Monitoring of CO 2 injected at Ketzin using 3D time-lapse seismic data Alexandra Ivanova 1,2 , Ursula Lengler 1 , Stefan Lüth 1 and Christopher Juhlin 2 (1)GFZ German Research Centre for Geosciences, Germany (2) Uppsala University, Sweden EGU 2011 5.04.2011, Vienna, Austria
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M onitoring of CO 2 injected at Ketzin using 3D time-lapse seismic data
M onitoring of CO 2 injected at Ketzin using 3D time-lapse seismic data. Alexandra Ivanova 1,2 , Ursula Lengler 1 , Stefan Lüth 1 and Christopher Juhlin 2 GFZ German Research Centre for Geosciences, Germany (2) Uppsala University, Sweden. EGU 2011 5.04.2011, Vienna, Austria. - PowerPoint PPT Presentation
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Monitoring of CO2 injected at Ketzin using3D time-lapse seismic data
Alexandra Ivanova1,2, Ursula Lengler1,Stefan Lüth1 and Christopher Juhlin2
(1) GFZ German Research Centre for Geosciences, Germany(2) Uppsala University, Sweden
Original parameters:Read raw SEGD dataVertical diversity stackBulk static shift to compensate for source delay: 6 msExtract and apply geometryTrace edit and polarity reversalPick first breaks: offset range 300–500 mRemove 50-Hz noise on selected receiver locationsSpherical divergence correction: v2tBand-pass filter: Butterworth 7–14–150–250 HzSurface consistent deconvolution: filter 120 ms, gap 16 ms, white noise 0.1%Ground roll muteSpectral equalization 20–40–90–120 HzBand-pass filter:0–300 ms:15–30–85–125 Hz 350–570 ms:14–28–80–120 Hz 620–1000 ms: 2–25–70–105 HzZero-phase filterRefraction statics: datum 30 m, replacement velocity 1800 m /s, v0 1000 m/sTrace balance using data windowVelocity analysis: every 20th CDP in the inline and crossline directionResidual staticsNormal moveout correction: 50% stretch muteStackTrace balance: 0–1000 msFX-Decon: Inline and crossline directionsTrace balance: 0–1000 msMigration: 3D FD using smoothed stacking velocitiesDepth conversion: using smoothed stacking velocities
Processing steps applied to 3D repeat compared with the original flow
Amplitude change anomaly over the CO2 injection site low fold area for anomaly
1. max change in amplitude ~ amplitude of K2 reflection
2. anomaly ~ centered on injection well
3. positive polarity
VOLUMETRICS
Volumetric estimation of mass of the injected CO2 visible in seismic data will be performed using
- average values of CO2 saturation in reservoir obtained for every well of the Ketzin site witha) Pulsed Neutron-Gamma Well Logging;b) Multiphase Flow Modeling;
- average CO2 density calculated witha) measured temperature and pressure in reservoir at the injection site (in the injection well) to
the time of the repeat survey;b) from Multiphase Flow Modeling for every well of the Ketzin site.
Results show that we can see approximately the same quantity of the injected CO2 in the time-lapse seismic data :
a) Pulsed Neutron-Gamma Well Logging (~ 94%);b) Multiphase Flow Modeling (~91%).
Parameters for volumetric estimationPARAMETER SOURCETime delay Velocity push-downP-Velocities/CO2 and brine saturation
Petrophysics on samples from reservoir saturated with CO2 and brine
1. Results of seismic interpretation and petrophysical data allowed a satisfactory CO2 mass estimation (91%-94% mass of injected CO2 to the time of the repeat survey) using values of CO2 saturation derived by
a) Pulsed Neutron-Gamma Logging;b) Multiphase-Flow Modeling;
and average CO2 density calculated with c) measured temperature and pressure in reservoir at the injected site
(in the injected well) to the time of the repeat survey;d) Multiphase Flow Modeling for every well of the Ketzin site.
2. Consequences for seismic data of CO2 effect on seismic velocities in reservoir rock (petrophysics) will be illustrated on synthetic seismic models.
3. ‘Predicted’ distributions will be used to generate synthetic seismic data that will be compared directly to seismic field data.