US3828867A - Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth - Google Patents

Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth Download PDF

Info

Publication number
US3828867A
US3828867A US00253544A US25354472A US3828867A US 3828867 A US3828867 A US 3828867A US 00253544 A US00253544 A US 00253544A US 25354472 A US25354472 A US 25354472A US 3828867 A US3828867 A US 3828867A
Authority
US
United States
Prior art keywords
earth
drill
low frequency
drill bit
location
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00253544A
Inventor
A Elwood
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US00253544A priority Critical patent/US3828867A/en
Application granted granted Critical
Publication of US3828867A publication Critical patent/US3828867A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V15/00—Tags attached to, or associated with, an object, in order to enable detection of the object
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
    • E21B41/0007—Equipment or details not covered by groups E21B15/00 - E21B40/00 for underwater installations
    • E21B41/0014—Underwater well locating or reentry systems
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E21B47/04—Measuring depth or liquid level
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E21B47/09—Locating or determining the position of objects in boreholes or wells, e.g. the position of an extending arm; Identifying the free or blocked portions of pipes
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves

Definitions

  • ABSTRACT An earth drill bit locating apparatus and method of detecting and locating the position of a drill bit below the surface of the earth utilizing very low frequency electromagnetic energy.
  • the apparatus includes a transmitter located adjacent the drill bit for transmitting a very low-frequency electromagnetic wave below 5,000 Hz and a plurality of receivers including antennae placed adjacent to the earths surface for detecting the low-frequency wave and computing the position of the drill bit by triangulation.
  • Each receiver is a directional indicating receiving means for obtaining raw data in order to display and plot the movement of the drill head as it moves into the earth.
  • the transmitter is powered by an alternator driven by a turbine in the mud supply conduit or collar just above the bit.
  • the drill collar is fitted with electrodes or wire loops which are connected to the transmitter output to cause the drill collar to act as an electric or magnetic radiating dipole.
  • FIG. 2 24 Pmm naus 1 31974 SHEET 2 [IF 3 III N 3 65 ENEQQ W m. 20E
  • This invention relates to apparatus and a method for locating and tracking drill bits as they pass through the earth, and, more particularly, to an apparatus and method utilizing a transmitted energy wave frequency of less than 5,000 Hz.
  • the present invention relates to a new and improved low frequency drill bit locating and tracking apparatus and method of detecting the location of a drill collar as it moves through the earth by transmitting and receiving a low-frequency electro-magnetic wave below 5,000 Hz.
  • the transmitter is placed adjacent the drill bit in the drill collar.
  • the transmitter includes an alternator driven by a turbine in the mud supply conduit in the drill collar.
  • the alternator functions as the transmitter for continuous operation during the drilling operation.
  • the transmitter may also be a battery powered very low-frequency power oscillator.
  • the drill collar is fitted with two electrodes or a wire loop connected to the transmitter output to cause the drill collar to act as an electrical or magnetic dipole.
  • a plurality of directional indicating receivers with a magnetic or electric dipole antenna systems located in the lowfrequency signal and the direction of the signal.
  • a computing means is utilized to manipulate the data in order to plot the movement of the drill collar by triangulation.
  • the method of operation is to place three receivers at known points with respect to the well head which acts as a reference for the system.
  • the arrangement of the three receivers is basically an equilateral triangle with the well head in the center. All relative angles and distances between stations and the well head are measured and entered into the computer as a basis of computation.
  • the transmitter is connected to the drill collar dipole for continuous operation during the entire drilling operation.
  • the low-frequency electromagnetic signal from the drill collar dipole passes relatively undistorted through the complex inhomogeneous media to each receiver antenna.
  • a vertical magnetic dipole comprising a small wire loop, buried or located at some depth beneath the earths surface will produce an electromagnetic field on the earth s surface if an alternating current is injected into the loop.
  • the conductivities of the overburden which may be quite complex, will modify the geometrical character of the vertical and horizontal magnetic field components observed at the surface. However, this effect is quite small provided the burial depths involved are small compared with the free-space wavelength, or electrical skin depth.
  • the basic reference for the drill bit location system are:
  • Sensors stations are initially set up at convenient locations on the corners of a rough equilateral triangle, spaced approximately equally from the well head at distances depending upon the intended maximum depth of the bit.
  • the sensors are two-axis, mutually orthogonal receiving loops mounted in highly accurate trunnions on a very stable base or platform.
  • the main trunnion provides means for rotation of the dual axis loop assembly about a vertical axis.
  • the secondary trunnion provides means for rotation of the dual axis loop assembly about a horizontal axis.
  • the main trunnion is established in the local vertical by use of a helium-neon gas laser interferometer/mercury pool optical level system, to within a few seconds of arc.
  • the main trunnion is rotated about the vertical axis to achieve a null in the horizontal sense loop. This establishes the azimuth angle in the horizontal plane between the well head reference and the location of the buried dipole.
  • the secondary trunnion is then rotated about the horizontal axis normal to the bearing line to buried dipole until a null is achieved. This establishes a vertical angle or dip angle between the horizontal plane and a line passing through the location of the buried dipole.
  • the azimuth and dip angles are measured at all sensor sites, digitized by shaft encoders attached to the trunnions and transmitted to the computer.
  • the computer solves the multiple triangulation problem and establishes position of the buried dipole in the coordinates desired.
  • a further object of this invention is to provide a means to plot the movement of a drill bit as it moves into the ground without removing the drill string.
  • Another object of this invention is to provide a transmitter powered by the movement of the flow of fluids in the drill string.
  • An additional object of this invention is to provide two or three receivers or transmitters just below ground level and the opposite component at the head of the drill.
  • FIG. 1A is a plan view of a geometric illustration of a portion of applicants invention.
  • FIG. 1B is an illustration showing geometric arrangement of the three receivers, the drill tower, drill string and drill collar dipole.
  • FIG. 2 is an elevation in partial cross section of the drill collar showing the turbine driven alternator, transmitter compartment and antenna.
  • FIG. 3 is a block diagram of the receiver illustrating the receiver antenna, computer and display means.
  • FIG. 4 is a perspective view in partial cutaway of Applicants receiver antenna.
  • FIGS. 1A and 1B show a cutaway portion of the earths surface, with the well head reference and sensors A, B, and C embedded in the earths surface with associated equipment resting on the earths surface and a drill string penetrating down into the earth, terminating in the drill collar and drill bit. Attached to the drill collar is an alternating dipole that radiates a SKHz or below electromagnetic wave which is detectable by sensors A, B and C.
  • a computer (not shown) receives sensed information from which it determines the location of the drill bit relative to the well head reference.
  • the drill and transmitter assembly (FIG. 2) is comprised of a drill collar removeably coupled at one end to the end of drill string 12 and at the other to a drill bit 13.
  • the mud flow supply is provided through internal conduit 19 by struts 15.
  • the alternator 14 is driven by rotating turbine blading 16 coupled to the alternator rotor (not shown).
  • Fixed turbine blading 17 directs the flow of liquid in the internal conduit 19 onto the rotating turbine blading.
  • the hole cut out by drill bit 13 in the earth 24 provides for a mud flow return (indicated by arrows 23).
  • the dipole for radiating the 5 KI-Iz wave is provided by a pair of electrodes 21 circumferentially disposed about the drill collar lland electrically coupled to the output of alternator 14 by electrical wires (not shown) in electrical conductor conduit 22.
  • FIG. 3 shows the sensing and computing systems comprising dual axis loop assembly 35 coupled to trunnions 36 moveably positionable by motors 34.
  • the shaft encoders 33 send a signal back to computer interface 29 disclosing the positon of the loop assembly.
  • VLF amplifiers 25 which are connected to null detectors 26, one output being to null indicator 27 and the other to servo amplifiers 28 which drive motors 34.
  • Digital angular information is received from other sensors B and C (not shown) at the computer interface 29 from which the information is sent to computer 30, which solves the geometrical problem and displays the results on display panel 32. Additional manual inputs 31 may be added to the computer.
  • FIG. 4 shows a receiver antenna comprised of orthogonal loops 45 mounted on support bar 50 coupled to U-shaped moveable mount 44.
  • a servo 46 rotates the loops 45 through support 50.
  • the entire antennae including dome 41 is mounted on base 42.
  • the dome 41 is filled with a liquid 43 having the same conductivity as the surrounding earth, thus permitting movement of the antenna with minimum wave distortion as it proceeds through the earths surface into the liquid 43.
  • the antenna mount 44 is rotated by shaft 48 coupled through cover plate 47.
  • the entire structure is anchored to base 42 by holding plate 49. In operation the antenna loops are rotated in three planes until a null signal is received.
  • the loop positions are received by the computer, and all antennae positions are correlated to provide an accurate location position of the drill mounted transmitter.
  • the transmitter in the drill bit housing may be replaced by a VLF receiver and the three surface receivers by three VLF transmitters positioned in a triangular array.
  • the transmitters are radiated individually during different time periods so that each transmitter antenna is moved until a signal null is indicated by the detector in the drill bit housing.
  • the received signals are transmitted up the drill pipe casing and sent to the computer along with signals from shaftencoders on the antennae for position azimuth and depression angles of the drill bit.
  • the horizontal and vertical position of each transmitter antenna at signal maximum provides sufficient information to determine drill bit location through triangulation.
  • the electromagnetic radiation is 5 K Hertz or below.
  • the antennae for transmitting as shown in the alternate embodiment are radio direction loops that are moveably mounted on a base and include shaft encoders for vertical and horizontal position information and servo drive devices for positioning in different reference planes.
  • both the transmitters or the receivers are properly coupled to the ground surface in order to prevent signal path refraction distortion as would happen at the boundary between the earth and the atmosphere.
  • each antenna is submerged in a fluid, the conductivity of which is very close to that'of the earths surface at that location.
  • the computer interface 29 may be a 3l6l model interface produced by Ocean Measurements, Inc. and made for a Honeywell 316 computer.
  • Position recorder 32 may be an XY recorder model 7004B produced by l-lewlett-Packerd.
  • Shaft encoders 33 that may be utilized are Series II, 2A s/11 from Computer Terminal Systems, Inc. while the amplifiers 25 are Khron-Hite tuneable amplifiers with VLF filters.
  • the transmitter on the preferred embodiment may be an alternator producing a power output in the range of five thousand watts and having a frequency between to 5,000 Hz.
  • the alternator is geared to a turbine blade that is placed in the mud supply conduit in the drill head. The mud flowing downward through the conduit will turn the turbine blade to rotate the alternator to produce the output frequency.
  • the head of the drill string will be the transmitting antenna.
  • the receiving system will have three dual axis receivers, each optically surveyed in place with respect to a horizontal azimuth reference. Each dual axis receiver will also have its sensor oriented with respect to a vertical reference. The vertical reference will be established by laser interferometer mercury level.
  • each receiver will be properly coupled to the surface of the earth.
  • Each receiver will determine the angle in the horizontal to the drill bit and the angle in the vertical (dip or depression angle to the drill bit). The intersection of the three lines determines the particular location within the earth of the drill bit.
  • the computer is utilized to continuously compute and plot the location of the transmitter and drill bit.
  • the low-frequency electromagnetic wave is relatively unaffected as it travels through the various layers of material between the transmitter and the receiver because small variations in media densities are negligible at these electromagnetic frequencies.
  • An apparatus for locating a drill bit within the earths crust relative to a predetermined reference position comprising:
  • analyzing means coupled to said receivers for analyzing the low frequency received signals providing information giving the reference location of said transmitter relative to said predetermined reference position
  • a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the free end of said drill string, said low frequency electro-magnetic transmitter coupled to said drill string, adjacent said drill bit.
  • a drill location apparatus as set forth in claim 1, wherein said transmitter includes:
  • a mud supply conduit coupled within said drill string
  • a drill location apparatus as set forth in claim 2 including:
  • indicating means coupled to said analyzing means for providing a visual display of said drill bit location.
  • a drill bit location apparatus as set forth in claim 3, wherein:
  • said receivers include a housing in contact with said earth surface
  • a fluid medium within said housing having a conductivity similar to that of the surrounding earth, said receiver antennas immersed in said medium.
  • a drill location apparatus as set forth in claim 4, wherein:
  • a method for detecting the location of a drill bit within the surface of the earth by transmitting low frequency electro-magnetic wave energy with reference to a known predetermined reference location comprising the steps of:
  • An apparatus for locating a drill bit within the earths crust relative to a predetermined reference position comprising:
  • At least two low frequency electro-magnetic transmitters in conductive communication with the earths crust for transmitting low frequency signals
  • an analyzing means coupled to said receiver for analyzing the low frequency received signals for providing information giving the reference location of said transmitters relative to said predetermined ref erence location;
  • a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the end of said drill string, said low frequency electro-magnetic receiver coupled to said drill string.

Abstract

An earth drill bit locating apparatus and method of detecting and locating the position of a drill bit below the surface of the earth utilizing very low frequency electromagnetic energy. The apparatus includes a transmitter located adjacent the drill bit for transmitting a very low-frequency electromagnetic wave below 5,000 Hz and a plurality of receivers including antennae placed adjacent to the earth''s surface for detecting the low-frequency wave and computing the position of the drill bit by triangulation. Each receiver is a directional indicating receiving means for obtaining raw data in order to display and plot the movement of the drill head as it moves into the earth. The transmitter is powered by an alternator driven by a turbine in the mud supply conduit or collar just above the bit. The drill collar is fitted with electrodes or wire loops which are connected to the transmitter output to cause the drill collar to act as an electric or magnetic radiating dipole.

Description

Elite Sttes Elwood 11] 3,28,87 [451 Aug. 13, 1974 [76] Inventor: Albert A. Elwood, PO. Box 10592,
Riviera Beach, Fla. 33404 22 Filed: May 15, 1972 21 Appl.No.:253,544,
52 us. Cl. 175/45, 175/61 51 Int. Cl E2lb 47/024 [58] Field of Search 175/1, 61, 73, 40, 45, 175/24; 102/2l.6
[56] References Cited UNITED STATES PATENTS 3,100,444 8/1963 Ball et a1 102/21.6
3,406,766 10/1968 Henderson 175/61 3,461,979 8/1969 Newfarmer 175/45 3,465,834 9/1969 Southworth 175/73 X 3,529,682 9/1970 Coyne et a1 175/45 3,693,142 9/1972 Jones 175/45 X 3,712,391 1/1973 Coyne 175/45 X 3,722,605 3/1973 lsham 175/40 3,739,871 6/1973 Bailey 175/1 X Primary Examiner-David H. Brown Attorney, Agent, or Firm-Malin & Haley [5 7] ABSTRACT An earth drill bit locating apparatus and method of detecting and locating the position of a drill bit below the surface of the earth utilizing very low frequency electromagnetic energy. The apparatus includes a transmitter located adjacent the drill bit for transmitting a very low-frequency electromagnetic wave below 5,000 Hz and a plurality of receivers including antennae placed adjacent to the earths surface for detecting the low-frequency wave and computing the position of the drill bit by triangulation. Each receiver is a directional indicating receiving means for obtaining raw data in order to display and plot the movement of the drill head as it moves into the earth. The transmitter is powered by an alternator driven by a turbine in the mud supply conduit or collar just above the bit. The drill collar is fitted with electrodes or wire loops which are connected to the transmitter output to cause the drill collar to act as an electric or magnetic radiating dipole.
7 Claims, 5 Drawing Figures PATENIEUAum 31314 $828,867,
FlG. IA
FIG. 2 24 Pmm naus 1 31974 SHEET 2 [IF 3 III N 3 65 ENEQQ W m. 20E
LOW FREQUENCY DRILL BIT APPARATUS AND METHOD OF LOCATING THE POSITION OF THE DRILL HEAD BELOW THE SURFACE OF THE EARTH BACKGROUND OF THE INVENTION This invention relates to apparatus and a method for locating and tracking drill bits as they pass through the earth, and, more particularly, to an apparatus and method utilizing a transmitted energy wave frequency of less than 5,000 Hz.
In the past, gyroscopic survey instruments were built for directionally surveying boreholes. Also single and multiple magnetic methods of orientation have been utilized in conjunction with non-magnetic drill collars. Such devices require the drill string to be pulled out of the drill hole or the drilling operation stopped while survey devices were lowered into the string down to the non-magnetic drill collar. These operations contribute heavily to the expense of drilling a well.
BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a new and improved low frequency drill bit locating and tracking apparatus and method of detecting the location of a drill collar as it moves through the earth by transmitting and receiving a low-frequency electro-magnetic wave below 5,000 Hz. The transmitter is placed adjacent the drill bit in the drill collar. The transmitter includes an alternator driven by a turbine in the mud supply conduit in the drill collar. The alternator functions as the transmitter for continuous operation during the drilling operation. The transmitter may also be a battery powered very low-frequency power oscillator. The drill collar is fitted with two electrodes or a wire loop connected to the transmitter output to cause the drill collar to act as an electrical or magnetic dipole. A plurality of directional indicating receivers with a magnetic or electric dipole antenna systems located in the lowfrequency signal and the direction of the signal. A computing means is utilized to manipulate the data in order to plot the movement of the drill collar by triangulation.
The method of operation is to place three receivers at known points with respect to the well head which acts as a reference for the system. The arrangement of the three receivers is basically an equilateral triangle with the well head in the center. All relative angles and distances between stations and the well head are measured and entered into the computer as a basis of computation. The transmitter is connected to the drill collar dipole for continuous operation during the entire drilling operation. The low-frequency electromagnetic signal from the drill collar dipole passes relatively undistorted through the complex inhomogeneous media to each receiver antenna. A vertical magnetic dipole comprising a small wire loop, buried or located at some depth beneath the earths surface will produce an electromagnetic field on the earth s surface if an alternating current is injected into the loop. The conductivities of the overburden, which may be quite complex, will modify the geometrical character of the vertical and horizontal magnetic field components observed at the surface. However, this effect is quite small provided the burial depths involved are small compared with the free-space wavelength, or electrical skin depth.
The basic reference for the drill bit location system are:
l. The well head 2. The positions of the sensors with respect to the well head 3. The local vertical passing through the positions of the sensors.
Sensors stations are initially set up at convenient locations on the corners of a rough equilateral triangle, spaced approximately equally from the well head at distances depending upon the intended maximum depth of the bit.
The sensors are two-axis, mutually orthogonal receiving loops mounted in highly accurate trunnions on a very stable base or platform. The main trunnion provides means for rotation of the dual axis loop assembly about a vertical axis. The secondary trunnion provides means for rotation of the dual axis loop assembly about a horizontal axis.
The main trunnion is established in the local vertical by use of a helium-neon gas laser interferometer/mercury pool optical level system, to within a few seconds of arc.
In operation, the main trunnion is rotated about the vertical axis to achieve a null in the horizontal sense loop. This establishes the azimuth angle in the horizontal plane between the well head reference and the location of the buried dipole. The secondary trunnion is then rotated about the horizontal axis normal to the bearing line to buried dipole until a null is achieved. This establishes a vertical angle or dip angle between the horizontal plane and a line passing through the location of the buried dipole.
The azimuth and dip angles are measured at all sensor sites, digitized by shaft encoders attached to the trunnions and transmitted to the computer. The computer solves the multiple triangulation problem and establishes position of the buried dipole in the coordinates desired.
It is an object of this invention to detect and plot the movement of a transmitter through an inhomogeneous solid media by transmitting and detecting lowfrequency electromagnetic waves below 5,000 I-lz.
A further object of this invention is to provide a means to plot the movement of a drill bit as it moves into the ground without removing the drill string.
Another object of this invention is to provide a transmitter powered by the movement of the flow of fluids in the drill string.
An additional object of this invention is to provide two or three receivers or transmitters just below ground level and the opposite component at the head of the drill.
In accordance with these and other objects which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING In the drawing:
FIG. 1A is a plan view of a geometric illustration of a portion of applicants invention.
FIG. 1B is an illustration showing geometric arrangement of the three receivers, the drill tower, drill string and drill collar dipole.
FIG. 2 is an elevation in partial cross section of the drill collar showing the turbine driven alternator, transmitter compartment and antenna.
FIG. 3 is a block diagram of the receiver illustrating the receiver antenna, computer and display means.
FIG. 4 is a perspective view in partial cutaway of Applicants receiver antenna.
PREFERRED EMBODIMENT OF THE INVENTION FIGS. 1A and 1B show a cutaway portion of the earths surface, with the well head reference and sensors A, B, and C embedded in the earths surface with associated equipment resting on the earths surface and a drill string penetrating down into the earth, terminating in the drill collar and drill bit. Attached to the drill collar is an alternating dipole that radiates a SKHz or below electromagnetic wave which is detectable by sensors A, B and C. A computer (not shown) receives sensed information from which it determines the location of the drill bit relative to the well head reference. It has been determined that employment of a SKHZ or below signal allows for a very accurate triangulation of the received signal because minimum accurate triangulation of the received signal because minimum distortion of the directional propagation of the radiated wave is experienced as the wave proceeds from the dipole through various strata of the earths surface to the sensors.
The drill and transmitter assembly (FIG. 2) is comprised of a drill collar removeably coupled at one end to the end of drill string 12 and at the other to a drill bit 13. The mud flow supply is provided through internal conduit 19 by struts 15. The alternator 14 is driven by rotating turbine blading 16 coupled to the alternator rotor (not shown). Fixed turbine blading 17 directs the flow of liquid in the internal conduit 19 onto the rotating turbine blading.
The hole cut out by drill bit 13 in the earth 24 provides for a mud flow return (indicated by arrows 23).
The dipole for radiating the 5 KI-Iz wave is provided by a pair of electrodes 21 circumferentially disposed about the drill collar lland electrically coupled to the output of alternator 14 by electrical wires (not shown) in electrical conductor conduit 22.
FIG. 3 shows the sensing and computing systems comprising dual axis loop assembly 35 coupled to trunnions 36 moveably positionable by motors 34. The shaft encoders 33 send a signal back to computer interface 29 disclosing the positon of the loop assembly.
Energy received in each loop from the dipole is sent to VLF amplifiers 25 which are connected to null detectors 26, one output being to null indicator 27 and the other to servo amplifiers 28 which drive motors 34.
Digital angular information is received from other sensors B and C (not shown) at the computer interface 29 from which the information is sent to computer 30, which solves the geometrical problem and displays the results on display panel 32. Additional manual inputs 31 may be added to the computer.
FIG. 4 shows a receiver antenna comprised of orthogonal loops 45 mounted on support bar 50 coupled to U-shaped moveable mount 44. A servo 46 rotates the loops 45 through support 50. The entire antennae including dome 41 is mounted on base 42. The dome 41 is filled with a liquid 43 having the same conductivity as the surrounding earth, thus permitting movement of the antenna with minimum wave distortion as it proceeds through the earths surface into the liquid 43. The antenna mount 44 is rotated by shaft 48 coupled through cover plate 47. The entire structure is anchored to base 42 by holding plate 49. In operation the antenna loops are rotated in three planes until a null signal is received. The loop positions are received by the computer, and all antennae positions are correlated to provide an accurate location position of the drill mounted transmitter.
In an alternate embodiment, the transmitter in the drill bit housing may be replaced by a VLF receiver and the three surface receivers by three VLF transmitters positioned in a triangular array. The transmitters are radiated individually during different time periods so that each transmitter antenna is moved until a signal null is indicated by the detector in the drill bit housing. The received signals are transmitted up the drill pipe casing and sent to the computer along with signals from shaftencoders on the antennae for position azimuth and depression angles of the drill bit. The horizontal and vertical position of each transmitter antenna at signal maximum provides sufficient information to determine drill bit location through triangulation. Again in the alternate embodiment the electromagnetic radiation is 5 K Hertz or below.
The antennae for transmitting as shown in the alternate embodiment are radio direction loops that are moveably mounted on a base and include shaft encoders for vertical and horizontal position information and servo drive devices for positioning in different reference planes.
It is essential in either embodiment that both the transmitters or the receivers are properly coupled to the ground surface in order to prevent signal path refraction distortion as would happen at the boundary between the earth and the atmosphere. In order to provide moveable antennae at the coupling point each antenna is submerged in a fluid, the conductivity of which is very close to that'of the earths surface at that location.
With regard to system components, (FIG. 3) the computer interface 29 may be a 3l6l model interface produced by Ocean Measurements, Inc. and made for a Honeywell 316 computer. Position recorder 32 may be an XY recorder model 7004B produced by l-lewlett-Packerd. Shaft encoders 33 that may be utilized are Series II, 2A s/11 from Computer Terminal Systems, Inc. while the amplifiers 25 are Khron-Hite tuneable amplifiers with VLF filters.
In operation, the transmitter on the preferred embodiment may be an alternator producing a power output in the range of five thousand watts and having a frequency between to 5,000 Hz. The alternator is geared to a turbine blade that is placed in the mud supply conduit in the drill head. The mud flowing downward through the conduit will turn the turbine blade to rotate the alternator to produce the output frequency. The head of the drill string will be the transmitting antenna. The receiving system will have three dual axis receivers, each optically surveyed in place with respect to a horizontal azimuth reference. Each dual axis receiver will also have its sensor oriented with respect to a vertical reference. The vertical reference will be established by laser interferometer mercury level. The
antenna for each receiver will be properly coupled to the surface of the earth. Each receiver will determine the angle in the horizontal to the drill bit and the angle in the vertical (dip or depression angle to the drill bit). The intersection of the three lines determines the particular location within the earth of the drill bit.
The computer is utilized to continuously compute and plot the location of the transmitter and drill bit. The low-frequency electromagnetic wave is relatively unaffected as it travels through the various layers of material between the transmitter and the receiver because small variations in media densities are negligible at these electromagnetic frequencies.
The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
What I claim is:
1. An apparatus for locating a drill bit within the earths crust relative to a predetermined reference position comprising:
a low frequency electro-magnetic wave transmitter within the earth for transmitting an output signal below 10,000 Hertz;
a power supply connected to said transmitter;
at least two directional indicating low frequency receivers in conductive communication with the earth for detecting the transmitted low frequency signals; and
analyzing means coupled to said receivers for analyzing the low frequency received signals providing information giving the reference location of said transmitter relative to said predetermined reference position; and
a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the free end of said drill string, said low frequency electro-magnetic transmitter coupled to said drill string, adjacent said drill bit.
2. A drill location apparatus, as set forth in claim 1, wherein said transmitter includes:
an alternator;
a turbine driveably connected to said alternator;
a mud supply conduit coupled within said drill string,
said turbine disposed within said mud supply conduit.
3. A drill location apparatus as set forth in claim 2 including:
indicating means coupled to said analyzing means for providing a visual display of said drill bit location.
4. A drill bit location apparatus as set forth in claim 3, wherein:
said receivers include a housing in contact with said earth surface,
. a fluid medium within said housing having a conductivity similar to that of the surrounding earth, said receiver antennas immersed in said medium.
5. A drill location apparatus as set forth in claim 4, wherein:
the lower end of said drill string is connected to the transmitter output to cause the lower end of the drill string to act as an electrical dipole antenna. 6. A method for detecting the location of a drill bit within the surface of the earth by transmitting low frequency electro-magnetic wave energy with reference to a known predetermined reference location comprising the steps of:
transmitting a low frequency electro-magnetic wave below 5,000 Hertz within the earths surface from a drill bit located within the earths surface while simultaneously moving the drill bit within the earths surface to perform drilling; receiving the transmitted low frequency electromagnetic energy within the earths surface; and comparing the received signals from the receivers with a known reference point location signal thereby determining the location of the transmitting source relative to the known reference point.
7. An apparatus for locating a drill bit within the earths crust relative to a predetermined reference position comprising:
a low frequency electro-magnetic receiver within the earth for receiving an electro-magnetic signal below 10,000 Hertz;
at least two low frequency electro-magnetic transmitters in conductive communication with the earths crust for transmitting low frequency signals;
a power supply connected to said transmitters;
an analyzing means coupled to said receiver for analyzing the low frequency received signals for providing information giving the reference location of said transmitters relative to said predetermined ref erence location; and
a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the end of said drill string, said low frequency electro-magnetic receiver coupled to said drill string.

Claims (7)

1. An apparatus for locating a drill bit within the earth''s crust relative to a predetermined reference position comprising: a low frequency electro-magnetic wave transmitter within the earth for transmitting an output signal below 10,000 Hertz; a power supply connecTed to said transmitter; at least two directional indicating low frequency receivers in conductive communication with the earth for detecting the transmitted low frequency signals; and analyzing means coupled to said receivers for analyzing the low frequency received signals providing information giving the reference location of said transmitter relative to said predetermined reference position; and a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the free end of said drill string, said low frequency electro-magnetic transmitter coupled to said drill string, adjacent said drill bit.
2. A drill location apparatus, as set forth in claim 1, wherein said transmitter includes: an alternator; a turbine driveably connected to said alternator; a mud supply conduit coupled within said drill string, said turbine disposed within said mud supply conduit.
3. A drill location apparatus as set forth in claim 2 including: indicating means coupled to said analyzing means for providing a visual display of said drill bit location.
4. A drill bit location apparatus as set forth in claim 3, wherein: said receivers include a housing in contact with said earth surface, a fluid medium within said housing having a conductivity similar to that of the surrounding earth, said receiver antennas immersed in said medium.
5. A drill location apparatus as set forth in claim 4, wherein: the lower end of said drill string is connected to the transmitter output to cause the lower end of the drill string to act as an electrical dipole antenna.
6. A method for detecting the location of a drill bit within the surface of the earth by transmitting low frequency electro-magnetic wave energy with reference to a known predetermined reference location comprising the steps of: transmitting a low frequency electro-magnetic wave below 5,000 Hertz within the earth''s surface from a drill bit located within the earth''s surface while simultaneously moving the drill bit within the earth''s surface to perform drilling; receiving the transmitted low frequency electro-magnetic energy within the earth''s surface; and comparing the received signals from the receivers with a known reference point location signal thereby determining the location of the transmitting source relative to the known reference point.
7. An apparatus for locating a drill bit within the earth''s crust relative to a predetermined reference position comprising: a low frequency electro-magnetic receiver within the earth for receiving an electro-magnetic signal below 10,000 Hertz; at least two low frequency electro-magnetic transmitters in conductive communication with the earth''s crust for transmitting low frequency signals; a power supply connected to said transmitters; an analyzing means coupled to said receiver for analyzing the low frequency received signals for providing information giving the reference location of said transmitters relative to said predetermined reference location; and a drill rig including a drive means, a drill string connected to said drive means, and a drill bit connected at the end of said drill string, said low frequency electro-magnetic receiver coupled to said drill string.
US00253544A 1972-05-15 1972-05-15 Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth Expired - Lifetime US3828867A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US00253544A US3828867A (en) 1972-05-15 1972-05-15 Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00253544A US3828867A (en) 1972-05-15 1972-05-15 Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth

Publications (1)

Publication Number Publication Date
US3828867A true US3828867A (en) 1974-08-13

Family

ID=22960712

Family Applications (1)

Application Number Title Priority Date Filing Date
US00253544A Expired - Lifetime US3828867A (en) 1972-05-15 1972-05-15 Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth

Country Status (1)

Country Link
US (1) US3828867A (en)

Cited By (86)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199026A (en) * 1978-07-17 1980-04-22 Standard Oil Company Method for detecting underground conditions
DE3029523A1 (en) * 1980-08-04 1982-02-18 Christensen, Inc., 84115 Salt Lake City, Utah GENERATOR FOR GENERATING ELECTRICAL ENERGY
DE3127337A1 (en) * 1980-07-17 1982-03-04 Dickinson Iii, Ben Wade Oakes METHOD AND DEVICE FOR DRILLING A HOLE IN A SUBTERRANEAN FORMATION
US4372398A (en) * 1980-11-04 1983-02-08 Cornell Research Foundation, Inc. Method of determining the location of a deep-well casing by magnetic field sensing
US4443762A (en) * 1981-06-12 1984-04-17 Cornell Research Foundation, Inc. Method and apparatus for detecting the direction and distance to a target well casing
US4474250A (en) * 1982-07-16 1984-10-02 David Dardick Measuring while drilling
US4710708A (en) * 1981-04-27 1987-12-01 Develco Method and apparatus employing received independent magnetic field components of a transmitted alternating magnetic field for determining location
US4864293A (en) * 1988-04-29 1989-09-05 Flowmole Corporation Inground boring technique including real time transducer
US5031158A (en) * 1984-03-23 1991-07-09 The Charles Stark Draper Laboratory, Inc. Method and apparatus for drill bit location
US5467290A (en) * 1993-08-18 1995-11-14 Atlantic Richfield Company Survey system and method
US6243657B1 (en) 1997-12-23 2001-06-05 Pii North America, Inc. Method and apparatus for determining location of characteristics of a pipeline
US6280000B1 (en) 1998-11-20 2001-08-28 Joseph A. Zupanick Method for production of gas from a coal seam using intersecting well bores
US6412556B1 (en) 2000-08-03 2002-07-02 Cdx Gas, Inc. Cavity positioning tool and method
US6425448B1 (en) 2001-01-30 2002-07-30 Cdx Gas, L.L.P. Method and system for accessing subterranean zones from a limited surface area
US6454000B1 (en) 1999-11-19 2002-09-24 Cdx Gas, Llc Cavity well positioning system and method
US6598686B1 (en) 1998-11-20 2003-07-29 Cdx Gas, Llc Method and system for enhanced access to a subterranean zone
US6662870B1 (en) 2001-01-30 2003-12-16 Cdx Gas, L.L.C. Method and system for accessing subterranean deposits from a limited surface area
US6679322B1 (en) 1998-11-20 2004-01-20 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US6681855B2 (en) 2001-10-19 2004-01-27 Cdx Gas, L.L.C. Method and system for management of by-products from subterranean zones
US6708764B2 (en) 2002-07-12 2004-03-23 Cdx Gas, L.L.C. Undulating well bore
US6725922B2 (en) 2002-07-12 2004-04-27 Cdx Gas, Llc Ramping well bores
US6848508B2 (en) 2001-10-30 2005-02-01 Cdx Gas, Llc Slant entry well system and method
US20050104776A1 (en) * 2003-11-14 2005-05-19 Anderson Peter T. Electromagnetic tracking system and method using a three-coil wireless transmitter
US20050109505A1 (en) * 2003-11-26 2005-05-26 Cdx Gas, Llc Method and system for extraction of resources from a subterranean well bore
US20050183887A1 (en) * 2004-02-23 2005-08-25 Halliburton Energy Services, Inc. Downhole positioning system
US6942030B2 (en) 2002-09-12 2005-09-13 Cdx Gas, Llc Three-dimensional well system for accessing subterranean zones
US6964308B1 (en) 2002-10-08 2005-11-15 Cdx Gas, Llc Method of drilling lateral wellbores from a slant well without utilizing a whipstock
US6988566B2 (en) 2002-02-19 2006-01-24 Cdx Gas, Llc Acoustic position measurement system for well bore formation
US6988548B2 (en) 2002-10-03 2006-01-24 Cdx Gas, Llc Method and system for removing fluid from a subterranean zone using an enlarged cavity
US6991048B2 (en) 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore plug system and method
US6991047B2 (en) 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore sealing system and method
US20060022840A1 (en) * 2003-01-07 2006-02-02 Spring Gregson W M Communication system for down hole use
US7025154B2 (en) 1998-11-20 2006-04-11 Cdx Gas, Llc Method and system for circulating fluid in a well system
US7073595B2 (en) 2002-09-12 2006-07-11 Cdx Gas, Llc Method and system for controlling pressure in a dual well system
US7100687B2 (en) 2003-11-17 2006-09-05 Cdx Gas, Llc Multi-purpose well bores and method for accessing a subterranean zone from the surface
US7134494B2 (en) 2003-06-05 2006-11-14 Cdx Gas, Llc Method and system for recirculating fluid in a well system
US7207390B1 (en) 2004-02-05 2007-04-24 Cdx Gas, Llc Method and system for lining multilateral wells
US7207395B2 (en) 2004-01-30 2007-04-24 Cdx Gas, Llc Method and system for testing a partially formed hydrocarbon well for evaluation and well planning refinement
US7222670B2 (en) 2004-02-27 2007-05-29 Cdx Gas, Llc System and method for multiple wells from a common surface location
US20070167744A1 (en) * 2005-11-23 2007-07-19 General Electric Company System and method for surgical navigation cross-reference to related applications
US7264048B2 (en) 2003-04-21 2007-09-04 Cdx Gas, Llc Slot cavity
US7299864B2 (en) 2004-12-22 2007-11-27 Cdx Gas, Llc Adjustable window liner
US7353877B2 (en) 2004-12-21 2008-04-08 Cdx Gas, Llc Accessing subterranean resources by formation collapse
US7360595B2 (en) 2002-05-08 2008-04-22 Cdx Gas, Llc Method and system for underground treatment of materials
US7373984B2 (en) 2004-12-22 2008-05-20 Cdx Gas, Llc Lining well bore junctions
US20080154120A1 (en) * 2006-12-22 2008-06-26 General Electric Company Systems and methods for intraoperative measurements on navigated placements of implants
US20080177203A1 (en) * 2006-12-22 2008-07-24 General Electric Company Surgical navigation planning system and method for placement of percutaneous instrumentation and implants
US7419223B2 (en) 2003-11-26 2008-09-02 Cdx Gas, Llc System and method for enhancing permeability of a subterranean zone at a horizontal well bore
US20080291345A1 (en) * 2007-05-23 2008-11-27 Antennas Direct, Inc. Picture frame antenna assemblies
US7471202B2 (en) 2006-03-29 2008-12-30 General Electric Co. Conformal coil array for a medical tracking system
US20090096443A1 (en) * 2007-10-11 2009-04-16 General Electric Company Coil arrangement for an electromagnetic tracking system
US7532997B2 (en) 2006-04-17 2009-05-12 General Electric Company Electromagnetic tracking using a discretized numerical field model
US7571771B2 (en) 2005-05-31 2009-08-11 Cdx Gas, Llc Cavity well system
US20100045551A1 (en) * 2007-12-05 2010-02-25 Antennas Direct, Inc. Antenna assemblies with antenna elements and reflectors
US20100195441A1 (en) * 2009-02-01 2010-08-05 Camwell Paul L Parallel-path acoustic telemetry isolation system and method
US20100200296A1 (en) * 2009-02-12 2010-08-12 Camwell Paul L System and method for accurate wellbore placement
US20100208552A1 (en) * 2009-02-13 2010-08-19 Camwell Paul L Acoustic telemetry stacked-ring wave delay isolator system and method
US20100311325A1 (en) * 2009-06-03 2010-12-09 Marshall Radio Telemetry, Inc. Systems and methods for through-the-earth communications
US20110141852A1 (en) * 2009-06-15 2011-06-16 Camwell Paul L Air hammer optimization using acoustic telemetry
US7990335B2 (en) * 2007-12-05 2011-08-02 Antennas Direct, Inc. Antenna assemblies with antenna elements and reflectors
USD664126S1 (en) 2010-08-26 2012-07-24 Antennas Direct, Inc. Antenna
USD666178S1 (en) 2008-02-29 2012-08-28 Antennas Direct, Inc. Antenna
US8291974B2 (en) 1998-11-20 2012-10-23 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US8333245B2 (en) 2002-09-17 2012-12-18 Vitruvian Exploration, Llc Accelerated production of gas from a subterranean zone
US8376052B2 (en) 1998-11-20 2013-02-19 Vitruvian Exploration, Llc Method and system for surface production of gas from a subterranean zone
US8648770B2 (en) 2008-09-05 2014-02-11 Antennas Direct, Inc. Smart antenna systems suitable for reception of digital television signals
US8922387B2 (en) 2010-04-19 2014-12-30 Xact Downhole Telemetry, Inc. Tapered thread EM gap sub self-aligning means and method
US20160024910A1 (en) * 2011-01-21 2016-01-28 Schlumberger Technology Corporation Downhole sand control apparatus and method with tool position sensor
US9761935B2 (en) 2015-09-02 2017-09-12 Antennas Direct, Inc. HDTV antenna assemblies
USD804459S1 (en) 2008-02-29 2017-12-05 Antennas Direct, Inc. Antennas
USD809490S1 (en) 2008-02-29 2018-02-06 Antennas Direct, Inc. Antenna
USD815073S1 (en) 2008-02-29 2018-04-10 Antennas Direct, Inc. Antenna
USD824884S1 (en) 2015-10-08 2018-08-07 Antennas Direct, Inc. Antenna element
USD827620S1 (en) 2015-10-08 2018-09-04 Antennas Direct, Inc. Antenna element
US10128575B2 (en) 2015-09-02 2018-11-13 Antennas Direct, Inc. HDTV antenna assemblies
US10400584B2 (en) * 2014-08-15 2019-09-03 Baker Hughes, A Ge Company, Llc Methods and systems for monitoring a subterranean formation and wellbore production
USD867347S1 (en) 2008-02-29 2019-11-19 Antennas Direct, Inc. Antenna
USD868045S1 (en) 2008-02-29 2019-11-26 Antennas Direct, Inc. Antenna
US10615501B2 (en) 2007-12-05 2020-04-07 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
USD881172S1 (en) 1975-11-03 2020-04-14 Antennas Direct, Inc. Antenna and base stand
USD883264S1 (en) 2008-02-29 2020-05-05 Antennas Direct, Inc. Antenna
USD883265S1 (en) 2008-02-29 2020-05-05 Antennas Direct, Inc. Antenna
US10957979B2 (en) 2018-12-06 2021-03-23 Antennas Direct, Inc. Antenna assemblies
USD920962S1 (en) 2008-02-29 2021-06-01 Antennas Direct, Inc. Base stand for antenna
USD951658S1 (en) 2015-10-08 2022-05-17 Antennas Direct, Inc. Picture frame antenna
US11929562B2 (en) 2007-12-05 2024-03-12 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements

Cited By (150)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD881172S1 (en) 1975-11-03 2020-04-14 Antennas Direct, Inc. Antenna and base stand
US4199026A (en) * 1978-07-17 1980-04-22 Standard Oil Company Method for detecting underground conditions
DE3127337A1 (en) * 1980-07-17 1982-03-04 Dickinson Iii, Ben Wade Oakes METHOD AND DEVICE FOR DRILLING A HOLE IN A SUBTERRANEAN FORMATION
DE3029523A1 (en) * 1980-08-04 1982-02-18 Christensen, Inc., 84115 Salt Lake City, Utah GENERATOR FOR GENERATING ELECTRICAL ENERGY
US4372398A (en) * 1980-11-04 1983-02-08 Cornell Research Foundation, Inc. Method of determining the location of a deep-well casing by magnetic field sensing
US4710708A (en) * 1981-04-27 1987-12-01 Develco Method and apparatus employing received independent magnetic field components of a transmitted alternating magnetic field for determining location
US4443762A (en) * 1981-06-12 1984-04-17 Cornell Research Foundation, Inc. Method and apparatus for detecting the direction and distance to a target well casing
US4474250A (en) * 1982-07-16 1984-10-02 David Dardick Measuring while drilling
US5031158A (en) * 1984-03-23 1991-07-09 The Charles Stark Draper Laboratory, Inc. Method and apparatus for drill bit location
US4864293A (en) * 1988-04-29 1989-09-05 Flowmole Corporation Inground boring technique including real time transducer
US5467290A (en) * 1993-08-18 1995-11-14 Atlantic Richfield Company Survey system and method
US6243657B1 (en) 1997-12-23 2001-06-05 Pii North America, Inc. Method and apparatus for determining location of characteristics of a pipeline
US8297350B2 (en) 1998-11-20 2012-10-30 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface
US6732792B2 (en) 1998-11-20 2004-05-11 Cdx Gas, Llc Multi-well structure for accessing subterranean deposits
US9551209B2 (en) 1998-11-20 2017-01-24 Effective Exploration, LLC System and method for accessing subterranean deposits
US6439320B2 (en) 1998-11-20 2002-08-27 Cdx Gas, Llc Wellbore pattern for uniform access to subterranean deposits
US8371399B2 (en) 1998-11-20 2013-02-12 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US6478085B2 (en) 1998-11-20 2002-11-12 Cdx Gas, Llp System for accessing subterranean deposits from the surface
US6561288B2 (en) 1998-11-20 2003-05-13 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US6575235B2 (en) 1998-11-20 2003-06-10 Cdx Gas, Llc Subterranean drainage pattern
US6598686B1 (en) 1998-11-20 2003-07-29 Cdx Gas, Llc Method and system for enhanced access to a subterranean zone
US6604580B2 (en) 1998-11-20 2003-08-12 Cdx Gas, Llc Method and system for accessing subterranean zones from a limited surface area
US6280000B1 (en) 1998-11-20 2001-08-28 Joseph A. Zupanick Method for production of gas from a coal seam using intersecting well bores
US6668918B2 (en) 1998-11-20 2003-12-30 Cdx Gas, L.L.C. Method and system for accessing subterranean deposit from the surface
US6679322B1 (en) 1998-11-20 2004-01-20 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US8813840B2 (en) 1998-11-20 2014-08-26 Efective Exploration, LLC Method and system for accessing subterranean deposits from the surface and tools therefor
US6688388B2 (en) 1998-11-20 2004-02-10 Cdx Gas, Llc Method for accessing subterranean deposits from the surface
US8511372B2 (en) 1998-11-20 2013-08-20 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface
US8505620B2 (en) 1998-11-20 2013-08-13 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US8291974B2 (en) 1998-11-20 2012-10-23 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US8479812B2 (en) 1998-11-20 2013-07-09 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US7025154B2 (en) 1998-11-20 2006-04-11 Cdx Gas, Llc Method and system for circulating fluid in a well system
US8316966B2 (en) 1998-11-20 2012-11-27 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US6357523B1 (en) 1998-11-20 2002-03-19 Cdx Gas, Llc Drainage pattern with intersecting wells drilled from surface
US8297377B2 (en) 1998-11-20 2012-10-30 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US8469119B2 (en) 1998-11-20 2013-06-25 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US6964298B2 (en) 1998-11-20 2005-11-15 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US8464784B2 (en) 1998-11-20 2013-06-18 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US6976533B2 (en) 1998-11-20 2005-12-20 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US8376052B2 (en) 1998-11-20 2013-02-19 Vitruvian Exploration, Llc Method and system for surface production of gas from a subterranean zone
US8434568B2 (en) 1998-11-20 2013-05-07 Vitruvian Exploration, Llc Method and system for circulating fluid in a well system
US8376039B2 (en) 1998-11-20 2013-02-19 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US6454000B1 (en) 1999-11-19 2002-09-24 Cdx Gas, Llc Cavity well positioning system and method
US6412556B1 (en) 2000-08-03 2002-07-02 Cdx Gas, Inc. Cavity positioning tool and method
US7213644B1 (en) 2000-08-03 2007-05-08 Cdx Gas, Llc Cavity positioning tool and method
US6986388B2 (en) 2001-01-30 2006-01-17 Cdx Gas, Llc Method and system for accessing a subterranean zone from a limited surface area
US6425448B1 (en) 2001-01-30 2002-07-30 Cdx Gas, L.L.P. Method and system for accessing subterranean zones from a limited surface area
US7036584B2 (en) 2001-01-30 2006-05-02 Cdx Gas, L.L.C. Method and system for accessing a subterranean zone from a limited surface area
US6662870B1 (en) 2001-01-30 2003-12-16 Cdx Gas, L.L.C. Method and system for accessing subterranean deposits from a limited surface area
US6681855B2 (en) 2001-10-19 2004-01-27 Cdx Gas, L.L.C. Method and system for management of by-products from subterranean zones
US6848508B2 (en) 2001-10-30 2005-02-01 Cdx Gas, Llc Slant entry well system and method
US7048049B2 (en) 2001-10-30 2006-05-23 Cdx Gas, Llc Slant entry well system and method
US6988566B2 (en) 2002-02-19 2006-01-24 Cdx Gas, Llc Acoustic position measurement system for well bore formation
US7360595B2 (en) 2002-05-08 2008-04-22 Cdx Gas, Llc Method and system for underground treatment of materials
US6991047B2 (en) 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore sealing system and method
US6991048B2 (en) 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore plug system and method
US6725922B2 (en) 2002-07-12 2004-04-27 Cdx Gas, Llc Ramping well bores
US6708764B2 (en) 2002-07-12 2004-03-23 Cdx Gas, L.L.C. Undulating well bore
US6942030B2 (en) 2002-09-12 2005-09-13 Cdx Gas, Llc Three-dimensional well system for accessing subterranean zones
US7090009B2 (en) 2002-09-12 2006-08-15 Cdx Gas, Llc Three-dimensional well system for accessing subterranean zones
US7073595B2 (en) 2002-09-12 2006-07-11 Cdx Gas, Llc Method and system for controlling pressure in a dual well system
US7025137B2 (en) 2002-09-12 2006-04-11 Cdx Gas, Llc Three-dimensional well system for accessing subterranean zones
US8333245B2 (en) 2002-09-17 2012-12-18 Vitruvian Exploration, Llc Accelerated production of gas from a subterranean zone
US6988548B2 (en) 2002-10-03 2006-01-24 Cdx Gas, Llc Method and system for removing fluid from a subterranean zone using an enlarged cavity
US6964308B1 (en) 2002-10-08 2005-11-15 Cdx Gas, Llc Method of drilling lateral wellbores from a slant well without utilizing a whipstock
US20060022840A1 (en) * 2003-01-07 2006-02-02 Spring Gregson W M Communication system for down hole use
US7378985B2 (en) * 2003-01-07 2008-05-27 Gregson William Martin Spring Communication system for down hole use
US7264048B2 (en) 2003-04-21 2007-09-04 Cdx Gas, Llc Slot cavity
US7134494B2 (en) 2003-06-05 2006-11-14 Cdx Gas, Llc Method and system for recirculating fluid in a well system
US20050104776A1 (en) * 2003-11-14 2005-05-19 Anderson Peter T. Electromagnetic tracking system and method using a three-coil wireless transmitter
US7015859B2 (en) * 2003-11-14 2006-03-21 General Electric Company Electromagnetic tracking system and method using a three-coil wireless transmitter
US7100687B2 (en) 2003-11-17 2006-09-05 Cdx Gas, Llc Multi-purpose well bores and method for accessing a subterranean zone from the surface
US20050109505A1 (en) * 2003-11-26 2005-05-26 Cdx Gas, Llc Method and system for extraction of resources from a subterranean well bore
US7419223B2 (en) 2003-11-26 2008-09-02 Cdx Gas, Llc System and method for enhancing permeability of a subterranean zone at a horizontal well bore
US7163063B2 (en) 2003-11-26 2007-01-16 Cdx Gas, Llc Method and system for extraction of resources from a subterranean well bore
US7207395B2 (en) 2004-01-30 2007-04-24 Cdx Gas, Llc Method and system for testing a partially formed hydrocarbon well for evaluation and well planning refinement
US7207390B1 (en) 2004-02-05 2007-04-24 Cdx Gas, Llc Method and system for lining multilateral wells
US8902703B2 (en) 2004-02-23 2014-12-02 Halliburton Energy Services, Inc. Downhole positioning system
WO2005081993A2 (en) * 2004-02-23 2005-09-09 Halliburton Energy Services, Inc. A downhole positioning system
NO341626B1 (en) * 2004-02-23 2017-12-11 Halliburton Energy Services Inc Method and system for positioning a signal source in a borehole
US20050183887A1 (en) * 2004-02-23 2005-08-25 Halliburton Energy Services, Inc. Downhole positioning system
US20100139976A1 (en) * 2004-02-23 2010-06-10 Halliburton Energy Services, Inc. Downhole positioning system
US7686099B2 (en) * 2004-02-23 2010-03-30 Halliburton Energy Services, Inc. Downhole positioning system
WO2005081993A3 (en) * 2004-02-23 2007-08-16 Halliburton Energy Serv Inc A downhole positioning system
US7222670B2 (en) 2004-02-27 2007-05-29 Cdx Gas, Llc System and method for multiple wells from a common surface location
US7353877B2 (en) 2004-12-21 2008-04-08 Cdx Gas, Llc Accessing subterranean resources by formation collapse
US7299864B2 (en) 2004-12-22 2007-11-27 Cdx Gas, Llc Adjustable window liner
US7373984B2 (en) 2004-12-22 2008-05-20 Cdx Gas, Llc Lining well bore junctions
US7571771B2 (en) 2005-05-31 2009-08-11 Cdx Gas, Llc Cavity well system
US20070167744A1 (en) * 2005-11-23 2007-07-19 General Electric Company System and method for surgical navigation cross-reference to related applications
US7471202B2 (en) 2006-03-29 2008-12-30 General Electric Co. Conformal coil array for a medical tracking system
US7532997B2 (en) 2006-04-17 2009-05-12 General Electric Company Electromagnetic tracking using a discretized numerical field model
US20080154120A1 (en) * 2006-12-22 2008-06-26 General Electric Company Systems and methods for intraoperative measurements on navigated placements of implants
US20080177203A1 (en) * 2006-12-22 2008-07-24 General Electric Company Surgical navigation planning system and method for placement of percutaneous instrumentation and implants
US20080291345A1 (en) * 2007-05-23 2008-11-27 Antennas Direct, Inc. Picture frame antenna assemblies
US8391952B2 (en) 2007-10-11 2013-03-05 General Electric Company Coil arrangement for an electromagnetic tracking system
US20090096443A1 (en) * 2007-10-11 2009-04-16 General Electric Company Coil arrangement for an electromagnetic tracking system
US11024968B2 (en) 2007-12-05 2021-06-01 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
US7990335B2 (en) * 2007-12-05 2011-08-02 Antennas Direct, Inc. Antenna assemblies with antenna elements and reflectors
US8368607B2 (en) 2007-12-05 2013-02-05 Antennas Direct, Inc. Antenna assemblies with antenna elements and reflectors
US20100045551A1 (en) * 2007-12-05 2010-02-25 Antennas Direct, Inc. Antenna assemblies with antenna elements and reflectors
US10615501B2 (en) 2007-12-05 2020-04-07 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
US11482783B2 (en) 2007-12-05 2022-10-25 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
US11929562B2 (en) 2007-12-05 2024-03-12 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
US8994600B2 (en) 2007-12-05 2015-03-31 Antennas Direct, Inc. Antenna assemblies with tapered loop antenna elements
USD892096S1 (en) 2008-02-29 2020-08-04 Antennas Direct, Inc. Antenna
USD809490S1 (en) 2008-02-29 2018-02-06 Antennas Direct, Inc. Antenna
USD666178S1 (en) 2008-02-29 2012-08-28 Antennas Direct, Inc. Antenna
USD931260S1 (en) 2008-02-29 2021-09-21 Antennas Direct, Inc. Antenna
USD883265S1 (en) 2008-02-29 2020-05-05 Antennas Direct, Inc. Antenna
USD883264S1 (en) 2008-02-29 2020-05-05 Antennas Direct, Inc. Antenna
USD928751S1 (en) 2008-02-29 2021-08-24 Antennas Direct, Inc. Antenna
USD922988S1 (en) 2008-02-29 2021-06-22 Antennas Direct, Inc. Antenna
USD888694S1 (en) 2008-02-29 2020-06-30 Antennas Direct, Inc. Antenna
USD868720S1 (en) 2008-02-29 2019-12-03 Antennas Direct, Inc. Antenna
USD920962S1 (en) 2008-02-29 2021-06-01 Antennas Direct, Inc. Base stand for antenna
USD804459S1 (en) 2008-02-29 2017-12-05 Antennas Direct, Inc. Antennas
USD868045S1 (en) 2008-02-29 2019-11-26 Antennas Direct, Inc. Antenna
USD888697S1 (en) 2008-02-29 2020-06-30 Antennas Direct, Inc. Antenna
USD815073S1 (en) 2008-02-29 2018-04-10 Antennas Direct, Inc. Antenna
USD918879S1 (en) 2008-02-29 2021-05-11 Antennas Direct, Inc. Antenna
USD918187S1 (en) 2008-02-29 2021-05-04 Antennas Direct, Inc. Antenna
USD904358S1 (en) 2008-02-29 2020-12-08 Antennas Direct, Inc. Antenna
USD902896S1 (en) 2008-02-29 2020-11-24 Antennas Direct, Inc. Antenna
USD867347S1 (en) 2008-02-29 2019-11-19 Antennas Direct, Inc. Antenna
US8648770B2 (en) 2008-09-05 2014-02-11 Antennas Direct, Inc. Smart antenna systems suitable for reception of digital television signals
US9024839B2 (en) 2008-09-05 2015-05-05 Antennas Direct, Inc. Smart antenna systems for reception of digital television signals
US8437220B2 (en) 2009-02-01 2013-05-07 Xact Downhold Telemetry, Inc. Parallel-path acoustic telemetry isolation system and method
US20100195441A1 (en) * 2009-02-01 2010-08-05 Camwell Paul L Parallel-path acoustic telemetry isolation system and method
US8393412B2 (en) * 2009-02-12 2013-03-12 Xact Downhole Telemetry, Inc. System and method for accurate wellbore placement
US20100200296A1 (en) * 2009-02-12 2010-08-12 Camwell Paul L System and method for accurate wellbore placement
US20100208552A1 (en) * 2009-02-13 2010-08-19 Camwell Paul L Acoustic telemetry stacked-ring wave delay isolator system and method
US9458712B2 (en) 2009-02-13 2016-10-04 Xact Downhole Telemetry, Inc. Acoustic telemetry stacked-ring wave delay isolator system and method
US8982667B2 (en) 2009-02-13 2015-03-17 Xact Downhole Telemetry, Inc. Acoustic telemetry stacked-ring wave delay isolator system and method
US20100311325A1 (en) * 2009-06-03 2010-12-09 Marshall Radio Telemetry, Inc. Systems and methods for through-the-earth communications
US20110141852A1 (en) * 2009-06-15 2011-06-16 Camwell Paul L Air hammer optimization using acoustic telemetry
US8922387B2 (en) 2010-04-19 2014-12-30 Xact Downhole Telemetry, Inc. Tapered thread EM gap sub self-aligning means and method
USD664126S1 (en) 2010-08-26 2012-07-24 Antennas Direct, Inc. Antenna
US9765611B2 (en) * 2011-01-21 2017-09-19 Schlumberger Technology Corporation Downhole sand control apparatus and method with tool position sensor
US20160024910A1 (en) * 2011-01-21 2016-01-28 Schlumberger Technology Corporation Downhole sand control apparatus and method with tool position sensor
US10400584B2 (en) * 2014-08-15 2019-09-03 Baker Hughes, A Ge Company, Llc Methods and systems for monitoring a subterranean formation and wellbore production
US10693239B2 (en) 2015-09-02 2020-06-23 Antennas Direct, Inc. HDTV antenna assemblies
US9761935B2 (en) 2015-09-02 2017-09-12 Antennas Direct, Inc. HDTV antenna assemblies
US10128575B2 (en) 2015-09-02 2018-11-13 Antennas Direct, Inc. HDTV antenna assemblies
USD824884S1 (en) 2015-10-08 2018-08-07 Antennas Direct, Inc. Antenna element
USD827620S1 (en) 2015-10-08 2018-09-04 Antennas Direct, Inc. Antenna element
USD951658S1 (en) 2015-10-08 2022-05-17 Antennas Direct, Inc. Picture frame antenna
US10957979B2 (en) 2018-12-06 2021-03-23 Antennas Direct, Inc. Antenna assemblies
US11276932B2 (en) 2018-12-06 2022-03-15 Atennas Direct, Inc. Antenna assemblies
US11769947B2 (en) 2018-12-06 2023-09-26 Antennas Direct, Inc. Antenna assemblies

Similar Documents

Publication Publication Date Title
US3828867A (en) Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth
US4710708A (en) Method and apparatus employing received independent magnetic field components of a transmitted alternating magnetic field for determining location
Sato et al. Analysis of a borehole radar in cross-hole mode
US10254425B2 (en) Locating arrangement and method using boring tool and cable locating signals
US4372398A (en) Method of determining the location of a deep-well casing by magnetic field sensing
KR101555311B1 (en) Positioning, detection and communication system and method
US6920943B2 (en) Mapping tool for tracking and/or guiding an underground boring tool
US7659722B2 (en) Method for azimuthal resistivity measurement and bed boundary detection
US5904210A (en) Apparatus and method for detecting a location and an orientation of an underground boring tool
US4529939A (en) System located in drill string for well logging while drilling
US5408182A (en) Facility and method for the detection and monitoring of plumes below a waste containment site with radiowave tomography scattering methods
MX2009000112A (en) Modular geosteering tool assembly.
US20120109527A1 (en) Apparatus and Methods for Drilling Wellbores by Ranging Existing Boreholes Using Induction Devices
US4161687A (en) Method for locating underground anomalies by diffraction of electromagnetic waves passing between spaced boreholes
CA2810196C (en) Method and apparatus to detect a conductive body
US20030048104A1 (en) Radio system for characterizing and outlining underground industrial developments and facilities
US20170299755A1 (en) Airborne Locator Of An Underground Object
US3866111A (en) Method of mineral exploration by detecting electromagnetic energy at power line frequency
MX2012013623A (en) Method for salt and cross-bed proximity detection using deep directional electromagnetic measurements while drilling.
EP0250986B1 (en) Method for constructing vertical images of anomalies in geological formations
US20130016582A1 (en) System for exploration of subterranean structures
KR102275670B1 (en) A device that calculates the trajectory of the underground pipeline simultaneously with geological exploration in four directions around the underground pipeline
Gard Magnetic field sensing in the underground construction environment
KR200194863Y1 (en) Detection apparatus for the survey of buried structures having receive signal saved device by used gpr system
JP2649046B2 (en) Ground exploration method using electromagnetic waves