Entries |
Document | Title | Date |
20080224707 | Array Antenna for Measurement-While-Drilling - An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance. | 09-18-2008 |
20090009174 | Borehole Conductivity Simulator Verification and Transverse Coil Balancing - Calibration of the arrays of a multicomponent induction logging tool is achieved by positioning the tool horizontally above ground. The upper and lower housings of the tool are connected by a borehole conductivity simulator which as a resistance comparable to that of a borehole. Axial and radial positioning of the transmitter coils is done by monitoring outputs at receiver coils to achieve a minimum. | 01-08-2009 |
20090039889 | REMOVING EFFECTS OF NEAR SURFACE GEOLOGY FROM SURFACE-TO-BOREHOLE ELECTROMAGNETIC DATA - A method that involves developing an electromagnetic property model of a near surface area and using this electromagnetic property model and electromagnetic data acquired using one or more electromagnetic transmitters located above the near surface area and one or more electromagnetic receivers located within a wellbore to determine one or more electromagnetic properties of a subsurface area. Also an electromagnetic data acquisition system that includes one or more electromagnetic transmitters capable of being operated on the earth's surface, one or more first electromagnetic receivers capable of being operated within a wellbore and capable of receiving signals from the one or more electromagnetic transmitters, and one or more second electromagnetic receivers capable of being located on the earth's surface near the one or more electromagnetic transmitters and capable of receiving signals from the one or more electromagnetic transmitters. Related embodiments are also described. | 02-12-2009 |
20090085570 | Apparatus and Method for Azimuthal MWD Resistivity Imaging at Multiple Depths of Investigation - A combination of a shallow-reading and a deep-reading, azimuthally sensitive, multiple propagation devices is used for providing depth images the earth formation with different depth of investigation. 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. 37 CFR 1.72(b). | 04-02-2009 |
20090091328 | Determining correction factors representing effects of different portions of a lining structure - To determine effect on a magnetic field caused by a lining structure in a wellbore, an array may be deployed into the wellbore lined with the lining structure. The array comprises a plurality of sensors including sensor A configured to operate as a transmitter, sensor B configured to operate as either a transmitter or a receiver, and sensor C configured to operate as a receiver. The array measures magnetic fields using sensor B as a receiver and sensor C in response to activation of sensor B as a transmitter and sensor A. A plurality of lining structure correction factors can be calculated based on the measured magnetic fields, based on the reciprocity of the sensors. | 04-09-2009 |
20090174409 | DOWNHOLE SENSOR INTERROGATION EMPLOYING COAXIAL CABLE - The present invention is directed to methods and systems for oil field downhole sensing and communication during drilling and/or production, wherein such methods and systems utilize coaxial cable to transmit electromagnetic (EM) energy, continuously or as a pulse, to passive downhole sensors. | 07-09-2009 |
20090237083 | METHOD FOR IMAGING SUBTERRANEAN FORMATIONS - A method for using a tool in a wellbore in a formation to predict an anomaly in the formation ahead of the device, the tool comprising a transmitter for transmitting electromagnetic signals through the formation and a receiver for detecting response signals. the method comprises a) bringing the tool to a first position inside the wellbore; b) energizing the transmitter to propagate a transient electromagnetic signal into the formation; c) detecting a response signal that has propagated through the formation as a result of the transient signal in step (b); d) calculating a derived quantity for the formation as a function of time based on the detected response signal for the formation; e) plotting the derived quantity for the formation against time; f) moving the tool to at least one other position within the wellbore and repeating steps (b) to (e); g) predicting an anomaly in the formation. | 09-24-2009 |
20090243618 | Method for Compensating Drill Pipe and Near-Borehole Effect on and Electronic Noise in Transient Resistivity Measurements - Transient measurements made at two spaced apart receivers responsive to separate activation of two transmitters symmetrically disposed about the two receivers. The transmitters and receivers are on an instrument having a conductive body induces currents in the earth formation. The effect of the conductive body is removed by using deconvolving the signal at one receiver using the measured signal at the other receiver. The symmetric transmitter configuration also enables compensation for receiver differences. | 10-01-2009 |
20090261832 | ELECTROMAGNETIC-SEISMIC LOGGING SYSTEM AND METHOD - An EMI-Seismic logging tool for use in a subterranean formation penetrated by a well bore, wherein the system makes electromagnetic and seismic measurements simultaneously using an EM receiver array for both measurements. A method of simultaneously making electromagnetic and seismic measurements in a subterranean formation is also provided. | 10-22-2009 |
20090302851 | MODULAR GEOSTEERING TOOL ASSEMBLY - A retrievable tool for steering through an earth formation includes a first tool assembly and a tilted antenna attached to the first tool assembly. The tool also includes a second tool assembly attached to the first tool assembly and a tilted antenna attached to the second tool assembly. The first tool assembly attaches to the second tool assembly so that the antennas are tilted in predetermined directions. The tilted antennas are transmitter antennas or receiver antennas. Each tool assembly is a tubular cylinder with a longitudinal axis running the length of the cylinder, wherein the tubular cylinder has two ends, each end including a rotational attachment mechanism. The tool assemblies attach to each other through their rotational attachment mechanisms. The rotational attachment mechanism may be a screw-on mechanism, press-fit mechanism, or welded mechanism. | 12-10-2009 |
20090302852 | MEASURING CASING ATTENUATION COEFFICIENT FOR ELECTRO-MAGNETICS MEASUREMENTS - Methods and related systems are described for making an electromagnetic induction survey of a formation surrounding a cased section of a borehole. An electromagnetic transmitter and/or receiver are deployed into the cased section of the borehole. One or more additional devices are used to measure the properties of a conductive casing relating to conductivity, thickness and magnetic permeability. A casing coefficient is then calculated that can then be used for the processing of the deep-sensing induction measurements. | 12-10-2009 |
20090309600 | MEASUREMENT OF FORMATION PARAMETERS USING ROTATING DIRECTIONAL EM ANTENNA - A logging tool and method to make subsurface measurements is disclosed, wherein the tool is placed within a borehole penetrating a formation. The tool has a transmitter antenna and a receiver antenna spaced apart along a longitudinal axis of the tool, and at least one of the transmitter or receiver antennas has a dipole moment that is non-coaxial with the longitudinal axis of the tool. The at least one non-coaxial antenna can rotate relative to the other antenna. Energy is transmitted from the transmitter antenna and a signal associated with the transmitted energy is measured at the receiver antenna while the at least one non-coaxial antenna rotates relative to the other antenna. | 12-17-2009 |
20100001734 | Circumferentially Spaced Magnetic Field Generating Devices - A downhole induction resistivity assembly that comprises a downhole tool string component. The tool string component comprises an induction transmitter. The transmitter is adapted to induce an induction field in the surrounding formation. A first induction receiver is spaced apart from the transmitter and is adapted to measure the induction field. A magnetic field generating mechanism is disposed circumferentially adjacent the transmitter and adapted to guide the transmitter's signal into the formation. | 01-07-2010 |
20100109672 | Transient EM for Geosteering and LWD/Wireline Formation Evaluation - A transmitter on an instrument is used to induce currents in an earth formation when it is turned on or off. A Fourier transform is applied to transient measurements made in the receivers. A multifrequency focusing of the transformed data is used for applications like determination of a distance to an interface in the formation, controlling the drilling direction, determination of formation resistivities and formation strike directions. | 05-06-2010 |
20100134111 | Method of Measuring and Imaging RXO (Near Wellbore Resistivity) Using Transient EM - A transient electromagnetic wave is generated using an electromagnetic instrument in a borehole. An apparent resistivity is estimated using a received signal responsive to the generated wave and further used to estimate a resistivity property of a fluid in the borehole. | 06-03-2010 |
20100148785 | APPARATUS AND METHOD FOR EVALUATING DOWNHOLE FLUIDS - An apparatus for evaluating downhole fluids is disclosed. The apparatus includes: an optical block having an adjustable opening that receives electromagnetic energy emitted by an electromagnetic energy source; a controller operatively associated with the optical block for adjusting the opening size, wherein the opening size is adjusted at least in part based on one or more estimated downhole parameters; and a sensor that receives the electromagnetic energy emitted by the electromagnetic energy source after the emitted electromagnetic energy interacts with a downhole fluid. A method for evaluating downhole fluids is also disclosed. | 06-17-2010 |
20100231220 | SYSTEMS AND METHODS FOR ELECTROMAGNETIC DETECTION OF A FORMATION ANOMALY FROM A NEAR BIT LOCATION WHILE DRILLING - A drill string is disposed in the borehole having a BHA and a drill bit advancing the borehole. Among other BHA components, including a telemetry unit and a data acquisition unit, in a surface-to-borehole configuration a receiver (or receiver array) is positioned immediately proximate the drill bit in the borehole, while a source (or source array) is positioned at the Earth's surface. Alternatively, in a borehole-to-surface configuration the source may be positioned immediately proximate the drill bit in the borehole while a receiver (or receiver array) is positioned at the surface. The surface-to-borehole, or borehole-to-surface, system enables an electromagnetic look about while drilling operations are underway. | 09-16-2010 |
20100244842 | APPARATUS AND METHOD FOR REMOVING ANISOTROPY EFFECT FROM DIRECTIONAL RESISTIVITY MEASUREMENTS - A directional resistivity tool includes at least one receiver deployed axially asymmetrically between at least one pair of transmitters. The transmitters are configured to transmit electromagnetic waves at first and second correspondingly distinct frequencies f | 09-30-2010 |
20100271030 | Borehole Transient EM System for Reservoir Monitoring - A transient electromagnetic borehole system uses an arrangement of sensors deployed in a borehole for reservoir monitoring. Non-conductive casing sections may be used along with an efficient transmitter configured to provide measurements up to 300 m from the borehole. By using multiple receivers, the method can also be used without nonconductive casing. | 10-28-2010 |
20100277177 | ANALYSIS OF SUBSURFACE ELECTROMAGNETIC DATA THROUGH INVERSION WITH CONSTRAINED CASING CORRECTION COEFFICIENTS - Methods and related systems are described for analyzing electromagnetic survey data. Electromagnetic survey data of a subterranean formation is obtained using at least a downhole transceiver deployed in a borehole and a transceiver positioned on the surface, or in the same or another borehole. Limits are defined for casing correction coefficients that account for effects of the borehole casing. A constrained inversion process is performed solving for the casing correction coefficients within the defined limits, and for one or more parameters of a model representing attributes, such as resistivity, of the subterranean formation. | 11-04-2010 |
20100283469 | METHODS FOR MAKING DIRECTIONAL RESISTIVITY MEASUREMENTS - One exemplary embodiment of a method for making directional resistivity measurements includes transmitting an axial electromagnetic wave in a borehole and receiving substantially pure axial and transverse components of the wave. A ratio of the axial and transverse components is computed and may be utilized as an indicator of various formation parameters. The invention advantageously enables the moment of the transmitting antenna to be canceled and therefore can result in improved accuracy. | 11-11-2010 |
20100283470 | COMPENSATED DIRECTIONAL RESISTIVITY MEASUREMENTS - A method for making directional resistivity measurements includes sequentially transmitting first and second axial and transverse electromagnetic waves in a borehole and receiving substantially pure axial and transverse components of each of the transmitted waves. A composite ratio of the received components is computed and may be utilized as an indicator of various formation parameters. The invention advantageously provides for the acquisition of compensated directional resistivity measurements. | 11-11-2010 |
20100308832 | Determining Correction Factors Representing Effects of Different Portions of a Lining Structure - To determine effect on a magnetic field caused by a lining structure in a wellbore, an array may be deployed into the wellbore lined with the lining structure. The array comprises a plurality of sensors including sensor A configured to operate as a transmitter, sensor B configured to operate as either a transmitter or a receiver, and sensor C configured to operate as a receiver. The array measures magnetic fields using sensor B as a receiver and sensor C in response to activation of sensor B as a transmitter and sensor A. A plurality of lining structure correction factors can be calculated based on the measured magnetic fields, based on the reciprocity of the sensors. | 12-09-2010 |
20100321022 | APPARATUS AND SYSTEM FOR WELL PLACEMENT AND RESERVOIR CHARACTERIZATION - A resistivity array having a modular design includes a transmitter module with at least one antenna, wherein the transmitter module has connectors on both ends adapted to connect with other downhole tools; and a receiver module with at least one antenna, wherein the transmitter module has connectors on both ends adapted to connect with other downhole tools; and wherein the transmitter module and the receiver module are spaced apart on a drill string and separated by at least one downhole tool. Each transmitter and receiver module may comprise at least one antenna coil with a magnetic moment orientation not limited to the tool longitudinal direction. A spacing between the transmitter and receiver module may be selected based on expected reservoir thickness. | 12-23-2010 |
20110068796 | FREQUENCY FILTERING AND ADJUSTMENT OF ELECTROMAGNETICALLY RECEIVED SIGNALS FROM ANTENNAS - An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus having: a carrier configured to be conveyed through the borehole; a transmitter disposed at the carrier and configured to transmit electromagnetic energy at a first frequency into the formation; a first antenna disposed at the carrier and configured to receive electromagnetic signals from the formation as a result of the transmitted electromagnetic energy interacting with the formation; and an active filter coupled to the antenna and configured to filter electromagnetic signals received by the antenna to let the electromagnetic signals at the first frequency pass for processing to estimate the property. | 03-24-2011 |
20110133740 | LOOK AHEAD LOGGING SYSTEM - A technique utilizes the acquisition of data from desired subterranean regions via a logging system. The logging system is constructed for use in a wellbore and comprises a transmitter module having a transmitter antenna. Additionally, the logging system utilizes a receiver module spaced from the transmitter module and having a receiver antenna. The transmitter antenna and the receiver antenna are oriented to enable sensitivity in desired directions, such as ahead of the logging system. | 06-09-2011 |
20110187373 | STEERABLE MAGNETIC DIPOLE ANTENNA FOR MEASUREMENT-WHILE-DRILLING APPLICATIONS - A steerable or non-steerable, magnetic dipole antenna for Measurement-While-Drilling (MWD) or Logging-While-Drilling (LWD) applications. The antenna elements use a hole arrangement in addition to grooves in a steel tool body, which is typically a drill collar. This antenna embodiment is extremely robust, meaning that does not significantly reduce the structural integrity of the tool body in which it is disposed. The antenna embodiment is also relatively wear resistant. The resultant magnetic dipole generated by this antenna is also electrically steerable in inclination angle from a common origin. A variable dipole moment inclination angle combined with independently measured tool rotation orientation during normal drilling allows the antenna to generate a magnetic dipole moment that may be directed at any three dimensional angle and from a common origin point at the centroid of the antenna. The antenna can also be embodied to be more sensitive to resitivity in a particular azimuthal direction. | 08-04-2011 |
20110210743 | PROVIDING MEASUREMENTS TO ENABLE DETERMINATION OF ELECTRICAL RESISTIVITY ANISOTROPY OF A SUBTERRANEAN STRUCTURE - 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. | 09-01-2011 |
20110221442 | TOROID GALVANIC AZIMUTHAL LWD TOOL - An apparatus and method for estimating a parameter of interest of an earth formation, particularly relating to borehole logging methods and apparatuses for estimating electrical resistivity properties using at least one transverse toroid. The apparatus may include one or more transmitters for introducing electrical current to the earth formation. The transverse toroid may detect responsive electric signals from the earth formation at one or more frequencies and provide data from one or more depths of investigation. Further multiple transverse toroids may be used for detecting electric signals from a larger azimuthal range than a single transverse toroid. The method includes steps for using the apparatus to obtain data that may be used to estimate the parameter of interest. | 09-15-2011 |
20110227577 | SINGLE WELL RESERVOIR IMAGING APPARATUS AND METHODS - An apparatus and related methods are described for detecting features of a reservoir surrounding a borehole, the apparatus being capable of emitting an electromagnetic wave signal and receiving a signal representing a response of the reservoir to the electromagnetic wave signal, wherein the emitted signal is a broadband signal selected from within the range of 1 Hz to 1000 Ghz and the received signal includes a directional characteristic to provide an azimuthal determination of the direction of a discontinuity within the formation as the discontinuity reflects or scatters at least part of the broadband signal; azimuthally scanning the surrounding formation; and inverting the received signal for deriving at least a distance of the reflecting discontinuity from the borehole using simultaneous inversion of the reflected or scattered wavefield at multiple frequencies. | 09-22-2011 |
20110248716 | CURRENT MEASUREMENT FOR WATER-BASED MUD GALVANIC ELECTRICAL IMAGING AND LATEROLOG TOOLS - An apparatus and method for estimating a resistivity property of an earth formation involving electric current injected into a wall of a borehole. The apparatus includes a first electrode, a second electrode, and a differential amplifier. The first electrode may be configured to impart an electric current into a borehole wall and be directly connected to a first input of the differential amplifier. The second electrode may be directly connected to a second input of the differential amplifier. The method may also include a summing circuit connected to the output of the differential amplifier. The method includes estimating a resistivity property using the output of the differential amplifier or the summing circuit. | 10-13-2011 |
20110291659 | Method and apparatus for measuring resistivity of formations - An apparatus for determining the resistivity of formation surrounding a borehole comprising:
| 12-01-2011 |
20110298461 | DEEP EVALUATION OF RESISTIVE ANOMALIES IN BOREHOLE ENVIRONMENTS - A drill string can include at least one transmit antenna and at least one receive antenna. The transmit antenna transmits at least one electromagnetic signal into a region of an earth formation. The receive antenna receives the signal from the region of the earth formation. The transmit antenna comprises one of a magnetic dipole and an electric dipole, and the receive antenna comprises the other of the magnetic dipole and the electric dipole. At least one characteristic of the region of the earth formation is determined, based at least partially on the signal received by the receive antenna. A homogenous part of the electromagnetic signal may be reduced, to thereby increase a depth of detection of the characteristic. | 12-08-2011 |
20110309833 | DETERMINING RESISTIVITY ANISTOTROPY AND FORMATION STRUCTURE FOR VERTICAL WELLBORE SECTIONS - Formation properties in a vertical section of a wellbore are determined by considering the vertical section as consisting of one or more segments. Measurements are obtained with a directional resistivity tool at two or more measurement stations within each segment for which the complex 0 | 12-22-2011 |
20120068712 | SYSTEM AND METHOD FOR USING A RESISTIVITY TOOL WITH WIRED DRILL PIPE AND ONE OR MORE WELLS - A resistivity tool is used with wired drill pipe and one or more wells. The resistivity tool has a transmitter, receiver modules located adjacent to the drill bit, and high sensitivity receiver modules located at greater distances from the drill bit relative to the receiver modules. The receiver modules and/or the high sensitivity receiver modules may also perform repeater functions for the wired drill pipe. The resistivity tool may provide information regarding a subsurface region of interest. The resistivity tool may be used in a system with sensors, and a distance between the sensors may be based on the type of measurement obtained by the sensors. | 03-22-2012 |
20120176138 | RELIABLE WIRED-PIPE DATA TRANSMISSION SYSTEM - A high-frequency data and/or power transmission system suitable for down-hole use including signal/power couplers, transmission line segments and signal repeaters. Signals and power are/is transmitted between couplers and/or between couplers and repeaters by means of electromagnetic resonance coupling. In at least a portion of the system, the transmission line segments form parallel data paths and the repeaters provide crossover capability between the data/power paths, thereby significantly improving reliability. The invention also includes methods of transmitting data and/or distributing high-frequency power through a downhole transmission system including multiple data/power paths and multiple crossovers wherein a fault location in one data/power path is bypassed by routing data and/or power to a parallel data/power path by means of electromagnetic resonance coupling. | 07-12-2012 |
20120217968 | Measurement Of Formation Parameters Using Rotating Directional Em Antenna - A logging tool and method to make subsurface measurements is disclosed, wherein the tool is placed within a borehole penetrating a formation. The tool has a transmitter antenna and a receiver antenna spaced apart along a longitudinal axis of the tool, and at least one of the transmitter or receiver antennas has a dipole moment that is non-coaxial with the longitudinal axis of the tool. The at least one non-coaxial antenna can rotate relative to the other antenna. Energy is transmitted from the transmitter antenna and a signal associated with the transmitted energy is measured at the receiver antenna while the at least one non-coaxial antenna rotates relative to the other antenna. | 08-30-2012 |
20120235686 | Non-Magnetic Transmitter Housing - A sonde assembly of the invention includes a sonde housing in the form of a nonmagnetic tube having windows therein for permitting a radio signal to be transmitted out the tube from the inside, means such as a device enclosing a front end of the tube, a sonde disposed inside the non-magnetic tube and closely fitting in a sonde cavity thereof in engagement with a front end plug. The sonde comprises a sensor and a transmitter connected to the sensor to transmit a directional signal based on sensor output, which sensor and transmitter are disposed inside a non-magnetic sonde cavity. | 09-20-2012 |
20120242342 | Correction of Deep Azimuthal Resistivity Measurements for Bending - A method and apparatus for estimating at least one parameter of interest in an earth formation using a signal from a receiver where a quadrature component of a signal at a plurality of frequencies is used to estimate a misalignment angle between the receiver and a transmitter. The apparatus may include at least one receiver, at least one transmitter, and at least one processor configured to excite the transmitter and estimate the misalignment angle. The method may include acquiring data at a plurality of frequencies, estimating a misalignment angle, and estimating at least one parameter of interest using the misalignment angle. The method may include performing multi-frequency focusing on the signal received at each of the plurality of frequencies. | 09-27-2012 |
20120256634 | ELECTRODE SYSTEM AND SENSOR FOR AN ELECTRICALLY ENHANCED UNDERGROUND PROCESS - An electrically stimulated electrode system comprises injection and return electrodes and a power supply for causing electrical current to flow through a subterranean formation. An electronic system for the injection electrode includes: a power harvester extracting electrical power from current flowing in the injection electrode, a control for the injection electrode current, a sensor of the injection electrode and/or formation, or a telemetry for the injection electrode and/or formation, or any combination thereof. A sensor comprises: a pair of spaced apart electrodes, a power conversion device connected to the spaced apart electrodes for providing electrical power, and a processor providing a representation of a current. The electronic system may include: a power harvester, a commandable and/or programmable current control; and a control system for commanding and/or programming the current control, whereby the current flowing in the injection electrodes may be independently controlled and/or sequenced in time. | 10-11-2012 |
20120268135 | Borehole to Surface Electromagnetic Transmitter - An electromagnetic energy transmitter is provided for borehole to surface electromagnetic (BSEM) surveying. The transmitter is lowered into a well borehole to a desired location in a well borehole to emit electromagnetic energy for the surveys. The transmitter affords more accurate measurements of its position in the well borehole. The transmitter also senses pressure and temperature conditions at its borehole location to provide indications of detected potential problems in the well from the survey or other sources, and to reduce risks and enhance safety and quality of the operations. | 10-25-2012 |
20120274329 | Imaging in Oil-Based Mud by Synchronizing Phases of Currents Injected Into a Formation - 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. A first transmitter electrode and a second transmitter electrode are disposed at the carrier and configured to inject an electrical current into the earth formation. A first measurement electrode and a second measurement electrode are disposed at the carrier and configured to measure the electrical current to estimate the property of the earth formation. A first bucker amplifier is coupled to the first measurement electrode and a second bucker amplifier is coupled to the second measurement electrode, wherein the first and second bucker amplifiers are configured to equalize electrical potentials of areas in front of the first and second measurement electrodes. | 11-01-2012 |
20120274330 | UNDERGROUND CAVITY DETECTION BY ELECTROMAGNETIC SHOCK WAVES - A method for detection of underground anomalies including in a system of distributed antennas ( | 11-01-2012 |
20120280690 | Method for Subsurface Electromagnetic Surveying Using Two or More Simultaneously Actuated Electromagnetic Sources - A method for electromagnetic exploration includes imparting a first electromagnetic signal into subsurface formations and imparting a second electromagnetic signal into the formations substantially contemporaneously with imparting the first electromagnetic signal. The first and second electromagnetic signals are substantially uncorrelated with each other. A combined electromagnetic response of the formations to the first and second imparted electromagnetic signals is detected. A response of the formations to each of the first and the second imparted signals is determined from the detected response. | 11-08-2012 |
20120286790 | Determining Formation Parameters Using Electromagnetic Coupling Components - A method and a downhole tool determine one or more parameters of a formation traversed by a borehole where at least a portion of the formation has substantially parallel boundaries. A tool is disposed in the borehole that includes a transmitter having a dipole moment at an angle θ | 11-15-2012 |
20120306500 | Antenna Coupling Component Measurement Tool Having a Rotating Antenna Configuration - Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy. | 12-06-2012 |
20130009646 | Electromagnetic Probe - A probe for measuring electromagnetic properties of a subsurface formation includes a pad having a face adapted for engagement with a borehole wall, a pair of transmitting antennas, and two pairs of receiving antennas. The transmitting antennas and receiving antennas are mounted in the face of the pad, and each of the two pairs of receiving antennas include a first and second antenna distributed on opposite sides of the pair of transmitting antennas. The probe further includes an electronic arrangement having a transmitter module and a receiver module. The transmitter module is arranged to operate the pair of transmitting antennas in either a broadside mode or an endfire mode by applying an excitation signal modulated by two or more frequencies, and the receiver module is arranged to determine an attenuation and a phase shift of each reception signal provided by each receiving antenna relatively to the excitation signal. | 01-10-2013 |
20130069654 | Method and System for Passive Electroseismic Surveying - A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation. | 03-21-2013 |
20130113490 | APPARATUS AND METHOD FOR DIRECTIONAL RESISTIVITY MEASUREMENT WHILE DRILLING USING INCOMPLETE CIRCULAR ANTENNA - An apparatus for making directional resistivity measurements of a subterranean formation includes a resistivity tool body with a longitudinal axis and an outer surface, a first antenna with two open ends deployed below the outer surface, a second antenna deployed below the outer surface and spaced at an axial distance from the first antenna, and at least one slot formed on the outer surface. A corresponding method for making directional resistivity measurements includes rotating a resistivity tool in a borehole, utilizing a transmitter-receiver antenna group formed in the resistivity tool to process an electromagnetic wave, and computing a resistivity-related measurement from the electromagnetic wave received on the receiver antenna. | 05-09-2013 |
20130119994 | APPARATUS, SYSTEM AND METHOD FOR ESTIMATING A PROPERTY OF A DOWNHOLE FLUID - An apparatus is disclosed for estimating a property of a downhole fluid, the apparatus including but not limited to a test cell that receives the downhole fluid; a swept frequency electromagnetic energy source that emits electromagnetic energy toward the downhole fluid in the test cell; an electromagnetic/mechanical device that is immersed in the fluid and receives the emitted electromagnetic energy, wherein the emitted electromagnetic energy being emitted is swept about a resonant frequency for the electromagnetic/mechanical device; and an electromagnetic energy detector in electromagnetic communication with the electromagnetic/mechanical device immersed in the fluid, the electromagnetic energy detector producing an output signal indicative of the downhole fluid property. A system and method for estimating a property of a downhole fluid are also disclosed. | 05-16-2013 |
20130141102 | OPTIMIZED ARRAYS FOR LOOK AHEAD-OF-BIT APPLICATIONS - Various embodiments include apparatus and methods of operation with respect to well logging. Apparatus and methods include a tool having an arrangement of transmitters and receivers to capture a signal from a first region relative to the tool such that signal contributions from a second region relative to the tool are cancelable, based on placement of the transmitters and receivers with respect to each other. Additional apparatus, systems, and methods are disclosed. | 06-06-2013 |
20130169278 | IMAGING AND SENSING OF SUBTERRANEAN RESERVOIRS - Various embodiments include apparatus and methods of sensing and/or mapping a subterranean reservoir. In various embodiments, arrangements of electromagnetic sensors are disposed relative to a subterranean reservoir such that a signal received by electromagnetic sensors of one arrangement, in response to activation of an electromagnetic transmitter, can be analyzed to map the subterranean reservoir. Additional apparatus, systems, and methods are disclosed. | 07-04-2013 |
20130169279 | HIGH RESOLUTION DOWNHOLE IMAGING - Apparatus having a focused transducer and methods of operating a focused transducer down-hole in a well can provide high resolution downhole imaging. In various embodiments, a focused transducer is used for imaging downhole in a well in which the imaging is based on a seismoelectric effect. In various embodiments, a focused transducer is used for imaging downhole in a well in which the imaging is based on an electroacoustic effect. Additional apparatus, systems, and methods are disclosed. | 07-04-2013 |
20130241560 | INDUCTION LOGGING SIGNALS AND ANTENNA SYSTEMS - An apparatus for estimating a property of an earth formation penetrated by a borehole includes: a carrier configured to be conveyed through the borehole; a transmitter antenna disposed at the carrier and configured to emit electromagnetic energy into the earth formation; a controller configured to control electrical current of frequency f transmitted to the transmitter antenna, wherein the transmitted electrical current is non-sinusoidal having a first section with a uniform positive slope and a second section with a uniform negative slope; a receiver antenna configured to receive a signal from the formation indicative of the property; and a processor configured to receive the signal from the receiver antenna and to estimate the property using the received signal. | 09-19-2013 |
20130241561 | INDUCTION LOGGING SIGNALS AND ANTENNA SYSTEMS - An apparatus for estimating a property of an earth formation penetrated by a borehole includes: a carrier configured to be conveyed through the borehole; a transmitter antenna disposed at the carrier and configured to emit electromagnetic energy; a direction guidance antenna configured to receive the electromagnetic energy from the transmitter antenna and direct the electromagnetic energy into the formation and to receive a signal from the formation indicative of the property; a receiver antenna configured to receive the signal from the direction guidance antenna; and a processor configured to receive the signal from the receiver antenna and to estimate the property using the received signal. | 09-19-2013 |
20130257435 | SYSTEM AND METHOD FOR MEASUREMENT INCORPORATING A CRYSTAL RESONATOR - A system, method and device for interrogating a downhole environment in a borehole beneath a surface includes a source of electromagnetic energy, operable to transmit an electromagnetic signal in the borehole, a sensor module, including a passive resonator having a resonant frequency that varies with changes in the condition in the downhole environment to reflect the electromagnetic signal and generates harmonic frequencies in response to a condition in the downhole environment in the borehole and a detector positionable to receive a returned electromagnetic signal. Embodiments include a filter to pass a harmonic of the resonant frequency of the resonating circuit and circuitry configured and arranged to measure the frequency of the harmonic signal. | 10-03-2013 |
20140035589 | DETECTION SYSTEM OF GEOLOGICAL FORMATIONS - A detection system of geological formations, particularly but not exclusively used for oil exploration, and for characterization and monitoring of hydrocarbon reservoirs. The detection system includes an electromagnetic transmission device positioned on a surface of a geological formation close to a first well having a vertical development direction, the first well being covered by a metal casing, and an electromagnetic reception device positioned deep inside the first well, the electromagnetic reception device including an electromagnetic detector. The electromagnetic transmission device includes a primary electromagnetic field generator configured to generate a primary electromagnetic field focalized in a direction of the metal casing, the metal casing irradiating the primary electromagnetic field into the geological formation. | 02-06-2014 |
20140035590 | DIELECTRIC TOOL-BASED FORMATION POROSITY LOGGING SYSTEM AND METHODS - A method and system for calculating formation porosity is presented. The method includes calculating formation porosity of a borehole by obtaining complex dielectric constant measurements with a high frequency dielectric tool. Next, a dielectric constant of formation water is derived from the complex dielectric constant measurements. Finally, a formation porosity is determined based at least in part on the measured complex dielectric constant and the derived dielectric constant formation water. | 02-06-2014 |
20140097848 | FIBEROPTIC SYSTEMS AND METHODS DETECTING EM SIGNALS VIA RESISTIVE HEATING - Fiberoptics can be employed to detect downhole electromagnetic signals via resistive heating. A disclosed electromagnetic energy detector embodiment includes an optically-interrogated temperature sensor; and a conductive element thermally coupled to the sensor, the conductive element having a temperature response to incident electromagnetic energy. The optically-interrogated temperature sensor may be a length or coil of optical fiber to which a distributed acoustic sensing (DAS) or distributed temperature sensing (DTS) system is attached. The conductive element may be a metal coating on the fiber that experiences resistive heating in response to electromagnetic energy and creates an optically-measurable thermal response in the sensor. | 04-10-2014 |
20140132271 | APPARATUS AND METHOD FOR DEEP RESISTIVITY MEASUREMENT USING COMMUNICATION SIGNALS NEAR DRILL BIT - An apparatus for utilizing a pre-existing telemetry transmitter near a drill bit for transmitting or receiving signals to make measurements of surrounding formation resistivity includes a drill collar, at least two toroidal receiving antennas deployed on the drill collar and spaced at an axial distance from each other for receiving or transmitting signals from or to the telemetry transmitter, at least two receiver modules coupled to the toroidal receiving antennas for processing signals received or to be transmitted from or to the telemetry transmitter and adjusting frequency the receiver modules work at, and a converting module coupled to the receiver modules. The converting module includes a microprocessor for calculating the surrounding formation resistivity and controlling the frequency tuners in the receiver modules. A corresponding method for utilizing a multiple dimensional conversion chart to convert data of measured flow-out current through the formation into data of formation resistivity is also provided. | 05-15-2014 |
20140203810 | INDUCED POLARIZATION LOGGING WITH BOREHOLE TO SURFACE ELECTROMAGNETIC TRANSMITTER - An electromagnetic energy transmitter is provided for induced polarization logging with a borehole to surface electromagnetic (BSEM) transmitter. The transmitter is lowered into a well borehole to a desired location in a well borehole to emit electromagnetic energy for the surveys. The transmitter affords more accurate measurements of its position in the well borehole. The transmitter also senses pressure and temperature conditions at its borehole location to provide indications of detected potential problems in the well from the survey or other sources, and to reduce risks and enhance safety and quality of the operations. | 07-24-2014 |
20140203811 | INDUCED POLARIZATION MAPPING WITH BOREHOLE TO SURFACE ELECTROMAGNETIC TRANSMITTER DATA - An electromagnetic energy transmitter is provided for induced polarization mapping with a borehole to surface electromagnetic (BSEM) transmitter. The transmitter is lowered into a well borehole to a desired location in a well borehole to emit electromagnetic energy. An array of receivers spaced over an area of the earth surface senses the induced polarization response to the emitted electromagnetic energy in areas of interest for mapping. Maps are formed of the induced polarization responses sensed by the array of receivers. | 07-24-2014 |
20140239959 | DOWNHOLE DETECTION - A system for use in downhole detection comprises a downhole arrangement defining a throughbore and a tool deployable through the throughbore of the downhole arrangement. The system further comprises a primary electromagnetic element provided on one of the downhole arrangement and the deployable tool and a secondary electromagnetic element provided on the other of the downhole arrangement and the deployable tool, wherein the primary and secondary electromagnetic elements are configurable for electromagnetic coupling therebetween. Such a system may be used for determining a status and/or an identity of a downhole tool in an oil or gas well from a determined degree of electromagnetic coupling between the primary and secondary electromagnetic elements. | 08-28-2014 |
20140253131 | Apparatus and Method for Directional Resistivity Measurement While Drilling Using Slot Antenna - An apparatus for making directional resistivity measurements of a subterranean formation includes a resistivity tool with a longitudinal axis and an outer surface, multiple slots formed on the outer surface of the resistivity tool and oriented substantially parallel to the longitude axis of the resistivity tool, and multiple wires posited in the slots and electrically connecting end walls of the slots to form magnetic dipole antennas. The mantic dipole antennas form at least one transmitter-receiver antenna group to perform transmission and reception of electromagnetic signals. A corresponding method for making directional resistivity measurements is also provided. | 09-11-2014 |
20140292340 | Antenna, Tool, and Methods for Directional Electromagnetic Well Logging - The present disclosure describes various antenna assemblies, each antenna coil being disposed about a tool body section in an antenna pathway. The antenna pathway passes through alternating grooves and lands. In each embodiment, at least one of the grooves is disposed in the tool body section at a non-axial direction relative to the longitudinal axis of the tool body section. In an embodiment, the antenna coil is an axial coil or a tilted coil. Additional grooves oriented at axial direction may be disposed on the tool body section. Each of the antenna assemblies disclosed may be employed in an electromagnetic logging tool for providing directional measurements while drilling. | 10-02-2014 |
20140347055 | SUPER-RESOLUTION FORMATION FLUID IMAGING WITH CONTRAST FLUIDS - Cross-well electromagnetic (EM) imaging is performed using high-power pulsed magnetic field sources, time-domain signal acquisition, low-noise magnetic field sensors, spatial oversampling and super-resolution image enhancement and injected contrast fluids. The contrast fluids increase the electromagnetic character of the formation and fluids, either the magnetic permeability or the dielectric permittivity. The acquired signals are processed and inter-well images are generated mapping electromagnetic (EM) signal speed (group velocity) rather than conductivity maps. EM velocity maps with improved resolution for both native and injected fluids are provided. | 11-27-2014 |
20140368200 | MODULAR RESISTIVITY SENSOR FOR DOWNHOLE MEASUREMENT WHILE DRILLING - A modular resistivity sensor disposable in a drillstring having a drill bit on a distal end for drilling a wellbore in a formation, includes a sensor body having a longitudinal axis radially offset from a longitudinal axis of the drillstring, one or more transmitting coil antennas disposed along a length of the sensor body, one or more receiving coil antennas disposed along a length of the sensor body, and a calibrating device configured to calibrate signals generated from the receiving coil antennas. | 12-18-2014 |
20150028874 | Apparatus and Method for At-Bit Resistivity Measurements By A Toroidal Transmitter - An apparatus for making formation resistivity measurements near a drill bit includes a tool body, a toroidal antenna deployed on the tool body near the drill bit, a coupler coupled to the toroidal antenna, a transmitter circuit coupled with the toroidal antenna via the coupler to provide voltage signals to energize the toroidal antenna, a receiver circuit coupled with the toroidal antenna via the coupler to couple electrical current signals flowing in the toroidal antenna to the receiver circuit, and a controller and processor module coupled to the transmitter circuit and the receiver circuit to control the measurement operation and calculate formation resistivity. Formation resistivity is computed based on the voltage signals to energize the toroidal antenna and the measured electrical current signals flowing in the toroidal antenna. A corresponding method for making formation resistivity measurements near a drill bit is also provided. | 01-29-2015 |
20150035535 | Apparatus and Method for At-Bit Resistivity Measurements - An apparatus for making resistivity measurements near a drill bit includes a tool body, a transmitter deployed on the tool body, a receiver deployed on the tool body and at an axial distance from the transmitter, and a transmitting signal coupler coupled to the transmitter antenna and the receiver. The transmitter generates electrical signals and converts the electrical signals into electromagnetic signals to be transmitted. The receiver measures the amplitudes and phases of the electromagnetic signals received from the transmitter. The transmitting signal coupler couples a portion of the electrical signals from the transmitter antenna and measures the amplitudes and phases of the coupled electrical signals. Amplitude attenuation and phase shift between the electromagnetic signals received at the receiver and the electrical signals coupled at the transmitting signal coupler are computed for calculating resistivity. | 02-05-2015 |
20150123665 | METHOD AND SYSTEM FOR DIRECT SLOWNESS DETERMINATION OF DISPERSIVE WAVES IN A WELLBORE ENVIRONMENT - A system and method for effective estimation of properties of a formation using acoustic array processing is disclosed. An acoustic tool is directed to a zone of interest in the formation and generates a first signal. Real data corresponding to the first signal is then received. One or more basic parameters are provided as input. The basic parameters may include parameters relating to the acoustic tool or parameters relating to the zone of interest. A time semblance shear slowness and a frequency semblance shear slowness are determined using the basic parameters. A mask is then selected using the determined time semblance and frequency semblance shear slowness values and used to isolate a dispersion curve. A shear slowness value is selected from the dispersion curve and quality control is performed on the selected shear slowness value. | 05-07-2015 |
20150145519 | INDUCTION TYPE BROADBAND 3-COMPONENT BOREHOLE MAGNETIC MEASURING SENSOR AND BOREHOLE ELECTROMAGNETIC TOMOGRAPHY METHOD USING THE SAME - Borehole electromagnetic exploration or tomography (EM tomography). An induction type broadband 3-component borehole magnetic measuring sensor can accurately and precisely measure a broadband magnetic field about x, y and z axes using a three-dimensional (3D) model within a borehole by monitoring natural variations in the earth's magnetic field or based on EM tomography using the borehole. The measuring sensor is applicable to energy resource fields such as petroleum and coal, mineral resources fields and civil engineering and environmental fields. | 05-28-2015 |
20150301222 | Inversion-based calibration of downhole electromagnetic tools - An inversion based calibration method for downhole electromagnetic tools includes processing an inversion of a formation model using acquired electromagnetic measurement data to obtain formation parameters and calibration parameters for at least one measurement array. | 10-22-2015 |
20150330216 | USE OF A FRACTAL ANTENNA IN ARRAY DIELECTRIC LOGGING - An apparatus for estimating a property of an earth formation includes: a carrier configured to be conveyed through a borehole penetrating an earth formation; a first fractal-shaped antenna element disposed on the carrier and configured to at least one of transmit electromagnetic energy into the formation and receive electromagnetic energy from the formation; and a second fractal-shaped antenna element electrically connected to the first fractal-shaped antenna element at a connection and configured to at least one of transmit electromagnetic energy into the formation and receive electromagnetic energy from the formation; wherein the second fractal-shaped antenna element is substantially a mirror image of the first fractal antenna element with respect to a reflection about the connection. | 11-19-2015 |
20150338541 | Electromagnetic Assessment of Multiple Conductive Tubulars - Systems, apparatuses, and methods for measuring material thickness of multiple tubulars by placing a logging tool in a well with multiple conductive tubulars and generating an electromagnetic field that interacts with the tubulars. A logging tool obtains the measurements using one or more receivers. A monitoring system or the logging tool applies the measurements to a mathematical model that considers at least a transition zone and one or both of a near field zone and a remote field zone of the electromagnetic field that interacts with the multiple conductive tubulars. Furthermore, the monitoring system or the logging tool may ascertain a thickness of the one or more conductive tubulars using the mathematical model. | 11-26-2015 |
20150346376 | TIME-LAPSE TIME-DOMAIN REFLECTOMETRY FOR TUBING AND FORMATION MONITORING - A system and method for monitoring a wellbore are disclosed herein. A pulse generator comprises a plurality of ports, wherein a first one of the plurality of ports is coupled to a first location of interest and a second one of the plurality of ports is coupled to a second location of interest. An electromagnetic pulse is generated at the first port and the second port. A reflected electromagnetic pulse is received at the first port and the second port. In another embodiment, the pulses are received at a separate pulse receiver with a plurality of receiving ports. A data storage device is coupled to the pulse generator or the pulse receiver, and data relating to the reflected magnetic pulse is stored at the data storage device. | 12-03-2015 |
20150369948 | DISTRIBUTED SURVEY SYSTEM FOR OBTAINING UNDERGROUND ELECTRICAL CHARACTERISTICS AND DISTRIBUTED SURVEY METHOD USING SAME - There are provided a distributed survey system for obtaining underground electrical characteristics and a distributed survey method using the same which can be flexibly compatible with the survey purposes, the geographical conditions of the survey region, etc. and which can obtain the underground electrical characteristics more efficiently in a shorter time. In the invention, survey units (1, 2, 3, . . . (N−1), N) are distributed across a region in which underground electrical characteristics are to be obtained. Each survey unit includes at least one current supply point TX and a current supply device for supplying a current underground from the relevant current supply point TX; and/or at least one measurement point RX and measurement device for measuring a response signal in response to the current supply from each measurement point RX, and synchronization control device which is disposed in each of the survey units for exerting control to supply currents with waveforms encoded so as to yield covariances of zero from the current supply points, and controlling the measurement device to measure the response signals in response to the relevant current supply, while synchronizing operation of the current supply means with operation of the measurement device. | 12-24-2015 |
20150369949 | Multi-Electrode Electric Field Downhole Logging Tool - A device can include a housing; external electrodes; circuitry disposed in the housing where the circuitry converts analog signals sensed by the external electrodes to digital signals. Various other apparatuses, systems, methods, etc., are also disclosed. | 12-24-2015 |
20160041294 | WELL RANGING APPARATUS, METHODS, AND SYSTEMS - Disclosed embodiments include well ranging apparatus, systems, and methods which operate to detect and determine a relative distance and/or azimuthal direction of nearby target well conductors such as pipes, well casing, etc., from within a borehole of a drilling well. | 02-11-2016 |
20160090835 | MULTI-MODE MEASUREMENTS WITH A DOWNHOLE TOOL USING CONFORMABLE SENSORS - An example downhole tool may include a tool body and a first conformable sensor coupled to the tool body. The first conformation sensor may include a flexible material, a transmitter coupled to the flexible material, and a plurality of receivers coupled to the flexible material. The downhole tool may further include a control unit with a processor and a memory device coupled to the processor, the memory device containing a set of instructions that, when executed by the processor, cause the processor to output control signals to a first combination of the plurality of receivers corresponding to a first operating mode; and output control signals to a second combination of the plurality of receivers corresponding to a second operating mode. | 03-31-2016 |
20160109611 | Antenna Of An Electromagnetic Probe For Investigating Geological Formations - An antenna | 04-21-2016 |
20160116627 | Compensated Deep Measurements Using A Tilted Antenna - A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes first and second transmitters, each of which includes a tilted antenna, and a receiver axially spaced apart from one another. Electromagnetic voltage measurements are made at the receiver while the tilted transmitting antenna in the first transmitter fires during tool rotation. The electromagnetic voltage measurements are mathematically rotated through at least the arbitrary angle to obtain rotated measurements, selected ratios of which are processing to compute gain compensated measurement quantities. | 04-28-2016 |
20160116628 | GAIN COMPENSATED SYMMETRIZED AND ANTI-SYMMETRIZED ANGLES - A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes a plurality of transmitter antennas and a plurality of receiver antennas symmetrically spaced along a logging while drilling tool body, the plurality of transmitter antennas including at least one axial transmitter antenna and at least one transverse transmitter antenna. The plurality of receiver antennas includes at least one axial receiver antenna and at least one transverse receiver antenna. The receiver antennas are used to acquire electromagnetic voltage measurements while rotating. The voltage measurements are processed to compute harmonic voltage coefficients, selected ratios of which are processed to compute gain compensated symmetrized and anti-symmetrized quantities and angles. These quantities may optionally be further processed to compute rotated gain compensated symmetrized and anti-symmetrized quantities. | 04-28-2016 |
20160124106 | APPARATUS AND METHOD FOR SIMULTANEOUSLY OBTAINING QUANTITATIVE MEASUREMENTS OF FORMATION RESISTIVITY AND PERMITTIVITY IN BOTH WATER AND OIL BASED MUD - An apparatus and method for simultaneously obtaining quantitative measurements of vertical and horizontal resistivity and permittivity formation parameters by firing, using at least one transmitter in each of a horizontally and vertically polarized array on opposite sides of a drill collar, signals in the direction of a downhole formation, the fired signals from the transmitters in the arrays being fired simultaneously and engaging the downhole formation. The apparatus and method continues by receiving, using at least one receiver in each of the arrays, signals associated with the fired signals after the fired signals have engaged the downhole formation, where the received signals represent apparent formation data. The apparatus and method further involves determining, using the measured apparent formation data, the true formation data including one or more vertical and horizontal formation parameters. | 05-05-2016 |
20160146967 | Compensated Deep Propagation Measurements with Differential Rotation - A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes a first transmitter and a first receiver deployed on a first sub and a second transmitter and a second receiver deployed on a second sub. Rotating the logging tool causes the first and second subs to rotate at different rates. A plurality of electromagnetic voltage measurements are acquired from the first and second receivers while rotating. The acquired voltage measurements are processed to compute harmonic coefficients which are mathematically rotated to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute gain compensated measurement quantities. | 05-26-2016 |
20160170069 | Systems and Methods for Determining Dielectric Constant or Resistivity from Electromagnetic Propagation Measurement Using Contraction Mapping | 06-16-2016 |
20160187521 | Multi-Frequency Electromagnetic Tensor Measurements - An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample. | 06-30-2016 |
20160194948 | DOWNHOLE MULTI-PIPE SCALE AND CORROSION DETECTION USING CONFORMABLE SENSORS | 07-07-2016 |
20160195634 | Full Tensor Gain Compensated Propagation Measurements | 07-07-2016 |
20160195635 | DOWNHOLE INSPECTION, DETECTION, AND IMAGING USING CONFORMABLE SENSORS | 07-07-2016 |
20160202381 | DOWNHOLE MEASUREMENT AND SURVEY TOOLS WITH CONFORMABLE SENSORS | 07-14-2016 |
20160252643 | Method and Apparatus for Determining Formation Properties Using Non-Directional Electromagnetic Measurements in High Angle or Horizontal Wells | 09-01-2016 |
20180024266 | Modular Resistivity Sensor for Downhole Measurement While Drilling | 01-25-2018 |