US3944910A — Method and apparatus utilizing microwave electrom…

Claim 1

Independent Claim 110 words

Apparatus for investigating earth formations surrounding a borehole to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means mounted in said member for injecting microwave electromagnetic energy into the surrounding formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the velocity of propagation of the microwave electromagnetic energy received at said first and second antennas, said velocity being indicative of the dielectric constant of the formations surrounding the first and second antennas.

Claim 2

Dependent Claim 110 words

Apparatus for investigating earth formations surrounding a borehole to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means mounted in said member for injecting microwave electromagnetic energy into the surrounding formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the velocity of propagation of the microwave electromagnetic energy received at said first and second antennas, said velocity being indicative of the dielectric constant of the formations surrounding the first and second antennas.

Claim 3

Dependent Claim 36 words

Apparatus as defined by claim 1 further comprising means coupled to said first and second antennas for measuring the attenuation of said microwave electromagnetic energy as it traverses the formations surrounding the first and second antennas.

Claim 4

Dependent Claim 37 words

Apparatus as defined by claim 2 further comprising computing means for combining said velocity measurement with said attenuation measurement to compute a loss-corrected value of the dielectric constant of the formations surrounding the first and second antennas.

Claim 5

Dependent Claim 150 words

Apparatus for investigating earth formations surrounding a borehole which contains drilling mud and has a mudcake formed on a substantial portion of its walls, to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means positionable in the borehole for injecting microwave electromagnetic energy into the surrounding formations and for establishing a lateral wave of such energy within the surrounding formations, said lateral wave traveling adjacent the interface between the mudcake and the formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the velocity of propagation of said lateral wave received at said first and second antennas, said velocity being indicative of the dielectric constant of formations surrounding the first and second antennas.

Claim 6

Dependent Claim 150 words

Apparatus for investigating earth formations surrounding a borehole which contains drilling mud and has a mudcake formed on a substantial portion of its walls, to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means positionable in the borehole for injecting microwave electromagnetic energy into the surrounding formations and for establishing a lateral wave of such energy within the surrounding formations, said lateral wave traveling adjacent the interface between the mudcake and the formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the velocity of propagation of said lateral wave received at said first and second antennas, said velocity being indicative of the dielectric constant of formations surrounding the first and second antennas.

Claim 7

Dependent Claim 107 words

Apparatus for investigating earth formations surrounding a borehole to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means mounted in said member for injecting microwave electromagnetic energy into the surrounding formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the phase difference between signals received at said first and second antennas, said phase difference being indicative of the dielectric constant of the formations surrounding said first and second antennas.

Claim 8

Dependent Claim 107 words

Apparatus for investigating earth formations surrounding a borehole to obtain an indication of the dielectric constant of the formations, comprising: a. a member adapted for engagement with the borehole wall; b. means mounted in said member for injecting microwave electromagnetic energy into the surrounding formations; c. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said member for receiving said microwave electromagnetic energy; and d. means coupled to said antennas for measuring the phase difference between signals received at said first and second antennas, said phase difference being indicative of the dielectric constant of the formations surrounding said first and second antennas.

Claim 9

Dependent Claim 39 words

Apparatus as defined by claim 5 wherein said means for injecting energy into the surrounding formations comprises a transmitting antenna mounted on the wall-engaging face of said member and means for supplying microwave electromagnetic energy to said transmitting antenna.

Claim 10

Dependent Claim 23 words

Apparatus as defined by claim 6 wherein said microwave electromagnetic energy has a frequency within the range of 500 MHz. and 2.0 GHz.

Claim 11

Dependent Claim 18 words

Apparatus as defined by claim 6 wherein said microwave electromagnetic energy has a frequency of about 1.1 GHz.

Claim 12

Dependent Claim 30 words

Apparatus as defined by claim 6 further comprising means coupled to said receiving antennas for measuring the relative attenuation as between signals received at said first and second receiving antennas.

Claim 13

Dependent Claim 15 words

Apparatus as defined by claim 6 wherein said transmitting antenna is a cavity-backed slot antenna.

Claim 14

Dependent Claim 14 words

Apparatus as defined by claim 10 wherein said receiving antennas are cavity-backed slot antennas.

Claim 15

Dependent Claim 44 words

Apparatus as defined by claim 9 further comrpising computing means for combining said phase difference measurement with said attenuation measurement and for computing a corrected value of the phase constant associated with the formations surrounding the area between said first and second receiving antennas.

Claim 16

Dependent Claim 44 words

Apparatus as defined by claim 9 further comprising computing means for combining said phase difference measurement with said attenuation measurement and for computing a loss-corrected value of the dielectric constant associated with the formations surrounding the area between said first and second receiving antennas.

Claim 17

Dependent Claim 66 words

Apparatus as defined by claim 7 further comprising means for computing a corrected value β corr . for the phase constant associated with the formations surrounding the area between said first and second receiving antennas in accordance with the relationship β.sub.corr. = √β.sup.2 -α.sup.2 where β and α are, respectively, phase and attenuation constants determined by said phase difference measuring means and said attenuation measuring means.

Claim 18

Dependent Claim 85 words

Apparatus as defined by claim 7 further comprising means for computing a loss-corrected value ε for the dielectric constant associated with the formations surrounding the area between said first and second receiving antennas in accordance with the relationship ##EQU19## where β and α are, respectively, phase and attenuation constants determined by said phase difference measuring means and said attenuation measuring means, ω is the angular frequency of the transmitted microwave energy, and μ is a constant associated with the magnetic permeability of the surrounding formations.

Claim 19

Dependent Claim 46 words

Apparatus as defined by claim 9 further comprising means for combining said phase difference measurement with said attenuation measurement to generate a signal representative of a corrected value of the phase constant associated with the formations surrounding the area between said first and second receiving antennas.

Claim 20

Dependent Claim 46 words

Apparatus as defined by claim 9 further comprising means for combining said phase difference measurement with said attenuation measurement to generate a signal representative of a loss-corrected value of the dielectric constant associated with the formations surrounding the area between said first and second receiving antennas.

Claim 21

Independent Claim 92 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. injecting microwave electromagnetic energy into the formations surrounding the borehole to establish a lateral wave in the surrounding formations; b. receiving wave energy from said lateral wave at first and second receiving locations within the borehole; and c. measuring the phase difference between wave energy received at said first and second receiving locations, said phase difference being indicative of the dielectric constant of the formations surrounding the area between the first and second receiving locations.

Claim 22

Independent Claim 92 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. injecting microwave electromagnetic energy into the formations surrounding the borehole to establish a lateral wave in the surrounding formations; b. receiving wave energy from said lateral wave at first and second receiving locations within the borehole; and c. measuring the phase difference between wave energy received at said first and second receiving locations, said phase difference being indicative of the dielectric constant of the formations surrounding the area between the first and second receiving locations.

Claim 23

Dependent Claim 60 words

The method as defined by claim 18 further comprising the steps of: d. measuring the relative attenuation as between wave energy received at said first and second receiving locations; and e. computing the loss-corrected dielectric constant associated with the formations surrounding the area between the first and second receiving locations by combining the phase difference measurement with the attenuation measurement.

Claim 24

Dependent Claim 64 words

the method as defined by claim 18 further comprising the steps of: d. measuring the relative attenuation as between wave energy received at said first and second receiving locations; and e. generating a signal representative of the loss-corrected dielectric constant associated with the formations surrounding the area between the first and second receiving locations by combining the phase difference measurement with the attenuation measurement.

Claim 25

Independent Claim 93 words

A method of determining the dielectric constant of earth formations surrounding a borehole, comprising the steps of: a. providing a member engageable with the borehole wall; b. injecting microwave electromagnetic energy into the surrounding formations from a transmitting antenna in said member; c. providing first and second receiving antennas in said member for receiving said microwave electromagnetic energy; and d. measuring the phase difference between signals received at said first and second receiving antennas, the phase difference being indicative of the dielectric constant of the formations surrounding the first and second receiving antennas.

Claim 26

Independent Claim 93 words

A method of determining the dielectric constant of earth formations surrounding a borehole, comprising the steps of: a. providing a member engageable with the borehole wall; b. injecting microwave electromagnetic energy into the surrounding formations from a transmitting antenna in said member; c. providing first and second receiving antennas in said member for receiving said microwave electromagnetic energy; and d. measuring the phase difference between signals received at said first and second receiving antennas, the phase difference being indicative of the dielectric constant of the formations surrounding the first and second receiving antennas.

Claim 27

Independent Claim 94 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. deriving a quantity representative of the phase constant of microwave energy passing through the formations at a particular depth range of the borehole; b. deriving a quantity representative of the attenuation constant of microwave energy passing through the formations at the particular depth range of the borehole; and c. computing the dielectric constant at the particular depth range by combining the derived quantity representative of the phase constant with the derived quantity representative of the attenuation constant.

Claim 28

Independent Claim 94 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. deriving a quantity representative of the phase constant of microwave energy passing through the formations at a particular depth range of the borehole; b. deriving a quantity representative of the attenuation constant of microwave energy passing through the formations at the particular depth range of the borehole; and c. computing the dielectric constant at the particular depth range by combining the derived quantity representative of the phase constant with the derived quantity representative of the attenuation constant.

Claim 29

Independent Claim 97 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. deriving a quantity β 2 , where β is the phase constant associated with microwave energy passing through the formations at a particular depth of the borehole; b. deriving a quantity α 2 , where α is the attenuation constant associated with microwave energy passing through the formations at the particular depth of the borehole; and c. computing the quantity β 2 -α 2 which is proportional to the loss-corrected dielectric constant of the formations at the particular depth range.

Claim 30

Independent Claim 97 words

A method of determining the dielectric constant of formations surrounding a borehole, comprising the steps of: a. deriving a quantity β 2 , where β is the phase constant associated with microwave energy passing through the formations at a particular depth of the borehole; b. deriving a quantity α 2 , where α is the attenuation constant associated with microwave energy passing through the formations at the particular depth of the borehole; and c. computing the quantity β 2 -α 2 which is proportional to the loss-corrected dielectric constant of the formations at the particular depth range.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-03-16	1979-09-15	1980-03-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-03-16	1983-09-15	1984-03-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-03-16	1987-09-15	1988-03-16	$7700.00	Window Closed / Lapsed

Method and apparatus utilizing microwave electromagnetic energy for investigating earth formations

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