US Patent No: 5,654,639

Number of patents in Portfolio can not be more than 2000

Induction measuring device in the presence of metal walls




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A device for the measurement by induction of a medium through a metal wall using a transmission portion permitting the induction of a signal in the medium beyond the metal wall and a receiver for receiving a signal transmitted by the medium in response to the induced signal. The transmission portion includes at least one current generator directly connected to the metal wall in such a way that the current passing into the wall induces a signal beyond the wall.

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Patent Owner(s)

Patent OwnerAddressTotal Patents

International Classification(s)


Inventor Name Address # of filed Patents Total Citations
Chaillout, Jean-Jacques St. Etienne de Crossey, FR 23 149
Jeandey, Christian St. Egreve, FR 20 137
Locatelli, Marcel Monbonnot, FR 21 166

Cited Art Landscape

Patent Info (Count) # Cites Year
Halliburton Logging Services, Inc. (1)
* 5,038,107 Method and apparatus for making induction measurements through casing 38 1989
Mobil Oil Corporation (1)
* 4,593,770 Method for preventing the drilling of a new well into one of a plurality of production wells 36 1984
* 4,901,023 Methods and apparatus for measurement of low frequency a.c. magnetic fields within cased boreholes to determine properties of geological formations 25 1988
Other [Check patent profile for assignment information] (2)
* 4,529,939 System located in drill string for well logging while drilling 80 1983
* 5,283,520 Method of determining thickness of magnetic pipe by measuring the time it takes the pipe to reach magnetic saturation 24 1991
* Cited By Examiner

Patent Citation Ranking

Forward Cite Landscape

Patent Info (Count) # Cites Year
EM-Tech Sensors LLC (6)
6,657,440 Propagation of waves through materials 1 1999
6,628,118 Method and apparatus for control of magnetic flux direction and concentration 9 2000
6,597,177 Through casing resistivity measurement in permanently installed downhole production environment 4 2000
* 6,744,263 Apparatus and method for the measurement of electrical properties of materials through non-magnetizable materials 2 2000
* 6,597,186 Through tank level gauging 0 2000
6,630,831 Measurements of electrical properties through non magneticially permeable metals using directed magnetic beams and magnetic lenses 15 2001
6,534,986 Permanently emplaced electromagnetic system and method for measuring formation resistivity adjacent to and between wells 16 2001
6,791,331 Method and apparatus for measuring characteristics of geological formations 7 2004
7,030,617 System, apparatus, and method for conducting electromagnetic induction surveys 15 2004
* 8,310,239 Detecting electrical current in a magnetic structure 1 2009
* 6,025,721 Determining resistivity of a formation adjacent to a borehole having casing by generating constant current flow in portion of casing and using at least two voltage measurement electrodes 18 1996
* 6,157,195 Formation resistivity measurements from within a cased well used to quantitatively determine the amount of oil and gas present 30 1997
6,246,240 Determining resistivity of a formation adjacent to a borehole having casing with an apparatus having all current conducting electrodes within the cased well 26 1999
6,987,386 Determining resistivity of a geological formation using circuitry located within a borehole casing 2 2002
6,392,421 Spectral EM frequency metallic thickness measurement using metallic transparencies 6 2000
6,553,838 Detection of anomalies on railroad tracks 3 2001
7,019,518 Non-contacting apparatus and method for measurement of ferromagnetic metal thickness 1 2001
6,975,121 System for measuring earth formation resistivity through and electrically conductive wellbore casing 5 2004
7,388,382 System for measuring Earth formation resistivity through an electrically conductive wellbore casing 4 2004
7,202,671 Method and apparatus for measuring formation conductivities from within cased wellbores by combined measurement of casing current leakage and electromagnetic response 6 2004
* 5,892,460 Logging while drilling tool with azimuthal sensistivity 49 1997
6,181,138 Directional resistivity measurements for azimuthal proximity detection of bed boundaries 104 1999
EMI, INC. (1)
6,294,917 Electromagnetic induction method and apparatus for the measurement of the electrical resistivity of geologic formations surrounding boreholes cased with a conductive liner 43 1999
Other [Check patent profile for assignment information] (2)
* 5,841,510 Rotatable diagnostic lens for evaluation of the irido-corneal angle, retina and other portions of the eye 7 1998
* 6,975,120 Measurement of subterranean lithology using electromagnetic energy 6 2002
* Cited By Examiner