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Electromagnetic fields in boreholes-measurements and theory in three dimensions

Malmqvist, Lennart; Pantze, Robert; Kristensson, Gerhard LU and Karlsson, Anders LU (1990) In Technical Report LUTEDX/(TEAT-7008)/1-17/(1990) TEAT-7008.
Abstract
A comparison between experimental measurements of the electromagnetic

field in boreholes and a mathematical model is made. The transmitting antenna

is a rectangular wire loop on the ground and the three orthogonal

components of the magnetic field are measured below the ground in the borehole.

In the mathematical model the ground is assumed to be a stratified half

space with a rectangular wire antenna on the ground. Excellent agreement

was found between the experimental results and the theoretical ones in most

cases and where deviations were found, the assumption of a stratified ground

was inaccurate due to present conductive inhomogeneities. The method... (More)
A comparison between experimental measurements of the electromagnetic

field in boreholes and a mathematical model is made. The transmitting antenna

is a rectangular wire loop on the ground and the three orthogonal

components of the magnetic field are measured below the ground in the borehole.

In the mathematical model the ground is assumed to be a stratified half

space with a rectangular wire antenna on the ground. Excellent agreement

was found between the experimental results and the theoretical ones in most

cases and where deviations were found, the assumption of a stratified ground

was inaccurate due to present conductive inhomogeneities. The method presented

in this paper is capable of determining an ore body within a radius of

100 m from the borehole. The position (direction and distance) of the target

can be estimated from the measurements in the borehole. The impact on

the economical effectiveness of a drilling programme is considerable when a

prediction of the location of additional boreholes can be made. In the case of

reconnaissance drilling of a geological structure or trend the distance between

adjacent boreholes can be considerably enlarged. (Less)
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Technical Report LUTEDX/(TEAT-7008)/1-17/(1990)
volume
TEAT-7008
pages
17 pages
publisher
[Publisher information missing]
language
English
LU publication?
yes
id
084d40e7-230f-4b6a-b57a-36cf85b5fb77 (old id 530179)
date added to LUP
2007-09-12 10:25:35
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2016-04-16 12:13:04
@misc{084d40e7-230f-4b6a-b57a-36cf85b5fb77,
  abstract     = {A comparison between experimental measurements of the electromagnetic<br/><br>
field in boreholes and a mathematical model is made. The transmitting antenna<br/><br>
is a rectangular wire loop on the ground and the three orthogonal<br/><br>
components of the magnetic field are measured below the ground in the borehole.<br/><br>
In the mathematical model the ground is assumed to be a stratified half<br/><br>
space with a rectangular wire antenna on the ground. Excellent agreement<br/><br>
was found between the experimental results and the theoretical ones in most<br/><br>
cases and where deviations were found, the assumption of a stratified ground<br/><br>
was inaccurate due to present conductive inhomogeneities. The method presented<br/><br>
in this paper is capable of determining an ore body within a radius of<br/><br>
100 m from the borehole. The position (direction and distance) of the target<br/><br>
can be estimated from the measurements in the borehole. The impact on<br/><br>
the economical effectiveness of a drilling programme is considerable when a<br/><br>
prediction of the location of additional boreholes can be made. In the case of<br/><br>
reconnaissance drilling of a geological structure or trend the distance between<br/><br>
adjacent boreholes can be considerably enlarged.},
  author       = {Malmqvist, Lennart and Pantze, Robert and Kristensson, Gerhard and Karlsson, Anders},
  language     = {eng},
  pages        = {17},
  publisher    = {ARRAY(0x9d8be68)},
  series       = {Technical Report LUTEDX/(TEAT-7008)/1-17/(1990)},
  title        = {Electromagnetic fields in boreholes-measurements and theory in three dimensions},
  volume       = {TEAT-7008},
  year         = {1990},
}