To Detect Transient Signals Patents (Class 324/336)
  • Patent number: 10725193
    Abstract: An electromagnetic geophysical exploration system includes transmitter-receiver pairs configured to transmit waveforms and sense signals in different frequency bands. A controller directs the transmitters of the transmitter-receiver pairs to transmit the waveforms at different moments while the electromagnetic geophysical exploration system is flown over a subsurface formation. The signals sensed by the receivers enable geophysical exploration of the subsurface formation.
    Type: Grant
    Filed: February 12, 2019
    Date of Patent: July 28, 2020
    Assignee: CGG SERVICES SAS
    Inventors: Adam Smiarowski, Jason Berringer, Philip Miles
  • Patent number: 10120104
    Abstract: Methods and apparatus for surveillance of a downhole environment: the response of least one optical fiber to an acoustic impulse is sampled and processed to provide an indication of the acoustic signals detected by at least one longitudinal sensing portion of the fiber(s). The data comprises data indicative of at least one characteristic of the acoustic impulse and data indicative of the downhole environment. The data indicative of at least one characteristic of the acoustic impulse is used to interpret the data indicative of the downhole environment to provide an indication of at least one characteristic of the downhole environment. For example, the data indicative of at least one characteristic of the acoustic impulse may provide a ‘signature’ of the impulse, which may be used to deconvolve the data indicative of the downhole environment to provide an indication of at least one characteristic of the downhole environment.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: November 6, 2018
    Assignee: Optasense Holdings Limited
    Inventors: James Roy, Carson Laing
  • Patent number: 9958568
    Abstract: A method and system for active cancellation of transient signals and dynamic loop configuration for geophysical exploration is disclosed. The method includes controlling a transmitter to transmit a waveform in a frequency spectrum during an on-time. The transmitter includes a plurality of turns of wire. The method also includes controlling a plurality of switches to direct an electrical signal through the plurality of turns of wire. The plurality of switches electrically coupled to the plurality of turns of wire. The method further includes controlling a switch of the plurality of switches to direct a first portion of a transient current in an opposite direction from a direction of a second portion of the transient current during an off-time.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: May 1, 2018
    Assignee: CGG SERVICES SAS
    Inventors: Philip Miles, Jason Berringer
  • Patent number: 9405034
    Abstract: A method for estimating a property of an earth formation in a zone of investigation, the earth formation having the zone of investigation and another zone, the method including: applying a compound pulse of electromagnetic energy to the earth formation, the compound pulse having a shape to induce a predominately greater amount of current in the zone of investigation than in the another zone, wherein the compound pulse includes a first pulse and a second pulse, the first pulse having an amplitude different from the amplitude of the second pulse; receiving a response of electromagnetic energy from the current induced by the compound pulse; and estimating the property from the response of electromagnetic energy.
    Type: Grant
    Filed: October 12, 2009
    Date of Patent: August 2, 2016
    Assignee: BAKER HUGHES INCORPORATED
    Inventor: Vladimir S. Mogilatov
  • Patent number: 9360583
    Abstract: Apparatus and methods are implemented to determine characteristics of geological formations in a well. One or more transmitters and receivers electrically imitate a moving antenna. The moving antenna produces a distribution of frequencies by utilizing the Doppler effect. Each anomaly in the well produces reflections with different frequency, amplitude and phase information. Location and characteristics of multiple anomalies can be identified simultaneously in a well.
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: June 7, 2016
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Burkay Donderici, Michael S. Bittar
  • Publication number: 20150137818
    Abstract: A system and method to compress transient signals are described. The system includes a transmitter disposed in a borehole to change a transmitted current and induce a current in an earth formation, and a receiver disposed in the borehole to receive the transient signals resulting from the transmitted current. The system also includes a processor to compress the transient signals, the processor compressing the transient signals based on a spline approximation method or an Eigen value method for each transient signal based on whether the spline approximation method or the Eigen value method results in a fewer number of parameters representing the transient signal.
    Type: Application
    Filed: November 18, 2014
    Publication date: May 21, 2015
    Applicant: Baker Hughes Incorporated
    Inventors: Marina N. Nikitenko, Arcady Reiderman, Michael Boris Rabinovich, Anton Mosin
  • Publication number: 20150048834
    Abstract: A towable transient electromagnetic survey device for connection to a land, water based or an airborne towing vehicle is provided. The towable transient electromagnetic survey device includes a central body structure and a number of booms extending therefrom to interconnect the central body structure to the towing vehicle and suspend a transmitter loop for generating a primary electromagnetic field. Receiving loop(s) and transmitter loop(s) may also be housed in the central body structure. The central body structure may also be configured for switching in and out of connection of various transmitter and receiver loop configurations. In particularly preferred arrangements, the location of a transmitter loop or a pair of transmitter loops relative to a receiver loop is effective for substantially nulling mutual inductance between the transmitter loop(s) and the receiver loop.
    Type: Application
    Filed: August 13, 2014
    Publication date: February 19, 2015
    Inventor: David Allen
  • Patent number: 8917094
    Abstract: Downhole tools and techniques acquire information regarding nearby conductors such as pipes, well casing, and conductive formations. At least some method embodiments provide a current flow along a drill string in a borehole. The current flow disperses into the surrounding formation and causes a secondary current flow in the nearby conductor. The magnetic field from the secondary current flow can be detected using one or more azimuthally-sensitive antennas. Direction and distance estimates may be obtainable from the azimuthally-sensitive measurements, and can be used as the basis for steering the drillstring relative to the distant conductor. Possible techniques for providing current flow in the drillstring include imposing a voltage across an insulated gap or using a toroid around the drillstring to induce the current flow.
    Type: Grant
    Filed: May 12, 2011
    Date of Patent: December 23, 2014
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Michael S. Bittar, Jing Li
  • Patent number: 8829899
    Abstract: A pneumatic vibration isolating suspension is disclosed for supporting a payload on a moving carrier while suppressing the transmission of vibrations in the 1 to 50 Hz band between the carrier and the payload. The disclosed invention can be deployed in the air in a towed carrier or sonde, and operated from aircraft power, making it a suitable platform for airborne geophysical instrumentation. It also has particular application to airborne electromagnetic surveying operating in the same frequency band because the sensor vibrations that result in noise created by the modulation of the sensor coupling with the earth's magnetic field are suppressed. Furthermore, the invention can be constructed from resistive composite materials and non-magnetic metals, so it can be operated without producing significant modification to the ambient electromagnetic field being measured.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: September 9, 2014
    Assignee: Vale S.A.
    Inventors: Benjamin David Polzer, Gordon Fox West, Peter White Walker
  • Patent number: 8829906
    Abstract: A method for noise signal analysis and communication with an underground transmitter. The method comprises the steps of measuring a noise floor when no signal is transmitted from a transmitter, detecting a signal when the transmitter is transmitting, and estimating the noise free component of the signal by removing the noise floor measurement. The measurement of the noise floor and detecting the signal from the transmitter may be done using a root mean square technique. The noise floor measurement can be removed from the measured signal by subtracting the noise floor measurement from the measured signal or alternatively by calculating the square root of the difference between the square of the measured signal and the square of the noise floor measurement. The noise estimation technique may be used in connection with a differential phased shift keying communication scheme or other modulation techniques.
    Type: Grant
    Filed: August 15, 2011
    Date of Patent: September 9, 2014
    Assignee: The Charles Machine Works, Inc.
    Inventors: Michael F. Gard, Scott Bryan Cole
  • Patent number: 8816689
    Abstract: A method and apparatus is provided for collecting reservoir data. The method includes providing one or more electromagnetic sources for generating an electromagnetic field in a reservoir and providing one or more electromagnetic sensors equipped with capacitive electrodes. The electromagnetic source is located separately from the electromagnetic sensor. The electromagnetic sensor may either be located within a well or at the surface, is capable of measuring the electromagnetic field in three dimensions, and may be isolated from the well fluids. The data collected by the electromagnetic sensors can be used to create a model of the oil reservoir, including the water saturation.
    Type: Grant
    Filed: May 17, 2011
    Date of Patent: August 26, 2014
    Assignee: Saudi Arabian Oil Company
    Inventors: Daniele Colombo, Timothy H. Keho, Michael Anthony Jervis, Brett W. Bouldin
  • Patent number: 8614577
    Abstract: A method of determining anisotropy in a borehole is disclosed. An array of measurements along the borehole is obtained and a first depth in the borehole is selected. An arbitrary plane oriented with respect to the borehole at the first depth is designated and an anisotropy for the first depth with respect to the arbitrary plane is determined. The arbitrary plane is repositioned at the first depth and an anisotropy for different positions of the arbitrary plane at the first depth is determined. A minimum anisotropy coefficient with respect to the arbitrary plane at the first depth is identified based on anisotropy for different positions of the arbitrary plane. An anisotropy tensor for the first depth is then identified.
    Type: Grant
    Filed: May 18, 2011
    Date of Patent: December 24, 2013
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Mark A. Proett, Tegwyn J. Perkins, Ronald Stamm
  • Publication number: 20130154650
    Abstract: Various embodiments include apparatus and methods to detect and locate conductive bodies and/or provide steam-assisted gravity drainage (SAGD) steering operation. Tools can be configured with receiving sensors (310) arranged to cancel substantially a primary signal associated with a probe signal without rotating the receiving sensors to cancel the primary signal and to capture a secondary signal generated from a conductive body (301) below the earth's surface. Additional apparatus, systems, and methods are disclosed.
    Type: Application
    Filed: August 3, 2011
    Publication date: June 20, 2013
    Applicant: Halliburton Energy Services, Inc.
    Inventors: Michael S. Bittar, Jing Li
  • Patent number: 8456159
    Abstract: A stabilized field sensor apparatus collects field data, in particular magnetic field data, with reduced motion noise. The apparatus includes a tear drop shaped housing, a tow frame in the housing, a plurality of vibration isolating dampers spaced around the frame, a base assembly mounted to the dampers, a support pedestal having a bottom end fixed to the base assembly and an upper free end, a single spherical air bearing connected to the upper free end of the pedestal, an instrument platform with a lower hollow funnel having an upper inside apex supported on the air bearing for a one point support, principal and secondary gyro stabilizers for maintaining pivotal and rotational stability, and at least one field sensor mounted to the instrument platform for collecting the field data while being stabilized against motion noise including vibration, pivoting and rotation from the base assembly, from the tow frame and from the housing.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: June 4, 2013
    Assignee: Vale S.A.
    Inventors: Benjamin David Polzer, Gordon Fox West, Peter Whyte Walker, Peter Anthony Hurley, Robert Leslie Scott Hogg
  • Patent number: 8450997
    Abstract: Magnetic tracking systems and methods for determining the position and orientation of a remote object. A magnetic tracking system includes a stationary transmitter for establishing a reference coordinate system, and at least one receiver. The remote object is attached to, mounted on, or otherwise coupled to the receiver. The transmitter can include a set of three mutually perpendicular coils having a common center point, or a set of three coplanar coils with separate centers. The receiver can include a set of three orthogonal coils. The position and orientation of the receiver and the remote object coupled thereto is determined by measuring the nine mutual inductances between the three transmitter coils and the three receiver coils. The magnetic tracking system provides reduced power consumption, increased efficiency, digital compensation for component variation, automatic self-calibration, automatic synchronization with no connections between transmitter and receiver, and rapid low-cost implementation.
    Type: Grant
    Filed: April 27, 2010
    Date of Patent: May 28, 2013
    Assignee: Brown University
    Inventor: Kenneth J. Silverman
  • Patent number: 8446156
    Abstract: The invention provides a method and apparatus for the analysis of rocks and rock fragments. A method for the analysis of a rock fragment including: feeding the rock fragment to a microwave irradiation zone of microwave energy generated by a microwave source; gauging energy absorbed by the rock fragment; and correlating rate of change of the gauged energy absorbed by the rock fragment with compositional characteristics of the rock fragment.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: May 21, 2013
    Assignee: The University of Queensland
    Inventor: Robert D. Morrison
  • Patent number: 8432167
    Abstract: A transmitter antenna assembly for transient electromagnetic well logging instrument comprises an antenna coil coupled with a current source and a magnetic core having residual magnetization. Switching current in the antenna coil results in magnetization reversal in the magnetic core and change in magnetic dipole moment of the antenna. After the magnetization reversal is complete the current is removed and the new vector of magnetic dipole of the antenna maintains constant (steady-state phase of the antenna dipole) due to magnetic hysteresis of magnetic material employed for the magnetic core. No power expenditure during the steady-state phase of the magnetic dipole facilitates highly effective generation and fast switching of a large magnetic dipole. The magnetic core also serves as a shield between the antenna coil and any conductive part of the antenna assembly.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: April 30, 2013
    Assignee: Baker Hughes Incorporated
    Inventor: Arcady Reiderman
  • Patent number: 8302687
    Abstract: Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: November 6, 2012
    Assignee: Schlumberger Technology Corporation
    Inventors: Min-Yi Chen, Bhavani Raghuraman, Ian Bryant, Michael G. Supp, Jose Navarro
  • Patent number: 8278928
    Abstract: An apparatus for detecting a position of a component in an earth formation is disclosed. The apparatus includes: a transmitter configured to emit a first magnetic field into the earth formation and induce an electric current in the component, the transmitter having a first magnetic dipole extending in a first direction; and a receiver for detecting a second magnetic field generated by the component in response to the first magnetic field, the receiver having a second magnetic dipole extending in a second direction orthogonal to the first direction. A method and computer program product for detecting a position of a component in an earth formation is also disclosed.
    Type: Grant
    Filed: August 25, 2008
    Date of Patent: October 2, 2012
    Assignee: Baker Hughes Incorporated
    Inventor: Alexandre N. Bespalov
  • Patent number: 8274288
    Abstract: A method for measuring resistivity variations in the earth comprising passing a transient current between two source electrodes; measuring the transient current at the source electrodes; measuring the resultant transient voltage between at least one pair of receiver electrodes; estimating one or more processing functions for applying to the measured input current to provide a step current profile, and applying the same one or more processing functions to the measured voltage to provide an estimate of the step response voltage between the receivers, using both the step current and the estimated step response voltage to determine the resulting apparent earth resistance, and using the apparent earth resistance to determine the resistivity of the earth.
    Type: Grant
    Filed: August 4, 2006
    Date of Patent: September 25, 2012
    Assignee: MTEM Ltd
    Inventors: Antoni Marjan Ziolkowski, Bruce Alan Hobbs
  • Patent number: 8222902
    Abstract: A retrievable tool for steering through an earth formation includes a first tool assembly and a tilted antenna attached to the first tool assembly. The tool also includes a second tool assembly attached to the first tool assembly and a tilted antenna attached to the second tool assembly. The first tool assembly attaches to the second tool assembly so that the antennas are tilted in predetermined directions. The tilted antennas are transmitter antennas or receiver antennas. Each tool assembly is a tubular cylinder with a longitudinal axis running the length of the cylinder, wherein the tubular cylinder has two ends, each end including a rotational attachment mechanism. The tool assemblies attach to each other through their rotational attachment mechanisms. The rotational attachment mechanism may be a screw-on mechanism, press-fit mechanism, or welded mechanism.
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: July 17, 2012
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Michael S. Bittar, Clive D. Menezes, Martin D. Paulk
  • Publication number: 20110298460
    Abstract: A method for noise signal analysis and communication with an underground transmitter. The method comprises the steps of measuring a noise floor when no signal is transmitted from a transmitter, detecting a signal when the transmitter is transmitting, and estimating the noise free component of the signal by removing the noise floor measurement. The measurement of the noise floor and detecting the signal from the transmitter may be done using a root mean square technique. The noise floor measurement can be removed from the measured signal by subtracting the noise floor measurement from the measured signal or alternatively by calculating the square root of the difference between the square of the measured signal and the square of the noise floor measurement. The noise estimation technique may be used in connection with a differential phased shift keying communication scheme or other modulation techniques.
    Type: Application
    Filed: August 15, 2011
    Publication date: December 8, 2011
    Applicant: The Charles Machine Works, Inc.
    Inventors: Michael F. Gard, Scott Bryan Cole
  • Patent number: 8035392
    Abstract: Structure for deep MWD resistivity measurements suitable for both geo-steering and measurements ahead of the drill bit is disclosed. The structure is capable of extracting information about resistivity of formation in the presence of conductive drill. In one embodiment, ahead-of-bit sensing is achieved via transient electromagnetic measurements when current is switched off in the transmitter loop and the transient signal is measured in the receiver loops placed at some distances from the receiver. To reduce a parasitic effect of the currents in the drill three-coil bucking system with magnetic nonconductive shield in combination with a highly conductive copper shield are applied. Specifically, a short (less than 1 m) copper cover and short (less than 0.2 m) ferrite cover are placed in the vicinity of transmitting and receiving coils. A bucking operation followed by an inversion is performed on received signals to obtain data reflecting parameters of the surrounding subsurface formations.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: October 11, 2011
    Assignee: Baker Hughes Incorporated
    Inventors: Gregory B. Itskovich, Arcady Reiderman
  • Patent number: 7999551
    Abstract: A method for noise signal analysis and communication with an underground transmitter. The method comprises the steps of measuring a noise floor when no signal is transmitted from a transmitter, detecting a signal when the transmitter is transmitting, and estimating the noise free component of the signal by removing the noise floor measurement. The measurement of the noise floor and detecting the signal from the transmitter may be done using a root mean square technique. The noise floor measurement can be removed from the measured signal by subtracting the noise floor measurement from the measured signal or alternatively by calculating the square root of the difference between the square of the measured signal and the square of the noise floor measurement. The noise estimation technique may be used in connection with, a differential phased shift keying communication scheme or other modulation techniques.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: August 16, 2011
    Assignee: The Charles Machine Works, Inc.
    Inventors: Michael F. Gard, Scott Bryan Cole
  • Publication number: 20100097065
    Abstract: Structure for deep MWD resistivity measurements suitable for both geo-steering and measurements ahead of the drill bit is disclosed. The structure is capable of extracting information about resistivity of formation in the presence of conductive drill. In one embodiment, ahead-of-bit sensing is achieved via transient electromagnetic measurements when current is switched off in the transmitter loop and the transient signal is measured in the receiver loops placed at some distances from the receiver. To reduce a parasitic effect of the currents in the drill three-coil bucking system with magnetic nonconductive shield in combination with a highly conductive copper shield are applied. Specifically, a short (less than 1 m) copper cover and short (less than 0.2 m) ferrite cover are placed in the vicinity of transmitting and receiving coils. A bucking operation followed by an inversion is performed on received signals to obtain data reflecting parameters of the surrounding subsurface formations.
    Type: Application
    Filed: October 17, 2008
    Publication date: April 22, 2010
    Inventors: Gregory B. Itskovich, Arcady Reiderman
  • Publication number: 20090243616
    Abstract: A method for determining a component of electric field response of the Earth's subsurface to a time-varying electromagnetic field induced in the Earth's subsurface is provided. The method includes measuring electric field response along a nonlinear pattern on at least one of the Earth's surface and the bottom of a body of water. The method includes measuring magnetic field response in three directions along the nonlinear pattern on at least one of the Earth's surface and the bottom of the body of water. The method further includes determining an electric field response in a direction normal to the measured electric field response using the electric field response and magnetic field response measurements.
    Type: Application
    Filed: June 8, 2009
    Publication date: October 1, 2009
    Applicant: KJT ENTERPRISES, INC.
    Inventors: Joern Loehken, Kurt M. Strack, Stefan L. HELWIG, Tilman Hanstein
  • Patent number: 7586309
    Abstract: A device for guiding energy in a subsurface electromagnetic measuring system is provided, the device including a transmitting member for transmitting an electromagnetic signal into a subsurface medium, an energy-guiding member disposed in magnetic communication with the electromagnetic signal, and a receiving member for receiving a return signal induced from the subsurface medium. A method of guiding energy in a subsurface measuring system is also provided, the method including transmitting an electromagnetic signal into a subsurface medium, modifying the electromagnetic signal using a magnetic field, and then receiving a modified return signal induced from the medium using a receiving member.
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: September 8, 2009
    Assignee: Baker Hughes, Inc.
    Inventors: Stanislav Forgang, Randy Gold
  • Patent number: 7567869
    Abstract: Measurements made with an induction logging tool are processed to provide a resistivity model of fluid invasion of the formation. Up to five zones can be determined over a radial distance of about 0.6 m. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: July 28, 2009
    Assignee: Baker Hughes Incorporated
    Inventors: Marina N. Nikitenko, Leonty A. Tabarovsky, Mikhail I. Epov
  • Publication number: 20080061790
    Abstract: A method for interpreting transient electromagnetic survey data includes imparting an electromagnetic field in the Earth's subsurface by passing electric current through a transmitter antenna. The electric current includes switched direct current at a selected switching frequency. Voltages induced in a receiver corresponding to electromagnetic effects induced in the Earth's subsurface are detected. Frequency domain electromagnetic response of the Earth's subsurface is determined from the detected voltages and transient electromagnetic response of the Earth's subsurface is determined from the detected voltages.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 13, 2008
    Inventor: Kurt M. Strack
  • Patent number: 7164123
    Abstract: A method for filtering spurious resonances from an NMR dataset comprises the steps of: (a) creating a first, non-oscillating magnetic field of a predetermined field strength across a sample, (b) intermittently exposing the sample to a second, oscillating magnetic field orthogonal to the first to generate an NMR signal, (c) detecting the NMR signal from the sample, (d) adjusting the first magnetic field to a different predetermined field strength and repeating steps (a) to (c), and (d) comparing the detected signals to obtain an NMR dataset from the sample from which spurious resonances have been filtered.
    Type: Grant
    Filed: December 28, 2005
    Date of Patent: January 16, 2007
    Assignee: Rolls-Royce plc
    Inventors: Peter G. Morris, Terry Moore, Paul Anuzis, Kenneth Astley
  • Patent number: 7031839
    Abstract: An induction logging tool is used on a MWD bottom hole assembly. Due to the finite, nonzero, conductivity of the mandrel, conventional multi frequency focusing (MFF) does not work. A correction is made to the induction logging data to give measurements simulating a perfectly conducting mandrel. MFF can then be applied to the corrected data to give formation resistivities.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: April 18, 2006
    Assignee: Baker Hughes Incorporated
    Inventors: Leonty A. Tabarovsky, Alexandre N. Bespalov, Stanislav W. Forgang, Michael B. Rabinovich
  • Patent number: 7026820
    Abstract: A method and apparatus for minimizing direct coupling between transmitters and receivers on a downhole logging tool are disclosed. One embodiment includes a transmitter, a bucking device, and a plurality of receivers, where signals may be directly coupled from the transmitter into the receivers and signals may be indirectly coupled from the transmitter into the receivers through the formation and borehole environment. The bucking device minimizes the magnitude of the signals that are directly coupled from the transmitter into multiple receivers within the plurality. By varying the current in the bucking device, the bucking device minimizes the magnitude of the directly coupled signal of each receiver in the plurality, and each receiver may utilize a common bucking device.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: April 11, 2006
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Jiaqi Xiao, Li Gao
  • Patent number: 6949930
    Abstract: A method and apparatus locates buried objects in conductive soil by creating a direct current in a transmitting loop, periodically terminating the direct current in the transmitting loop to create an eddy current in the conductive soil using time domain induction, receiving a magnetic field resulting from the eddy current running through the conductive soil, and locating the buried object using the received magnetic field.
    Type: Grant
    Filed: April 8, 2002
    Date of Patent: September 27, 2005
    Assignee: Witten Technologies, Inc.
    Inventors: Thorkild Hansen, Michael L. Oristaglio
  • Patent number: 6914433
    Abstract: The invention relates to a method of mapping subsurface resistivity contrasts by making multichannel transient electromagnetic (MTEM) measurements on or near the earth's surface using at least one source, receiving means for measuring the system response and at least one receiver for measuring the resultant earth response. All signals from the or each source-receiver pair are processed to recover the corresponding electromagnetic impulse response of the earth and such impulse responses, or any transformation of such impulse responses, are displayed to create a subsurface representation of resistivity contrasts. The invention enables subsurface fluid deposits to be located and identified and the movement of such fluids to be monitored.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: July 5, 2005
    Assignee: The University Court of the University of Edinburgh
    Inventors: David A Wright, Antoni M Ziolkowski, Bruce A Hobbs
  • Publication number: 20040232917
    Abstract: The invention relates to a method of mapping subsurface resistivity contrasts by making multichannel transient electromagnetic (MTEM) measurements on or near the earth's surface using at least one source, receiving means for measuring the system response and at least one receiver for measuring the resultant earth response. All signals from the or each source-receiver pair are processed to recover the corresponding electromagnetic impulse response of the earth and such impulse responses, or any transformation of such impulse responses, are displayed to create a subsurface representation of resistivity contrasts. The invention enables subsurface fluid deposits to be located and identified and the movement of such fluids to be monitored.
    Type: Application
    Filed: June 17, 2004
    Publication date: November 25, 2004
    Inventors: David A Wright, Antoni M Ziolkowski, Bruce A Hobbs
  • Patent number: 6653838
    Abstract: A metal detector with a transmit coil which transmits a magnetic field, transmit timing control circuitry, and receive signal circuitry and receive signal processing circuitry, and a low voltage and a high voltage power supply. The timing sequence generated within the transmit timing control circuitry produces control signals such that there are at least two different transmit periods, a short and a long period, and such that there are periods when no current flows through the transmit coil. The timing sequence is such that an average transmit coil energy at termination of the long periods is similar to that of an average transmit coil energy at termination of the short periods.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: November 25, 2003
    Assignee: BHC Consulting PTY Ltd.
    Inventor: Bruce Halcro Candy
  • Patent number: 6636044
    Abstract: Metal detection apparatus wherein a transmit coil will transmit magnetic pulses, and the processing circuitry will weight a receive signal more heavily soon after a transmit pulse transition and less heavily after a longer period following the transmit pulse transition.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: October 21, 2003
    Assignee: BHC Consulting PTY Ltd.
    Inventor: Bruce Halcro Candy
  • Patent number: 6600320
    Abstract: A unique time-domain electromagnetic system and data processing technique which, using low frequency electromagnetic fields, can localize, in three-dimensions, the position of buried metallic objects is disclosed. The measurement system uses time-domain electromagnetic techniques on a scanning frame similar to a X-Y plotter. The system collects magnetic data over a large area above the buried object. The spatial information of the field detected on the ground is then processed with an unique ‘nearfield holographic’ data processing method to reconstruct the field image of the buried object.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: July 29, 2003
    Assignee: The Johns Hopkins University
    Inventors: Yanping Guo, Harvey W. Ko, Carl V. Nelson, David M. White
  • Patent number: 6573721
    Abstract: An inspection system include a transmitter and a receiver configured for communication with a remotely positioned processing means. The transmitter and receiver are arranged as a mobile apparatus configured for insertion into any duct, conduit, pipeline, mining shaft, or the like, or any diameter or cross section. The transmitter is configured to transmit an electromagnetic signal to induce an electromagnetic response in the duct and the electromagnetic response is detected by the receiver. The mobile apparatus is self-powered and processes the electromagnetic response prior to communicating the processed response to the remotely positioned processing means as a discrete signal.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: June 3, 2003
    Assignee: Rock Solid Research Pty. Ltd.
    Inventor: James Phillip Cull
  • Patent number: 6335624
    Abstract: A process is described to detect conducting objects buried in the ground by sending a series of electromagnetic pulses and the return signal. The signal characteristics stored in the database are sets of numerical data which each define characteristics of decreasing curves of the values of previously-received signals then, in a search phase, the numerical values of samples ranked 1, 2, . . . n are recorded, representing a real decreasing curve of a received signal. The average real decreasing curve is created by determination of the average value of the samples, each of which represents the average value of the values of the samples of the same rank. A value representing the difference between the set of characteristics of the real average decreasing curve and each of the sets with the same database characteristics is calculated. The smallest of the differences is compared with the threshold value.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: January 1, 2002
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Jean Berthier, Francis Robach, Pascal Manet
  • Patent number: 6326791
    Abstract: A method is disclosed for discriminating electromagnetic responses of metallic objects in soil to application of an electromagnetic pulse from superposed responses due to magnetic susceptibility of the soil, comprising substantially eliminating, from at least a portion of the response, any component having a power law decay characteristic with an exponent which is characteristic of the soil.
    Type: Grant
    Filed: May 19, 1999
    Date of Patent: December 4, 2001
    Assignee: Geonics Limited
    Inventor: Miro Bosnar
  • Patent number: 6084412
    Abstract: A unique time-domain electromagnetic system and data processing technique which, using low frequency electromagnetic fields, can localize, in three-dimensions, the position of buried metallic objects is disclosed. The measurement system uses time-domain electromagnetic techniques on a scanning frame similar to a X-Y plotter. The system collects magnetic data over a large area above the buried object. The spatial information of the field detected on the ground is then processed with an unique `nearfield holographic` data processing method to reconstruct the field image of the buried object.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: July 4, 2000
    Assignee: The Johns Hopkins University
    Inventors: Yanping Guo, Harvey W. Ko, Carl V. Nelson, David M. White
  • Patent number: 6021373
    Abstract: A back-up proximity sensor for a vehicle is formed with an array of sensor pairs. Each sensor pair includes a lower passive infrared sensor (PIR) having a first field of view and an upper PIR having a second field of view. Each lower PIR and upper PIR is vertically mounted with respect to one another. The lower PIR and upper PIR of each sensor pair are angularly directed such that the respective fields of view intersect, thereby establishing a detection zone in a region behind a vehicle. The sensor pairs are arranged in a substantially adjacent, semicircular configuration to provide a continuous area of coverage behind a vehicle. A detection circuit receives output signals from each sensor pair and generates an output signal indicative of a warm body being detected by both the upper and lower sensors in a selected sensor pair, eliminating false alarms generated by warm bodies outside the region of the desired detection zone.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: February 1, 2000
    Assignee: Eaton Corporation
    Inventors: Joseph C. Zuercher, Russell P. Schuchmann, Steven C. Schmalz
  • Patent number: 5796253
    Abstract: In a time domain electromagnetic mapping technique of the type using transmitter pulses of half-sinusoidal waveform, with the half sinusoids being segments of a sinusoidal waveform having a frequency and corresponding to a resonant frequency of the transmitter coil, an improved current fall time at the end of each pulse is obtained by forming each transmitter pulse of plural immediately successive half sinusoids, the transmitter coil being tuned to an appropriately increased resonant frequency relative to the pulse repetition rate. Circuits for generating the improved pulse waveforms are disclosed.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: August 18, 1998
    Inventors: Miro Bosnar, J. Duncan McNeill
  • Patent number: 5498958
    Abstract: An inductive proximity sensor determines if a metallic object is in close proximity. An inductor is placed near the object. Several switches control the direction of the voltage passing through the inductor. During a first time period, the voltage flows through the inductor to induce a magnetic field in the object. During the second time period, the voltage is reversed in the inductor to quickly eliminate any current in the inductor. The decaying magnetic field in the object induces a voltage in the inductor which is measured during a third time period and compared to a reference value to determine the proximity of the object to the sensor.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: March 12, 1996
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab
  • Patent number: 5467018
    Abstract: A method of geophysical analysis includes transmitting an electromagnetic signal into the earth and measuring the resulting transmission of that signal through the earth to a plurality of spaced recording units. The values of the transmitted signal are locally digitized and stored at each recording unit. The stored data from each recording unit is subsequently transmitted through a telemetric link to a central processing or analyzing unit, the stored data being transmitted from one recording unit at a time and in a preselected sequence. The data may be transmitted from each recording unit in a block and stored in the central processing unit. The digitizing and storing of the measured values at each unit is accomplished through a yield point amplifier. Automatic drift correction processing may also be applied to the measured values obtained from each recording unit.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: November 14, 1995
    Assignee: Bergwerksverband GmbH
    Inventors: Horst Ruter, Kurt-Martin Strack
  • Patent number: 4894619
    Abstract: The invention relates to a method and an apparatus for detecting metal objects in a metal detecting apparatus using impulse techniques. The metal detector comprises a compensation circuit arranged in between the transmitter system (13) and the receiver system (14) in order to compensate the mutual inductance between the transmitter (11) and the receiver (12). The compensation circuit is advantageously operated so that the signal caused by the metal object in this detector is measurable during both at least two measuring sequences (21,22) located within the range of the cut-off peak of the transmitter current and during at least one measuring sequence (23) located outside the range of the cut-off peak of the transmitter current.
    Type: Grant
    Filed: July 22, 1987
    Date of Patent: January 16, 1990
    Assignee: Outokumpu Oy
    Inventors: Erkki I. Leinonen, Kari T. J. Aittoniemi
  • Patent number: 4837514
    Abstract: A method for reducing noise in electromagnetic geophysical exploration data simultaneously measures three orthogonal components of the ambient noise to produce noise records and simultaneously measures three orthogonal components of the decay of current induced into the earth to produce response records. In measuring the records, the receiving antenna is positioned near the electromagnetic center of the transmitting antenna, whereby the maximum component of the induced current decay signal is vertical or perpendicular to the strata in the earth. The impulse response of the earth is determined from the noise records. The noise portion of the vertical response record is determined from the impulse response and the non-vertical response records, whereby the noise portion is removed from the vertical response record.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: June 6, 1989
    Assignee: Atlantic Richfield Company
    Inventor: Brian R. Spies
  • Patent number: 4595877
    Abstract: An eddy-current loop detector operates to sense the presence of an electrically conductive object by applying D.C. onto a conducting loop so that a permanent magnetic field is induced, which field partly penetrates into the object; ensuring the quick cessation of self-inductive transient operation of the loop when the D.C. is switched off; and measuring the change in the part of the flux passing through the measuring loop arising from eddy-currents induced in the conductive object, and evaluating such change while the relatively slowly decreasing flux is maintained. By repeating these operations with the desired frequency, the eddy-current detector is well suited for continuous measuring of the position of the object.
    Type: Grant
    Filed: October 18, 1984
    Date of Patent: June 17, 1986
    Assignee: Vilati Villamos Automatika Fovallalkozo es Gyarto Vallalat
    Inventor: Karoly Dulk
  • Patent number: 4544892
    Abstract: A frequency domain geophysical electromagnetic surveying system is provided in which intermittent primary fields having sharp terminations are generated in a cycle having a fundamental frequency by a transmitter, and a receiver includes a gate passing only secondary signals received during interruptions of the primary field, the gated signal being applied to filters tuned to harmonics of the predetermined frequency. The filter outputs are synchronously demodulated to provide signals corresponding to at least the in-phase component of the secondary signal at the fundamental frequency, and preferably in-phase and quadrature components at at least two harmonics. The system can provide improved resolution particularly of the characteristics of in-phase secondary signals received from terrain being surveyed.
    Type: Grant
    Filed: August 17, 1982
    Date of Patent: October 1, 1985
    Assignee: Geonics Limited
    Inventors: Alexander A. Kaufman, James D. McNeill