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7579833 Water mapping using surface NMR  
A method for selecting a location of a wellbore includes: using a nuclear magnetic resonance (NMR) instrument deployed on a surface of a production area, determining a location of ground water in...
7567079 Methods suitable for measuring capillary pressure and relative permeability curves of porous rocks  
Single-shot methods suitable for determining capillary pressure and relative permeability curves in petroleum reservoir core plugs are proposed. Three classes of measurement are outlined. (i)...
7564240 Method and apparatus for measuring free induction decay signal and its application to composition analysis  
A method to obtain a free induction decay signal using includes inducing a static magnetic field in a sample volume. A radio frequency (RF) magnetic field is then induced in the sample volume. The...
7541806 Method for molecule examination by NMR spectroscopy  
The invention relates to a method and a device for examining molecules by means of NMR spectroscopy. It is the object of the invention to be able to characterize a sample with a high resolution and...
7538547 Method and apparatus for integrating NMR data and conventional log data  
A method to determine one or more properties of a substance in a downhole region of investigation is disclosed. The method includes obtaining NMR measurements from the region of investigation,...
7532007 Remote sensing nuclear magnetic resonance apparatus  
An apparatus and methods that can be used to determine various qualitative parameters of an earth formation from nuclear magnetic resonance (NMR) measurements. One embodiment provides a method of...
7528600 System and method for downhole time-of-flight sensing, remote NMR detection of fluid flow in rock formations  
A system and method for measuring fluid flow in a wellbore in an earth formation using time-of-flight (TOF) sensing and remote detection nuclear magnetic resonance (NMR) techniques, by applying a...
7511488 Viscosity determination from logarithmic mean ratio of relaxation times  
A method for determining viscosity, η, of a fluid downhole, calls for performing a nuclear magnetic resonance (NMR) survey of the fluid; determining a longitudinal relaxation time, T 1 , and an...
7511487 Logging method for determining characteristic of fluid in a downhole measurement region  
For use in logging downhole in an earth borehole, a method for determining a characteristic of oil, includes: providing and determining the viscosity of a plurality of crude oil samples; performing...
7501818 System and methods for T1-based logging  
System and methods for using nuclear magnetic resonance (NMR) T 1 measurements for wireline, LWD and MWD applications and down-hole NMR fluid analyzers. The T 1 measurements are characterized by...
7501817 Method and apparatus for generating an axisymmetric magnetic field  
The present invention is directed to a nuclear magnetic resonance apparatus and method for generating an axisymmetric magnetic field having long, straight contour lines in the resonance region. A...
7495436 Rock properties prediction, categorization, and recognition from NMR echo-trains using linear and nonlinear regression  
A partial least squares (PLS) regression relates spin echo signals with samples having a known parameter such as bound water (BW), clay bound water (CBW), bound volume irreducible (BVI), porosity...
7486071 Fluid monitoring arrangement  
A fluid monitoring arrangement 1 for an engine is operated in accordance with a method whereby nuclear magnetic resonance (NMR) interrogation of the fluid flow 3 it is possible to determine...
7486070 Devices, systems and methods for assessing porous media properties  
Certain embodiments are directed to devices, systems and methods for determining a penetration depth of an induced oscillation in a porous medium. In certain examples, the devices, systems and...
7463027 Systems and methods for deep-looking NMR logging  
An NMR logging tool for conducting NMR measurements in a plurality of sensitive volumes ranging up to a meter from the tool. The tool comprises a magnetic assembly using one or more permanent...
7459907 Flow measurement using NMR  
A nuclear magnetic resonance (NMR) method is used to determine a velocity distribution or velocity image of a flowing fluid in a downhole environment. The method comprises applying a radio...
7432711 Radial coil arrangement for a magnetic resonance apparatus  
A coil arrangement for a magnetic resonance apparatus has a number of coil elements that are capable of being operated independently of one another and are situated around a common central area....
7425827 Method and apparatus for formation evaluation and borehole size determination  
The quality factor of a NMR-antenna depends upon mud conductivity, formation resistivity and the borehole size. The Q of the antenna is measured. From measurement of one of formation conductivity...
7423426 Selective excitation in earth's magnetic field nuclear magnetic resonance well logging tool  
A downhole nuclear magnetic resonance method for measuring a property of a formation, the method includes applying a polarizing magnetic field to the formation, the field including a spatial...
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...
7417426 Compact and portable low-field pulsed NMR dispersion analyzer  
A compact and integrated portable device is provided for the analysis of dispersions by low-field pulsed NMR including: an NMR probe module, a means for generating radio frequency and magnetic...
7405563 Compensation of magnetic influence in a MWD system  
The present disclosure provides a downhole tool that includes a magnetometer and a nuclear magnetic resonance (NMR) sensor. One or more compensating magnets are provided on the tool to cancel or...
7397240 Method of measuring rock wettability by means of nuclear magnetic resonance  
A method for measuring the wettability of rocks by low-field nuclear magnetic resonance is described which has application for hydrocarbon reservoir engineering or development, or in civil...
7388374 Interpretation methods for NMR diffusion-T2 maps  
A method is disclosed for interpretation of multi-dimensional nuclear magnetic resonance data taken on a sample of an earth formation. Specifically, a set of NMR data is acquired for a fluid sample...
7388373 Method of determining the permeability of an underground medium from NMR measurements of the permeability of rock fragments from the medium  
Method of determining the permeability of an underground medium from NMR logs of the permeability of rock fragments from the medium, based on prior calibration of the permeability resulting from...
7372264 Contamination estimation using fluid analysis models  
Methods and systems are described for estimating of the level of contamination of downhole fluid using physical property measurements, and mathematical modeling of contamination functions and fluid...
7372263 Apparatus and method for measuring cased hole fluid flow with NMR  
A method and apparatus useful to determine characteristics of fluid flow, such as fluid holdup and flow velocity. The apparatus comprises a flow tube, a permanent magnet, a first set of coils, and...
7368909 Downhole high resolution NMR spectroscopy with polarization enhancement  
An apparatus and method is discussed for characterizing a fluid sample downhole of aliphatic hydrocarbon compounds, aromatic hydrocarbon compound, or connate mud filtrates containing carbon-13...
7363161 Pore-scale geometric models for interpretation of downhole formation evaluation data  
The grain size of a pore-scale geometric model of a clastic earth formation are adjusted so that the NMR relaxation time distribution output of the model matches a measured NMR distribution. Fluid...
7359845 Method and system for predictive stratigraphy images  
Methods and systems are provided for displaying and forecasting the lithology and wellbore conditions to be encountered while conducting drill string operations in a wellbore. A method and system...
7358725 Correction of NMR artifacts due to axial motion and spin-lattice relaxation  
NMR spin echo signals are corrected for axial motion of the borehole logging tool. The correction is applied to an averaged echo train using an average velocity determined from surface measurements...
7352179 Methods and apparatus for measuring capillary pressure in a sample  
A method and apparatus are provided for measuring a parameter such as capillary pressure in porous media such as rock samples. The method comprises mounting a sample in a centrifuge such that...
RE40167 Nuclear magnetic resonance 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...
7336071 Enhancement of NMR vertical resolution using walsh function based inversion  
NMR data are acquired using a phase-alternation of the tipping pulse. Averaged properties are estimated over a window length. The averaged properties are inverted to undo the effects of the...
7330575 Determination of subencoding MRI coil sensitivities in a lower order magnetic field  
A novel magnetic resonance imaging method is presented for forming an image of an object from a plurality of signals acquired by an array of receiver antennae, whereas prior to imaging a...
7309983 Method for determining characteristics of earth formations  
A method for determining a characteristic of earth formations from measurements taken on the formations, includes the following steps: producing a data base that includes a multiplicity of data...
7301339 Estimating the concentration of a substance in a sample using NMR  
A method for estimating a concentration of a substance in a test sample of formation fluid, comprising measuring an NMR parameter of a first sample of formation fluid to obtain a first measurement,...
7301337 Frequency dithering to avoid excitation pulse ringing  
An apparatus and method of obtaining information about a property of interest relating to an earth formation resulting in reduced ringing effects is discussed. A Nuclear Magnetic Resonance (NMR)...
7298142 Method and apparatus for reservoir fluid characterization in nuclear magnetic resonance logging  
A method and apparatus for obtaining a parameter of interest relating to a region proximate a nuclear magnetic resonance (NMR) logging tool suitable for subterranean well logging is disclosed. The...
7295005 Azimuthal NMR imaging while drilling  
NMR measurements are made with a MWD tool having azimuthal sensitivity. The permanent magnet may be a U-shaped magnet or may have an opposed pair of magnets with axial orientation. The tool is...
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...
7268552 Capillary toroid cavity detector for high pressure NMR  
A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity...
7268547 Correction of motion influences in NMR signals  
An apparatus and method for compensating for the effect of tool motion in NMR MWD measurements. Signals obtained from a directionally sensitive receiver are compensated for the effects of tool...
7253618 Method for determining more accurate diffusion coefficient distributions of reservoir fluids using Bi-polar pulsed field gradients  
A method for determining a property of a substance in a downhole measurement region includes the following steps: providing a static magnetic field having a static magnetic field gradient in the...
7253617 Method and apparatus for characterizing heavy oil components in petroleum reservoirs  
A method for obtaining a parameter of interest relating to a region investigated by a nuclear magnetic resonance (NMR) tool and a non-NMR tool is disclosed. Data arising from the NMR tool is...
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...
7227355 Method of detecting, quantifying and correcting borehole contaminations from multi-frequency, multi-sensitive-volume NMR logging data  
Spin echo signals measured with a multifrequency NMR logging tool are analyzed to determine if one or more of the regions of examination associated with each of the frequencies has signal...
7224162 System and methods for upscaling petrophysical data  
System and methods for estimating properties of a geologic formation are disclosed. A preferred embodiment includes a method for estimating properties of a geologic formation, comprising the steps...
7221158 Permeability determinations from nuclear magnetic resonance measurements  
Permeability determinations are made from NMR measurements of a logging tool. The NMR measurements are used to find an observed critical spin—spin relaxation time which is used in conjunction...
7196517 Combining NMR and density measurements for determining properties of reservoir fluid  
A method for evaluating formation fluids includes measuring a nuclear magnetic resonance property related to a total volume of the formation fluids, measuring a dielectric property related to an...
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