Simulation of time-lapse for the Ketzin CO2 storage site assuming single seismic ACROSS and multi-seismic receivers

Author(s):  
J. Kasahara ◽  
A. Kato ◽  
M. Takanashi ◽  
Y. Hasada ◽  
S. Lüth ◽  
...  
Keyword(s):  
Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. WA1-WA13 ◽  
Author(s):  
Lisa A. N. Roach ◽  
Donald J. White ◽  
Brian Roberts

Two 3D time-lapse seismic surveys were acquired in 2012 and 2013 at the Aquistore [Formula: see text] storage site prior to the start of [Formula: see text] injection. Using these surveys, we determined the background time-lapse noise at the site and assessed the feasibility of using a sparse areal permanent receiver array as a monitoring tool. Applying a standard processing sequence to these data, we adequately imaged the reservoir at 3150–3350 m depth. Evaluation of the impact of each processing step on the repeatability revealed a general monotonic increase in similarity between the data sets as a function of processing. The prestack processing sequence reduced the normalized root mean squared difference (nrms) from 1.13 between the raw stacks to 0.13 after poststack time migration. The postmigration cross-equalization sequence further reduced the global nrms to 0.07. A simulation of the changes in seismic response due to a range of [Formula: see text] injection scenarios suggested that [Formula: see text] was detectable within the reservoir at the Aquistore site provided that zones of greater thickness than 6–13 m have reached [Formula: see text] saturations of greater than 5%.


2016 ◽  
Author(s):  
Masashi Nakatsukasa ◽  
Isao Kurosawa ◽  
Ayato Kato ◽  
Mamoru Takanashi ◽  
Don J White ◽  
...  

Geophysics ◽  
2017 ◽  
Vol 82 (3) ◽  
pp. B79-B93 ◽  
Author(s):  
Saeid Cheraghi ◽  
Donald J. White ◽  
Deyan Draganov ◽  
Gilles Bellefleur ◽  
James A. Craven ◽  
...  

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.


Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. B37-B50 ◽  
Author(s):  
P. Bergmann ◽  
M. Ivandic ◽  
B. Norden ◽  
C. Rücker ◽  
D. Kiessling ◽  
...  

A combination of seismic and geoelectric processing was studied by means of a structurally constrained inversion approach. Structural constraints were interpreted from the seismic data and integrated into the geoelectric inversion through a local regularization, which allowed inverted resistivities to behave discontinuously across defined boundaries. This arranged seismic processing and constrained resistivity inversion in a sequential workflow, making the generic assumption that the petrophysical parameters of both methods change across common lithostructural boundaries. We evaluated the approach using a numerical example and a real data example from the Ketzin [Formula: see text] pilot storage site, Germany. The latter demonstrated the efficiency of this approach for combining 4D seismic and surface-downhole geoelectric data. In consistence with the synthetic example, the constrained resistivity inversions produced clearer delineated images along the boundary between caprock and reservoir formation. Near the [Formula: see text]-flooded reservoir, the seismic and geoelectric time-lapse anomalies correlated well. At some distance to the downhole electrodes, however, the geoelectric images conveyed a notably lower resolution in comparison to the corresponding seismic images. Both methods confirm a northwesterly trend for the [Formula: see text] migration at the Ketzin site, although a rather northerly direction was initially expected. The results demonstrate the relevance of the presented approach for the combination of both methods for integrated geophysical [Formula: see text] storage monitoring.


Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. WA35-WA48 ◽  
Author(s):  
Don J. White ◽  
Lisa A. N. Roach ◽  
Brian Roberts

A sparse areal permanent array of buried geophones was deployed at the Aquistore [Formula: see text] storage site in Saskatchewan, Canada. The purpose of this array is to facilitate 4D seismic monitoring of [Formula: see text] that is to be injected to the deep subsurface. Use of a sparse buried array is designed to improve the repeatability of time-lapse data and to economize the monitoring effort. Prior to the start of [Formula: see text] injection, two 3D dynamite seismic surveys were acquired in March 2012 and May 2013 using the permanent array. The objective of acquiring these data was to allow an assessment of the data repeatability and overall performance of the permanent array. A comparison of the raw data from these surveys and with a conventional high-resolution 3D vibroseis survey demonstrated that (1) the signal-to-noise ratio for the buried geophones was increased by 6–7 dB relative to surface-deployed geophones and by an additional 20 dB for dynamite relative to a vibroseis source, (2) the use of buried sensors and sources at this site did not appear to be significantly degraded by the effects of ghosting, (3) repeatability for the permanent array data was excellent with a mean normalized root-mean-square (nrms) value of 57% for the raw baseline-monitor difference, (4) the variance of nrms values was higher for shot gathers (18%) compared with receiver gathers (7%), and (5) the raw data repeatability was a factor of three improved over that of comparable surface-geophone data acquired at a nearby location. The use of a sparse buried permanent array at the Aquistore site has demonstrably achieved a reduction in ambient noise levels and overall enhanced data repeatability, both of which are keys to successful 4D seismic monitoring.


2019 ◽  
Author(s):  
Niklas Heinemann ◽  
Hazel Robertson ◽  
Juan Alcalde ◽  
Alan James ◽  
Saeed Ghanbari ◽  
...  

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