The initial appraisal of buried DAS system in CO2CRC Otway Project: the comparison of buried standard fibre-optic and helically wound cables using 2D imaging

Journal Article · Wed Feb 06 00:00:00 EST 2019 · Exploration Geophysics

DOI:https://doi.org/10.1080/08123985.2018.1561147· OSTI ID:1571955

Yavuz, Sinem ^[1]; Freifeld, Barry ^[2]; Pevzner, Roman ^[1]; Dzunic, Aleksandar ^[1]; Ziramov, Sasha ^[1]; Bóna, Andrej ^[1]; Correa, Julia ^[1]; Tertyshnikov, Konstantin ^[1]; Urosevic, Milovan ^[1]; Robertson, Michelle ^[2]; Daley, Thomas ^[2]

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1. Curtin Univ., Perth, Western Australia (Australia). Exploration Geophysics, WA School of Mines: Minerals, Energy and Chemical Engineering; CO2CRC, Carlton, VIC (Australia)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

This study aims to assess the ability of shallow distributed acoustic sensing (DAS) to serve as a cost-effective seismic sensor array for permanent monitoring applications. To this end, as part of the CO2CRC seismic monitoring program, a fibre-optic DAS array was deployed alongside a permanently buried geophone array at the Otway Project site (Victoria, Australia). The DAS array consisted of a standard commercially available tactical fibre-optic cable, which was deployed in 0.8m deep trenches. A custom-designed helically wound (HW) cable was also deployed in one of the DAS trenches for comparison of the cable designs. Simultaneous acquisition of the seismic data was carried out using 3000 vibroseis source points and geophones, DAS standard and HW cables. For initial assessment of the seismic images acquired with DAS and to compare different cable designs, preliminary 2D seismic reflection processing is conducted on both DAS cables and geophone data along a single 2D line. The geophone data processing guided processing of the DAS data. Several shallow structures (100-450ms) and some important reflectors at 450-600ms are observed on the final DAS images. Comparison of the two different DAS cable types demonstrated that seismic imaging would benefit DAS technology. However, the benefit of utilising HW cable is modest compared with the standard cable. The workflows and results of this study pave the way for processing of the 3D seismic data set acquired with the DAS array, as well as further detailed analysis of the DAS cables and the system itself.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1571955
• Journal Information: Exploration Geophysics, Journal Name: Exploration Geophysics Journal Issue: 1 Vol. 50; ISSN 0812-3985
• Publisher: Taylor & Francis
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
distributed acoustic sensor
helically wound cable
seismic monitoring