| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 324357000 | Including separate pickup of generated fields or potentials | 72 |
| 20080265897 | Method of Detecting Soil Structure Using Voltage Slope and Measuring Earth Resistance - Provided is a method of accurately measuring earth resistance even when the composition state of soil that affects the installation of a metering device for measuring earth resistance is unknown. The method comprises measuring a potential at a first potential electrode point, measuring a potential at a second potential electrode point, calculating a voltage slope corresponding to a change rate of potential difference, using a potential difference between the first and second potential electrode points, and setting a potential point according to voltage slope characteristics and measuring earth resistance. A measurement approximating an accurate value of earth resistance can be performed even when soil composition characteristics are unknown at a site. | 10-30-2008 |
| 20090072834 | METHOD AND APPARATUS FOR CONDUCTING ELECTROMAGNETIC EXPLORATION - The invention is concerned with electromagnetic exploration of the earth's surface. In a method proposed by the invention, a primary coil is powered to generate a primary field and the primary field is applied to the earth and a receiver, used to detect a secondary field generated by the earth in response to the primary field, is moved over the surface of the earth. According to the invention, Helmholtz coils ( | 03-19-2009 |
| 20090121720 | Method for controlled source electromagnetic reconnaissance surveying - Method for conducting an efficient and interpretable controlled-source electromagnetic reconnaissance survey for buried hydrocarbons. While a part of the survey area is being set up for measurement and data are being acquired, data from a nearby part of the survey area, surveyed just previously, are being rapidly processed and analyzed ( | 05-14-2009 |
| 20100194396 | Remotely reconfigurable system for mapping subsurface geological anomalies - A method and apparatus are provided for detecting and transmitting geophysical data from a plurality of electrodes inserted into the soil utilizing a set of identical dynamically reconfigurable voltage control units located on each electrode and connected together by a communications and power cable. A test sequence is provided in each voltage control unit. Each voltage control unit records data measurements for transmission to a central data collector. Each voltage control unit incorporates and determines its positional relationship to other voltage control units by logging when the unit is attached to the electrode. Each voltage control unit I equipped with a magnetic switch for detecting when they are in contact with the electrode. | 08-05-2010 |
| 20160084980 | METHOD AND APPARATUS FOR DETECTING AND MAPPING SUBSURFACE ANOMALIES - A method for estimating at least one geophysical property is disclosed. The method includes using a plurality of transmitter electrodes distributed in a conductive medium, periodically passing rectangular current impulses through the media; collecting a sequence of sounding data between each of the impulses with a receiver electrode disposed between the plurality, determining a first difference and a second difference of the electric potential between points of the collected data; when each of the transmitters is excited, acquiring a focused measurement by simultaneously calculating a combination of at least one orthogonally weighted measurement and at least one axially weighted measurement obtained by the receiver, wherein the weighting is obtained from a condition of equipotentiality in four outer electrodes of the receiver; and, applying a time-differentiation technique to obtain deep measurements that exhibit low noise contribution from shallow features. An apparatus is also disclosed. | 03-24-2016 |
| 20160252640 | SYSTEM AND METHOD FOR GEOPHYSICAL DATA COLLECTION | 09-01-2016 |
| 324358000 | With three electrodes | 1 |
| 20100134114 | Apparatus and Method for Three-Pole Type Measuring Specific Soil Resistance Measurement for Distribution Grounding - Disclosed herein is an apparatus and method for measuring a specific soil resistance for distribution grounding by a three-electrode method. The apparatus uses three electrodes to measure a specific soil resistance as well as an earth resistance based on a three-electrode method in specific soil resistance measurement that is the most basic but likely to be overlooked in a practical distribution work. | 06-03-2010 |
| 324360000 | Using a pulse-type current source | 1 |
| 324362000 | To measure induced polarization | 1 |
| 20100164500 | Method for quantitative separation of electromagnetic induction and induced polarization effects - The invention relates to the field of electrical exploration and to the methods of determination of subterranean formations properties by means of electric parameters of subterranean formations measuring and separating of the parameters measured. The invention can be applied both in surface and marine electrical exploration using controlled sources of electromagnetic field, and is used in gas and oil exploration for searching and delimitation of oil and gas reservoirs basing on segregation of response from stratum, secondarily changed due to hydrocarbons migration, to split the measured signal to available components. The invention provides for a set of techniques that enable a layer-by-layer determination of geoelectrical parameters values, as well as process characteristics of induced medium polarization and electromagnetic induction. | 07-01-2010 |
| 324365000 | Offshore | 29 |
| 20090091329 | ELECTRIC FIELD SENSOR FOR MARINE ENVIRONMENTS - A sensor (S) for marine measurements of an electric field, the sensor (S) including at least two electrodes ( | 04-09-2009 |
| 20100148786 | METHOD AND DEVICE FOR CARRYING OUT MARINE ELECTRICAL EXPLORATION DURING A SHIP TRAVEL - The inventive method for reducing a noise effect during a ship travel consists in generating direct current pulses, the parameters of which are set up according to a section conductivity and the depth of a formation, in simultaneously measuring the electric field on pairs of receiving electrodes on the basis of the space average of a double electric layer potential originated at the electrode-water interface during the pulses and intervals therebetween and in determining geoelectrical parameters. The inventive device comprises a unit for forming an exciting field, in which a switchboard generates pulses on feeding electrodes and a generator consists of two mutually parallel cable lines with emitting electrodes, a nonradiative dummy device in the form of a pair of opposite electric dipoles having equal moments and a measuring unit with pairs of sectional receiving electrodes, wherein the total length of the electrode section is equal to or less than 5% the interelectode distance and the communication between the electrode elements connected to a receiving line via a common input/output makes it possible to add electromotive forces generated therein. | 06-17-2010 |
| 20100225324 | MULTI-COMPONENT MARINE ELECTROMAGNETIC SIGNAL AQUISITION METHOD - 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. | 09-09-2010 |
| 20100231223 | INSTRUMENT FOR MEASURING ELECTROMAGNETIC SIGNALS - A device and method for measuring electromagnetic signals that can be used to take measurements at or near the sea floor. The device comprises a central housing, a data management system located within the housing and at least two arms extending outwards from the housing. Each arm comprises a flexible elongate sheath attached to the housing, a sensor head, a flexible electrical cable attached to the sheath and connecting the sensor head to the data management system and a rod which is removeably locatable within the sheath. The rod is connectable relative to the housing at one end and connectable relative to the sensor head at the end remote from the housing. | 09-16-2010 |
| 20100231224 | Method and system for calibrating streamer electrodes in a marine electromagnetic survey system - A marine electromagnetic sensor system includes a sensor cable having at least one electromagnetic sensor thereon. A first calibration electrode is disposed on the cable on one side of the sensor. A second calibration electrode is disposed on the cable on an opposite side of the sensor. A calibration power supply is coupled to the first and second calibration electrodes. A measuring circuit is coupled to the sensor. A method for calibrating marine electromagnetic survey electrodes includes imparting electric current between calibration electrodes disposed at spaced apart locations on a cable deployed in the water. Voltages impressed across a pair of electrodes disposed on the cable between the calibration electrodes are detected in response to the current. A change in sensitivity of the at least one pair of electrodes is determined using the detected voltages. | 09-16-2010 |
| 20100259269 | SYSTEM FOR STREAMER ELECTRICAL RESISTIVITY SURVEY AND METHOD FOR ANALYSIS OF UNDERGROUND STRUCTURE BELOW A RIVERBED - 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 comprises 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. | 10-14-2010 |
| 20100271032 | Method of testing electric field recording of a marine electromagnetic sensor cable - A method of testing the electric field recording of a marine electromagnetic sensor cable including electrodes is provided. The method includes causing current to flow between a pair of first electrodes disposed along the marine electromagnetic sensor cable. The flow of current generates a voltage that is impressed on a pair of second electrodes disposed along the marine electromagnetic sensor cable. A potential difference between the pair of second electrodes is measured. Accuracy of the electric field recording is inferred from the measured potential difference | 10-28-2010 |
| 20110248718 | Marine sensor streamer having pressure activated stiffness enhancement - 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. | 10-13-2011 |
| 20110260730 | Switchable front-end measurement unit for towed marine electromagnetic survey cables - A marine electromagnetic streamer includes a plurality of electrodes disposed along a longitudinal dimension of the streamer. At least one signal processing module is disposed at a selected position along the streamer. A multipole switch associated with the at least one module is electrically coupled between a signal input of the signal processing module and selected pairs of the electrodes. The switch is configured to enable the selected pairs coupled to the switch such that selection thereof results in at least one of selected electrode spacing and selected electrode offset from an electromagnetic energy source. | 10-27-2011 |
| 20120153959 | Electrode structure for marine electromagnetic geophysical survey transducers - 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. | 06-21-2012 |
| 20120182017 | Subsurface electromagnetic survey technique using expendable conductivity, temperature, and depth measurement devices - A method for modeling conductivity distribution in a formation below a body of water includes measuring electromagnetic response of the formation with an electromagnetic survey system; measuring at least one of water conductivity, water dielectric constant, and water temperature with respect to depth in the water; generating an initial model of conductivity distribution of the formation; discretizing the measurements of at least one of water conductivity, water dielectric constant, and water temperature with respect to depth into at least one layer; generating a forward model of a response of the electromagnetic survey system to the initial model and the discretized measurements; comparing the forward model to the measured electromagnetic response to determine differences; adjusting the initial model to reduce the differences; and repeating generating a forward model, comparing the forward model to the measured electromagnetic response, and adjusting the initial model until the differences fall below a selected threshold. | 07-19-2012 |
| 20120194196 | Electromagnetic Source to Produce Multiple Electromagnetic Components - An electromagnetic (EM) source assembly for performing marine subterranean surveying includes electrodes in an arrangement configured for towing through a body of water. A controller is configured to selectively activate different sets of the plurality of electrodes, where a first of the sets produces an EM field in a first direction, and where a second of the sets produces an EM field in a second, different direction. | 08-02-2012 |
| 20120223718 | High voltage DC power for electromagnetic survey source - 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. | 09-06-2012 |
| 20120242343 | CARBON AEROGEL BASED ELECTRODE FOR ELECTRIC FIELD MEASUREMENTS IN WATER - 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. | 09-27-2012 |
| 20130069657 | ELECTROMAGNETIC SENSOR CABLE AND ELECTRICAL CONFIGURATION THEREFOR - 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. | 03-21-2013 |
| 20130093426 | POWER CONVERTER AND ELECTRODE COMBINATIONS FOR ELECTROMAGNETIC SURVEY SOURCE - 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. | 04-18-2013 |
| 20130162257 | METHOD OF POLES CONFIGURATION WITH FOUR POLES INTER-COMBINATION FOR MARINE ELECTROMAGNETIC SURVEYING - 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. It is ensured that the activation field source and the couple pole for recording the electric field are under strong coupling, the requirements on the orientation of the acquisition station and on the dragging direction and position of the activation field source in data acquisition are lowered, and loss of electromagnetic data is prevented. | 06-27-2013 |
| 20130187655 | System and Method for In-Sea Electrode Conditioning - 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. | 07-25-2013 |
| 20130300420 | Acquisition System and Method for Towed Electromagnetic Sensor Cable and Source - 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. | 11-14-2013 |
| 20130300421 | SYSTEM FOR DETECTING UNDERWATER GEOLOGICAL FORMATIONS IN PARTICULAR FOR THE LOCALIZATION OF HYDROCARBON FORMULATIONS - The present invention relates to a system ( | 11-14-2013 |
| 20140167768 | Methods and Systems for Using a Combined Electromagnetic Source Electrode and Deflector - 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. | 06-19-2014 |
| 20140253132 | SWITCHABLE FRONT-END MEASUREMENT UNIT FOR TOWED MARINE ELECTROMAGNETIC STREAMER CABLES - 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. | 09-11-2014 |
| 20140266215 | SYSTEMS AND METHODS FOR MEASURING WATER PROPERTIES IN ELECTROMAGNETIC MARINE SURVEYS - 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. | 09-18-2014 |
| 20140266216 | Method and System for Suppressing Swell-Induced Electromagnetic Noise - 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. | 09-18-2014 |
| 20150035537 | ACQUISITION SYSTEM AND METHOD FOR TOWED ELECTROMAGNETIC SENSOR CABLE AND SOURCE - 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. | 02-05-2015 |
| 20150061685 | BUOYANT MARINE ELECTROMAGNETIC CABLE ASSEMBLY - 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. | 03-05-2015 |
| 20150301217 | ULTRA-LONG ELECTROMAGNETIC SOURCE - An electromagnetic source. At least some illustrative embodiments are electromagnetic sources including a first electrode and a second electrode. The electromagnetic source also includes a cable disposed between the first electrode and the second electrode. The second electrode separated from the first electrode by the length L, and the length L of the cable between the electrodes in the range from 1000 meters to 20000 meters (20 kilometers). | 10-22-2015 |
| 20150369946 | MARINE STREAMER CONNECTOR USED AS AN ELECTRODE - Streamer section connector used as an electrode. A first streamer section includes a first outer surface that defines an interior volume, a first connector coupled to a first end of the first outer surface, and a first digitizer node. The digitizer node defines a first input port and second input port, the first digitizer node disposed within the interior volume of the first outer surface, and the first input port is electrically coupled to the first connector such that the portion of the first connector that is electrically conductive is a first electrode. The first digitizer node configured to measure a potential difference between the first electrode at a first potential and a second potential coupled to the second input port. | 12-24-2015 |
| 20160109609 | ELECTRICALLY ISOLATED STREAMER SECTION - Aspects described herein provide for a sensor assembly having an electrically isolated cable segment that may be used for geophysical prospecting. The sensor assembly generally includes a first cable segment comprising at least one electromagnetic (EM) sensor, and a second cable segment connected to the first cable segment and electrically isolated from the first cable segment. The second cable segment may be free of electrically conductive components. Alternatively, the second cable segment may have electrically conductive components that are not electrically connected to the first cable segment. The electrically isolated cable segment may reduce or eliminate undesired signal cross-feed from the EM source to the first cable segment, which may aid in maintaining data quality. | 04-21-2016 |
| 324366000 | For well logging | 35 |
| 20080252296 | Multiple Frequency Based Leakage Correction for Imaging in Oil Based Muds - Oil-based mud imaging systems and methods having leakage current compensation. In some embodiments, disclosed logging systems include a logging tool in communication with surface computing facilities. The logging tool is provided with a sensor array having at least two voltage electrodes positioned between at least two current electrodes that create an electric field in a borehole wall, and is further provided with electronics coupled to the current electrodes to determine a differential voltage between the voltage electrodes in response to different current frequencies from the current electrodes. From the voltage measurements at different frequencies, the computing facilities determine borehole wall resistivity as a function of depth and azimuth, and may display the resistivity as a borehole wall image. | 10-16-2008 |
| 20080265898 | DETERMINING ELECTRICAL CHARACTERISTICS OF AN ELECTRICAL CABLE - To characterize an electrical cable that is deployed in a well, a voltage input is applied to the electrical cable at an earth surface location, where the well extends from the earth surface location. A current response resulting from the voltage input is measured at the earth surface location. At least one parameter of the electrical cable is computed according to the measured current response. | 10-30-2008 |
| 20080315884 | MULTI-MODE OIL BASE MUD IMAGER - A multi-mode oil base mud imager for use in non-conductive drilling fluid includes at least one current source-a current return pair, and one or more monitor electrodes not located between the current source and the current return of the current source-current return pair. Where more than one current source-current return pair is included, the tool is capable of multiple depths of investigation into surrounding formation. This data can be used as a gauge to establish the reliability of the data and to determine the resistance of the invaded zone around the borehole, as well as standoff distance of the tool from the borehole wall. | 12-25-2008 |
| 20100127709 | METHOD FOR ELECTRICAL INVESTIGATION OF A BOREHOLE - A method used in electrical investigation of geological formations surrounding a borehole comprising: determining S | 05-27-2010 |
| 20100148787 | High Frequency or Multifrequency Resistivity Tool - A system and method for determining material resistivity. A current of one or more frequencies is generated using a circuitry ( | 06-17-2010 |
| 20100231225 | Oil Based Mud Imaging Tool with Common Mode Voltage Compensation - An apparatus and method for minimizing the effects of a common mode voltage signal in downhole logging tools utilized to determine the resistivity of an adjacent portion of a borehole wall. Two current electrodes are energized by an excitation source to create an oscillatory electric field in a borehole wall. A voltage drop across a segment of the borehole wall is measured by two voltage electrodes, and the differential voltage is used in combination with a measured current flow to determine a resistivity value for the borehole wall. A common mode voltage in front of the two voltage electrodes is measured and minimized by controlling the excitation source, thereby reducing the resistivity measurement error. | 09-16-2010 |
| 20110156709 | MICRORESISTIVITY ANISOTROPY LOGGING TOOL EMPLOYING A MONOPOLE CURRENT INJECTION ELECTRODE - A microresistivity logging tool includes a monopole current injection electrode and at least first and second pairs of potential electrodes. The tool may further include a controller configured for making microresistivity anisotropy measurements using a single firing of the monopole current injection electrode. The controller may be configured to compute a two-dimensional tensor of the local formation resistivity from a single firing of the monopole current injection electrode. The use of a single firing tends to decrease measurement time, which in turn tends to improved azimuthal sensitivity in microresistivity anisotropy imaging while drilling applications. | 06-30-2011 |
| 20110156710 | CALIBRATION METHOD FOR A MICRORESISTIVITY LOGGING TOOL - Methods for making calibrated microresistivity logging measurements in nonconductive drilling fluid are disclosed. A calibrated measurement parameter (e.g., a calibrated electrical impedance or a calibrated potential difference) is obtained and further utilized to compute a formation resistivity. The methods tend to be particularly well suited for drilling applications in which the borehole environment is highly resistive (i.e., boreholes in which both the drilling fluid and the formation have a high resistivity). | 06-30-2011 |
| 20110227580 | METHOD FOR MITIGATING LEAKAGE CURRENTS - An apparatus and method for reducing an electric current leakage in a logging tool, particularly relating to reducing electric current leakage by altering a phase difference between a biasing element and an electric current produced by a first power source. The apparatus may include one or more measure electrodes for imparting electric current into a formation, a current meter, at least one current return electrode, a controller, and a biasing element. The method includes adjusting a phase angle difference between the current leaving the measure electrode and a biasing signal applied to the biasing element from a second power source to reduce the current leakage of the apparatus. | 09-22-2011 |
| 20110254553 | Electrically conductive oil-based drilling fluids - A method of servicing a wellbore comprising placing an oil-based wellbore servicing fluid comprising an electrical conductivity enhancer into the wellbore and logging the wellbore by resistivity imaging. A method of servicing a wellbore comprising introducing an oil-based drilling fluid to a wellbore, identifying a subsection of the wellbore for imaging, introducing to the subsection of the wellbore a oil-based wellbore servicing fluid comprising a carbon nanotube wherein the servicing fluid comprising the electrical conductivity enhancer mixes with the oil-based drilling fluid; and imaging the subsection of the wellbore. | 10-20-2011 |
| 20130027045 | FORMATION RESISTIVITY MEASUREMENTS USING PHASE CONTROLLED CURRENTS - Disclosed is an apparatus for estimating a property of an earth formation penetrated by a borehole. The apparatus includes a carrier configured to be conveyed through the borehole and having a first transmitter electrode configured to inject electrical current into the formation and a first measurement electrode configured to receive electrical current for measurement due to the current injection in order to estimate the property of the earth formation. A controller is configured to determine a phase difference between injected electrical current and received electrical current. A first bucker amplifier is coupled to the first measurement electrode and configured to apply a voltage to the first measurement electrode based on the determined phase difference in order for a phase of current received by the first measurement electrode to be substantially in phase with the current injected by the first transmitter electrode. | 01-31-2013 |
| 20140002089 | POWER GENERATING COMMUNICATION DEVICE | 01-02-2014 |
| 20150346374 | PROCESS FOR MINING ALLUVIAL DEPOSITS - Disclosed herein is a remote operating vehicle (ROV) for use in a subterranean mining process, such as to extract material from beneath a rock layer. The ROV may be provided as a number of components each including their own umbilical cord. Each of the components may be lowered through a borehole and assembled together to form the ROV underground. Also disclosed herein is a device and method for in-line monitoring of a mining material to determine the presence of a material of interest in the mining material. The device includes conductive plates that are spaced apart. The device detects the presence of a material of interest as it passes through the spacing between the conductive plates. | 12-03-2015 |
| 20150355365 | Well-Logging Device with Dielectric Thermoset Material - A tool for geological formation having a borehole includes a housing to be positioned within the borehole and a device carried by the housing and including at least one electrical conductor in a dielectric thermoset material surrounding the at least one electrical conductor. The dielectric thermoset material is formed as a cyanate ester and molecular sieve blended therewith. The molecular sieve in one example is formed from zeolite and in another example is formed as a 5A molecular sieve and in yet another example a 13X molecular sieve. | 12-10-2015 |
| 20160091627 | CROSSTALK SUPPRESSION OR REMOVAL FOR GALVANIC MEASUREMENTS - Apparatus and techniques are described, such as for obtaining information indicative of a formation resistivity, such as using information from a galvanic measurement apparatus. A resistive parameter related to a geologic formation is estimated through use of a model. An electrical excitation is coupled from a well tool in a borehole to the geologic formation. Induced voltages resulting from the excitation are received using monitor electrodes selected according to the specified excitation mode, including receiving magnitude and phase information corresponding to the induced voltages. The resistive parameter of the model is then determined using the magnitude and phase information of the received voltages, and using magnitude and phase information about the excitation. | 03-31-2016 |
| 20160139289 | IMPROVED ARRAY LATEROLOG TOOL TECHNIQUES - Apparatus and techniques are described, such as for obtaining information indicative of a formation resistivity, such as using an array laterolog apparatus. For example, an electrical excitation is coupled from a well tool in a borehole to a geologic formation through which the borehole extends, the excitation coupled through excitation electrodes on the well tool selected according to a specified excitation mode, and induced voltages are received from the geologic formation resulting from the excitation using monitor electrodes selected according to the specified excitation mode. In some examples, a voltage difference between a first pair of monitor electrodes is estimated through use of the induced voltage received through at least one additional monitor electrode. | 05-19-2016 |
| 324367000 | Using a pad member | 7 |
| 20080303526 | Imaging Based on 4-Terminal Dual-Resistor Voltage Measurements - Measurements made by a four terminal resistivity imaging tool in a borehole using a voltage measurement device with two different input impedances. From the two measurements, formation resistivity is determined with minimal sensitivity to standoff. 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. | 12-11-2008 |
| 20100013487 | TOOL FOR ELECTRICAL INVESTIGATION OF A BOREHOLE | 01-21-2010 |
| 20100097068 | Method and apparatus for borehole wall resisitivity imaging with full circumferential coverage - A logging tool for performing resistivity measurements on the sidewall of a borehole in an earth formation is provided with a circumferential series of evenly-spaced measurement electrodes providing complete circumferential coverage of resistivity measurements. In one embodiment, the measurement electrodes are carried on a conductive pad circumferentially surrounding an elongate mandrel or tubular. The conductive pad is held at a voltage adapted to focus measurement current into the sidewall of the borehole. Preferably, the pad has dimensions relative to the measurement electrodes and a standoff distance between the measurement electrodes and said borehole wall to effectively focus the measurement current into the borehole wall. In accordance with one aspect of the invention, the measurement electrodes are spaced apart by a distance that is less than the width of each measurement electrode, thereby ensuring full circumferential resolution. | 04-22-2010 |
| 20110025336 | Method and apparatus for well logging resistivity image tomography - A method and apparatus for evaluating an earth formation penetrated by a borehole comprises taking resistivity measurements using a plurality of resistivity arrays or pads positioned within the borehole proximal the borehole wall. In one embodiment, pads are spaced apart azimuthally around the perimeter of a tool body, each pad carrying at least one electrode thereon. A sequence of resistivity measurement operations are performed involving sequentially operating each pad, in turn, as a transmitter, with remaining pads and electrodes operated as return electrodes. The sequence preferably involves a succession of adjacent pads around the perimeter of the tool body, resulting in a full rotational (360°) imaging of the formation penetrated by the borehole. In one embodiment, the pads include at least two electrodes spaced vertically apart from one another, such that helical current paths are defined between transmitting electrodes and return electrodes. | 02-03-2011 |
| 20140111212 | FORMATION RESISTIVITY IMAGING IN CONDUCTIVE BOREHOLES - An apparatus for providing an image of a resistivity property of an earth formation surrounding a borehole is provided. The apparatus, in one aspect, may include a plurality of measure electrodes that are configured to convey an electrical current into the earth formation. In one aspect, each measure electrode may be substantially surrounded by an associated insulator that extends away from a tool body in a manner that blocks at least a portion of a vertical current flowing in a conductive fluid when the tool is operated to log the borehole. A processor provides an image of the resistivity property of the earth formation using the current in plurality of measure electrodes. | 04-24-2014 |
| 20140306711 | Method and Apparatus for Detection and Quantification of Borehole Standoff - A method of quantifying borehole properties, comprising: injecting an electric current from an outer button and an inner button disposed on an equipotential pad into a subterranean formation surround by the borehole, measuring an apparent conductivity or a scaled current for each button, modeling the measurements at a sequence of standoff locations, and, using an inversion technique to determine at least one of the following borehole properties: mudcake thickness, mudcake resistivity, diameter of invasion, flushed zone resistivity and true formation resistivity. | 10-16-2014 |
| 20160123130 | Borehole Tool - A borehole tool used in a borehole comprises a tool body, a plurality of arms connected to the tool body so as to be movable radially relative thereto between a closed position and an open position, and a plurality of pads with a totally rounded outer shape. Each of the pads is mounted on each movable portion of the arms so as to be rotatable about a radial axis relative to the tool body according to the arm movement between the closed position and the open position. | 05-05-2016 |
| 324369000 | While drilling | 9 |
| 20100123462 | Electromagnetic Wave Resistivity Tool Having a Tilted Antenna for Geosteering within a Desired Payzone - This invention is directed to a downhole method and apparatus for simultaneously determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic earth formations. The present invention accomplishes this objective by using an antenna configuration in which a transmitter antenna and a receiver antenna are oriented in non-parallel planes such that the vertical resistivity and the relative dip angle are decoupled. Preferably, either the transmitter or the receiver is mounted in a conventional orientation in a first plane that is normal to the tool axis, and the other antenna is mounted in a second plane that is not parallel to the first plane. This invention also relates to a method and apparatus for steering a downhole tool during a drilling operation in order to maintain the borehole within a desired earth formation. The steering capability is enabled by computing the difference or the ratio of the phase-based or amplitude-based responses of the receiver antennas which are mounted in planes that are not parallel to the planes of the transmitter antennas. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications. | 05-20-2010 |
| 20100148788 | High Resolution Voltage Sensing Array - An apparatus and method for performing high transverse resolution voltage measurements in downhole logging tools utilized to determine the resistivity of an adjacent portion of a borehole wall Two current electrodes | 06-17-2010 |
| 20110057656 | Drilling System for Making LWD Measurements Ahead of the Bit - A drilling system includes integral drill bit body and logging while drilling tool body portions. There are no threads between the drill bit and the LWD tool. In one exemplary embodiment the drilling system includes a unitary tool body, i.e., a tool body formed from a single work piece. In another exemplary embodiment the drill bit body portion is welded to the LWD tool body portion. At least one LWD sensor is deployed in the drill bit. The drilling system enables multiple LWD sensors to be deployed in and near the bit (e.g., on both the side and bottom faces of the bit). The absence a threaded connection facilitates the placement of electrical connectors, LWD sensors, and electronic control circuitry at the bit. | 03-10-2011 |
| 20110089950 | Microresistivity Imaging at Multiple Depths of Investigation - A microresistivity logging tool includes a dual function electrode deployed between a guard electrode and a return electrode. A drive circuit enables the electrical potential of the dual function electrode to be independently controlled so as to control a depth of investigation of a microresistivity measurement. The depth of investigation tends to increase with increasing electrical potential of the dual function electrode. | 04-21-2011 |
| 20110089951 | Microresistivity Imaging in Conductive and Nonconductive Drilling Fluid - A microresistivity logging tool includes a shield electrode deployed between a guard electrode and a return electrode. A measuring electrode is deployed in and electrically isolated from the guard electrode and first and second potential electrodes are deployed in and electrically isolated from the shield electrode. The tool further includes at least one switch configured to switch the tool between distinct first and second microresistivity measurement modes. The first measurement mode is configured for making microresistivity measurements in conductive (water based) drilling fluid and the second measurement mode is configured for making microresistivity measurements in non-conductive (oil based) drilling fluid, thereby enabling the tool to be utilized in either type of drilling fluid. | 04-21-2011 |
| 20110156711 | LOGGING TOOL EMPLOYING A MONOPOLE CURRENT INJECTION ELECTRODE FOR MICRORESISTIVITY IMAGING - A microresistivity logging tool includes a monopole current injection electrode and first and second potential electrodes deployed on a downhole tool body. A controller is configured to apply a high frequency alternating current between the monopole current injection electrode and a return and measure a corresponding AC potential difference between the first and second electrodes. | 06-30-2011 |
| 20110187374 | Microresistivity Imaging with Differentially Raised Electrodes - A microresistivity logging tool includes a measuring electrode deployed in and electrically isolated from a guard electrode. The measuring electrode is radially recessed with respect to at least a portion of the guard electrode. The raised portion of the guard electrode preferably extends radially outward from the tool body such that it contacts the borehole wall during drilling. A return electrode is spaced and electrically insulated from the guard electrode. Tools in accordance with the present invention enable good current focusing to be achieved while at the same time providing protection for the measuring electrode. | 08-04-2011 |
| 20130043874 | DRILL BIT ASSEMBLY HAVING ELECTRICALLY ISOLATED GAP JOINT FOR MEASUREMENT OF RESERVOIR PROPERTIES - A drill bit assembly for measuring reservoir formation properties comprises a bit head and a pin body, and an electrically insulated gap joint between two conductive parts of the drill bit assembly. The bit head has a cutting end and an opposite connecting end with an engagement section. The pin body comprises a connecting end with an engagement section. The pin connecting end is connected to the bit head connecting end such that the engagement sections overlap. The electrically insulating gap joint can fill a gap between the bit head and pin body engagement sections such that the bit head and pin body are mechanically connected together at the connecting ends but electrically separated. Alternatively or additionally, the pin body can have two pieces which are separated by an electrically insulating gap joint. An electrical conductor is electrically connected at a first end to the bit head and is communicable at a second end with an alternating current signal to transmit an alternating current into the bit head, thereby inducing an electric current into a reservoir formation adjacent the bit head. Electronic equipment includes measurement circuitry configured to determine the alternating current at the bit head, the alternating current being inversely proportional to a bit resistivity of the formation. | 02-21-2013 |
| 20140184229 | Systems and Methods for Resistivity Measurement at Multiple Angles of Rotation - Systems and methods are provided to obtain multiple resistivity measurements using a resistivity tool eccentered and rotating in a wellbore, which may be used to ascertain information relating to a drilling fluid in the wellbore. One such system includes a resistivity tool and data processing circuitry. The resistivity tool may become eccentered in a wellbore filled with drilling mud at least when the wellbore is at least partially deviated. The resistivity tool may also rotate within the wellbore and to obtain at least two resistivity measurements at different corresponding angles of rotation within the wellbore. The data processing circuitry may determine a mud phase angle by comparing the resistivity measurements obtained by the resistivity tool. | 07-03-2014 |
| 324372000 | Between spaced boreholes | 1 |
| 20090033332 | TELEMETRY SUBSYSTEM TO COMMUNICATE WITH PLURAL DOWNHOLE MODULES - A system for use in a wellbore includes plural modules for positioning in the wellbore and including respective interfaces, where the plural modules are configured to perform predefined downhole tasks in the wellbore. The plural modules are associated with respective local power sources. A telemetry subsystem enables communication between at least two of the plural modules, where the communication between the at least two of the plural modules allows one of the two modules to affect an operation of another of the two modules. | 02-05-2009 |
| 324373000 | Using current focussing means | 2 |
| 20100007349 | METHOD AND APPARATUS FOR FOCUSING IN RESISTIVITY MEASUREMENT TOOLS USING INDEPENDENT ELECTRICAL SOURCES - A system for measuring a resistivity parameter of an earth formation includes: at least one measurement electrode electrically connected to a first electrical source; at least one guard electrode; a shielding electrode interposed between the at least one guard electrode and the at least one measurement electrode, the shielding electrode being electrically connected to a second electrical source independent from the first electrical source, and the guard electrode being electrically connected to a third electrical source independent of the first and second electrical sources; at least one return electrode; insulators positioned between (i) the measurement electrode and the shielding electrode, (ii) the shielding electrode and the guard electrode and (iii) the measurement electrode, the guard electrode and the return electrode; and a processor configured to adjust at least one of the first electrical source and the second electrical source to minimize a current flow through the shielding electrode. | 01-14-2010 |
| 324374000 | Including a pad member | 1 |
| 20100013488 | MEASURING HEAD AND MEASURING METHOD - A measuring head for use in electrical measurements conducted in holes drilled in the ground comprises an elongated body, adaptable in the hole and comprising an electrode, electrically connecting the measuring head with its surroundings, for transmitting an electrical signal between the measuring head and its surroundings. In accordance with the invention, the measuring head comprises insulating means, placed on the body on both sides of the electrode along the length of the hole in order to form a measuring area, electrically insulated from other parts of the hole, around the electrode placed in the hole. | 01-21-2010 |
