Studying CO2 storage with ambient-noise seismic interferometry: A combined numerical feasibility study and field-data example for Ketzin, Germany

Seismic interferometry applied to ambient-noise measurements allows the retrieval of the seismic response between pairs of receivers. We studied ambient-noise seismic interferometry (ANSI) to retrieve time-lapse reflection responses from a reservoir during [Formula: see text] geologic sequestration, using the case of the experimental site of Ketzin, Germany. We applied ANSI to numerically modeled data to retrieve base and repeat reflection responses characterizing the impedances occurring at the reservoir both with and without the injection of [Formula: see text]. The modeled data represented global transmission responses from band-limited noise sources randomly triggered in space and time. We found that strong constraints on the spatial distribution of the passive sources were not required to retrieve the time-lapse signal as long as sufficient source-location repeatability was observed between the base and the repeat passive survey. To illustrate the potential of the technique, ANSI was applied to three days of passive field data recorded in 2012 at Ketzin. Comparison with the modeled results illustrated the potential to retrieve key reflection events using ANSI on field data from Ketzin. This study supports the idea that the geologic setting and characteristics of ambient noise at Ketzin may be opportune to monitor [Formula: see text] sequestration.

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Seismic Interferometry from Correlated Noise Sources

Remote Sensing ◽

10.3390/rs13142703 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2703

Author(s):

Daniella Ayala-Garcia ◽

Andrew Curtis ◽

Michal Branicki

Keyword(s):

Green’S Function ◽

Green's Function ◽

Ambient Noise ◽

Ocean Waves ◽

Seismic Interferometry ◽

Correlated Noise ◽

Highway Traffic ◽

Noise Sources ◽

Estimation Errors ◽

Band Limited

It is a well-established principle that cross-correlating seismic observations at different receiver locations can yield estimates of band-limited inter-receiver Green’s functions. This principle, known as Green’s function retrieval or seismic interferometry, is a powerful technique that can transform noise into signals which enable remote interrogation and imaging of the Earth’s subsurface. In practice it is often necessary and even desirable to rely on noise already present in the environment. Theory that underpins many applications of ambient noise interferometry assumes that the sources of noise are uncorrelated in time. However, many real-world noise sources such as trains, highway traffic and ocean waves are inherently correlated in space and time, in direct contradiction to the these theoretical foundations. Applying standard interferometric techniques to recordings from correlated energy sources makes the Green’s function liable to estimation errors that so far have not been fully accounted for theoretically nor in practice. We show that these errors are significant for common noise sources, always perturbing or entirely obscuring the phase one wishes to retrieve. Our analysis explains why stacking may reduce the phase errors, but also shows that in commonly encountered circumstances stacking will not remediate the problem. This analytical insight allowed us to develop a novel workflow that significantly mitigates effects arising from the use of correlated noise sources. Our methodology can be used in conjunction with already existing approaches, and improves results from both correlated and uncorrelated ambient noise. Hence, we expect it to be widely applicable in ambient noise studies.

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Feasibility of Retrieving Time-lapse Reflection Signals Using Ambient-noise Seismic Interferometry at Ketzin, Germany

77th EAGE Conference and Exhibition - Workshops ◽

10.3997/2214-4609.201413576 ◽

2015 ◽

Author(s):

B. Boullenger ◽

A. Verdel ◽

B. Paap ◽

J. Thorbecke ◽

D. Draganov

Keyword(s):

Ambient Noise ◽

Time Lapse ◽

Seismic Interferometry

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Comparison of seismic interferometry techniques for the retrieval of seismic body waves in CO2 sequestration monitoring

Journal of Geophysics and Engineering ◽

10.1093/jge/gxz079 ◽

2019 ◽

Vol 16 (6) ◽

pp. 1094-1115

Author(s):

Haitao Cao ◽

Roohollah Askari

Keyword(s):

Co2 Sequestration ◽

Field Data ◽

Cross Correlation ◽

Time Lapse ◽

Body Waves ◽

Seismic Interferometry ◽

Storage Site ◽

Phase Information ◽

Wave Data ◽

The Cross

Abstract Ambient noise seismic interferometry performed by cross-correlation has been proven to be a potential cost-effective technique for geological studies. To improve the resolution of images created by interferometry, additional techniques using deconvolution and cross-coherence have been introduced. While all three methods have previously been evaluated using surface wave data for shear-wave imaging of the near surface, comparatively little study has been devoted to assess the three methods for the retrieval of body waves in reflection surveys for time-lapse application. Moreover, although the application of seismic interferometry to CO2 sequestration by cross-correlation has been investigated by many researchers, to our knowledge, similar time-lapse studies have not been conducted using deconvolution and cross-coherence methods. We evaluate the three methods of cross-correlation, deconvolution and cross-coherence for the retrieval of phase information contained in virtual seismic records by applying seismic interferometry to synthetic data, using a model reservoir before and after CO2 injection. By examining two approaches of regularization and smoothing factors to suppress spurious reflection events observed on the deconvolution and cross-coherence results, we note that both approaches provide similar results. We investigate noise effects by adding random noise independently at each geophone. Finally, we apply these techniques to field data recorded near the CO2 storage site in Ketzin, Germany. For both our numerical and field data studies, we find that the cross-coherence technique retrieves the phase information of body-wave data more effectively than the cross-correlation and deconvolution techniques, and is less sensitive to uncorrelated noise from shallow sources.

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Seismic interferometry using multidimensional deconvolution and crosscorrelation for crosswell seismic reflection data without borehole sources

Geophysics ◽

10.1190/1.3511357 ◽

2011 ◽

Vol 76 (1) ◽

pp. SA19-SA34 ◽

Cited By ~ 37

Author(s):

Shohei Minato ◽

Toshifumi Matsuoka ◽

Takeshi Tsuji ◽

Deyan Draganov ◽

Jürg Hunziker ◽

...

Keyword(s):

Seismic Reflection ◽

Field Data ◽

Time Lapse ◽

P Wave ◽

Source Distribution ◽

Seismic Interferometry ◽

Imaging Method ◽

Seismic Reflection Data ◽

Reflection Data ◽

Receiver Arrays

Crosswell reflection method is a high-resolution seismic imaging method that uses recordings between boreholes. The need for downhole sources is a restrictive factor in its application, for example, to time-lapse surveys. An alternative is to use surface sources in combination with seismic interferometry. Seismic interferometry (SI) could retrieve the reflection response at one of the boreholes as if from a source inside the other borehole. We investigate the applicability of SI for the retrieval of the reflection response between two boreholes using numerically modeled field data. We compare two SI approaches — crosscorrelation (CC) and multidimensional deconvolution (MDD). SI by MDD is less sensitive to underillumination from the source distribution, but requires inversion of the recordings at one of the receiver arrays from all the available sources. We find that the inversion problem is ill-posed, and propose to stabilize it using singular-value decomposition. The results show that the reflections from deep boundaries are retrieved very well using both the CC and MDD methods. Furthermore, the MDD results exhibit more realistic amplitudes than those from the CC method for downgoing reflections from shallow boundaries. We find that the results retrieved from the application of both methods to field data agree well with crosswell seismic-reflection data using borehole sources and with the logged P-wave velocity.

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Passive seismic reflection interferometry: A case study from the Aquistore CO2 storage site, Saskatchewan, Canada

Geophysics ◽

10.1190/geo2016-0370.1 ◽

2017 ◽

Vol 82 (3) ◽

pp. B79-B93 ◽

Cited By ~ 10

Author(s):

Saeid Cheraghi ◽

Donald J. White ◽

Deyan Draganov ◽

Gilles Bellefleur ◽

James A. Craven ◽

...

Keyword(s):

Seismic Reflection ◽

Ambient Noise ◽

Co2 Storage ◽

Time Lapse ◽

Body Waves ◽

Time Range ◽

Storage Site ◽

Passive Seismic ◽

Forming Analysis ◽

Time Lapse Imaging

Seismic reflection interferometry has recently been tested in a few resource-exploration applications. We have evaluated passive seismic interferometry results for data from the Aquistore [Formula: see text] storage site, Saskatchewan, Canada, with the objective of testing the method’s ability to image the subsurface geology and its potential for time-lapse imaging. We analyzed passive seismic data recorded along two perpendicular geophone lines for two time periods that include 23 days in June 2014 and 13 days in February 2015. Beam-forming analysis showed that a nearby power plant is the dominant source of ambient noise. We retrieved virtual shot gathers not only by correlating long noise panels (1 h) for both recording periods, but also by correlating shorter noise panels (10 s) from two days of each recording period. We applied illumination diagnosis to the noise panels from the two chosen days for each period to help suppress the surface waves. Comparisons of the common-midpoints stacked sections, resulting from the virtual shot gathers, with colocated active-source images and log-based synthetic seismograms showed that the best ambient-noise images were obtained for the longest recording periods. The application of illumination diagnosis revealed that only a small percentage of the noise panels are dominated by body waves. Thus, images formed using only this subset of noise panels failed to improve the images obtained from the 23 and 13 days of noise recording. To evaluate the passive images, we performed log-based correlations that showed moderate correlation ranging from approximately 0.5–0.65 in the two-way time range of 0.8–1.5 s. For the 13 to 23 days of noise used in our analysis, the resulting images at the reservoir depth of 3200 m or [Formula: see text] are unlikely to be suitable for time-lapse imaging at this site. This is most likely due to the limited directional illumination and dominance of surface-wave noise.

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Seismic interferometry from correlated noise sources

10.5194/egusphere-egu21-625 ◽

2021 ◽

Author(s):

Daniella Ayala ◽

Andrew Curtis ◽

Michal Branicki

Keyword(s):

Ambient Noise ◽

Real Life ◽

Seismic Energy ◽

Seismic Interferometry ◽

Correlated Noise ◽

Highway Traffic ◽

Noise Sources ◽

Estimation Errors ◽

Space And Time ◽

Receiver Array

It is a well-established principle that cross-correlating seismic observations at different receiver locations yields new seismic responses that, under certain conditions, provide a useful estimate of the Green's function between the given receiver locations (that is, the medium response at one receiver location, had there been an impulsive source located at the other receiver). This principle, known as seismic interferometry, is a powerful technique that transforms previously discarded data such as seismic codas or background noise into useful signals that allow us to remotely illuminate subsurface Earth structures.&#160;In practice it is often necessary and even desirable to rely on noise already present in the environment, since this type of seismic energy is freely and widely available in many regions around the globe.&#160; Across many applications of ambient noise interferometry there exists a persistent assumption that the noise sources in question are uncorrelated in space and time, and that energy arrives at the receiver array more-less equally from all directions. That this assumption is so tenaciously made comes as no surprise since the underlying theory unambiguously requires that the noise sources be uncorrelated for interferometry to work.&#160;However, many real-world noise sources such as trains or highway traffic are inherently correlated both in space and time, in direct contradiction to these theoretical foundations. Violating the uncorrelatedness condition makes the Green&#8217;s function and associated phases liable to estimation errors that so far have not been accounted for. We show that these errors are indeed significant for commonly used noise sources, in some cases completely obscuring the phase one wishes to retrieve. Furthermore, we perform analysis that explains why stacking has the potential to reduce these errors in the interferometric estimate, as well as some limitations of this approach. This analytical insight allowed us to develop a novel workflow that mitigates or even completely removes the spurious effects arising from the use of correlated noise sources. Our methodology can be used in conjunction with already existing approaches, and hence we expect it to be widely applicable in real life ambient noise studies.

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New developments in ambient noise analysis to characterise the seismic response of landslide prone slopes

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-1-1319-2013 ◽

2013 ◽

Vol 1 (2) ◽

pp. 1319-1353 ◽

Cited By ~ 1

Author(s):

V. Del Gaudio ◽

J. Wasowski ◽

S. Muscillo

Keyword(s):

Ambient Noise ◽

Noise Analysis ◽

Central Italy ◽

Spectral Ratio ◽

Specific Response ◽

Accelerometer Data ◽

Noise Sources ◽

New Developments ◽

Resonance Frequencies ◽

Noise Measurements

Abstract. We report on new developments in the application of ambient noise analysis applied to investigate the dynamic response of landslide prone slopes to seismic shaking with special attention to the directional resonance phenomena recognised in previous studies. Investigations relying on the calculation of horizontal-to-vertical noise spectral ratio (HVNR) were carried out in the area of Caramanico Terme (central Italy) where an ongoing accelerometer monitoring on slopes with different characteristics offers the possibility of validation of HVNR analysis. The noise measurements, carried out in different times to test the result repeatability, revealed that sites affected by response directivity persistently show major peaks with a common orientation consistent with the resonance direction inferred from accelerometer data. At sites where directivity is absent, the HVNR peaks do not generally show a preferential orientation, with rare exceptions that could be linked to the presence of temporarily active sources of polarised noise. The observed spectral ratio amplitude variations can be related to temporal changes in site conditions, which can hinder the recognition of main resonance frequencies. Therefore, it is recommended to conduct simultaneous measurements at nearby sites within the same study area and to repeat measurements at different times in order to distinguish significant systematic polarisation caused by site specific response directivity from polarisation controlled by properties of noise sources. Furthermore, an analysis of persistence in noise recordings of signals with systematic directivity showed that only a~portion of recordings contains wave trains having a clear polarisation representative of site directional resonance. Thus a careful selection of signals for HVNR analysis is needed for a correct characterisation of site directional properties.

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