1887

Abstract

Summary

Distributed acoustic sensing offers the possibility of high-resolution passive monitoring of seismic events. Local coherency of the recorded wavefields allows for array-based processing techniques. In this study, we apply such techniques in a downhole array at the San Andreas Fault Observatory at Depth. We begin by estimating the seismic velocity along the well using both earthquake records and ambient noise interferometry. Results are compared to a conventional near-offset VSP geophone survey. DAS earthquake records also allow for S-wave velocity estimation. We utilize the computed velocity in a moveout-based detection algorithm. The method takes into account velocity along the array as well as the range of possible incidence angles of incoming events. We apply it to 20 days of data, recorded in June-July 2017. Above 70% of catalogued events in the area are detected, and a new, weak, uncatalogued event is discovered. These results set the path for DAS monitoring of natural and induced events.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201901242
2019-06-03
2019-12-10
Loading full text...

Full text loading...

References

  1. Biondi, B.
    [1992] Velocity estimation by beam stack. Geophysics, 57(8),1034–1047.
    [Google Scholar]
  2. Daley, T.M., Miller, D.E., Dodds, K., Cook, P., and Freifeld, B.M.
    [2016] Field testing of modular borehole monitoring with simultaneous distributed acoustic sensing and geophone vertical seismic profiles at Citronelle, Alabama. Geophysical Prospecting, 64(5), 1318–1334.
    [Google Scholar]
  3. Dou, S., Lindsey, N., Wagner, A.M., Daley, T.M., Freifeld, B., Robertson, M., Peterson, J., Ulrich, C, Martin, E.R., and Ajo-Franklin, J.B.
    [2017] Distributed acoustic sensing for seismic monitoring of the near surface: A traffic-noise interferometry case study. Scientific Reports, 7, 11620.
    [Google Scholar]
  4. Hole, J.A., Ryberg, T., Fuis, G.S., Bleibinhaus, F., and Sharma, A.K.
    [2006] Structure of the San Andreas fault zone at SAFOD from a seismic refraction survey. Geophysical Research Letters, 33(7), L07312.
    [Google Scholar]
  5. Karrenbach, M., Cole, S., Ridge, A., Boone, K., Kahn, D., Rich, J., Silver, K., and Langton, D.
    [2018] DAS microseismic, strain and temperature monitoring during hydraulic fracturing. Geophysics, 84(1), D11–D23.
    [Google Scholar]
  6. Lindsey, N.J., Martin, E.R., Dreger, D.S., Freifeld, B., Cole, S., James, S.R., Biondi, B.L. and Ajo-Franklin, J.B.
    [2017] Fiber-Optic network observations of earthquake Wavefields. Geophysical Research Letters, 44(11), 792–799.
    [Google Scholar]
  7. Martin, E.R., Castillo, C.M., Cole, S., Sawasdee, P.S., Yuan, S., Clapp, R., Karrenbach, M., and Biondi, B.L.
    [2017] Seismic monitoring leveraging existing telecom infrastructure at the SDASA : active , passive , and ambient-noise analysis. The Leading Edge, 36, 1025–1031.
    [Google Scholar]
  8. Martin, E.R., Biondi, B., Karrenbach, M., and Cole, S.
    [2017] Ambient noise interferometry from DAS array in underground telecommunication conduits. 79th EAGE Conference & Exhibition, Expanded abstracts
    [Google Scholar]
  9. Miyazawa, M., Snieder, R., and Venkataraman, A.
    [2008] Application of seismic interferometry to extract P- and S-wave propagation and observation of shear-wave splitting from noise data at Cold Lake, Alberta, Canada. Geophysics, 73(4), D35-D40. https://doi.org/10.1190/1.2937172
    [Google Scholar]
  10. Spica, Z.J., Perton, M., Nakata, N., Liu, X., and Beroza, G.C.
    [2018] Site characterization at Groningen gas field area through joint surface-borehole H/V analysis. Geophysical Journal International, 212(1), 412–421.
    [Google Scholar]
  11. Zoback, M., Hickman, S., and Ellsworth, W.
    [2011] Scientific drilling into the San Andreas fault zone - An overview of SAFOD's first five years. Scientific Drilling, 11, 14–28.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201901242
Loading
/content/papers/10.3997/2214-4609.201901242
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error