Patent application number | Description | Published |
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 |
20080258733 | 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. | 10-23-2008 |
20080278169 | Electromagnetic Wave Resistivity Tool Having a Tilted Antenna for Determining the Horizontal and Vertical Resistivities and Relative Dip Angle in Anisotropic Earth Formations - 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. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications. | 11-13-2008 |
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 |
20090015260 | ANTENNA CUTOUT IN A DOWNHOLE TUBULAR - In some embodiments, an apparatus ( | 01-15-2009 |
20090278543 | Systems and Methods Having Radially Offset Antennas for Electromagnetic Resistivity Logging - Disclosed herein are electromagnetic resistivity logging systems and methods that employ magnetic dipole antennas embedded in wall-contacting surfaces. In some embodiments, the antennas are pot-core or ferrite-rod antennas. Prototypes of electromagnetic resistivity logging tools having such antennas exhibit good resistivity logging performance in both water-based and oil-based borehole fluids, indicating that this architecture may yield a logging tool that is suitable for use with borehole fluids of all types. Moreover, the tool offers good spatial resolution, enabling the creation of formation resistivity images for the borehole walls. | 11-12-2009 |
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 |
20090309798 | Method and Apparatus for Building a Tilted Antenna - Logging tools having protected tilted antennas are disclosed, along with construction methods therefor. In one method embodiment, a tilted antenna on a retrievable segment of a downhole tool is constructed by: forming an elliptical recess on the segment; forming an antenna within the elliptical recess; and forming an elliptical pattern of windows over and perpendicular to the axis of the elliptical antenna. Some tool embodiments comprise a retrievable segment of a downhole tool having an elliptical recess; an elliptical antenna disposed within the elliptical recess; and an elliptical pattern of windows formed over and perpendicular to the plane of the elliptical antenna. | 12-17-2009 |
20100117655 | Tool for Azimuthal Resistivity Measurement and Bed Boundary Detection - Systems and methods for performing bed boundary detection and azimuthal resistivity logging with a single tool are disclosed. Some method embodiments include logging a borehole with an azimuthally-sensitive resistivity logging tool; deriving both a resistivity log and a boundary detection signal from measurements provided by said tool; and displaying at least one of the boundary detection signal and the resistivity log. The resistivity log measurements may be compensated logs, i.e., logs derived from measurements by one or more symmetric transmitter-receiver arrangements. Though symmetric arrangements can also serve as the basis for the boundary detection signal, a greater depth of investigation can be obtained with an asymmetric arrangement. Hence the boundary detection signal may be uncompensated. | 05-13-2010 |
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 |
20100127708 | Resistivity Logging with Reduced Dip Artifacts - Systems and methods are disclosed for reducing boundary-related artifacts in logs taken from resistivity logging tools. Such tools often exhibit “horns” at boundaries between formation beds having different resistivities. A boundary indicator signal serves to identify the location of these boundaries. When derived from an azimuthally-sensitive resistivity tool, the bed boundary indicator may have a magnitude and shape that serves to nearly eliminate the horns even in high-dip angle environments. Logs that are processed to eliminate these artifacts are expected to be more accurate and thus easier to interpret. | 05-27-2010 |
20100156424 | Robust Inversion Systems and Methods for Azimuthally Sensitive Resistivity Logging Tools - Methods and systems for determining the horizontal resistivity, vertical resistivity, and relative dip angle of anisotropic earth formations. Some of the disclosed methods and systems measure sinusoidal variation of azimuthally sensitive resistivity logging tool measurements, determine parameters representative of the sinusoidal variation, and perform inversion based on the sinusoidal parameters. When cast in this manner, the inversion process may yield more accurate and consistent resistivity and dip angle estimates. The sinusoidal parameters preferably take the form of average and peak-to-peak measurements, but may also take other forms. Moreover, use of such sinusoidal parameters enables a condensed representation of the resistivity logging tool measurements, enabling significantly more efficient communication and storage of these measurements. The condensed representations continue to enable directional boundary detection and geosteering. | 06-24-2010 |
20100176812 | LOOK-AHEAD BOUNDARY DETECTION AND DISTANCE MEASUREMENT - Systems and methods for look-ahead boundary detection and distance estimation are disclosed. In some embodiments, a drilling method includes extending a borehole with a drill string that includes a resistivity logging tool. The logging tool makes upward-looking and downward-looking resistivity measurements based on radial current flow. The upward looking and downward looking resistivity measurements are processed to estimate the distance to approaching bed boundaries, and drilling can be halted when the estimated distance reaches a desired value. Such information can be used to anchor casing at advantageous points and can further be used to avoid penetrating water-containing formations below a hydrocarbon reservoir. | 07-15-2010 |
20100262370 | Data Transmission Systems and Methods for Azimuthally Sensitive Tools with Multiple Depths of Investigation - Disclosed herein are various telemetry systems and methods suitable for communicating a cylindrical volume of formation property measurements to the surface. Some system embodiments include a downhole processor coupled to a telemetry transmitter. The downhole processor determines a compressed representation of the formation property measurements and/or selects a subset of the measurements for transmission uphole. The subset selection can be based on selected radial distances having characteristics that potentially indicate features of interest to a user. Such features include bed boundaries, and the characteristics include sinusoidal variation as a function of azimuth, large changes in this sinusoidal variation versus radial distance, or inversion suggesting the presence of a bed boundary. Various compressed representations of the cylindrical data volume are disclosed, including representations based on parameters of a sinusoidal model, representations based on a two dimensional transform, and representations based on estimates of distance and direction to a bed boundary. | 10-14-2010 |
20100284250 | ACOUSTIC STEERING FOR BOREHOLE PLACEMENT - Apparatus ( | 11-11-2010 |
20110006773 | EM-Guided Drilling Relative to an Existing Borehole - Parallel drilling systems and methods suitable for drilling wells for steam-assisted gravity drainage (SAGD). In some method embodiments, a tilted-antenna tool gathers azimuthally-sensitive electromagnetic signal measurements. Such measurements enable accurate measurement of inter-well distance and direction, thereby providing the necessary information for drilling accurately-spaced wells having reduced vulnerability to “short-circuits” that inhibit effective reservoir exploitation. In some other method embodiments, a tilted-antenna tool transmits azimuthally non-uniform signals as it rotates. The attenuation and azimuthal variation detected by one or more receivers enables accurate direction and distance determination. The transmitter and receiver antennas can in some cases be combined into a single tool, while in other cases the transmitters and receivers are placed in separate wells to increase detection range. | 01-13-2011 |
20110175899 | SYSTEMS AND METHODS FOR DISPLAYING LOGGING DATA - Borehole data presentation systems and methods that facilitate communication of volumetric logging data to a surface processing system for presentation to a driller or other user interested in visualizing the formations surrounding a borehole. The disclosed systems optionally tailor the telemetry stream to match the chosen display technique, thereby maximizing the logging system utility for the driller. Variable opacity of certain data regions or certain data discontinuities greatly facilitates data comprehension, particularly when true three-dimensional display technologies are employed. Holographic or stereoscopic display technologies may be employed to show the three-dimensional dependence of measured formation properties such as resistivity, density, and porosity. Alternatively, the radial axis can be used to represent a formation parameter value, thereby enabling cylindrical cross-plots of multiple measurements. The user can control viewing position and orientation to more fully explore the three dimensional representation. | 07-21-2011 |
20110180327 | Mulitmodal Geosteering Systems and Methods - Multimodal geosteering systems and methods are disclosed. Some disclosed tool embodiments include first and second transmitter-receiver arrangements that make geosteering measurements using different forms of energy (such as acoustic and electromagnetic energy) to provide geosteering measurements that at least indicate a boundary direction but may also indicate a boundary distance. Some disclosed method embodiments include: determining a direction to a bed boundary using measurements with different energy types; and adjusting a drilling direction based at least in part on said determination. Combinations of (or selections between) the different measurements may be made based on, inter alia, measurement range, resolution, and contrast. Some disclosed system embodiments include a memory and a processor. The memory stores geosteering display software that configures the processor to generate an image with different regions based on the different types of geosteering measurements. Characteristics such as opacity, resolution, and intensity may visually distinguish the different regions. | 07-28-2011 |
20110199088 | Electromagnetic Wave Resistivity Tool Having A Tilted Antenna For Determining The Horizontal And Vertical Resistivities And Relative Dip Angle In Anisotropic Earth Formations - 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. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications. | 08-18-2011 |
20110204897 | Method and Apparatus with High Resolution Electrode Configuration for Imaging in Oil-Based Muds - Various disclosed resistivity imaging tools and methods provide a high-resolution electrode configuration for imaging in oil-based imaging in oil-based muds. Some tool embodiments have a sensing surface that comprises: a measurement electrode, a focus electrode surrounding the measurement electrode, and a return electrode surrounding the focus electrode. The sensing surface can be provided on an extendable sensor pad or on the wall-contacting portion of a stabilizer. Some method embodiments include measuring the measurement electrode current while driving a voltage signal between the measurement electrode and the return electrode. The voltage signal may simultaneously or sequentially provide energy at different frequencies. The resistivity measurements are combined with tool position and orientation measurements to form a borehole wall image. Robust and reliable performance is expected in the hostile conditions often experienced by logging while drilling (LWD) tools, coupled with the ability to make micro-resistivity measurements with a resolution approaching that of electrode-grid tool designs. | 08-25-2011 |
20110221443 | High Frequency Dielectric Measurement Tool - Disclosed dielectric logging tools and methods employ three or more receive horn antennas positioned between at least two transmit antennas, which can also be horn antennas. The logging tools can operate in the range between 100 MHz and 10 GHz to provide logs of formation permittivity, formation conductivity, standoff distance, and electrical properties of material in the standoff gap. Logs of water-saturated porosity and/or oil movability can be readily derived. The presence of additional receive antennas offers a significantly extended operating range, additional depths of investigation, increased measurement accuracy, and further offers compensation for tool standoff and mudcake effects. In both wireline and logging while drilling embodiments, at least some disclosed dielectric logging tools employ a set of three axially-spaced receive antennas positioned between pairs of axially-spaced transmit antennas. At least some disclosed methods employ absolute amplitude and phase measurements in response to alternate firings of the transmit antennas. | 09-15-2011 |
20110234230 | Azimuthal At-Bit Resistivity and Geosteering Methods and Systems - Logging tools and methods employing an at-bit loop antenna to acquire azimuthal resistivity measurements proximate to the bit enable low-latency geosteering signals to be generated. In some embodiments, the at-bit antenna is part of a bottom hole assembly that includes a drill bit, a mud motor, and a resistivity tool. The mud motor is positioned between the at-bit antenna and the resistivity tool. The resistivity tool includes at least one loop antenna that is not parallel to the at-bit loop antenna. The at-bit antenna is part of an at-bit module that, in some embodiments, transmits periodic electromagnetic signal pulses for the resistivity tool to measure. In other embodiments, the at-bit module measures characteristics of electromagnetic signal pulses sent by the resistivity tool and communicates the measured characteristics to the resistivity tool via a short hop telemetry link. | 09-29-2011 |
20110251794 | 3D Borehole Imager - Logging tools and methods for obtaining a three-dimensional (3D) image of the region around a borehole. In at least some embodiments, a 3D imaging tool rotates, transmitting pulses that are approximately a nanosecond long and measuring the time it takes to receive reflections of these pulses. Multiple receivers are employed to provide accurate triangulation of the reflectors. In some cases, multiple transmitters are employed to obtain compensated measurements, i.e., measurements that compensate for variations in the receiver electronics. Because reflections occur at boundaries between materials having different dielectric constants, the 3D imaging tool can map out such boundaries in the neighborhood of the borehole. Such boundaries can include: the borehole wall itself, boundaries between different formation materials, faults or other discontinuities in a formation, and boundaries between fluids in a formation. Depending on various factors, the size of the borehole neighborhood mapped out can be as large as 1 meter. | 10-13-2011 |
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 |
20110308794 | Real Time Determination of Casing Location and Distance with Tilted Antenna Measurement - Methods and apparatus for detecting nearby conductors such as pipes, well casing, etc., from within a borehole. A nearby casing string can be detected by transmitting an electromagnetic signal from a first antenna on a downhole logging tool and measuring a response signal with a second antenna. As the tool rotates, the transmitting and measuring are repeated to determine the azimuthal dependence of the response signal. The azimuthal dependence is analyzed to determine an diagonal component and a cross component. The amplitude of the diagonal component is indicative of distance to the conductive feature. Direction can be determined based on the diagonal component alone or in combination with the cross component. Sinusoidal curve fitting can be employed to improve accuracy of the distance and direction estimates. At least one of the antennas is preferably tilted. Measurement results are presented for parallel tilted and perpendicular tilted antennas. | 12-22-2011 |
20110308859 | System and Method for EM Ranging in Oil-Based Mud - Nearby conductors such as pipes, well casing, etc., are detectable from within a borehole filled with an oil-based fluid. At least some method embodiments provide a current flow between axially-spaced conductive bridges on a drillstring. The current flow disperses into the surrounding formation and causes a secondary current flow in the nearby conductor. The magnetic field from the secondary current flow can be detected using one or more azimuthally-sensitive antennas. Direction and distance estimates are obtainable from the azimuthally-sensitive measurements, and can be used as the basis for steering the drillstring relative to the distant conductor. Possible techniques for providing current flow in the drillstring include imposing a voltage across an insulated gap or using a toroid around the drillstring to induce the current flow. | 12-22-2011 |
20110309836 | Method and Apparatus for Detecting Deep Conductive Pipe - Downhole tools and techniques acquire information regarding nearby conductors such as pipes, well casing, and conductive formations. At least some method embodiments provide a current flow along a drill string in a borehole. The current flow disperses into the surrounding formation and causes a secondary current flow in the nearby conductor. The magnetic field from the secondary current flow can be detected using one or more azimuthally-sensitive antennas. Direction and distance estimates may be obtainable from the azimuthally-sensitive measurements, and can be used as the basis for steering the drillstring relative to the distant conductor. Possible techniques for providing current flow in the drillstring include imposing a voltage across an insulated gap or using a toroid around the drillstring to induce the current flow. | 12-22-2011 |
20120001637 | CORRECTING FOR MAGNETIC INTERFERENCE IN AZIMUTHAL TOOL MEASUREMENTS - Methods and systems that compensate for magnetic interference in azimuthal tool measurements. At least some method embodiments include a downhole logging method that includes taking measurements as a function of orientation from inside a borehole. The measurements are associated with different azimuthal bins, and an azimuthal direction is determined for each azimuthal bin. Because the tool rotates at a constant rate, the relative number of measurements associated which the different bins can be used to measure the effective sizes of the different bins and to redetermine the effective angles of the bins in the presence of magnetic interference. The tool measurements may include, but are not limited to, formation resistivity, magnetic field, and formation density. | 01-05-2012 |
20120024600 | Method and Apparatus for Resistivity Measurements - An apparatus for measuring a resistivity of a formation comprising an instrumented bit assembly coupled to a bottom end of the apparatus. At least one first electromagnetic wave antenna transmits an electromagnetic wave signal into the formation. At least one second electromagnetic wave antenna located on the instrumented bit assembly and longitudinally spaced apart from the at least one first electromagnetic wave antenna receives the electromagnetic wave signal transmitted through the formation. Electronic circuitry is operably coupled to the at least one second electromagnetic wave antenna to process the received signal to determine a resistivity of the formation proximate the instrumented bit assembly. | 02-02-2012 |
20120133367 | Fracture Characterization Using Directional Electromagnetic Resistivity Measurements - A disclosed fracture characterization method includes: collecting three-dimensional resistivity measurements of a volume surrounding an open borehole; analyzing the measurements to determine parameters describing fractures in the volume; and providing a report to a user based at least in part on said parameters. A fluid with a contrasting resistivity is employed to make the fractures detectable by a directional electromagnetic logging tool in the borehole. illustrative parameters include fracture direction, height, extent, length, and thickness. The resistivity measurements can be augmented using a borehole wall image logging tool. Also disclosed are fracturing methods that include: positioning a directional electromagnetic logging tool proximate to a formation; fracturing the formation; monitoring fracture progression with said tool; and halting the fracturing when measurements by said tool indicate that a predetermined set of criteria have been satisfied. | 05-31-2012 |
20120186873 | WELL DRILLING METHOD UTILIZING REAL TIME RESPONSE TO AHEAD OF BIT MEASUREMENTS - A well drilling method utilizing real time response to ahead of bit measurements. A well drilling method includes measuring a property of a portion of the earth prior to drilling a wellbore into the earth portion; and varying a drilling parameter in real time while drilling the wellbore, in response to measuring the property. | 07-26-2012 |
20120199394 | PROCESSING AND GEOSTEERING WITH A ROTATING TOOL - Various embodiments include apparatus and methods of processing and geosteering with respect to well logging. Apparatus and methods may include acquiring signals generated from operating a tool rotating in a borehole of a well, where the tool includes a receiver antenna tilted with respect to the longitudinal axis of the tool and two transmitter antennas. The acquired signals can be processed with respect to a direction in the rotation of the tool to determine properties associated with a formation and/or to determine a geosignal for geosteering a drilling operation. | 08-09-2012 |
20120234605 | APPARATUS AND METHODS OF LOCATING DOWNHOLE ANOMALIES - Various embodiments include apparatus and methods of determining the characteristics of geological formations in a well. One or more transmitters and receivers electrically imitate a moving antenna. The moving antenna produces a distribution of frequencies by utilizing the Doppler effect. Each anomaly in the well produces reflections with different frequency, amplitude and phase information. In various embodiments, location and characteristics of multiple anomalies can be identified simultaneously in a well. | 09-20-2012 |
20120249149 | 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. | 10-04-2012 |
20120283952 | REAL-TIME CASING DETECTION USING TILTED AND CROSSED ANTENNA MEASUREMENT - Methods and apparatus for detecting nearby conductors such as pipes, well casing, etc., from within a borehole. A nearby casing string can be detected by transmitting an electromagnetic signal from a transmit antenna on a downhole logging tool and measuring a parallel response signal with a first receive antenna parallel to the transmit antenna and a perpendicular response signal with a second receive antenna perpendicular to the transmit antenna, both receive antennas on the downhole logging tool. As the tool rotates, the transmitting and measuring are repeated to determine the azimuthal dependence of the parallel and perpendicular response signals. The azimuthal dependence is analyzed to determine a diagonal component of said azimuthal dependence for each response signal. Distance to a casing string can be estimated using the diagonal component of each response signal. At least one of the antennas is preferably tilted. | 11-08-2012 |
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 |
20120326825 | INDUCTIVE DOWNHOLE TOOL HAVING MULTILAYER TRANSMITTER AND RECEIVER AND RELATED METHODS - A downhole tool including a transmitter coil assembly and a receiver coil assembly. The coil assembly includes at least one first coil having a first support member with a first single layer of wire wound therearound. The coil assembly further includes at least one second coil. The second coil includes a second support member having a second single layer of wire wound therearound. The first support member is disposed within the second support member, and the first single layer spaced apart from the second single wire by a distance of D. | 12-27-2012 |
20130046474 | Efficient Inversion Systems and Methods for Directionally-Sensitive Resistivity Logging Tools - Various resistivity logging tools, systems, and methods are disclosed. At least some tool embodiments include transmit and receive antennas that measure the electromagnetic response of the formation, at least one of which is tilted to provide a directional sensitivity. A processor converts the response (measured as a function of the tool's rotation angle) into a set of inversion parameters, which are then used to estimate the anisotropic properties of the formation. The set of inversion parameters includes at least one parameter based on an antipodal sum of the response signal, and may further include parameters based on an antipodal difference and an average of the signal response. Antipodal sum and difference values at different rotational orientations can be included in the set of inversion parameters, and they may be normalized to reduce environmental effects. Some tool embodiments collect the relevant formation measurements using parallel or perpendicular tilted antennas. | 02-21-2013 |
20130054145 | Apparatus and Methods of Determining Formation Resistivity - In various embodiments, apparatus and methods are provided to determine formation resistivity associated with a well. Measurements taken using sub-arrays of a tool at different distances of investigation can be used to determine formation resistivity, where the sub-arrays are arranged to make azimuthal related measurements. Separations readings related to resistivity can be generated from signals received from different directions and can be analyzed to characterize validity of a measurement reading. Additional apparatus, systems, and methods are disclosed. | 02-28-2013 |
20130088364 | METHOD AND APPARATUS FOR MAKING RESISTIVITY MEASUREMENTS IN A WELLBORE - During drilling of an earth borehole, resistance measurements may be made at the drill bit through use of a bottom hole assembly that includes a drill bit having a sensor, such as an electrode, located generally at an exterior surface of the drill bit. The current will be induced in the formation from multiple transmitters, at least one of which will be supported on, or very close to the drill bit. Connection mechanisms are described that enable the releasable engagement of electrical conductors to circuitry within the drill bits. The obtained resistivity measurements at the drill bit can be used for many purposes, including formation imaging and geosteering of the drilling operation. | 04-11-2013 |
20130099808 | FLUID RESISTIVITY SENSOR - Various embodiments include apparatus and methods of determining resistivity of fluids downhole in a well. The apparatus and methods may include using a sensor that employs a focused electric dipole as a transmitter and a uses a receiver to detect the electric current strength in the fluid under measurement responsive to the transmitter. Additional apparatus, systems, and methods are disclosed. | 04-25-2013 |
20130105224 | Method and Apparatus For Sensing Elongated Subterranean Anomalies | 05-02-2013 |
20130113487 | INSTRUMENTED CORE BARRELS AND METHODS OF MONITORING A CORE WHILE THE CORE IS BEING CUT - A formation core analysis system can include an inner barrel and a toroidal electromagnetic antenna which transmits electromagnetic signals into a formation core when the core is received in the inner barrel. Another formation core analysis system can include an inner barrel and multiple longitudinally spaced apart electrodes which electrically contact a formation core when the core is received in the inner barrel. A speed of displacement of the core into the inner barrel may be indicated by differences between measurements taken via the electrodes as the core displaces into the inner barrel. A method of measuring resistivity of a formation core as the core is being cut can include transmitting electromagnetic signals into the core from a toroidal electromagnetic antenna as the core is being cut by a coring bit. | 05-09-2013 |
20130113488 | APPARATUS AND METHODS FOR MONITORING A CORE DURING CORING OPERATIONS - One method of monitoring a formation core during coring operations can include measuring resistivities of a formation internal and external to a core barrel assembly, comparing the resistivities of the formation internal and external to the core barrel assembly, and determining a displacement of the core into the core barrel assembly, based at least in part on the comparing, while the core is being cut. A formation core analysis system can include multiple longitudinally spaced apart sets of transmitters and receivers which measure resistivity of a core while the core displaces into a core barrel assembly, and multiple longitudinally spaced apart sets of transmitters and receivers which measure resistivity of a formation external to the core barrel assembly while a coring bit penetrates the formation. A speed of displacement of the core may be indicated by differences in time between measurements taken via the different sets as the core displaces. | 05-09-2013 |
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 |
20130144530 | METHOD AND APPARATUS FOR DOWNHOLE MEASUREMENT TOOLS - 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 that are operated at different positions downhole and a processing unit to process collected signals such that the arrangement of transmitters and receivers provides measurements that mimic operation of a different arrangement of transmitters and receivers. Additional apparatus, systems, and methods are disclosed. | 06-06-2013 |
20130154650 | METHOD AND APPARATUS TO DETECT A CONDUCTIVE BODY - Various embodiments include apparatus and methods to detect and locate conductive bodies and/or provide steam-assisted gravity drainage (SAGD) steering operation. Tools can be configured with receiving sensors ( | 06-20-2013 |
20130166215 | SYSTEM AND METHOD OF MAKING ENVIRONMENTAL MEASUREMENTS - Various embodiments include apparatus and methods to operate with respect to environmental measurements. Apparatus and methods include a processing unit to generate a ratio from signals measured relating to an underground environment and to determine parameters of the underground environment based on the generated ratio. | 06-27-2013 |
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 |
20130226461 | METHOD FOR REAL-TIME DOWNHOLE PROCESSING AND DETECTION OF BED BOUNDARY FOR GEOSTEERING APPLICATION - In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire input data to determine properties of a formation, using a combination of down hole transmitters and receivers, to select a portion of the input data using a formation model chosen from a plurality of down hole tool response models in a formation model database, based on a valid sensitive range for the bed boundary distance and a greatest signal-to-noise ratio (SNR), and to solve for at least resistivity formation parameters in the properties using the chosen formation model and the selected portion of the input data. The database may be updated with boundary distance and the resistivity formation parameters. Additional apparatus, systems, and methods are disclosed. | 08-29-2013 |
20130234718 | MULTI-ARRAY LATEROLOG TOOLS AND METHODS WITH DIFFERENTIAL VOLTAGE MEASUREMENTS - Multi-array laterolog tool systems and methods acquire a set of array measurements sufficient to provide laterolog tool measurements of differing array sizes. Such systems and method offer multiple depths of investigation while offering greater measurement stability in borehole environments having high resistivity contrasts. In at least some system embodiments, a wireline or LWD tool body has a center electrode positioned between multiple pairs of guard electrodes and a pair of return electrodes. The tool's electronics provide a current from the center electrode to the pair of return electrodes and currents from each pair of guard electrodes to the pair of return electrodes. Each of the currents may be distinguishable by frequency or distinguishable by some other means. This novel arrangement of currents provides a complete set of measurements that enables one tool to simultaneously emulate a whole range of laterolog tools. | 09-12-2013 |
20130248250 | APPARATUS AND METHOD OF LANDING A WELL IN A TARGET ZONE - Various embodiments include apparatus and methods to land a well in a target zone with minimal or no overshoot of target zone. The well may be directed to a target in the target zone based on the separation distance between a transmitter sensor ( | 09-26-2013 |
20130257436 | Multi-Array Laterolog Tools and Methods - Multi-array laterolog tool systems and methods acquire a set of array measurements sufficient to provide laterolog tool measurements of differing array sizes. Such systems and method offer multiple depths of investigation while offering greater measurement stability in borehole environments having high resistivity contrasts. In at least some system embodiments, a wireline or LWD tool body has a center electrode positioned between multiple pairs of guard electrodes and a pair of return electrodes. The tool's electronics provide a current from the center electrode to the pair of return electrodes and currents from each pair of guard electrodes to the pair of return electrodes. Each of the currents may be distinguishable by frequency or distinguishable by some other means. This novel arrangement of currents provides a complete set of measurements that enables one tool to simultaneously emulate a whole range of laterolog tools. | 10-03-2013 |
20130311094 | APPARATUS AND METHOD FOR MAKING INDUCTION MEASUREMENTS - Various embodiments include apparatus and methods to operate an induction measurement process in a borehole that addresses direct coupling of a signal between sensors of a measuring tool. Apparatus and methods can include a processing unit to generate formation parameters from signals received in the measurement tool. Additional apparatus, systems, and methods are disclosed. | 11-21-2013 |
20140032116 | MULTICOMPONENT BOREHOLE RADAR SYSTEMS AND METHODS - Disclosed herein are multicomponent borehole radar tools and methods. At least some tool embodiments employ at least two antennas that receive reflections of electromagnetic pulses transmitted from the tool. A processor processes the receive signals to identify reflection signals and to determine a direction and/or distance to the sources of the reflection signals. Possible sources include formation boundaries, fluid boundaries, cased wells, and other features that cause contrasts in electromagnetic properties. In addition to reflection signals, the measured responses may include direct signal measurements that are useful for determining formation resistivity and permittivity. Each of the antennas may transmit and receive, and they may be collocated to reduce tool size and reduce processing complexity. Disclosed logging tool examples employ both electric and magnetic dipole antennas. | 01-30-2014 |
20140188391 | SYSTEMS AND METHODOLOGY FOR DETECTING A CONDUCTIVE STRUCTURE - Various embodiments include apparatus and methods to detect and locate conductive structures below the earth's surface. Tools can be configured with receiving sensors arranged to receive signals generated from a conductive structure in response to a current flowing on the conductive structure. Magnetic-related values from the signals can be processed, relative to the tool, to determine a position of a conductive structure from which the signal was generated in response to current flowing on the conductive structure. Additional apparatus, systems, and methods are disclosed. | 07-03-2014 |
20140191879 | CASING DETECTION TOOLS AND METHODS - Methods and tools for detecting casing position downhole is presented. The method utilizes electromagnetic. (EM) tools with tilted antenna systems to detect casing position. Sometimes titled antenna designs also increase EM tools' sensitivity to formation parameters, which can lead to false signals for casing detection. In addition, it is very difficult to distinguish measured signals between a casing source and a formation source. The methods presented help to distinguish between the two sources more clearly. The methods and tools presented also help to minimize those environmental effects, as well as enhance the signals from a surrounding conductive casing. The methods herein provide ideas of EM tool's design to precisely determine casing position within a certain distance to casing position. | 07-10-2014 |
20140244174 | SYSTEMS AND METHODOLOGY FOR DETECTING A CONDUCTIVE STRUCTURE - Various embodiments include apparatus and methods to detect and locate conductive structures below the earth's surface. Tools can be configured with receiving sensors arranged to receive signals generated from a conductive structure in response to a current flowing on the conductive structure. Magnetic-related values from the signals can be processed, relative to the tool, to determine a position of a conductive structure from which the signal was generated in response to current flowing on the conductive structure. Additional apparatus, systems, and methods are disclosed. | 08-28-2014 |
20140244175 | COMPENSATED CROSSWELL TOMOGRAPHY METHODS AND SYSTEMS - A method and system to compensate for inaccuracies in crosswell tomography is presented. The method includes obtaining data from at least two receivers in response to transmissions from at least two transmitters. Next, at least one compensated value is derived based on the responses of the receivers to the transmitters. Finally, an inversion is performed based at least in part on the compensated value derived. This method eliminates inaccuracies that can be caused by sensor gain and phase variations in the inversion process. Inversion results with gain and phase compensation produce better imaging results that can better help determine the shape and boundaries of the reservoir. | 08-28-2014 |
20140249754 | LOOK-AHEAD OF THE BIT APPLICATIONS - Various embodiments include apparatus and methods of operation with respect to well logging. Apparatus and methods can include a tool having an arrangement of spaced apart transmitter antennas and receiver antennas in transmitter-receiver antenna pairs to make shallow measurements and deep measurements. The signals acquired from the shallow measurements and deep measurements can be processed to provide a look-ahead signal in a drilling operation. The transmitter and receiver antennas can be oriented to cancel or substantially cancel out signals from layers between the transmitter antenna and the receiver antenna in response to the transmitter being operated downhole in a well. Additional apparatus, systems, and methods are disclosed. | 09-04-2014 |
20140311803 | Directing a Drilling Operation Using an Optical Computation Element - Various embodiments include apparatus and methods to operate a tool downhole in a well, where the tool has an optical computation element to determine different properties of downhole structures. Such an optical computation element can be structured to provide optical analysis of fluid and material composition of the downhole environment associated with a drilling operation. The data measurements from the optical computation element can be used in a geosteering operation. Additional apparatus, systems, and methods are disclosed. | 10-23-2014 |
20140368199 | DOWNHOLE SENSING 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 homogeneous part of the electromagnetic signal may be reduced, to thereby increase a depth of detection of the characteristic. | 12-18-2014 |
20150047902 | SYSTEMS AND METHODS OF ROBUST DETERMINATION OF BOUNDARIES - Various embodiments include apparatus and methods to operate a drilling operation relative to formation boundaries. The apparatus and methods can include operating one or more transmitters in a borehole in a formation having a thickness between two boundaries, selecting thickness models based on applying responses from operating the one or more transmitters such that the thickness of the formation is between the two thickness models, and generating a value of a distance to a nearest boundary based on linearization of the thickness models with respect to a long distance investigation parameter and a short distance investigation parameter. Additional apparatus, systems, and methods are disclosed. | 02-19-2015 |