Offshore Patents (Class 324/365)
  • Patent number: 10082546
    Abstract: An underwater EM measurement system, which is substantially smaller, much simpler to use, and more robust than prior systems, is formed as a sensor package integrated into a single pressure vessel includes two magnetic sensors including induction coils disposed substantially horizontally so as to measure fields in orthogonal directions. The package also includes two electric field sensors including electric potential antennas adapted to couple to a water potential via a capacitive electrode having a conducting material and an electrically insulative layer formed of an insulating material. The capacitive electrode has a capacitance to the medium of greater than 1 mF. Preferably, the insulating material is a metal oxide.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: September 25, 2018
    Assignee: Quasar Federal Systems
    Inventors: Andrew D. Hibbs, Thomas Kurt Nielsen
  • Patent number: 9903970
    Abstract: A method for towing a streamer array includes moving a vessel along a body of water. Streamers are towed by vessel. A relative position is determined at selected points along each streamer with respect to the vessel. At least one of the streamers is deflected at at least one longitudinal position along the streamer in response to the determined positions to maintain the streamers in a selected geometry. The selected geometry is related to one of survey vessel heading, energy source trajectory, previously plotted sensor trajectory and a lateral separation related to distance from the towing vessel.
    Type: Grant
    Filed: January 26, 2015
    Date of Patent: February 27, 2018
    Assignee: PGS Geophysical AS
    Inventors: Øyvind Hillesund, Nils Lunde
  • Patent number: 9864088
    Abstract: Disclosed are methods and apparatus for adaptive source electromagnetic (EM) surveying. In accordance with one embodiment, a source waveform signal is generated, and an outgoing EM signal which is based on the source waveform signal is transmitted using an antenna. A responsive electromagnetic signal is detected using at least one electromagnetic sensor, and a receiver waveform signal based on the responsive electromagnetic signal is obtained. A feedback control signal which depends on at least one input signal is determined. Based on the feedback control signal, the source waveform signal is adapted. Other embodiments, aspects, and features are also disclosed.
    Type: Grant
    Filed: May 6, 2014
    Date of Patent: January 9, 2018
    Assignee: PGS Geophysical AS
    Inventors: Dougal Kennedy, Gustav Goran Mattias Sudow, Robert Juhasz
  • Patent number: 9372280
    Abstract: Disclosed are methods and systems for conditioning electrodes while deployed in the sea with a marine electromagnetic survey system. An embodiment of the method may comprise deploying electrodes in seawater during a marine electromagnetic survey. The method further may comprise coupling at least one of the electrodes to a controllable current/voltage source while the electrodes are deployed in the seawater. The method further may comprise sending a first conditioning signal from the controllable current/voltage source to the at least one of the electrodes coupled to the controllable current/voltage source.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: June 21, 2016
    Assignee: PGS Geophysical AS
    Inventors: Andras Robert Juhasz, Ulf Peter Lindqvist
  • Patent number: 9274241
    Abstract: Disclosed are methods and systems for suppression of noise in electromagnetic surveying that includes stacking two or more frames of electromagnetic data. An example embodiment discloses a method for suppressing swell-induced noise in an electromagnetic survey, comprising: measuring an electromagnetic field parameter at one or more positions to provide an electromagnetic signal, the electromagnetic signal comprising a swell-induced portion; and stacking two or more frames of the electromagnetic signal to provide a stacked signal in which the swell-induced portion is suppressed, wherein the swell-induced portion is out of phase between the two or more frames.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 1, 2016
    Assignee: PGS Geophysical AS
    Inventors: Ulf Peter Lindqvist, Andras Robert Juhasz, Rune Johan Magnus Mattsson, Lars Erik Magnus Björnemo
  • Patent number: 9176254
    Abstract: A geophysical sensor cable has one or more sensor cable sections. Each of the sensor cable sections is provided with seismic and electromagnetic sensors arranged along said cable. The seismic sensors include a hydrophone and a seismic component receiver for seismic vector measurements while the sensor cable is at the sea-floor. The electromagnetic sensors include both E-field sensors and H-field sensors. The E-field sensors include pairs of first and second electrodes arranged with different positions along the cable and connected to a voltage amplifier. The H-field sensors include three mutually orthogonally arranged H-field component sensors.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: November 3, 2015
    Assignee: MULTIFIELD GEOPHYSICS AS
    Inventor: Svein Erling Johnstad
  • Patent number: 9097815
    Abstract: A method for determining a formation response form a detected electromagnetic signal resulting from a first electromagnetic signal imparted into a subsurface earth formation and from a second electromagnetic signal imparted into the formation, the first and second signals being imparted substantially contemporaneously. The detected signals are deconvolved using the first electromagnetic signal. The deconvolved detected signal is used to estimate the formation response to the first electromagnetic signal. Convolving the estimated formation response from the estimated formation response with the first electromagnetic signal and subtracting a result of the convulsion with the first electromagnetic signal from the detected signal.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: August 4, 2015
    Assignee: PGS EM Ltd.
    Inventor: Antoni Marjan Ziolkowski
  • Patent number: 9069096
    Abstract: A method is provided for processing marine controlled source electromagnetic data. Inline and broadside marine controlled source electromagnetic data are provided, for example by means of one or more horizontal electric dipoles and one or more receivers disposed in a water column above a subsurface to be surveyed. A linear combination of the inline and broadside data is formed so as to reduce the airwave content.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: June 30, 2015
    Assignee: STATOIL PETROLEUM AS
    Inventors: Lars Løseth, Lasse Amundsen
  • Patent number: 8994378
    Abstract: An electromagnetic survey acquisition system includes a sensor cable and a source cable, each deployable in a body of water, and a recording system. The sensor cable includes an electromagnetic sensor thereon. The source cable includes an electromagnetic antenna thereon. The recording system includes a source current generator, a current sensor, and an acquisition controller. The source current generator powers the source cable to emit an electromagnetic field from the antenna. The current sensor is coupled to the source current generator. The acquisition controller interrogates the electromagnetic sensor and the current sensor at selected times in a synchronized fashion.
    Type: Grant
    Filed: May 9, 2012
    Date of Patent: March 31, 2015
    Assignee: PGS Geophysical AS
    Inventors: Andras Robert Juhasz, Gustav Göran Mattias Südow, Ulf Peter Lindqvist
  • Publication number: 20150061685
    Abstract: Embodiments described herein provide an EM source cable assembly with a buoyant member having first and second ends, and a longitudinal axis connecting the first end to the second end, and a plurality of indentations disposed along a surface of the buoyant member between the first end and the second end, wherein the indentations are operable to receive corresponding cables. The indentations extend along the longitudinal axis, and may be arranged helically about the longitudinal axis. The buoyant member may have a low density core material and a dense outer material, each of which may be a polymeric material. The low density material may be a foam, and the buoyant member may be formed by coextruding the low density material and the dense outer material.
    Type: Application
    Filed: February 21, 2014
    Publication date: March 5, 2015
    Inventors: James MACKAY, Philip HEELAN, Peter LINDQVIST
  • Patent number: 8963549
    Abstract: To survey a subterranean structure, for acquiring an electromagnetic (EM) measurement signal across EM receivers having a target axial spacing, a group of more than two EM receivers in an interval defined by the target axial spacing along a sensor cable is provided. The spacing between successive ones of at least some EM receivers in the group is less than the target axial spacing. EM measurements are acquired using the EM receivers in the group.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: February 24, 2015
    Assignee: WesternGeco L.L.C.
    Inventor: Leendert Combee
  • Publication number: 20150035537
    Abstract: An electromagnetic survey acquisition system includes a sensor cable and a source cable, each deployable in a body of water, and a recording system. The sensor cable includes an electromagnetic sensor thereon. The source cable includes an electromagnetic antenna thereon. The recording system includes a source current generator, a current sensor, and an acquisition controller. The source current generator powers the source cable to emit an electromagnetic field from the antenna. The current sensor is coupled to the source current generator. The acquisition controller interrogates the electromagnetic sensor and the current sensor at selected times in a synchronized fashion.
    Type: Application
    Filed: October 20, 2014
    Publication date: February 5, 2015
    Applicant: PGS Geophysical AS
    Inventors: Andras Robert Juhasz, Gustav Göran Mattias Südow, Ulf Peter Lindqvist
  • Patent number: 8922214
    Abstract: The present disclosure describes various geophysical survey systems and methods for mapping an electric potential field. At least one illustrative embodiment includes an electromagnetic (EM) source and geophysical survey cables that each includes multiple electrodes spaced apart along each geophysical survey cable's length, and multiple data acquisition units that each obtains measurements indicative of an electric potential between two the electrodes. A modeling module is included and configured to calculate a reference potential at a selected electrode for each of the plurality of geophysical survey cables, as well as a calculation module to combine signals representative of the measurements to produce signals indicative of the electric potential of each electrode relative to the reference potential.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: December 30, 2014
    Assignee: PGS Geophysical AS
    Inventors: Mattias Südow, Frederick James Barr, Jr., Peter Lindqvist, Robert Juhasz
  • Patent number: 8896314
    Abstract: A method for marine electromagnetic surveying includes transmitting a first electromagnetic field oriented in a first direction into a body of water. A second electromagnetic field oriented in a second direction is transmitted into the body of water, wherein the second direction is substantially transverse to the first direction. A parameter related to electromagnetic field amplitude is detected at a plurality of longitudinally and laterally spaced apart positions behind a vessel. The components of the detected electromagnetic field parameter are resolved into components along the first and second directions by using the geometrical symmetries and asymmetries of the transmitting source. Systems for implementing such methods are also provided.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: November 25, 2014
    Assignee: PGS Geophysical AS
    Inventor: Gustav Göran Mattias Südow
  • Patent number: 8890532
    Abstract: A method for determining a component of electric field response to a time varying electromagnetic field induced in the Earth's subsurface involves measuring magnetic field gradient in at least two orthogonal directions in response to the induced electromagnetic field and determining an electric field response in a direction normal to the magnetic field gradient measurements. 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 involves measuring electric field response along a substantially closed pattern on at least one of the Earth's surface and the bottom of a body of water and determining an electric field response in a direction normal to the measured electric field response using electric field response measurements made at opposed positions along the closed pattern.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: November 18, 2014
    Assignee: KJT Enterprises, Inc.
    Inventors: Kurt M. Strack, Stefan L. Helwig
  • Publication number: 20140266216
    Abstract: Disclosed are methods and systems for suppression of noise in electromagnetic surveying that includes stacking two or more frames of electromagnetic data. An example embodiment discloses a method for suppressing swell-induced noise in an electromagnetic survey, comprising: measuring an electromagnetic field parameter at one or more positions to provide an electromagnetic signal, the electromagnetic signal comprising a swell-induced portion; and stacking two or more frames of the electromagnetic signal to provide a stacked signal in which the swell-induced portion is suppressed, wherein the swell-induced portion is out of phase between the two or more frames.
    Type: Application
    Filed: March 14, 2013
    Publication date: September 18, 2014
    Inventors: Ulf Peter Lindqvist, Andras Robert Juhasz, Rune Johan Magnus Mattsson, Lars Erik Magnus Bjornemo
  • Publication number: 20140266215
    Abstract: Systems and methods for measuring water properties during a marine survey are disclosed. While electromagnetic-field (“EM-field”) receivers located along streamers towed by a survey vessel measure surrounding EM fields, horizontal conductivity profiles of a body of water located above a subterranean formation are also measured. By inputting a substantially continuous, conductivity profile of the body of water along with EM-field data into an EM inversion process, estimates of the subterranean formation properties, such as resistivities, can be generated with a higher degree of confidence than estimates of properties based on a speculated or sparse conductivities of the body of water.
    Type: Application
    Filed: March 12, 2013
    Publication date: September 18, 2014
    Applicant: PGS Geophysical AS
    Inventors: Erik Bjornemo, Johnathan Linfoot
  • Patent number: 8836336
    Abstract: First electromagnetic data is acquired for a subterranean structure using a first survey technique, and second electromagnetic data is acquired for the subterranean structure using a second, different survey technique in which static positioning of at least one electromagnetic source is employed. The first and second electromagnetic data are combined to characterize the subterranean structure.
    Type: Grant
    Filed: August 12, 2011
    Date of Patent: September 16, 2014
    Assignees: WesternGeco L.L.C.
    Inventors: Tracy Campbell, Jostein Kjerstad, Graham Paterson Birkett
  • Publication number: 20140253132
    Abstract: Electromagnetic streamer cables and methods of use. Example systems include: a first electrode, the first electrode at a first location along the streamer cable; a second electrode at a second location along the streamer cable; a first sensor module electrically coupled to the first electrode and second electrode, the first sensor module configured to measure a voltage across the first and second electrodes; a third electrode at a third location between the first and second electrodes; a fourth electrode at a fourth location along the streamer cable, the fourth location distal to the second location; and a second sensor module electrically coupled to the third electrode and fourth electrode, the second sensor module configured to measure a voltage across the third and fourth electrodes.
    Type: Application
    Filed: May 20, 2014
    Publication date: September 11, 2014
    Applicant: PGS Geophysical AS
    Inventors: Robert Juhasz, U. Peter Lindqvist, Gustav Göran Mattias Südow
  • Patent number: 8816716
    Abstract: A diagnostic apparatus for erroneous installation of power storage stacks includes a first connector portion included in a first power storage stack, a second connector portion included in a second power storage stack capable of connection to the first power storage stack, and a third connector portion included in a third power storage stack which should be prohibited from connection to the first power storage stack, wherein the first connector portion and the second connector portion provides a first circuit when they are connected to each other, and the first connector portion and the third connector portion provides a second circuit when they are connected to each other, the second circuit having a different circuit configuration from that of the first circuit.
    Type: Grant
    Filed: February 14, 2011
    Date of Patent: August 26, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Ryutaro Tokitsu, Koichi Nagamine
  • Patent number: 8816690
    Abstract: A marine electromagnetic sensor cable system includes a first sensor cable subsystem including at least a first sensor cable segment. The first sensor cable segment includes a plurality of spaced apart electrodes which electrically contact a body of water when the first sensor cable segment is immersed therein, and an electrical conductor coupled to each electrode, each electrical conductor extending from one longitudinal end of the sensor cable segment to the other. The system includes a first signal processing module electrically coupled to a longitudinal end of the first sensor cable segment, and including a voltage measuring circuit electrically connected between two or more electrodes from the first plurality of electrodes. Marine electromagnetic surveys are conducted using the marine electromagnetic sensor cable system.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: August 26, 2014
    Assignee: PGS Geophysical AS
    Inventors: Gustav Göran Mattias Südow, Ulf Peter Lindqvist, Andras Robert Juhasz, Robert A. P. Fernihough
  • Patent number: 8810248
    Abstract: A method of testing the electric field recording of a marine electromagnetic sensor cable including electrodes is provided. The method includes causing time varying current to flow between at least one pair of current electrodes disposed along the marine electromagnetic sensor cable. The flow of current generates a voltage in a body of water, thereby causing a secondary field impressed on a pair of sensor electrodes disposed along the marine electromagnetic sensor cable. A potential difference between the pair of sensor electrodes is measured. Accuracy of the electric field recording is inferred from the measured potential difference.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: August 19, 2014
    Assignee: KJT Enterprises, Inc.
    Inventor: Stefan L. Helwig
  • Patent number: 8797036
    Abstract: Disclosed are methods and apparatus for adaptive source electromagnetic (EM) surveying. In accordance with one embodiment, a source waveform signal is generated, and an outgoing EM signal which is based on the source waveform signal is transmitted using an antenna. A responsive electromagnetic signal is detected using at least one electromagnetic sensor, and a receiver waveform signal based on the responsive electromagnetic signal is obtained. A feedback control signal which depends on at least one input signal is determined. Based on the feedback control signal, the source waveform signal is adapted. Other embodiments, aspects, and features are also disclosed.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: August 5, 2014
    Assignee: PGS Geophysical
    Inventors: Dougal Kennedy, Mattias Sudow, Robert Juhasz
  • Patent number: 8797038
    Abstract: A marine electromagnetic survey system includes a power cable configured to couple to a power supply at one axial end, and to a head unit at the other end. The power supply includes a source of direct current which is coupled to the power cable. The head unit includes equipment configured to output a lower voltage at a higher current than the source of direct current. At least one electromagnetic antenna is coupled to the head unit and is configured to receive the output of the head unit equipment.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: August 5, 2014
    Assignee: PGS Geophysical AS
    Inventors: Oliver Peppe, Prawin Bhadani
  • Patent number: 8786286
    Abstract: According to one example embodiment is a time domain electromagnetic (TDEM) geophysical survey system for producing a B-field measurement, comprising: a transmitter coil; a bucking coil positioned in a substantially concentric and coplanar orientation relative to the transmitter coil; a receiver coil positioned in a substantially concentric and coplanar orientation relative to the bucking coil; an electrical current source connected to the transmitter coil and bucking coil for applying a periodic current thereto; and a data collection system configured to receive a magnetic field time-derivative signal dB/dt from the receiver coil and integrate the magnetic field time-derivative signal dB/dt to generate, a magnetic B-field measurement, the transmitter coil, bucking coil and receiver coil being positioned relative to each other such that, at the location of the receiver coil, a magnetic field generated by the bucking coil has a cancelling effect on a primary magnetic field generated by the transmitter coil.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: July 22, 2014
    Assignee: Geotech Airborne Limited
    Inventors: Petr Valentinovich Kuzmin, Edward Beverly Morrison
  • Publication number: 20140167768
    Abstract: Disclosed are methods and systems for marine geophysical surveying that include a combined electromagnetic source electrode and deflector. An example embodiment discloses an electromagnetic source assembly comprising: a deflector-source electrode, wherein the deflector-source electrode comprises an electromagnetic source electrode integrated into a deflector; a separate electromagnetic source electrode; and a power source coupled to the electromagnetic source electrode and the separate electromagnetic source electrode.
    Type: Application
    Filed: December 19, 2012
    Publication date: June 19, 2014
    Applicant: PGS GEOPHYSICAL AS
    Inventors: Johnathan P. Linfoot, Oliver Colin Peppe
  • Patent number: 8736269
    Abstract: The present disclosure describes various geophysical survey systems and methods for mapping an electric potential field. At least one illustrative embodiment includes an electromagnetic (EM) source and geophysical survey cables that each includes multiple electrodes spaced apart along each geophysical survey cable's length, and multiple data acquisition units that each obtains measurements indicative of an electric potential between two the electrodes. A calculation module is included and configured to combine signals representative of the measurements to produce signals indicative of the electric potential of each electrode relative to a reference potential assumed to be present at a selected electrode for each of the plurality of geophysical survey cables. Each reference potential is assumed to be of a magnitude that is within a tolerance range of a common reference potential.
    Type: Grant
    Filed: December 27, 2011
    Date of Patent: May 27, 2014
    Assignee: PGS Geophysical AS
    Inventors: Mattias Südow, Frederick James Barr, Jr., Peter Lindqvist, Robert Juhasz
  • Patent number: 8710845
    Abstract: An electromagnetic sensor cable has components including a first sensor cable segment having a plurality of spaced apart electrodes on the first sensor cable segment an electrical conductors coupled to the electrodes such that at least one of the electrodes is electrically connectible at at least one longitudinal end of the first sensor cable segment. The sensor cable includes a second sensor cable segment configured substantially the same as the first sensor cable segment. A first signal processing and configuration module has signal processing circuitry configured to perform at least one of measuring voltages across selected pairs of electrodes, and communicating signals representative of voltages measured across selected pairs of electrodes. The cable components are each configured to connect at the lateral ends one to another.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: April 29, 2014
    Assignee: PGS Geophysical AS
    Inventors: Ulf Peter Lindqvist, Robert Andras Juhasz, Gustav Göran Mattias Südow
  • Patent number: 8712693
    Abstract: A method for measuring an enhanced electromagnetic field response, especially in a submarine environment, for the purposes of subsurface data acquisition and processing. An electromagnetic field is applied to subterranean strata at two or more different frequencies, a response at each frequency is detected, and the responses at different frequencies are resolved. The differences in the phase and/or amplitude of the responses are analyzed and the nature of the strata is determined. The same method can be used to determine the hydrocarbon content of a reservoir via the use of a borehole.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: April 29, 2014
    Assignee: Electromagnetic Geoservices ASA
    Inventor: Frank Agnar Maao
  • Patent number: 8686730
    Abstract: A system for measuring electrical resistivity survey checks a border of bedrock or a thickness of a sedimentary layer in a riverbed of a river or lake within a short time. A method for analysis of an underground structure of a riverbed using the same is also provided. The system for streamer electric resistivity survey using a survey boat includes a streamer cable connected to the survey boat and having a plurality of electrodes attached thereto, a multi-channel resistivity meter loaded on the survey boat to measure electric resistivity from the plurality of electrodes, a first RTK GPS (Real Time Kinematic Global Positioning System) loaded on the survey boat to measure a position of the survey boat in real time, and a second RTK GPS installed to a tail of the streamer cable to measure a position of the tail in real time.
    Type: Grant
    Filed: September 8, 2011
    Date of Patent: April 1, 2014
    Assignee: Korea Institute of Geoscience & Mineral Resources
    Inventors: Seong-Jun Cho, Jung-Ho Kim, Myeong-Jong Yi, Jeong Sul Son
  • Patent number: 8669766
    Abstract: The present disclosure relates to methods and systems for detecting electric potential difference in water. A first electrode comprising a first electrode body is configured to be in electrical contact with the water when the device is disposed in the water. A second electrode comprising a second electrode body is configured to be in electrical contact with the water when the device is disposed in the water. An electrical connection exists amongst the first electrode, the second electrode, and a voltage measuring device. At least one of the first electrode body and the second electrode body is formed at least partially of a carbon aerogel material.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: March 11, 2014
    Assignee: PGS Geophysical AS
    Inventor: Ulf Peter Lindqvist
  • Patent number: 8643374
    Abstract: A marine electromagnetic geophysical survey transducer cable includes a tow cable configured to couple to a tow vessel. A first electrode cable is coupled at a forward end to the tow cable. A second electrode cable is disposed aft of the first electrode cable and configured to indirectly couple to the tow vessel. At least one of the first and second electrode cables includes a cable core comprising a first core material having a first density selected to provide the transducer cable with a selected overall density, and at least one layer of electrically conductive strands disposed exterior to the cable core.
    Type: Grant
    Filed: December 16, 2010
    Date of Patent: February 4, 2014
    Assignee: PGS Geophyscial AS
    Inventor: James Mackay
  • Patent number: 8638103
    Abstract: The present disclosure relates to determining a property, such as resistivity, of an earth formation. A transmitter is disposed in a wellbore penetrating the formation, and a plurality of receivers are distributed on or near the earth's surface. The transmitter sends electromagnetic energy into the formation and the resulting signal, after passing through the formation, is detected by the array of receivers. The received signal is used to determine the property of the formation. This is often achieved using an inversion or numerical model of the formation being measured. The inversion takes into account changes in the background formation model due to transmitting from various locations. The measurements made on the formation can be performed while drilling the wellbore or subsequent to the drilling.
    Type: Grant
    Filed: October 21, 2009
    Date of Patent: January 28, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Richard Rosthal, Edward Nichols, John Lovell, Christopher Bogath
  • Patent number: 8614580
    Abstract: To perform surveying of a subterranean structure, an electromagnetic (EM) source array has a plurality of electrodes. Different subsets of the electrodes are dynamically activated to provide corresponding EM radiation patterns to survey the subterranean structure.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: December 24, 2013
    Assignee: WesternGeco L.L.C.
    Inventor: Leendert Combee
  • Patent number: 8587316
    Abstract: A disclosed geophysical survey cable includes a signal amplifier coupled between two electrodes spaced apart along the length of the geophysical survey cable (the electrodes being coupled to the signal amplifier by a first conductor pair), and a noise amplifier coupled to a second conductor pair positioned substantially parallel to the first conductor pair. The geophysical survey cable further includes a combiner that combines a noise signal provided by the noise amplifier with a sensor signal provided by the signal amplifier to provide a sensor signal with a reduced noise component.
    Type: Grant
    Filed: December 8, 2011
    Date of Patent: November 19, 2013
    Assignee: PGS Geophysical AS
    Inventors: Robert Juhasz, Mattias Südow, Joel Skogman, Panagiotis Verras, Peter Lindqvist
  • Publication number: 20130300421
    Abstract: The present invention relates to a system (100) for detecting underwater geological formations, in particular for the localization of reservoirs of hydrocarbons such as oil and/or natural gas, comprising an electromagnetic transmission device (10) which can be moved within an area to be surveyed (101) through sea surface tow means (14) along an advance direction (A) and at least one electromagnetic reception device (20) positioned in the area to be surveyed (101) and characterized in that the electromagnetic reception device (20) comprises at least one flat structure (20a) consisting of a plurality of linear elements (21) constrained to each other according to a bidimensional lattice configuration and a plurality of reception electrodes (22, 22a), wherein each reception electrode (22, 22a), of the plurality of reception electrodes (22, 22a) is constrained in correspondence with an intersection between pairs of said linear elements (21).
    Type: Application
    Filed: December 16, 2011
    Publication date: November 14, 2013
    Applicant: Eni S.P.A.
    Inventors: Paolo Dell'Aversana, Michele Filippini, Matteo Pasquini
  • Publication number: 20130300420
    Abstract: An electromagnetic survey acquisition system includes a sensor cable and a source cable, each deployable in a body of water, and a recording system. The sensor cable includes an electromagnetic sensor thereon. The source cable includes an electromagnetic antenna thereon. The recording system includes a source current generator, a current sensor, and an acquisition controller. The source current generator powers the source cable to emit an electromagnetic field from the antenna. The current sensor is coupled to the source current generator. The acquisition controller interrogates the electromagnetic sensor and the current sensor at selected times in a synchronized fashion.
    Type: Application
    Filed: May 9, 2012
    Publication date: November 14, 2013
    Inventors: Andras Robert Juhasz, Gustav Göran Mattias Südow, Ulf Peter Lindqvist
  • Patent number: 8575938
    Abstract: A marine electromagnetic receiver cable includes a plurality of signal processing modules disposed at spaced apart locations along the receiver cable. A power supply line is connected to each of the signal processing modules and to an electric current source. A current regulation device is connected in the power supply line proximate each signal processing module. The current regulation devices are connected such that an amount of current flowing through the power supply line is substantially constant. At least one electromagnetic receiver is functionally coupled to an input of each signal processing module.
    Type: Grant
    Filed: April 20, 2010
    Date of Patent: November 5, 2013
    Assignee: PGS Geophysical AS
    Inventors: Kenneth Karlsen, Ulf Peter Lindqvist
  • Patent number: 8570044
    Abstract: To analyze content of a subterranean structure, electric field measurements at plural source-receiver azimuths in a predefined range are received. Total magnetic field measurements are also received at plural source-receiver azimuths in the predefined range. The electric field measurements and the total magnetic field measurements are provided to an analysis module to enable determination of electrical resistivity anisotropy of the subterranean structure.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: October 29, 2013
    Assignee: WesternGeco L.L.C.
    Inventors: Michael Tompkins, David L. Alumbaugh
  • Patent number: 8514656
    Abstract: An electromagnetic sensor streamer may include a jacket, at least one electromagnetic sensor in operational communication with a voltage measuring circuit disposed inside the jacket, and at least one wire coil. The at least one wire coil is in signal communication with the voltage measuring circuit, and the voltage measuring circuit is configured to determine motion-induced voltages imparted to the at least one electromagnetic sensor in the streamer.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: August 20, 2013
    Assignee: PGS Geophysical AS
    Inventors: Andras Robert Juhasz, Gustav Göran Mattias Südow, Ulf Peter Lindqvist
  • Publication number: 20130187655
    Abstract: Disclosed are methods and systems for conditioning electrodes while deployed in the sea with a marine electromagnetic survey system. An embodiment of the method may comprise deploying electrodes in seawater during a marine electromagnetic survey. The method further may comprise coupling at least one of the electrodes to a controllable current/voltage source while the electrodes are deployed in the seawater. The method further may comprise sending a first conditioning signal from the controllable current/voltage source to the at least one of the electrodes coupled to the controllable current/voltage source.
    Type: Application
    Filed: January 25, 2012
    Publication date: July 25, 2013
    Applicant: PGS Geophysical AS
    Inventors: Andras Robert Juhasz, Ulf Peter Lindqvist
  • Patent number: 8482287
    Abstract: Method of determining electrical anisotropy in a subsurface formation, wherein electromagnetic field data from a multi-offset electromagnetic survey obtained by using an electromagnetic source and a plurality of electromagnetic receivers at varying offset distances from the source is provided. The electromagnetic field data comprises a first set of multi-offset response signals received at each receiver with the electromagnetic source emitting at a first frequency, and at least one additional set of multi-offset response signals received at each receiver with the electromagnetic source emitting at a different frequency. The presence of electrical anisotropy in the subsurface formation is determined using the first and at least one additional sets of multi-offset response signals.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: July 9, 2013
    Assignee: Shell Oil Company
    Inventor: Michael John Tompkins
  • Publication number: 20130162257
    Abstract: The present invention is a method of poles configuration with four poles inter-combination for marine electromagnetic surveying and acquisition. The method of the present invention adopts six horizontal electric field components with four poles inter-combination. The six horizontal electric field components are respectively constituted from tri-pins grounding electrodes of four poles pairwise. One of the pins of each of the tri-pins grounding electrodes and the pins of the other three tri-pins grounding electrodes mutually constitute the six horizontal electric field components. The data for electromagnetic field over time series are simultaneously recorded. The present invention effectively ensure that the electric field recording with an angle less than 22.5 degree to the activation direction is achieved regardless of the orientation of the acquisition station, and that the worst effective activation signal may reach 76.5% of that under collinear activation.
    Type: Application
    Filed: March 11, 2011
    Publication date: June 27, 2013
    Applicants: BGP INC., CHINA NATIONAL PETROLEUM CORPORATION, CHINA NATIONAL PETROLEUM CORPORATION
    Inventor: Zhanxiang He
  • Patent number: 8471555
    Abstract: Method for determining receiver orientation angles in a controlled source electromagnetic survey, by analyzing the survey data. For a given survey receiver, two data subsets are selected. (43, 44). The two subsets may be from two offset ranges that are geometrically symmetrical relative to the receiver location. Alternatively, the second subset may be a computer simulation of actual survey data. In either instance, an orientation is assumed for the receiver (45), and that orientation is used to compare component data from the two subsets that can be expected to match if the assumed orientation angle(s) is (are) correct (46). The mismatch is ascertained, and the assumed orientation is adjusted (45) and the process is repeated.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: June 25, 2013
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Dmitriy A. Pavlov, Charlie Jing, Dennis E. Willen
  • Patent number: 8427165
    Abstract: A method for removing the effects of an airwave from marine electromagnetic data comprising providing an electromagnetic source and at least one receiver in the water; measuring the electromagnetic response at a first source-receiver separation; determining a scaled version of the airwave response at a source-receiver separation where the earth response is negligible and using the scaled airwave response to determine the earth response measured at the first separation. Using this method, an improved estimate of the earth's response can be achieved.
    Type: Grant
    Filed: February 11, 2008
    Date of Patent: April 23, 2013
    Assignee: PGS EM Limited
    Inventor: Antoni Marjan Ziolkowski
  • Publication number: 20130093426
    Abstract: A marine electromagnetic survey source includes a power cable configured to couple to a high voltage power supply at one axial end and to a head unit at the other axial end. The head unit includes equipment configured to output a lower voltage at higher current than the current imparted thereto by high voltage power supply. The head unit has an electrically conductive exterior coupled to one output terminal of the equipment. An electromagnetic antenna cable having an electrode thereon is coupled to the head unit and configured to receive the output of another terminal of the head unit equipment. In some implementations, electromagnetic fields are induced in formations by conducting current to the equipment. Marine geophysical surveys are conducted utilizing such induction of electromagnetic fields.
    Type: Application
    Filed: October 17, 2011
    Publication date: April 18, 2013
    Applicant: PGS Geophysical AS
    Inventors: Oliver Peppe, Ulf Peter Lindqvist
  • Publication number: 20130069657
    Abstract: An electromagnetic sensor cable has components including a first sensor cable segment having a plurality of spaced apart electrodes on the first sensor cable segment an electrical conductors coupled to the electrodes such that at least one of the electrodes is electrically connectible at at least one longitudinal end of the first sensor cable segment. The sensor cable includes a second sensor cable segment configured substantially the same as the first sensor cable segment. A first signal processing and configuration module has signal processing circuitry configured to perform at least one of measuring voltages across selected pairs of electrodes, and communicating signals representative of voltages measured across selected pairs of electrodes. The cable components are each configured to connect at the lateral ends one to another.
    Type: Application
    Filed: September 19, 2011
    Publication date: March 21, 2013
    Applicant: PGS Geophysical AS
    Inventors: Ulf Peter Lindqvist, Andras Robert Juhasz, Gustav Göran Mattias Sudow
  • Patent number: 8378671
    Abstract: Cost-effective compact magnetometers can be deployed across large ocean areas to record magnetic field strengths. Each magnetometer has a canister containing a magnetometer sensor at its upper end to detect magnetic field strengths of magnetic influence sweep systems and provide representative data signals. Each magnetometer also has sensors to collect data representative of the orientation of the magnetometer as well as temperature and depth to aid in post operational evaluation of the gathered magnetic strength data. A computer processor connected to the sensors controls receipt of the data signals and stores them in a memory device. Batteries at the canister's lower end supply power for the sensors, processor, and memory. An anchor release mechanism causes an anchor to separate from the canister, allowing it to float to the surface for recovery or to transmit data via a UHF transceiver.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: February 19, 2013
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Morgan Mahoney
  • Patent number: 8319497
    Abstract: A marine sensor streamer includes a jacket covering an exterior of the streamer. At least one strength member extends the length of the jacket. At least one stiffener element extends inside the length of the jacket. The at least one stiffener element includes a gas filling the interior of a flexible, compressible tube and filler elements disposed in the gas. The filler elements have exterior shape and surface roughness such that upon compression of the gas, the filler elements are urged into contact with each other, causing the streamer to become substantially rigid.
    Type: Grant
    Filed: April 7, 2010
    Date of Patent: November 27, 2012
    Assignee: PGS Geophysical AS
    Inventors: Gustav Göran Mattias Südow, Ulf Peter Lindqvist, Andras Robert Juhasz
  • Patent number: 8299794
    Abstract: A method for electromagnetic geophysical surveying of rock formations (1) under a sea-floor (3) comprising the following steps: *—towing first and second alternating field (E1, E2) emitting sources (s1, S2) in first and second depths below the sea surface, said first field (E1) having a first phase (?1);—said second alternating field (E2) given a second phase (?2) different from said first phase (?1), said sources (S1, S2) constituting a phased array emitter antenna with directivity for transmitting a major proportion of the combined electromagnetic energy downwards;—said first and second fields (E1, E2) for propagating partly down through the sea-floor (3) and being reflected and/or refracted through said rock formations (1) and partly propagating back through the seafloor (3);—said first and said second fields (E1, E2) for merging to a total field and being measured by electromagnetic receivers (r1, r2, . . . , rn) recording corresponding field registrations (Er1(t), Er2(t), Er3(t), . . . , Ern(t)).
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: October 30, 2012
    Assignee: Norsk Hydro ASA
    Inventors: Brian Anthony Farrelly, Svein Erling Johnstad