TY - JOUR

T1 - Transient electromagnetic surveys with unimodal transverse magnetic field

T2 - ideas and results

AU - Mogilatov, Vladimir S.

AU - Zlobinskiy, Arkadiy V.

AU - Balashov, Boris P.

PY - 2017/9/1

Y1 - 2017/9/1

N2 - The theory behind transient electromagnetic surveys can be well described in terms of transverse magnetic and transverse electric modes. Soundings using transverse magnetic and transverse electric modes require different source configurations. In this study, we consider an alternating transverse magnetic field excitation by a circular electric dipole. The circular electric dipole transmitter is a horizontal analogue of the vertical electric dipole. Offshore surveys using circular electric dipole might represent an alternative to the conventional marine controlled-source electromagnetic method at shallow sea and/or for exploring relatively small targets. Field acquisition is carried out by recording either electric or magnetic responses. Electric responses bear information on the 1D structure of a layered earth and successfully resolve high-resistivity targets in marine surveys. Land-based circular electric dipole soundings are affected by induced polarisation. On the contrary, magnetic responses are absent on the surface of a 1D earth, and as a result, they are very sensitive to any and even very small 3D conductivity perturbations. In addition, they are sensitive to induced polarisation or some other polarisation effects in the subsurface. At present, circular electric dipole transmitters and magnetic receivers are successfully used in on-land mineral and petroleum exploration.

AB - The theory behind transient electromagnetic surveys can be well described in terms of transverse magnetic and transverse electric modes. Soundings using transverse magnetic and transverse electric modes require different source configurations. In this study, we consider an alternating transverse magnetic field excitation by a circular electric dipole. The circular electric dipole transmitter is a horizontal analogue of the vertical electric dipole. Offshore surveys using circular electric dipole might represent an alternative to the conventional marine controlled-source electromagnetic method at shallow sea and/or for exploring relatively small targets. Field acquisition is carried out by recording either electric or magnetic responses. Electric responses bear information on the 1D structure of a layered earth and successfully resolve high-resistivity targets in marine surveys. Land-based circular electric dipole soundings are affected by induced polarisation. On the contrary, magnetic responses are absent on the surface of a 1D earth, and as a result, they are very sensitive to any and even very small 3D conductivity perturbations. In addition, they are sensitive to induced polarisation or some other polarisation effects in the subsurface. At present, circular electric dipole transmitters and magnetic receivers are successfully used in on-land mineral and petroleum exploration.

KW - Circular electric dipole

KW - Electrical prospecting

KW - Lorentz's force

KW - Transient electromagnetic

KW - Transverse magnetic field

UR - http://www.scopus.com/inward/record.url?scp=85003828394&partnerID=8YFLogxK

U2 - 10.1111/1365-2478.12473

DO - 10.1111/1365-2478.12473

M3 - Article

AN - SCOPUS:85003828394

VL - 65

SP - 1380

EP - 1397

JO - Geophysical Prospecting

JF - Geophysical Prospecting

SN - 0016-8025

IS - 5

ER -