Matches 251 - 300 out of 434 < 1 2 3 4 5 6 7 8 9 >


Match Document Document Title
6353321 Uncompensated electromagnetic wave resistivity tool for bed boundary detection and invasion profiling  
A resistivity tool and associated method include measuring the phase shift of an electromagnetic signal at different locations. Preferably, this is accomplished by a resistivity tool having three...
6351127 Shielding method and 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...
6344746 Method for processing the lapse measurements  
Resistivity data acquired at two different epochs using different types of tools are jointly inverted. For example, a multiple propagation resistivity (MPR) tool is run first, preferably at...
6304086 Method and apparatus for evaluating the resistivity of formations with high dip angles or high-contrast thin layers  
A method and apparatus for evaluating the resistivity of earth formations surrounding a borehole, particularly high-contrast thin-layer formations or at high dip angles. The method involves...
6300762 Use of polyaryletherketone-type thermoplastics in a production well  
The present invention relates generally to the use of polyaryletherketone-based thermoplastic materials in high pressure, high temperature, production logging applications. A polyaryletherketone...
6297639 Method and apparatus for directional well logging with a shield having sloped slots  
Methods and apparatus for making directional measurements of earth formations surrounding a borehole. New antenna coil shield designs are utilized to provide selective attenuation of at least one...
6272232 Method for performing a morphological survey of geological formations traversed by a borehole  
A morphological survey of geological formations traversed by a borehole includes constructing, from an initial image of the wall of the borehole representative of variations in a physical...
6218842 Multi-frequency electromagnetic wave resistivity tool with improved calibration measurement  
A resistivity tool for use in an LWD system includes an asymmetric transmitter design with multiple transmitters capable of generating EM signals at multiple frequencies. A pair of receivers are...
6211678 Method for radial profiling of resistivity at multiple depths of investigation  
A resistivity tool suitable for use in a borehole and configured to obtain a resistivity radial profile at multiple depths of investigation in a geological formation comprises a receiver pair and...
6191586 Method and apparatus for azimuthal electromagnetic well logging using shielded antennas  
An apparatus and method for implementing azimuthal capabilities on electromagnetic wave resistivity well logging tools. The apparatus comprises a structurally simple antenna shield positioned...
6184685 Mulitiple spacing resistivity measurements with receiver arrays  
A wireline, coiled tubing, and measurement while drilling resistivity tool having three or more receivers is disclosed. This results in a tool capable of gathering substantial resistivity data...
6181138 Directional resistivity measurements for azimuthal proximity detection of bed boundaries  
An azimuthally tunable resistivity measurement tool is provided. In one embodiment, the tool comprises a set of three skewed receiver antennas and a transmitter antenna. The three skewed receiver...
6161630 Apparatus and method for controlling 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...
6150822 Sensor in bit for measuring formation properties while drilling  
Earth formation evaluation for detection of hydrocarbon fluids is carried out by a microwave frequency range sensor (antenna or wave guide) disposed in the face of a diamond or PDC drill bit...
6100696 Method and apparatus for directional measurement of subsurface electrical properties  
A directional induction logging tool is provided for measurement while drilling. This tool is preferably placed in a side pocket of a drill collar, and it comprises transmitter and receiver coils...
6075462 Adjacent well electromagnetic telemetry system and method for use of the same  
An adjacent well telemetry system for changing the operational state of a downhole device and a method for use of the system is disclosed. The system comprises an electromagnetic transmitter...
6064210 Retrievable resistivity logging system for use in measurement while drilling  
A retrievable resistivity logging system is provided for obtaining directional resistivity information while drilling (e.g., in an MWD system). The information obtained by this system can be used...
6057784 Apparatus and system for making at-bit measurements while drilling  
The system of the present invention includes measurement instrumentation that is located in or near the drill bit and used in a measuring-while-drilling system. The instrumentation can be located...
5963036 Well logging apparatus and method for determining properties of earth formations that have been invaded by borehole fluid  
A method and apparatus is disclosed for determining the properties of formations surrounding an earth borehole that have been invaded by borehole fluid to form an invaded zone. Properties...
5939885 Well logging apparatus having a separate mounting member on which a plurality of antennas are located  
Apparatus for sensing the resistivity of geological formations surrounding a borehole includes a tubular body member (1) which is adapted to form a portion of a length of drill string. An antenna...
5923300 Multi-phase transmitter with single receive antenna for transponder interrogator  
An antenna includes a transmitter including a first transmit coil wound in a first direction. A second transmit coil is electrically coupled to the first transmitter and wound in a second...
5900733 Well logging method and apparatus for determining downhole Borehole fluid resistivity, borehole diameter, and borehole corrected formation resistivity  
A well logging method and apparatus are disclosed for determining borehole corrected formation resistivity, borehole diameter, and downhole borehole fluid (mud) resistivity with improved accuracy....
5892361 Use of raw amplitude and phase in propagation resistivity measurements to measure borehole environmental parameters  
A propagation resistivity measurement-while-drilling device is used to measure borehole environmental parameters along with electromagnetic properties of the formation. Multiple...
5886526 Apparatus and method for determining properties of anisotropic earth formations  
A method is disclosed for determining the horizontal resistivity, vertical resistivity, and dip of formations surrounding a borehole, comprising the following steps: (a) suspending a logging...
5869968 Method and apparatus for avoiding mutual coupling between receivers in measurement while drilling  
An arrangement of two closely spaced transmitters and two spaced apart receivers symmetrically disposed about the transmitters in a measurement while drilling tool avoids the effects of mutual...
5841281 Method for determining electrical conductivity of earth formations from electromagnetic induction voltage measurements  
A method of determining the conductivity of earth formations penetrated by a wellbore. The method includes inserting an induction well logging instrument into the wellbore. The instrument includes...
5811972 Method and apparatus for determining influence of mutual magnetic coupling in electromagnetic propagation tools  
The present invention is directed to a measurement-while-drilling logging tool which includes a minimum number of analog electrical and electronic components, and which instead utilizes...
5811973 Determination of dielectric properties with propagation resistivity tools using both real and imaginary components of measurements  
A propagation resistivity measurement-while-drilling system is used to determine the resistivity (or conductivity) of the conate formation fluid, the dielectric constant of the dry rock matrix,...
5753813 Apparatus and method for monitoring formation compaction with improved accuracy  
Method and an apparatus for determining a vertical distance between a first marker and a second marker embedded in a formation traversed by a borehole so as to quantify the occurrence of earth...
5689068 Determination of the porosity and permeability of a geological formation from an electrofiltering phenomenon  
The porosity and permeability of a geological formation (2) are determined on the basis of an electrofiltering phenomenon by exploiting the existence of non-linear electrofiltering phenomena. One...
5682099 Method and apparatus for signal bandpass sampling in measurement-while-drilling applications  
A logging apparatus is provided for use in a wellbore for measuring an attribute of at least one of the wellbore and a surrounding formation, when coupled to a wellbore tubular expended in the...
5675488 Location determination using vector measurements  
A method for locating underground cylindrically symmetrical magnetic sources, particularly boreholes, from magnetic field measurements. The method is based on the shape of magnetic field produced...
5672971 Well logging system arranged for stable, high-sensitivity reception of propagating electromagnetic waves  
The present invention is directed to an improved logging apparatus. The logging apparatus includes transmitters, receivers, and a controller member. The controller member is utilized to...
5661402 Sealed modular downhole antenna  
A sealed, modular downhole antenna for measuring electrical characteristics of wellbore fluids and formations. An antenna includes a thin-walled curved metal tube, which houses coil of a length of...
5656930 Method for determining the anisotropic properties of a subterranean formation consisting of a thinly laminated sand/shale sequence using an induction type logging tool  
Formation anisotropic properties are determined using knowledge of the borehole dip angle and an induction logging instrument to obtain two formation derived resistivities. Separate shale layer...
5631563 Resistivity antenna shield, wear band and stabilizer assembly for measuring-while-drilling tool  
A sensor protection system for use with an MWD tool includes a tubular body having lesser and greater diameter portions, antennas mounted in grooves in the lesser diameter portion, shield sleeves...
5594344 Method and apparatus for generating and detecting amplitude and phase modulated sensor signals  
A method of extracting a phase and amplitude modulation signal impressed on a carrier is disclosed. The method includes generating the carrier at a frequency which is a multiple of the bandwidth...
5594343 Well logging apparatus and method with borehole compensation including multiple transmitting antennas asymmetrically disposed about a pair of receiving antennas  
An apparatus for determining a property of earth formations surrounding a borehole is presented. In accordance with a particular embodiment, an elongated logging device movable through a borehole...
5574374 Method and apparatus for interrogating a borehole and surrounding formation utilizing digitally controlled oscillators  
The present invention is directed to a measurement-while-drilling logging tool which includes a minimum number of analog electrical and electronic components, and which instead utilizes...
5563512 Well logging apparatus having a removable sleeve for sealing and protecting multiple antenna arrays  
A well logging apparatus is disclosed having an elongate body supporting a plurality of antenna coils housed in recesses formed on the body. A sleeve covers the segment of the body containing the...
5550473 Method for locating thin bed hydrocarbon reserves utilizing electrical anisotropy  
A method of locating thin bed hydrocarbon reserves in laminated subterranean formations comprising thin beds. The method comprised of drilling a well penetrating the subterranean formations,...
5548219 Digital two frequency generator for use in borehole heterodyne measurement systems  
A system for generating two or more frequencies for a borehole heterodyne measurement system for use in measuring electromagnetic propagation properties of rock is disclosed. A precision clock...
5530358 Method and apparatus for measurement-while-drilling utilizing improved antennas  
A method and apparatus is provided for measurement-while-drilling utilizing improved antennas. An elongated tubular member is provided with an outer peripheral surface having a contoured portion...
5530359 Borehole logging tools and methods using reflected electromagnetic signals  
A borehole logging tool such as a wireline logging tool or a logging-while drilling tool includes a tool body; a transmitting antenna located in the body; a pulser for causing the transmitting...
5469062 Multiple depths and frequencies for simultaneous inversion of electromagnetic borehole measurements  
A wave propagation measurement-while-drilling system is used to determine selected formation and borehole properties. One or more transmitter-receiver pairs are utilized with the transmitter...
5453693 Logging system for measuring dielectric properties of fluids in a cased well using multiple mini-wave guides  
An improved system for measuring dielectric properties of fluids in an oil well, utilizing the well casing as a waveguide for certain electromagnetic signals. A production logging tool in...
5446654 Shoulder effect logging method  
In a resistivity log, a curve is obtained showing the values of resistivity where adjacent beds impact the measured resistivity. The curve as a function of well depth is first converted into a...
5438267 Single-switching method of eliminating the effect of electromagnetic coupling between a pair of receivers  
The invention is directed toward the elimination of the effects of electromagnetic coupling between pairs of receivers. The preferred embodiment encompasses the measurement of resistivity and...
5434507 Method and apparatus for electromagnetic logging with two dimensional antenna array  
A two-dimensional array of slot antennas which can provide two-dimensional quantitative dielectric and conductivity images of formations in the region surrounding an earth borehole. The antennas...
5408182 Facility and method for the detection and monitoring of plumes below a waste containment site with radiowave tomography scattering methods  
An embodiment of the present invention is a toxic waste containment facility subject to leaking hazardous plumes into soils beneath and adjacent to the site. The facility includes a plurality of...

Matches 251 - 300 out of 434 < 1 2 3 4 5 6 7 8 9 >