Matches 201 - 250 out of 434 < 1 2 3 4 5 6 7 8 9 >


Match Document Document Title
6917303 Logging sondes for use in boreholes  
A wireline logging sonde for sensing fluid properties in a bore hole. The sonde has a main body and a plurality of sensor capsules mounted peripherally to the main body on fingers. A sensor...
6898967 Azimuthal resistivity using a non-directional device  
A method of measuring resistivity values in relation to the azimuthal displacement of a measurement sensor displayed on a measurement-while-drilling device in a wellbore environment is disclosed....
6836218 Modified tubular equipped with a tilted or transverse magnetic dipole for downhole logging  
Method and system for subsurface logging utilizing a modified metallic tubular having an elongated body with tubular walls and a central bore adapted to receive a support member. The tubular...
6822455 Multiple transmitter and receiver well logging system and method to compensate for response symmetry and borehole rugosity effects  
The invention provides a system for determining geologic formation resistivity while drilling and a new method providing compensation for the vertical asymmetries of the tool response and the...
6819110 Electromagnetic resistivity logging instrument with transverse magnetic dipole component antennas providing axially extended response  
An electromagnetic well logging instrument is disclosed which includes at least one transmitter antenna oriented to have at least some magnetic dipole moment component transverse to an axis of the...
6814162 One cone bit with interchangeable cutting structures, a box-end connection, and integral sensory devices  
A drill bit, comprising a bit body, a sensor disposed in the bit body, a single journal removably mounted to the bit body, and a roller cone rotatably mounted to the single journal.
6791330 Well logging tool and method for determining resistivity by using phase difference and/or attenuation measurements  
An apparatus and method for determining resistivity of a formation surrounding a borehole comprises a housing, at least first and second transmitting antennas affixed to the housing for...
6788263 Replaceable antennas for subsurface monitoring apparatus  
An antenna structure is separately and independently formed with respect to a tubular adapted for long-term disposal within a wellbore. The antenna is adapted for easy and rapid deployment on the...
6788065 Slotted tubulars for subsurface monitoring in directed orientations  
Tubulars for monitoring subsurface reservoir characteristics in directed orientations. Elongated tubulars for permanent subsurface disposal are equipped with antennas adapted to transmit or...
6784666 Flexible cushion probe for detecting a dielectric medium defined by a dielectric boundary surface  
A probe serving for detecting the structure of a dielectric medium. The probe includes at least one transmitter/receiver antenna located near a dielectric boundary surface that defines a...
6777940 Apparatus and method for resistivity well logging  
Well logging apparatus and methods for determining formation resistivity at multiple (>3) depths of investigation. At least one transmitter antenna and at least two receiver antennas are mounted...
6765385 Method, apparatus and system for compensating the effects of borehole variations  
System and method for borehole compensation. The method includes simultaneously transmitting at least two modulated signals from one or more transmitters; receiving the at least two modulated...
6765384 Method and apparatus employing phase cycling for reducing crosstalk in downhole tools  
An apparatus and method for reducing crosstalk and other noise sources in downhole tools is disclosed. Due to confined space in the downhole tool environment and the fact that the transmit path...
6744253 Synchronous radio-imaging of underground structures  
A coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The transmitter...
6727705 Subsurface monitoring and borehole placement using a modified tubular equipped with tilted or transverse magnetic dipoles  
Systems and methods for monitoring a subsurface formation property and for placing a borehole in the vicinity of a well in the formation. A slotted tubular is utilized to provide through-tubular...
6725162 Method for determining wellbore diameter by processing multiple sensor measurements  
A method is disclosed for producing a single logging-while-drilling (LWD) merged caliper from several indirect LWD borehole size measurements. The merging accounts for the varying validity of each...
6719068 Probing device with microwave transmission  
Geological probing device comprising a hollow probing rod to be extended into the geological matter to be probed, and a measuring probe fitted to the probing rod, said measuring probe comprising...
6710600 Drillpipe structures to accommodate downhole testing  
A drill collar structure to facilitate measurement-while-drilling (MWD) techniques while at the same time having sufficient rigidity to facilitate the drilling operation is disclosed. In some...
6703837 Wellbore resistivity tool with simultaneous multiple frequencies  
The present invention is a propagation resistivity system that utilizes one or more transmitter coil antennas, or “transmitters” and at least two receiver coil antennas, or “receivers”. The system...
6693430 Passive, active and semi-active cancellation of borehole effects for well logging  
Methods and apparatus for making subsurface measurements with reduced or eliminated borehole effects. Antenna and electrode configurations address the undesired axial electric currents that are...
6670813 Integrated borehole system for reservoir detection and monitoring  
A method is disclosed for generating an image of earth formations penetrated by a wellbore. The method includes generating an initial model of the earth formations using formation resistivity...
6671623 Methods and system for characterizing the response of subsurface measurements to determine wellbore and formation characteristics  
Methods and systems are disclosed for characterizing the response of a subsurface resistivity measurement to determine a characteristic of a borehole within the subsurface and/or a characteristic...
6646441 Well logging system for determining resistivity using multiple transmitter-receiver groups operating at three frequencies  
An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole...
6630830 Shielding method and apparatus using flexible strip  
A shielding method and apparatus for an antenna disposed on an elongated support adapted for disposal within a borehole. The shield providing predetermined attenuation of one or more...
6624634 Borehole current correction methods and apparatus  
Methods and apparatus are disclosed for minimizing or eliminating an undesired axial electric current induced along a subsurface borehole in the process of subsurface measurements with transmitter...
6614229 System and method for monitoring a reservoir and placing a borehole using a modified tubular  
Systems and methods for monitoring a characteristic of a subterranean hydrocarbon reservoir and for placing a borehole in the vicinity of a well in an earth formation. New well completion systems...
6593746 Method and system for radio-imaging underground geologic structures  
A coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The transmitter...
6591195 Method of and apparatus for independently determining the resistivity and/or dielectric constant of an earth formation  
Techniques are provided to transform attenuation and phase measurements taken in conjunction with a drilling operation into independent electrical parameters such as electrical resistivity and...
6584408 Subsurface formation parameters from tri-axial measurements  
Systems and methods are provided for determining various subsurface formation parameters from electromagnetic measurements. Formulas are disclosed for field components in a coordinate system tied...
6577129 Well logging system for determining directional resistivity using multiple transmitter-receiver groups focused with magnetic reluctance material  
An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole...
6566881 Shielding method and apparatus using transverse slots  
A shielding method and apparatus for an antenna disposed on an elongated support adapted for disposal within a borehole. The shield providing predetermined attenuation of one or more...
6557794 Coil shielding method for selective attenuation of an electromagnetic energy field component  
A shield apparatus for use in conjunction with a well tool to selectively attenuate one or more electromagnetic energy field components as the components interact with the shield. The shield...
6556014 Device and method for measurement by guided waves on a metal string in a well  
A device for detecting changes of resistivity or dielectrical properties due to changes of fluid composition in the near-well area about a well in a geological formation, comprising an...
6556015 Method and system for determining formation anisotropic resistivity with reduced borehole effects from tilted or transverse magnetic dipoles  
Systems and methods are provided for determining subsurface formation properties using an antenna system disposed within a borehole traversing the formation. A logging system includes a well tool...
6541979 Multi-coil electromagnetic focusing methods and apparatus to reduce borehole eccentricity effects  
Methods and apparatus are disclosed for canceling or eliminating borehole eccentricity effects on a formation resistivity measurement obtained with transmitter and/or receiver antennas which are...
6538447 Compensated multi-mode elctromagnetic wave resistivity tool  
A multi-mode resistivity tool for use in a logging-while-drilling (LWD) system includes an asymmetric transmitter design with multiple transmitters capable of generating electromagnetic (EM)...
6531871 Extension assembly for an electromagnetic antenna and method of connection  
An electromagnetic antenna extension assembly for connection downhole into a pipe string between a data transmission unit and an electromagnetic antenna. Further, a method for connecting the data...
6525540 Method and device for detection of em waves in a well  
A method for detecting electrical properties in a geological formation in a well which has within it a tubing string comprising the steps of mounting a transmitter antenna outside of the tubing...
6497457 Drilling, image, and coal-bed methane production ahead of mining  
A coal mining operation begins by using directional drilling to bore several horizontal shafts through a coal deposit with its natural overburden still intact. Any methane gas permeating the coal...
6483310 Retrievable, formation resistivity tool, having a slotted collar  
A sonde is movable lengthwise in and relative to tubular structure such as a drill collar; slits extend through the tubular structure; and antennae coils on the sonde come into registration with...
6480000 Device and method for measurement of resistivity outside of a wellpipe  
The invention is a device for measuring and surveillance of resistivity in a petroleum reservoir in a geological formation with an injection-, observation- or production well comprising an...
6462549 Method and system for electroseismic monitoring of microseismicity  
A method and system for determining the location of a microseismic event is disclosed. An electromagnetic sensor measures the electromagnetic energy which is caused by a microseismic event....
6452564 RF surface wave attenuating dielectric coatings composed of conducting, high aspect ratio biologically-derived particles in a polymer matrix  
A coating composite is provided for a platform surface of an antenna array for, when applied to the platform, affording isolation of radiating and receiving antennas of the array. The coating...
6435286 Apparatus and method for detecting a location and an orientation of an underground boring tool  
An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a...
6426917 Reservoir monitoring through modified casing joint  
An apparatus and a method for controlling oilfield production to improve efficiency includes a remote sensing unit that is placed within a subsurface formation, an antenna structure for...
6417667 Method for logging and determining wellbore diameter by processing of progressive subsurface electromagnetic resistivity measurements  
A method is disclosed for determining a diameter of a wellbore. The method includes inducing an electromagnetic field in the wellbore and a formation surrounding the wellbore from a first location...
6384605 Method and apparatus for measurement of borehole size and the resistivity of surrounding earth formations  
A method and apparatus for determining the size or diameter of boreholes extending to a wide range of dimensions and/or the resistivity of the surrounding earth formations utilizing a well tool...
6380744 Shielding apparatus for selective attenuation of an electromagnetic energy field component  
A shield apparatus for use in conjunction with a well tool to selectively attenuate one or more electromagnetic energy field components as the components interact with the shield. The shield...
6377050 LWD resistivity device with inner transmitters and outer receivers, and azimuthal sensitivity  
A borehole tool for logging resistivity of geologic formations, having at least two inner transmitters surrounded by at least two outer receivers. Each transmitter is sequentially excited, and...
6366088 Method to enhance vertical resolution of time-decay log using forward modeling deconvolution of time-decay spectra  
A method for enhancing measurement resolution is disclosed. In one embodiment, the method includes (1) obtaining multiple measurement samples at each of multiple positions along a borehole; (2)...

Matches 201 - 250 out of 434 < 1 2 3 4 5 6 7 8 9 >