Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Improvement of measuring accurary of magnetic fields in borehole drilling
2019 (English)Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Abstract [en]

To increase measuring accuracy in magnetotellurgic measurements anelectrode can be lowered into a borehole to create constraints forthe inversion. For this method a long cable is need to connect tothe electrode. This creates a new type of problems with parasiticeffects when the cable is placed on a winch made of metal. Toaccount for this, the behavior of the cable while on the winchwas measured. It was considered to be a multilayered multi rowcoil with a resistance of 2,4Ohm. The inductance of the winch wasmeasured for different frequencies and with different amount ofcable on the winch. With this data the physical properties of amultilayered multi row coil was numerically fitted. To explain thefrequency dependency of the inductance two different models wherecreated. Model one described the frequency dependency as randomand fitted the physical properties of the multilayered multi rowcoil once for every frequency. The second model (cftool-model)described the frequency dependency of the coil as a power-functionand fitted this behavior numerically in MATLABs curvefittingtoolbox (cf-tool). Both models predicted an inductance which increased with more cable on the winch and with lowerfrequencies. The models fitted the measured data points well insome areas. But for the measurements made with 135m of cable ofthe winch both models fitted poorly with relative errors of up to43%. This can be because of a systematic error made in how thecable was wound on the winch. To help to improve furthermeasurements the error needed to be within 10% which it overallfails to be. It is uncertain if more data and a better model wouldallow the error to reach tolerable levels or if the dependency ofthe winding of the cable onto the winch is too large.

Place, publisher, year, edition, pages
2019.
Series
TVE-F ; 19014
National Category
Geophysical Engineering
Identifiers
URN: urn:nbn:se:uu:diva-388086OAI: oai:DiVA.org:uu-388086DiVA, id: diva2:1331529
Educational program
Master Programme in Engineering Physics
Examiners
Available from: 2019-06-28 Created: 2019-06-26 Last updated: 2019-06-28Bibliographically approved

Open Access in DiVA

Improvement of measuring accurary of magnetic fieldsin borehole drilling(1049 kB)6 downloads
File information
File name FULLTEXT01.pdfFile size 1049 kBChecksum SHA-512
1fb7ee6d6ae23dd9cfb92cf92310748e935120912f19e8eb2ca2607468b62a110adac1a44d2f4af0f917bb9dd50a30928f1e27ad7c982acc118f4ca0d9636b2d
Type fulltextMimetype application/pdf

Geophysical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 6 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 48 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf