrophysical data, etc.)
Synthetic seismic
-
PRM system
-
Optimized repeatability
-
Optimized Imaging
Acquisition
Dynamic model
-
-
Update of static and dynamic parameters to make them consistent with the seismic measurements
Real 4D seismic
-
4D specific processing
-
4D QC -
Potential update of the reservoir model
inSAR
Base
4D Petrophysical Inversion
4D Processing Sequence Monitor
Conventional 4D Land Seismic +2 ms
0
ΔT
Difference before/after gas injection
-2 ms November 1997 0.3
April - November 0.3
+12 dB
During gas production 0.5
0.5
0.7
0.7
0.9
0.9
+0.4 ms
0
ΔT
April 1997
-0.4 ms
Measuring fast & subtle 4D variations during a EOR process is a challenge
Challenges for Conventional 4D Surface Seismic The high sensitivity required for EOR monitoring is hard to achieve due to:
Sparse time intervals between monitor surveys Repeatability issues (geometry issues, coupling issues, weathered zone variations)
PRM vs Conventional 4D Seismic
4D seismic variations
Small
Strong
daily 0,01 ms
∆T (ms) 1 ms
Time interval between 2 seismic acquisitions 2 weeks
1 month
3 months
1 year
> 1 year
Buried sensors + Buried sources
High
0,1 %
Permanent Reservoir Monitoring (PRM)
SeisMovie TM 10 ms
6 months
Long
Buried sensors
∆A (%) 10 %
Conventional 4D Surface Seismic 20 %
Monitoring system repeatability
Short
Low
Continuous Onshore Seismic Reservoir Monitoring SeisMovieTM
Areal buried, single sensor spread
Sources and receivers are permanently buried beneath the weathered zone, ensuring better 4D repeatability. Continuous (24/7) and automatic transmission to the processing center for final processing and analysis.
Buried source
High sensitivity of the continuous monitoring brings enormous value in understanding the reservoir dynamics for increase recovery
4D Seismic - from the field to the office automatically Recording Unit SERCEL428 + Remote Control QC & Processing
Buried Sources
Simultaneous Sources 1 different frequency for each source every 30s
Continuous and Permanent Emission & Recording
Buried Receivers S1 S6 S7 S2
100
S5
100
S8
100
200 200
900 30
Simultaneous multi sources Data reconstruction & QC
10
20
60 900 30
600
700
10
50 20
60 900 30
600
700
800
40
500
600
700
800 50
500
600
700
40
400
500
600
800
900
400
500
600
800
300
400
500
700
800
300
400
500 600
700
200
300
400
500 600
700
200
300
400
500 600
100
200
300
400
500
100
200
300
400
20
100
200
300
400
S9
100
200
300
10
S4
100
200
300
Real time processing & 4D attributes computation
S3
100
700
800
40
10
50
20
60 900 30
700
800
40
10
50
20
60 900 30
800
40
10
50
20
60 900 30
800
40 10
50 20
60 900 30
40 10
50 20
60 900 30
40 10
Remote Control & Data Transmission
50 20
60 30
40
50
60
SeisMovieTM: Continuous Land Seismic Monitoring
Mapping of the reservoir changes in real time
Case study: onshore EOR monitoring
Case study: onshore EOR monitoring
After Hornman & al., SPE 2012
Onshore heavy oil (25 API) field Steam assisted gravity drainage scheme
Location
Schoonebeek
1st Phase: 2D Monitoring Horizontal Wells: Injector Producer Observation CGG’s Buried Source
Steam Injection (tone/day)
200 m
Dec-2010 Cold production Install
Dec-2011 Steam injection
2D Continuous monitoring
Install
Dec-2012 Buried
200 m
3D Continuous monitoring
Hydrophone
2nd Phase: 3D Monitoring Horizontal Wells: Injector Producer Observation CGG’s Buried Source
Steam Injection (tone/day)
200 m
Dec-2010 Cold production Install 17
2D Continuous monitoring
Dec-2011 Steam injection Install
Dec-2012 3D Continuous monitoring
Buried Hydrophone
Buried seismic installation st Phase: 21nd Phase: 2D 3D Monitoring Monitoring
Cold production Install
Dec-2010
2D Continuous monitoring
Steam injection Install
Dec-2011
3D Continuous monitoring Dec-2012
…months later monitoring is ongoing Automatic & continuous seismic monitoring is ongoing underneath
Cold production Install
Dec-2010
2D Continuous monitoring
Steam injection Install
Dec-2011
3D Continuous monitoring Dec-2012
Near Surface Variations Needs for very high repeatability Cannot be obtained with surface acquisition
Weathering zone
4D Reservoir variation
Near Surface Ray Paths Much better repeatability when sources and receivers are buried
Other waves are still transmitted into the weathering layer
Receiver ghost
Near Surface converted wave Weathering zone
Source ghost
4D Reservoir variation
Raw data Steam Injection (tone/day)
0.3
100
200
200
300
Base
6 51
100
CMP Section
Calendar trace
300
Difference
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
SPReceiver waves interfere with just primaries at the target level Ghost vary below the primaries
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After SP Waves Attenuation Steam Injection (tone/day)
0.3
100
200
200
300
Base
6 51
100
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After Receiver Deghosting Injection curve (t/day)
Base
6 51
0.3
100
100
200
200
300
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
800
20
40
60
80
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After Receiver & Source Deghosting Injection curve (t/day)
Base
6 51
0.3
100
100
200
200
300
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
Measurement at injection well N
time shift and amplitudes at the reservoir follow the steam injection.
Almost no variation above the reservoir showing the high repeatability of the data
4D Difference Maps Steam Injection (tone/day)
Base 3D
N
27
Measurement at observation wells N
Very good correlation between the pressure measured at observation well and the time shifts obtained with continuous seismic monitoring
Where is the steam going ? Injected steam rate
Sources & Sensors
Observation wells
100 ms
29
4D Inversion: From Amplitudes to Impedance Amplitude from Seismic
Impedance from Inversion
100 ms
Impedance variations Steam injection (t/d)
April 300 200 100 0
Cold production
2011
September
2012
Steam injection Steam injection 3D Continuous monitoring O1
O2 P1 I P2 Base reservoir (m) 696 711
SeisMovieTM key takeaways Continuous seismic monitoring for enhanced oil recovery (EOR) methods Automated permanent buried system enabling minimal disruptions, footprint, and HSE exposure. Providing reservoir engineers with real-time information on rapid and subtle variations in the reservoir
Can be used as part of an integrated alarm system for cap rock & casing integrity with microseismic
Thank you
SeisMovieTM Continuous 4D seismic in Real Time
Outline Introduction to 4D or Time Lapse seismic SeisMovie – a continuous 4D seismic solution
Case Study: Monitoring a Heavy Oil field with Steam Assisted Gravity Drainage (SAGD) Conclusion
4D Seismic Basics
Base
-
Monitor
=
Difference
1. Acquire & process Base & Monitor seismic surveys 2. Measure differences in time and amplitude 3. Changes in the seismic is an indicator of fluid movement during production
Benefits of 4D
Better understanding of the reservoir during production
Ekofisk formation
Tight zone
Maximizes O&G recovery
Optimizes production prediction
Minimizes production hazards
Tor formation
Source: ConocoPhillips
4D Feasibility
Survey design -
-
compute 4-D synthetics from flow simulation model Include all relevant information (well logs, petrophysical data, etc.)
Synthetic seismic
-
PRM system
-
Optimized repeatability
-
Optimized Imaging
Acquisition
Dynamic model
-
-
Update of static and dynamic parameters to make them consistent with the seismic measurements
Real 4D seismic
-
4D specific processing
-
4D QC -
Potential update of the reservoir model
inSAR
Base
4D Petrophysical Inversion
4D Processing Sequence Monitor
Conventional 4D Land Seismic +2 ms
0
ΔT
Difference before/after gas injection
-2 ms November 1997 0.3
April - November 0.3
+12 dB
During gas production 0.5
0.5
0.7
0.7
0.9
0.9
+0.4 ms
0
ΔT
April 1997
-0.4 ms
Measuring fast & subtle 4D variations during a EOR process is a challenge
Challenges for Conventional 4D Surface Seismic The high sensitivity required for EOR monitoring is hard to achieve due to:
Sparse time intervals between monitor surveys Repeatability issues (geometry issues, coupling issues, weathered zone variations)
PRM vs Conventional 4D Seismic
4D seismic variations
Small
Strong
daily 0,01 ms
∆T (ms) 1 ms
Time interval between 2 seismic acquisitions 2 weeks
1 month
3 months
1 year
> 1 year
Buried sensors + Buried sources
High
0,1 %
Permanent Reservoir Monitoring (PRM)
SeisMovie TM 10 ms
6 months
Long
Buried sensors
∆A (%) 10 %
Conventional 4D Surface Seismic 20 %
Monitoring system repeatability
Short
Low
Continuous Onshore Seismic Reservoir Monitoring SeisMovieTM
Areal buried, single sensor spread
Sources and receivers are permanently buried beneath the weathered zone, ensuring better 4D repeatability. Continuous (24/7) and automatic transmission to the processing center for final processing and analysis.
Buried source
High sensitivity of the continuous monitoring brings enormous value in understanding the reservoir dynamics for increase recovery
4D Seismic - from the field to the office automatically Recording Unit SERCEL428 + Remote Control QC & Processing
Buried Sources
Simultaneous Sources 1 different frequency for each source every 30s
Continuous and Permanent Emission & Recording
Buried Receivers S1 S6 S7 S2
100
S5
100
S8
100
200 200
900 30
Simultaneous multi sources Data reconstruction & QC
10
20
60 900 30
600
700
10
50 20
60 900 30
600
700
800
40
500
600
700
800 50
500
600
700
40
400
500
600
800
900
400
500
600
800
300
400
500
700
800
300
400
500 600
700
200
300
400
500 600
700
200
300
400
500 600
100
200
300
400
500
100
200
300
400
20
100
200
300
400
S9
100
200
300
10
S4
100
200
300
Real time processing & 4D attributes computation
S3
100
700
800
40
10
50
20
60 900 30
700
800
40
10
50
20
60 900 30
800
40
10
50
20
60 900 30
800
40 10
50 20
60 900 30
40 10
50 20
60 900 30
40 10
Remote Control & Data Transmission
50 20
60 30
40
50
60
SeisMovieTM: Continuous Land Seismic Monitoring
Mapping of the reservoir changes in real time
Case study: onshore EOR monitoring
Case study: onshore EOR monitoring
After Hornman & al., SPE 2012
Onshore heavy oil (25 API) field Steam assisted gravity drainage scheme
Location
Schoonebeek
1st Phase: 2D Monitoring Horizontal Wells: Injector Producer Observation CGG’s Buried Source
Steam Injection (tone/day)
200 m
Dec-2010 Cold production Install
Dec-2011 Steam injection
2D Continuous monitoring
Install
Dec-2012 Buried
200 m
3D Continuous monitoring
Hydrophone
2nd Phase: 3D Monitoring Horizontal Wells: Injector Producer Observation CGG’s Buried Source
Steam Injection (tone/day)
200 m
Dec-2010 Cold production Install 17
2D Continuous monitoring
Dec-2011 Steam injection Install
Dec-2012 3D Continuous monitoring
Buried Hydrophone
Buried seismic installation st Phase: 21nd Phase: 2D 3D Monitoring Monitoring
Cold production Install
Dec-2010
2D Continuous monitoring
Steam injection Install
Dec-2011
3D Continuous monitoring Dec-2012
…months later monitoring is ongoing Automatic & continuous seismic monitoring is ongoing underneath
Cold production Install
Dec-2010
2D Continuous monitoring
Steam injection Install
Dec-2011
3D Continuous monitoring Dec-2012
Near Surface Variations Needs for very high repeatability Cannot be obtained with surface acquisition
Weathering zone
4D Reservoir variation
Near Surface Ray Paths Much better repeatability when sources and receivers are buried
Other waves are still transmitted into the weathering layer
Receiver ghost
Near Surface converted wave Weathering zone
Source ghost
4D Reservoir variation
Raw data Steam Injection (tone/day)
0.3
100
200
200
300
Base
6 51
100
CMP Section
Calendar trace
300
Difference
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
SPReceiver waves interfere with just primaries at the target level Ghost vary below the primaries
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After SP Waves Attenuation Steam Injection (tone/day)
0.3
100
200
200
300
Base
6 51
100
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After Receiver Deghosting Injection curve (t/day)
Base
6 51
0.3
100
100
200
200
300
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
800
20
40
60
80
100
50
120
100
140
150
160
200
250
300
350
400
450
500
After Receiver & Source Deghosting Injection curve (t/day)
Base
6 51
0.3
100
100
200
200
300
CMP Section
Calendar trace
300
Diff.
Calendar trace
6 51
Variation X5
Chalk
Buried Sensor
0.4
400
400
0.5
500
500
0.6
600
600
0.7
700
R
Reservoir
Buried Source
800
700
20
40
60
80
800
100
50
120
100
140
150
160
200
250
300
350
400
450
500
Measurement at injection well N
time shift and amplitudes at the reservoir follow the steam injection.
Almost no variation above the reservoir showing the high repeatability of the data
4D Difference Maps Steam Injection (tone/day)
Base 3D
N
27
Measurement at observation wells N
Very good correlation between the pressure measured at observation well and the time shifts obtained with continuous seismic monitoring
Where is the steam going ? Injected steam rate
Sources & Sensors
Observation wells
100 ms
29
4D Inversion: From Amplitudes to Impedance Amplitude from Seismic
Impedance from Inversion
100 ms
Impedance variations Steam injection (t/d)
April 300 200 100 0
Cold production
2011
September
2012
Steam injection Steam injection 3D Continuous monitoring O1
O2 P1 I P2 Base reservoir (m) 696 711
SeisMovieTM key takeaways Continuous seismic monitoring for enhanced oil recovery (EOR) methods Automated permanent buried system enabling minimal disruptions, footprint, and HSE exposure. Providing reservoir engineers with real-time information on rapid and subtle variations in the reservoir
Can be used as part of an integrated alarm system for cap rock & casing integrity with microseismic
Thank you
SeisMovieTM Continuous 4D seismic in Real Time
