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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)...
6366086 Apparatus and method for magnetic resonance logging  
A method for the determining a nuclear magnetic resonance characteristic of earth formations surrounding a borehole, includes the following steps: providing a logging device that is movable through...
6348792 Side-looking NMR probe for oil well logging  
A side-looking NMR logging tool incorporates a permanent magnet arrangement having a magnetization direction oriented towards a side of the tool and a dipole RF antenna displaced towards the front...
6344744 Multiple frequency method for nuclear magnetic resonance longitudinal relaxation measurement and pulsing sequence for power use optimization  
A method for determining nuclear magnetic resonance longitudinal relaxation time of a medium. The method includes magnetically polarizing nuclei in the medium along a static magnetic field,...
6342784 Method for resistivity well logging utilizing nuclear magnetic resonance  
There is provided a method and apparatus for determining resistivity in a formation surrounding a borehole. In one embodiment, the apparatus includes a magnetic resonance well logging tool disposed...
6337568 System and method for enhanced vertical resolution magnetic resonance imaging logs  
An interpretation method and system for NMR echo-train data in thinly laminated sequences. The invention uses geological information obtained at higher vertical resolution, such as using Electric...
6331775 Gas zone evaluation by combining dual wait time NMR data with density data  
A method for acquiring nuclear magnetic resonance measurements of a medium uses a modified CPMG pulse sequence wherein the refocusing pulses may be optiimized, having a shorter duration than a...
6326785 Nuclear magnetic resonance tool with magnetostrictive noise compensation  
An NMR logging apparatus and method are provided including an antenna having compensation for magnetostrictive ringing. The antenna comprises at least one inductive winding and a core having a...
6326784 Nuclear magnetic resonance logging with azimuthal resolution using gradient coils  
The present invention relates generally to an apparatus and method for obtaining an azimuthally resolved nuclear magnetic resonance measurement of an earth formation traversed by a borehole. The...
6316940 System and method for identification of hydrocarbons using enhanced diffusion  
A novel method and system is disclosed for the separation of fluid phases in NMR borehole measurements. The method is based on forcing diffusion as the dominant relaxation mechanism for certain...
6297632 Detecting tool motion effects on spin echoes obtained with nuclear magnetic resonance measurements  
An NMR measurement obtained with a logging tool is potentially subject to relative motion between the apparatus and a sample. An echo train is produced having a plurality of spin echo signals. At...
6291995 Apparatus and method for generating a pulse sequence  
The present invention is directed to a method for generating a pulse sequence using a logging tool. A pulse programmer is provided for adaptively controlling the creation and application of a...
6268727 Measurement of flow fractions flow velocities and flow rates of a multiphase fluid using ESR sensing  
Various flowmeters (10, 70, 110, 120) each have an ESR sensor (13, 73, 112, 121) for measuring the crude oil fraction and/or velocity of a fluid containing crude oil. In combination with an NMR...
6255819 System and method for geologically-enhanced magnetic resonance imaging logs  
An interpretation method and system for NMR echo-train data in thinly laminated sequences. The invention uses geological information obtained at higher vertical resolution, such as using Electric...
6255818 Method and apparatus for performing magnetic resonance measurements  
A magnetic resonance measurement apparatus that is subject to relative motion between the apparatus and a specimen along a path includes a magnet, antennae and a circuit. The magnet polarizes the...
6246236 Apparatus and method for obtaining a nuclear magnetic resonance measurement while drilling  
The present invention is directed to a nuclear magnetic resonance logging-while-drilling tool. The tool comprises a drill bit, drill string, a plurality of RF antennas, and at least one gradient...
6242913 Method for formation evaluation while drilling  
A logging while drilling (LWD) and measuring while drilling (MWD) method and device are disclosed for reducing the sensitivity of NMR measurements to tool motions. The invention is based on NMR...
6242912 System and method for lithology-independent gas detection using multifrequency gradient NMR logging  
A well logging system and method are disclosed for detecting the presence and estimating the quantity of gaseous and liquid hydrocarbons in the near wellbore zone. The system uses a gradient-based,...
6232778 Method for obtaining NMR bound fluid volume using partial polarization  
The present invention provides methods for determining the bound fluid volume (BFV) of a formation utilizing nuclear magnetic resonance (NMR) techniques in which less than full polarization occurs...
6229308 Formation evaluation using magnetic resonance logging measurements  
A form of the invention is directed to a method for determining properties of earth formations surrounding a borehole, including the following steps: (a) providing a logging device that is moveable...
6225803 NMR log processing using wavelet filter and iterative inversion  
A method of nuclear magnetic resonance (NMR) well log processing. A wavelet decomposition of an NMR echo train is preformed. The resulting small scale coefficients, which may be discretely or...
6218833 Temperature compensated nuclear magnetic resonance apparatus and method  
A method and apparatus for determining a characteristic of an earth formation surrounding a borehole in which a pulsed nuclear magnetic resonance (NMR) tool is received. A static magnetic field is...
6215304 NMR sensor  
An NMR sensor including a magnetic field generating assembly, an RF antenna, and a plurality of ferrite members which couple with RF magnetic fields transmitted or received by the RF antenna. The...
6204663 Pulse sequence and method for suppression of magneto-acoustic artifacts in NMR data  
Novel pulse sequence and data acquisition method are disclosed which eliminate the effects of spurious NMR signals caused by mechanical resonances within the measurement apparatus. The proposed...
6184681 Apparatus and method for computing a distribution of spin-spin relaxation times  
The present invention is directed to a method for computing a distribution of spin--spin relaxation times. The spin-echo amplitudes are obtained by hardware integration of the receiver voltages...
6181132 NMR logging assembly  
A logging assembly for application in a wellbore formed in an earth formation is provided. The assembly comprises a casing suitable to be lowered through the wellbore and to be arranged in a...
6177794 Use of earth field spin echo NMR to search for liquid minerals  
An instrument for measuring the spatial, qualitative and quantitative parameters of an underground nuclear magnetic resonance (NMR) active liquid mineral deposit, including oil and water. A phased...
6166543 Method and apparatus for measuring nuclear magnetic resonance  
The present invention relates generally to an apparatus and method for measuring nuclear magnetic resonance properties of an earth formation traversed by a borehole by generating gradient-echoes....
6163151 Apparatus and method for making nuclear magnetic measurements in a borehole  
An NMR logging tool has a conducting permanent magnet with its axis parallel to the borehole axis to produce a static field in a portion of the formation surrounding a borehole that is parallel to...
6147489 Method and apparatus for measuring total nuclear magnetic resonance porosity  
A method and apparatus for determining gas corrected porosity using nuclear magnetic resonance (NMR) and density measurements is disclosed. The total porosity (TCMR) or an earth formation is...
6140818 NMR logging tool and method for fast logging  
A high speed, NMR, porosity measuring technique and instrument, is described. The instrument is configured with a long prepolarization region of up to approximately six feet disposed ahead of a...
6140817 Magnetic resonance well logging method and apparatus  
Technique and apparatus are disclosed for identifying characteristics of hydrocarbons, such as distinguishing light and heavy formation oil, in formations surrounding an earth borehole. The...
6133734 Method and apparatus for evaluating an earth formation using nuclear magnetic resonance techiques  
This invention makes an NMR measurement at extended depths into the formation using the earth's magnet field to generate an NMR measurement and using a magnet field from a permanent magnetic to...
6133735 Magnetic resonance logging method and apparatus  
A technique is provided for determining a nuclear magnetic resonance characteristic of formations surrounding an earth borehole, including the following steps: providing a logging device that is...
6121774 Method for eliminating ringing during a nuclear magnetic resonance measurement  
The present invention relates generally to a method for eliminating ringing while measuring nuclear magnetic resonance properties of an earth formation traversed by a borehole. The measurement can...
6121773 Longitudinal NMR well logging apparatus and method  
The invention is a nuclear magnetic resonance sensing apparatus comprising a magnet for inducing a static magnetic field in a region containing materials to be analyzed. The static magnetic field...
6115671 Method for estimating rock petrophysical parameters using temperature modified NMR data  
Carbonate formations yield unreliable, down hole NMR results. Inter alia, these results must be corrected for temperature. The invention features several methods for obtaining more reliable NMR...
6111408 Nuclear magnetic resonance sensing apparatus and techniques for downhole measurements  
A method and apparatus are disclosed for using nuclear magnetic resonance (NMR) techniques to obtain information relating to fluids present near geologic structures. A modular NMR tester which can...
6111409 Nuclear magnetic reasonance fluid characterization apparatus and method for using with electric wireline formation testing instruments  
A method for characterizing a fluid sample withdrawn from an earth formation. The method includes performing nuclear magnetic resonant spin echo measurements on the fluid sample at a nuclear...
6107796 Method and apparatus for differentiating oil based mud filtrate from connate oil  
A method and apparatus for processing nuclear magnetic resonance (NMR) information to differentiate between oil based mud filtrate (OBM), and connate oils, during subsurface exploration. An NMR...
6107797 Magnetic resonance logging apparatus and method  
A logging device for measuring nuclear magnetic resonance characteristics of earth formations surrounding a borehole having means for producing a static magnetic field in formations surrounding the...
6097184 Nuclear magnetic resonance well logging to determine gas-filled porosity and oil-filled porosity of earth formations without a constant static magnetic field gradient  
A technique is disclosed for determining the gas-filled porosity and oil-filled porosity in a region of investigation of earth formations surrounding a borehole including the following steps: (a)...
6094048 NMR logging of natural gas reservoirs  
A method is provided to estimate the pore volume of a formation occupied by hydrocarbon phase or phases, the method comprising the steps of: obtaining a first pulsed NMR log of the formation, the...
6091241 Device for examining a volume of small depth by nuclear magnetic resonance  
A device for examining by nuclear magnetic resonance a volume having small depth, including means for creating a static homogeneous magnetic field B 0 in which a volume to be examine is...
6084408 Methods for acquisition and processing of nuclear magnetic resonance signals for determining fluid properties in petroleum reservoirs having more than one fluid phase  
A method for determining intrinsic transverse relaxation time of a first mobile phase in a porous medium using nuclear magnetic resonance measurement sequences. The sequences are measured at first...
6081116 Nuclear magnetic resonance apparatus and method for geological applications  
The present invention provides a nuclear magnetic resonance ("NMR") tool for determining geological properties of formations surrounding a borehole when said tool is traversed in the borehole. One...
6072315 Magnetic field pulse generator  
An rf magnetic field pulse generator for generating a pulse train comprising a plurality of rf magnetic field pulses for use in an NMR investigation, the generator comprising (i) an amplifier...
6072314 NMR interpretation technique using error minimization with variable T2 cutoff  
This invention provides improved geological formation evaluation, resulting in a more accurate prediction of the location of hydrocarbon. It also increases the yield at those sites. The disclosed...
6069477 Method for improving the accuracy of NMR relaxation distribution analysis with two echo trains  
The total porosity of a subterranean formation is calculated by summing the effective Porosity and the clay bound water (CBW) porosity. With the invention described in this patent, the distortion...
6046590 MR imaging method with time dependence provided in multiple spatial encoding directions  
A method is provided for acquiring MR image data, which comprises the steps of applying a succession of RF excitation pulses to a selected region of an imaging subject to produce a corresponding...
Matches 201 - 250 out of 402 < 1 2 3 4 5 6 7 8 9 >