US5153514A — Antenna and wear plates for borehole logging appa…

Claim 1

Independent Claim 118 words

For use in a well logging apparatus wherein a logging device is moveable through an earth borehole and includes means for transmitting electromagnetic energy into formations traversed by the borehole, an antenna assembly supported in said logging device, comprising: an open-ended shell formed of a relatively thick material; an open-ended body conforming generally in shape to the inner surface of said shell and being spaced therefrom, said body being formed of an electrically conductive material that is thin relative to the thickness of said shell; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and means coupled between said body and said probe for receiving electronic signals from said antenna.

Claim 2

Dependent Claim 118 words

For use in a well logging apparatus wherein a logging device is moveable through an earth borehole and includes means for transmitting electromagnetic energy into formations traversed by the borehole, an antenna assembly supported in said logging device, comprising: an open-ended shell formed of a relatively thick material; an open-ended body conforming generally in shape to the inner surface of said shell and being spaced therefrom, said body being formed of an electrically conductive material that is thin relative to the thickness of said shell; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and means coupled between said body and said probe for receiving electronic signals from said antenna.

Claim 3

Dependent Claim 45 words

The antenna assembly as defined by claim 1, wherein the material of said body is a metal having a thickness that is less than the minimum thickness that would support an acoustic resonance mode in its thickness direction at the frequency of said electromagnetic energy.

Claim 4

Dependent Claim 36 words

The antenna assembly as defined by claim 2, wherein the material of said body is a metal having a thickness of at least several skin depths in said metal at the frequency of said electromagnetic energy.

Claim 5

Dependent Claim 32 words

The antenna as defined by claim 1, wherein said body is formed of copper having a thickness less than 1.135×10 3 /f m, where f is the frequency of said electromagnetic energy.

Claim 6

Dependent Claim 31 words

The antenna as defined by claim 4, wherein said body is formed of copper having a thickness greater than 195/f 1/2 mm., where f is the frequency of said electromagnetic energy.

Claim 7

Dependent Claim 54 words

The antenna assembly as defined by claim 1, wherein said shell is formed of a metal, and wherein said medium is a material having an acoustic impedance that is substantially less than the acoustic impedance of the material of said shell and substantially less than the acoustic impedance of the material of said body.

Claim 8

Dependent Claim 54 words

The antenna assembly as defined by claim 3, wherein said shell is formed of a metal, and wherein said medium is a material having an acoustic impedance that is substantially less than the acoustic impedance of the material of said shell and substantially less than the acoustic impedance of the material of said body.

Claim 9

Dependent Claim 48 words

The antenna assembly as defined by claim 7, wherein said medium is a material having an acoustic impedance that is at least about an order of magnitude less than the acoustic impedance of the material of said shell and the acoustic impedance of the material of said body.

Claim 10

Dependent Claim 48 words

The antenna assembly as defined by claim 8, wherein said medium is a material having an acoustic impedance that is at least about an order of magnitude less than the acoustic impedance of the material of said shell and the acoustic impedance of the material of said body.

Claim 11

Dependent Claim 13 words

The antenna assembly as defined by claim 1, wherein said medium is rubber.

Claim 12

Dependent Claim 13 words

The antenna assembly as defined by claim 3, wherein said medium is rubber.

Claim 13

Dependent Claim 34 words

The antenna assembly as defined by claim 6, wherein said medium has a thickness which is an odd multiple of a quarter of the acoustic wavelength of said electromagnetic energy in the separating medium.

Claim 14

Dependent Claim 19 words

The antenna as defined by claim 12, wherein said medium is rubber, and said thickness is about 1.4 mm.

Claim 15

Dependent Claim 29 words

The antenna as defined by claim 1, further comprising ferrite loaded in said body, and wherein the material of said shell has a magnetic permeability of at least 500.

Claim 16

Dependent Claim 30 words

The antenna as defined by claim 3, further comprising a ferrite loaded in said body, and wherein the material of said shell has a magnetic permeability of at least 500.

Claim 17

Dependent Claim 146 words

Apparatus for investigating a characteristic of earth formations traversed by a borehole including a logging device adapted for longitudinal movement in the borehole, said device comprising: first means for producing a static magnetic field in the formations; and second means for transmitting electromagnetic energy into said formations and for detecting electromagnetic energy from said formations; said second means comprising an antenna assembly which includes an open-ended shell formed of a magnetically permeable material; an open-ended electrically conductive body disposed within said shell and spaced therefrom; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and an electrically insulating magnetically permeable loading material disposed in said body; said shell being formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of said loading material several times the magnetic reluctance of said shell.

Claim 18

Dependent Claim 146 words

Apparatus for investigating a characteristic of earth formations traversed by a borehole including a logging device adapted for longitudinal movement in the borehole, said device comprising: first means for producing a static magnetic field in the formations; and second means for transmitting electromagnetic energy into said formations and for detecting electromagnetic energy from said formations; said second means comprising an antenna assembly which includes an open-ended shell formed of a magnetically permeable material; an open-ended electrically conductive body disposed within said shell and spaced therefrom; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and an electrically insulating magnetically permeable loading material disposed in said body; said shell being formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of said loading material several times the magnetic reluctance of said shell.

Claim 19

Dependent Claim 26 words

Apparatus as defined by claim 16, wherein said second means includes means coupled between said body and said probe for receiving electronic signals from said antenna.

Claim 20

Dependent Claim 17 words

Apparatus as defined by claim 16, wherein said loading material disposed in said body comprises a ferrite.

Claim 21

Dependent Claim 15 words

Apparatus as defined by claim 16, wherein said shell is formed of a mild steel.

Claim 22

Dependent Claim 15 words

Apparatus as defined by claim 18, wherein said shell is formed of a mild steel.

Claim 23

Dependent Claim 22 words

Apparatus as defined by claim 16, wherein said shell is formed of a material having a magnetic permeability of at least 500.

Claim 24

Dependent Claim 59 words

Apparatus as defined by claim 16, wherein said body is formed of a metal having a thickness that is at least several skin depths in said metal at the frequency of said electromagnetic energy and is less than the minimum thickness that would support an acoustic resonance mode in its thickness direction at the frequency of said electromagnetic energy.

Claim 25

Dependent Claim 185 words

Apparatus for investigating a characteristic of earth formations traversed by a borehole, comprising: a logging device adapted for longitudinal movement in the borehole; first means, in said device, for producing a static magnetic field in the formations; second means, in said device, for transmitting electromagnetic energy into said formations and for detecting electromagnetic energy from the formations, said second means comprising an antenna assembly which includes: a trough-shaped shell formed of a magnetically permeable material, said shell being elongated in the longitudinal direction of the borehole; a trough-shaped electrically conductive body, elongated in the longitudinal direction of the borehole, disposed in said shell and spaced therefrom; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body, said probe being elongated in the longitudinal direction of the borehole; an electrically insulating magnetically permeable loading material disposed in said body in the region between the inner surface of said body and said probe; said second means including means coupled between said body and said probe for transmitting electromagnetic energy via said antenna and for receiving electromagnetic energy via said antenna.

Claim 26

Dependent Claim 185 words

Apparatus for investigating a characteristic of earth formations traversed by a borehole, comprising: a logging device adapted for longitudinal movement in the borehole; first means, in said device, for producing a static magnetic field in the formations; second means, in said device, for transmitting electromagnetic energy into said formations and for detecting electromagnetic energy from the formations, said second means comprising an antenna assembly which includes: a trough-shaped shell formed of a magnetically permeable material, said shell being elongated in the longitudinal direction of the borehole; a trough-shaped electrically conductive body, elongated in the longitudinal direction of the borehole, disposed in said shell and spaced therefrom; a medium disposed between said shell and said body; an electrically conductive probe disposed in said body, said probe being elongated in the longitudinal direction of the borehole; an electrically insulating magnetically permeable loading material disposed in said body in the region between the inner surface of said body and said probe; said second means including means coupled between said body and said probe for transmitting electromagnetic energy via said antenna and for receiving electromagnetic energy via said antenna.

Claim 27

Dependent Claim 34 words

Apparatus as defined by claim 23, wherein said body includes electrically conductive side panels at the respective ends of the trough-shaped body, and wherein said probe is connected to one of said side panels.

Claim 28

Dependent Claim 13 words

Apparatus as defined by claim 24, wherein said body is formed of copper.

Claim 29

Dependent Claim 31 words

Apparatus as defined by claim 23, wherein said body is formed of copper having a thickness less than 1.135×10 3 /f m, where f is the frequency of said electromagnetic energy.

Claim 30

Dependent Claim 30 words

Apparatus as defined by claim 26, wherein said body is formed of copper having a thickness greater than 195/f 1/2 mm., where f is the frequency of said electromagnetic energy.

Claim 31

Dependent Claim 36 words

Apparatus as defined by claim 25, wherein the frequency of said electromagnetic energy is about 2 MHz, and wherein the thickness of the copper body is in the range between about 0.1 mm and 0.6 mm.

Claim 32

Dependent Claim 39 words

Apparatus as defined by claim 23, wherein said shell is formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of said loading material several times the magnetic reluctance of said shell.

Claim 33

Dependent Claim 15 words

Apparatus as defined by claim 23, wherein said shell is formed of a mild steel.

Claim 34

Dependent Claim 43 words

Apparatus as defined by claim 23, further comprising at least one capacitor in said body coupled between said probe and said body, said at least one capacitor having surface area contact regions that are respectively coupled to said probe and to said body.

Claim 35

Dependent Claim 20 words

Apparatus as defined by claim 23, wherein said probe comprises a hollow elongated copper tube filled with a non-conductive material.

Claim 36

Dependent Claim 46 words

Apparatus as defined by claim 23, wherein said medium is a material having an acoustic impedance that is at least about an order of magnitude less than the acoustic impedance of the material of said shell and the acoustic impedance of the material of said body.

Claim 37

Dependent Claim 11 words

Apparatus as defined by claim 23, wherein said medium is rubber.

Claim 38

Dependent Claim 32 words

Apparatus as defined by claim 23, wherein said medium has a thickness which is an odd multiple of a quarter of the acoustic wavelength of said electromagnetic energy in the separating medium.

Claim 39

Dependent Claim 121 words

Apparatus for measuring nuclear magnetic resonance properties, comprising: first means for producing a static magnetic field; and second means for transmitting electromagnetic energy and for detecting received electromagnetic energy; said second means comprising an antenna assembly which includes an open-ended shell formed of a magnetically permeable material; an open-ended electrically conductive body disposed within said shell and spaced therefrom; a separating medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and an electrically insulating magnetically permeable loading material disposed in said body; said shell being formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of said loading material several times the magnetic reluctance of said shell.

Claim 40

Dependent Claim 121 words

Apparatus for measuring nuclear magnetic resonance properties, comprising: first means for producing a static magnetic field; and second means for transmitting electromagnetic energy and for detecting received electromagnetic energy; said second means comprising an antenna assembly which includes an open-ended shell formed of a magnetically permeable material; an open-ended electrically conductive body disposed within said shell and spaced therefrom; a separating medium disposed between said shell and said body; an electrically conductive probe disposed in said body; and an electrically insulating magnetically permeable loading material disposed in said body; said shell being formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of said loading material several times the magnetic reluctance of said shell.

Claim 41

Dependent Claim 26 words

Apparatus as defined by claim 36, wherein said second means includes means coupled between said body and said probe for receiving electronic signals from said antenna.

Claim 42

Dependent Claim 15 words

Apparatus as defined by claim 36, wherein said shell is formed of a mild steel.

Claim 43

Dependent Claim 22 words

Apparatus as defined by claim 36, wherein said shell is formed of a material having a magnetic permeability of at least 500.

Claim 44

Dependent Claim 59 words

Apparatus as defined by claim 36, wherein said body is formed of a metal having a thickness that is at least several skin depths in said metal at the frequency of said electromagnetic energy and is less than the minimum thickness that would support an acoustic resonance mode in its thickness direction at the frequency of said electromagnetic energy.

Claim 45

Dependent Claim 52 words

Apparatus as defined by claim 36, wherein said shell is formed of a metal, and wherein said medium is a material having an acoustic impedance that is substantially less than the acoustic impedance of the material of said shell and substantially less than the acoustic impedance of the material of said body.

Claim 46

Dependent Claim 46 words

Apparatus as defined by claim 41, wherein said medium is a material having an acoustic impedance that is at least about an order of magnitude less than the acoustic impedance of the material of said shell and the acoustic impedance of the material of said body.

Claim 47

Dependent Claim 95 words

For use in a well logging apparatus wherein a logging device is moveable through an earth borehole and includes means for transmitting electromagnetic energy into formations traversed by the borehole and means for receiving electromagnetic energy from the formation; a wear plate assembly mounted on said logging device, and adapted for sliding engagement with the borehole wall, comprising: a support member mounted on said logging device; an electrically conductive layer spaced from said support member; a medium disposed between said member and said conductive layer; and a non-metallic wear surface disposed over said conductive layer.

Claim 48

Dependent Claim 95 words

For use in a well logging apparatus wherein a logging device is moveable through an earth borehole and includes means for transmitting electromagnetic energy into formations traversed by the borehole and means for receiving electromagnetic energy from the formation; a wear plate assembly mounted on said logging device, and adapted for sliding engagement with the borehole wall, comprising: a support member mounted on said logging device; an electrically conductive layer spaced from said support member; a medium disposed between said member and said conductive layer; and a non-metallic wear surface disposed over said conductive layer.

Claim 49

Dependent Claim 41 words

The wear plate assembly as defined by claim 43, wherein said electrically conductive layer has a thickness that is less than the thickness that would support an acoustic resonance mode in its thickness direction at the frequency of said electromagnetic energy.

Claim 50

Dependent Claim 26 words

The wear plate assembly as defined by claim 43, wherein said electrically conductive layer comprises a metal screen having a multiplicity of openings in its thickness.

Claim 51

Dependent Claim 14 words

The wear plate assembly as defined by claim 43, wherein said medium comprises rubber.

Claim 52

Dependent Claim 22 words

The wear plate assembly as defined by claim 44, wherein said medium comprises rubber, and wherein said screen is impregnated with rubber.

Claim 53

Dependent Claim 36 words

The wear plate assembly as defined by claim 43, wherein said electrically conductive layer is formed of copper having a thickness less than 1.135×10 3 /f m, where f is the frequency of said electromagnetic energy.

Claim 54

Dependent Claim 17 words

The wear plate assembly as defined by claim 43, wherein said support member is formed of metal.

Claim 55

Dependent Claim 17 words

The wear plate assembly as defined by claim 43, wherein said electrically conductive layer is electrically grounded.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-10-06	1996-04-06	1996-10-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-10-06	2000-04-06	2000-10-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-10-06	2004-04-06	2004-10-06	$7700.00	Window Closed / Lapsed

Antenna and wear plates for borehole logging apparatus

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