METADATA IN ENGLISH
About the journal
SEISMICHESKIE PRIBORY, ISSN: 0131-6230, eISSN: 2312-6965, DOI: 10.21455/si,
http://elibrary.ru/title_about.asp?id=25597
English Translation: Seismic Instruments, ISSN: 0747-9239 (Print) 1934-7871 (Online),
https://link.springer.com/journal/11990
Use
of fiber-optic communication lines
with a phase-sensitive
reflectometer
for recording seismic signals
D.A. Ilinskiy1,2, A.E. Alekseev3,4, O.Yu. Ganzha2, D.E. Semikin3,4, M. Ojha5
1 Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow region, Russia
2 Shirshov Institute of Oceanology of Russian Academy of Sciences, Moscow, Russia
3 PetroFiber Ltd., Moscow, Russia
4
Friazino Branch of Kotelnikov Institute of Radiotechnics and
Electronics, Russian Academy of Sciences,
Friazino, Russia
5 CSIR – National Geophysical Research Institute, Hyderabad, India
Corresponding author: D.A. Ilinskiy, e-mail: dilinskiy61@mail.ru
Abstract. Distributed acoustic or vibration measurements on a fiber-optic line (FOCL) began to develop rapidly in 2005. One of the effects used for this purpose is the Rayleigh scattering effect. Rayleigh scattering is an elastic process caused by local inhomogeneities of the refractive index of a fiber-optic line. Optical pulses with a certain time interval are launched into the optical fiber and a small part of the backscattered light is registered on the detector. Small deformations of the optical fiber associated with vibration (or seismic) events change the intensity of backscattered light. Analysis of the interference pattern for each section of the fiber allows you to identify the characteristics of the vibration effect on a specific section of the fiber. A key feature of the phase-sensitive reflectometer used in the experiment is the use of a two-pulse phase-modulated optical parcel as a probing signal.
An
experiment was conducted to compare the records of seismic
excitations recorded on standard seismic equipment and on the records
of a reflectometer. The experiment was carried out on a straight-line
single-mode fiber-optic line 200 m buried in the ground to a depth of
30 cm. A 5 kg hammer was used as a source of seismic vibrations. The
blows were delivered on a metal substrate lying on the ground. Time
synchronization of the seismic data with the reflectometer data was
performed based on the detected first shock intakes. The experience
of simultaneous recording of low-power seismic excitations has shown
that direct comparison of the response of a fiber-optic system and
geophones is impossible. The registered data must be converted to the
same physical values. In a specific experiment, the acceleration
values measured by the seismic system were converted into
displacements. Analysis of the transformed data and the reflectometer
data showed that for small deformations
of less than one strain, the optical channels show good signal repeatability. Optical channel data obtained even with large deformations show that they can be used for engineering seismic purposes and allow us to obtain reliable seismic sections, despite some discrepancies in the signal form. Due to the density of channels, this disadvantage can be compensated for.
Keywords: seismic sensors, seismic sources, engineering seismic, autonomous three-component seismometers, seismic data processing, fiber-optic communication lines, reflectometers, Rayleigh back scattering
About the authors
ILINSKIY Dmitry Anatolievich – Moscow Institute of Physics and Technology. Russia, 141701, Moscow oblast, Dolgoprudny, Institutski per., 9; Shirshov Istitute of Oceanology, Russian Academy of Sciences. Russia, 117997, Moscow, Nakhimovskiy Prospect, 36. E-mail: dilinskiy61@mail.ru
ALEXEEV
Alexei Eduardovich
– PetroFiber Ltd. Russia, 105082, Moscow, Spartakovskaya pl.,
14, bld. 4, off. 4101; Friazino Branch of Kotelnikov Institute
of Radiotechnics and Electronics, Russian Academy of Sciences.
Friazino, Russia, 141190, Moscow oblast, Friazino, Vvedenskogo pl.,
1.
E-mail: aleksey_aled@mail.ru
GANZHA Oleg Yurievitch – Shirshov Istitute of Oceanology, Russian Academy of Sciences. Russia, 117997, Moscow, Nakhimovskiy Prospect, 36. E-mail: ganzhaoy@mail.ru
SIMIKIN
Denis Eugenievich
– PetroFiber Ltd. Russia, 105082, Moscow, Spartakovskaya pl.,
14, bld. 4, off. 4101; Friazino Branch of Kotelnikov Institute
of Radiotechnics and Electronics, Russian Academy of Sciences.
Friazino, Russia, 141190, Moscow oblast, Friazino, Vvedenskogo pl.,
1.
E-mail:
denis.simikin@gmail.com
OJHA Maheshwar – CSIR – National Geophysical Research Institute. 500007 Telangana, Uppal Road, Hyderabad, India. E-mail: maheswar_ojha@ngri.res.in
Cite this article as: Ilinskiy D.A., Alekseev A.E., Ganzha O.Yu., Semikin D.E., Ojha M. Use of fiber-optic communication lines with a phase-sensitive reflectometer for recording seismic signals, Seismicheskie Pribory, 2020, vol. 56, no. 4, pp. 5–28. (in Russian). https://doi.org/10.21455/si2020.4-1
English translation of the article will be published in Seismic Instruments, ISSN: 0747-9239 (Print) 1934-7871 (Online), https://link.springer.com/journal/11990)