3D Imaging of Geothermal Faults from a Vertical DAS Fiber at Brady Hot Spring, NV USA
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Department of Geophysics, Colorado School of Mines, Golden, CO 80401, USA
2
DownUnder Geosolutions, Golden, CO 80401, USA
3
Cimarex, Tulsa, OK 74104, USA
*
Author to whom correspondence should be addressed.
Energies 2019, 12(7), 1401; https://doi.org/10.3390/en12071401
Received: 3 March 2019
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Revised: 3 April 2019
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Accepted: 8 April 2019
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Published: 11 April 2019
(This article belongs to the Special Issue Innovation in Geothermal Energy Exploration and Production)
In March 2016, arguably the most ambitious 4D (3D space + over time) active-source seismic survey for geothermal exploration in the U.S. was acquired at Brady Natural Laboratory, outside Fernley, Nevada. The four-week experiment included 191 vibroseis source locations, and approximately 130 m of distributed acoustic sensing (DAS) in a vertical well, located at the southern end of the survey area. The imaging of the geothermal faults is done with reverse time migration of the DAS data for both P-P and P-S events in order to generate 3D models of reflectivity, which can identify subsurface fault locations. Three scenarios of receiver data are explored to investigate the reliability of the reflectivity models obtained: (1) Migration of synthetic P-P and P-S DAS data, (2) migration of the observed field DAS data and (3) migration of pure random noise to better assess the validity of our results. The comparisons of the 3D reflectivity models from these three scenarios confirm that sections of three known faults at Brady produce reflected energy observed by the DAS. Two faults that are imaged are ~1 km away from the DAS well; one of these faults (middle west-dipping) is well-constructed for over 400 m along the fault’s strike, and 300 m in depth. These results confirm that the DAS data, together with an imaging engine such as reverse time migration, can be used to position important geothermal features such as faults.
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Keywords:
distributed acoustic sensing; depth migration; faults
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MDPI and ACS Style
Trainor-Guitton, W.; Guitton, A.; Jreij, S.; Powers, H.; Sullivan, B. 3D Imaging of Geothermal Faults from a Vertical DAS Fiber at Brady Hot Spring, NV USA. Energies 2019, 12, 1401. https://doi.org/10.3390/en12071401
AMA Style
Trainor-Guitton W, Guitton A, Jreij S, Powers H, Sullivan B. 3D Imaging of Geothermal Faults from a Vertical DAS Fiber at Brady Hot Spring, NV USA. Energies. 2019; 12(7):1401. https://doi.org/10.3390/en12071401
Chicago/Turabian StyleTrainor-Guitton, Whitney, Antoine Guitton, Samir Jreij, Hayden Powers, and Bane Sullivan. 2019. "3D Imaging of Geothermal Faults from a Vertical DAS Fiber at Brady Hot Spring, NV USA" Energies 12, no. 7: 1401. https://doi.org/10.3390/en12071401
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