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Match Document Document Title
7619540 Apparatus and methods for determining isotropic and anisotropic formation resistivity in the presence of invasion  
A logging tool includes a tool body; a simple transmitter comprising a single antenna disposed on the tool body; four simple receivers, each comprising a single antenna, disposed on the tool body...
7609065 System and method for locating an anomaly  
A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one...
7595636 Apparatus and method of using accelerometer measurements for casing evaluation  
A casing inspection device with magnets and flux sensors. Measurements of axial motion of the device are used to get better definition of the axial extent of casing defects. A contact device may be...
7586307 Locating arrangement and method using boring tool and cable locating signals  
An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and...
7583085 Downhole sensor assembly  
In one aspect of the invention, a sensor assembly for incorporation into a downhole tool string comprises at least one sensor adapted to detect changes in magnetic flux proximate a first portion of...
7579840 Broadband resistivity interpretation  
Resistivity measurements are made at a plurality of frequencies. An asymptotic high-frequency limit is determined and the electrical efficiency is estimated as a ratio of the high frequency...
7576543 Apparatus and method for resistivity measurements during rotational drilling  
A resistivity sub including a resistivity sensor forms part of a bottom hole drilling assembly. The sensor is maintained at a substantially fixed offset from the wall of a borehole during drilling...
7567869 Induction tool for detail evaluation of near borehole zone  
Measurements made with an induction logging tool are processed to provide a resistivity model of fluid invasion of the formation. Up to five zones can be determined over a radial distance of about...
7557582 Logging while drilling tool for obtaining azimuthally sensitive formation resistivity measurements  
An apparatus for making azimuthally sensitive resistivity measurements of a subterranean formation is disclosed. The apparatus includes a magnetically permeably ring deployed about an electrically...
7557581 Method for imaging subterranean formations  
A method of imaging a subterranean formation traversed by a wellbore using a tool comprising a transmitter for transmitting electromagnetic signals through the formation and a receiver for...
7538555 System and method for locating an anomaly ahead of a drill bit  
A method and a system are provided for allowing determination of a distance from a tool to anomaly ahead of the tool. The apparatus for performing the method includes at least one transmitter and...
7536261 Anti-symmetrized electromagnetic measurements  
A method to determine a parameter of a subsurface formation such as anisotropy and dip comprises making at least two cross dipole measurements and forming an anti-symmetrized combination from the...
7501829 Extra bucking coils as an alternative way to balance induction arrays  
An electromagnetic logging that includes a support; and at least one four-coil array disposed on the support, wherein the at least one four-coil array comprises: a transmitter, a bucking coil, a...
7495446 Formation evaluation system and method  
A formation evaluation system for a subterranean formation penetrated by a wellbore. The formation evaluation system is provided with a downhole tool and a sensor. The downhole tool is positionable...
7482812 Series-resonant tuning of an LWD receiver  
A loop antenna useful, for example, in investigation of earth formations. Embodiments of the invention provide a loop antenna circuit comprising a loop antenna disposed to generate, in response to...
7477161 Bidirectional telemetry apparatus and methods for wellbore operations  
A system and method for communicating data between a downhole tool and a surface controller is provided that comprises a rotating drill string extending in a borehole and having a downhole...
7477160 Wireless communications associated with a wellbore  
A subsea communication system includes addressable nodes in a wellbore and addressable nodes on a floor, where the nodes in the wellbore and on the floor are able to communicate wirelessly with...
7474101 Method for combined transient and frequency domain electromagnetic measurements  
A method for interpreting transient electromagnetic survey data includes imparting an electromagnetic field in the Earth's subsurface by passing electric current through a transmitter antenna. The...
7450053 Logging device with down-hole transceiver for operation in extreme temperatures  
A logging radar system and method for measuring propped fractures and down-hole formation conditions in a subterranean formation including: a radar source; an optical source; an optical modulator...
7437251 Correction of sensor non-equipotentiality in a resistivity imaging device  
A method for correcting data from at least one sensor electrode in a sensor includes determining a potential difference (V) between two electrodes; from the potential difference (V), determining a...
7436184 Well logging apparatus for obtaining azimuthally sensitive formation resistivity measurements  
An apparatus for making azimuthally sensitive resistivity measurements of a subterranean formation is disclosed. The apparatus includes a magnetically permeably ring deployed about an electrically...
7436183 Replaceable antennas for wellbore apparatus  
An antenna structure is separately and independently formed with respect to a downhole tool. The antenna is adapted for easy and rapid deployment on the tool. An independently formed ‘partial...
7425831 System and method for locating an anomaly  
A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one...
7420367 High-frequency induction imager with concentric coils for MWD and wireline applications  
An induction logging tool having concentric transmitter and receiver antennas can be used to make measurements of earth formations at frequencies up to 500 MHz. The antennas may be mounted on the...
7417436 Selectable tap induction coil  
An electromagnetic logging tool includes a support configured for disposal in a well; at least one antenna mounted on the support; and a plurality of coils mounted on the support proximate the at...
7414407 Method and apparatus for directional resistivity measurement while drilling  
A resistivity tool has a body with at lest one pair of grooves on its exterior oriented orthogonal to the tool axis. A coil antenna is oriented orthogonal to the grooves in a hole intersecting the...
7414405 Measurement tool for obtaining tool face on a rotating drill collar  
An apparatus for obtaining tool face angles on a rotating drill collar in substantially real time is disclosed. In one exemplary embodiment the apparatus includes a magnetoresistive magnetic field...
7403013 Boring tool tracking/guiding system and method with unconstrained target location geometry  
Tracking a boring tool is performed within an underground region using a locating signal. The boring tool is moved through the ground during a series of distance movements such that potential...
7403000 Apparatus and method of determining casing thickness and permeability  
A casing inspection device with magnets and flux sensors. The sensors provide measurements of absolute levels of magnetic flux that are indicative of changes in casing thickness and/or permeability.
7391216 Locating arrangement and method using boring tool and cable locating signals  
An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and...
7388379 Series-resonant tuning of a downhole loop antenna  
A loop antenna useful, for example, in investigation of earth formations. Embodiments of the invention provide a loop antenna circuit comprising a loop antenna disposed to generate, in response to...
7385400 Azimuthally sensitive receiver array for an electromagnetic measurement tool  
An azimuthally sensitive logging while drilling tool is disclosed. The tool may be suitable, for example, to measure azimuthal variations of electrical properties of a subterranean formation. The...
7382135 Directional electromagnetic wave resistivity apparatus and method  
A novel on-the-fly data processing technique is useful for extracting signals from the azimuthal variation of the directional measurements acquired by a logging tool within a borehole. The relevant...
7363159 Method of determining resistivity and/or dielectric values of an earth formation as a function of position within the earth formation  
A technique of estimating electrical parameters of an earth formation accounts for spatial inhomogeneities and frequency dispersion. The results are achieved using a model which is evaluated to...
7347271 Wireless communications associated with a wellbore  
A subsea communication system includes devices in a wellbore and devices on a floor, where the devices in the wellbore and on the floor are able to communicate wirelessly with each other, such as...
7345487 Method and system of controlling drilling direction using directionally sensitive resistivity readings  
A method and system of controlling drilling direction using directionally sensitive resistivity readings. At least some of the illustrative embodiments are methods comprising transmitting an...
7336080 Method and apparatus for use of the real component of a magnetic field of multicomponent resistivity measurements  
Multi-component induction measurements are made using a resistivity logging tool in an anistropic earth formation. A subset of the multi-component measurements are inverted to first determine...
7327145 Azimuthally focused electromagnetic measurement tool  
An azimuthally sensitive electromagnetic measurement tool is provided. The tool may be suitable, for example, to measure azimuthal variations of electrical properties of a subterranean formation....
7307425 Receiver electronics proximate antenna  
A resistivity tool includes receiver electronics near each receiver antenna loop. Placement of the electronics in this position such as at the circuit card between the terminal ends of the receiver...
7282704 Method for determining formation porosity and gas saturation in a gas reservoir  
Measurements made with porosity and density logging tools in a gas reservoir may differ due to invasion effects. The effects are particularly large on measurement-while-drilling applications where...
7259564 Method and device for determining the position of an interface in relation to a bore hole  
The invention concerns a method for determining the position, in a formation ( 1 ) containing at least one electrolytic liquid, of an interface ( 6 ) in relation to a bore hole ( 2 ). One...
7250768 Apparatus and method for resistivity measurements during rotational drilling  
A resistivity sub including a resistivity sensor forms part of a bottom hole drilling assembly. The sensor is maintained at a substantially fixed offset from the wall of a borehole during drilling...
7235970 Antenna core material for use in MWD resistivity measurements and NMR measurements  
The present invention provides a novel use of a material having a high internal magnetostrictive damping and/or using material with explicitly low magnetostriction as an antenna core material for...
7228903 Apparatus and method for wireline imaging in nonconductive muds  
A pad mounted resistivity imaging device includes at least one transmitter and two or more arrays of receivers. Analysis of the received signals is done using either amplitude and phase differences...
7227363 Determining formation anisotropy based in part on lateral current flow measurements  
Disclosed herein are methods and apparatus using one or more toroids to measure formation anisotropy and/or vertical conductivity. In one embodiment, a disclosed method comprises: inducing a...
7202670 Method for characterizing a subsurface formation with a logging instrument disposed in a borehole penetrating the formation  
A method is described for characterizing a subsurface formation with a logging instrument disposed in a borehole penetrating the formation. The logging instrument is equipped with at least a...
7183771 Multiple transmitter and receiver well logging device with error calibration system including calibration injection system  
A device and method for obtaining an electromagnetic propagation measurement of a subterranean geologic formation, with the formation being intersected by a borehole. The device comprises a...
7170294 Subsurface imagery for temperature measurement and fluid flow for oil recovery using electromagnetic impedance tomography (EMIT)  
A new application of electromagnetic tomography is described directly related to the efficient recovery of oil and gas as well the removal of unwanted liquids from subsurface formations. The...
7167006 Method for measuring transient electromagnetic components to perform deep geosteering while drilling  
A transverse induction transmitter on an instrument induces currents in an earth formation when it is pulsed. Transient measurements made at transverse and axial receivers are used for...
7157915 Combined characterization and inversion of reservoir parameters from nuclear, NMR and resistivity measurements  
A method of determining the distribution of shales, sands and water in a reservoir including laminated shaly sands using vertical and horizontal conductivities derived from nuclear, NMR, and...
Matches 1 - 50 out of 299 1 2 3 4 5 6 >