Abstract: A laboratory NMR methodology (and corresponding laboratory apparatus) defines a sample volume. The method stores downhole tool data corresponding to a hydrocarbon-bearing sample collected from a given subsurface formation. The downhole tool data includes parameters pertaining to magnetic fields used by a downhole tool during a suite of NMR measurements of the given subsurface formation. The sample is positioned in the sample volume of the laboratory apparatus, which applies a static magnetic field in the sample volume. Furthermore, the laboratory apparatus applies a suite of NMR measurements to the sample volume to thereby determine a property of the sample. The NMR measurements of the suite each include a pulse sequence of oscillating magnetic field in conjunction with a pulsed-mode gradient field. The pulsed-mode gradient field is based on the stored downhole tool data corresponding to the sample. A laboratory NMR methodology for optimizing downhole NMR measurements is also described.

Abstract: Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

Abstract: NMR logging in a wellbore is used to monitor an oil reservoir during oil recovery by miscible displacement. Diffusivity distributions found by NMR logging indicate whether one or two phases are present and composition of residual oil. Operation of the oil recovery procedure may be maintained or modified in response to monitoring of the reservoir.

Abstract: A method for determining particle size distribution of a subsurface rock formation using measurements of at least one nuclear magnetic resonance property made from within a wellbore penetrating the rock formation includes determining a distribution of nuclear magnetic relaxation times from the measurements of the at least one nuclear magnetic resonance property. A surface relaxivity of the formation is determined from measurements of a formation parameter. The relaxation time distribution and surface relaxivity are used to determine the particle size distribution.

Abstract: A dipole antenna may be created by surrounding a portion of the continuous conductor with a nonconductive magnetic bead, and then applying a power source to the continuous conductor across the nonconductive magnetic bead. The nonconductive magnetic bead creates a driving discontinuity without requiring a break or gap in the conductor. The power source may be connected or applied to the continuous conductor using a variety of preferably shielded configurations, including a coaxial or twin-axial inset or offset feed, a triaxial inset feed, or a diaxial offset feed. A second nonconductive magnetic bead may be positioned to surround a second portion of the continuous conductor to effectively create two nearly equal length dipole antenna sections on either side of the first nonconductive magnetic bead. The nonconductive magnetic beads may be comprised of various nonconductive magnetic materials, and preformed for installation around the conductor, or injected around the conductor in subsurface applications.

Abstract: A nuclear magnetic resonance relaxation time cutoff between results for a bound-water index of rock and a free-fluid index of the rock is determined. The determination is made based on measured and predicted values for permeability and/or wettability over a set of core plugs. The determination does not require a nuclear magnetic resonance operation performed on the core plugs under irreducible water saturation.

Abstract: A system and method for determining fluid distribution in subterranean reservoirs including determining a water saturation in macroporosity from the capillary pressure data representative of the macroporosity using a saturation height function, correcting capillary pressure data representative of microporosity to have an entry pore value equivalent to a pore size defining the microporosity, determining a water saturation in the microporosity from the corrected capillary pressure data representative of the microporosity, and using the macroporosity water saturation and the microporosity water saturation to estimate fluid distribution within the subterranean reservoir. The system and method may also include the estimation of hydrocarbon reserves.

Abstract: Nuclear Magnetic Resonance (NMR) measurement apparatus, NMR sensors, NMR measurement methods are disclosed to determine NMR properties of engineered flow management structures, and to estimate engineering properties using determined NMR properties. Example engineered flow management structures include engineered water storage, water management, water production, water sampling structures, and/or structures that serve as conduits or barriers to water movement. Technologies disclosed herein are also applicable to measuring properties relating to other fluid and/or gas flow in engineered flow management structures.

Abstract: The present disclosure relates to a method to estimate a subsurface formation property. A downhole logging tool is provided and disposed in a wellbore. Multiple measurements of various measurement types are obtained at various depths of investigation using the downhole logging tool. The multiple measurements may include natural gamma ray measurements, density measurements, resistivity measurements, nuclear measurements, and nuclear magnetic resonance measurements. The signal-to-noise ratio of the measured signals is increased using, for example, lateral stacking and multi-shell inversion. The subsurface formation property is estimated using the increased signal-to-noise ratio signals. The subsurface formation property may include porosity, adsorbed gas volume, free gas volume, bound water volume, free water volume, oil volume, and kerogen volume. A fluid analysis may be performed using a multi-dimensional nuclear magnetic resonance technique.

Abstract: An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus includes: a carrier configured to be conveyed through the borehole; a nuclear magnetic resonance (NMR) instrument disposed at the carrier and configured to perform an NMR measurement on a volume sensitive to the NMR measurement; and a contrast agent disposed in the volume and comprising particles that form a suspension in a liquid, the suspension of particles being configured increase a magnetic field gradient of at least one earth formation material in the volume to change an NMR relaxation time constant of the at least one earth formation material; wherein the NMR measurement on the volume containing the at least one earth formation material and the contrast agent is used to estimate the property.

Abstract: In accordance with an embodiment of the present invention, a method of processing large volumes of data to allow for real-time reservoir management is disclosed, comprising: a) acquiring a first data series from a first reservoir sensor; b) establishing a set of criteria based on reservoir management objectives, sensor characteristics, sensor location, nature of the reservoir, and data storage optimization, etc.; c) identifying one or more subsets of the first data series meeting at least one of the criteria; and optionally d) generating one or more second data series based on at least one of the subsets. This methodology may be repeated for numerous reservoir sensors. This methodology allows for intelligent evaluation of sensor data by using carefully established criteria to intelligently select one or more subsets of data. In an alternative embodiment, sensor data from one or more sensors may be evaluated while processing data from a different sensor.

Abstract: NMR spin echo signals are measured in a borehole during drilling. Signals measured in a plurality of regions of investigation with different depths of investigation in the borehole are processed to give a radial profile of formation properties, including a potential gas kick.

Abstract: Evaluating a formation by lowering a downhole tool in a wellbore penetrating the formation, injecting a fluid into the formation at an injection zone via the downhole tool, and using a formation evaluation sensor to perform a measurement at each of a plurality of locations in the wellbore each proximate the injection zone. At least two of the plurality of measurements are compared, and a formation property is determined based on the comparison.

Abstract: Methods and related systems are described for estimating fluid or rock properties from NMR measurements. A modified pulse sequence is provided that can directly provide moments of relaxation-time or diffusion distributions. This pulse sequence can be adapted to the desired moment of relaxation-time or diffusion coefficient. The data from this pulse sequence provides direct estimates of fluid properties such as average chain length and viscosity of a hydrocarbon. In comparison to the uniformly-spaced pulse sequence, these pulse sequences are faster and have a lower error bar in computing the fluid properties.

Abstract: NMR spin echo signals are measured in a borehole during underbalanced drilling. A magnetic field gradient in the region of examination is selected to suppress an effect of a formation fluid flow on the produced signals, the fluid flow being caused by the excess of the formation pressure over the borehole fluid pressure.

Abstract: Downhole orientation sensing with a nuclear spin gyroscope. A method of sensing orientation of an instrument assembly in a subterranean well can include incorporating an atomic comagnetometer and an optical source into the instrument assembly, and installing the instrument assembly in the well. A downhole orientation sensing system for use in conjunction with a subterranean well can include a downhole instrument assembly positioned in the well, the instrument assembly including an atomic comagnetometer and an optical source which transmits light to the atomic comagnetometer.

Abstract: Technologies applicable to NMR detection of water and hydrocarbons during induced alteration: processes are disclosed. NMR measurements may be used to monitor properties of subsurface fluids within a subsurface formation. NMR measurement devices may be deployed proximal to or within a subsurface formation that contains hydrocarbons. Multiple NMR measurements may be performed during an induced alteration process applied, to the subsurface formation to determine properties of the subsurface formation or fluid as the induced alteration process progresses. Changes in properties of the subsurface formation or fluid may be determined and may be used to determine efficacy of optimize, or otherwise modify the induced alteration process.

Abstract: A method for mineral analysis of a sample based on detection of NQR and/or Local Field Magnetic Resonance (LFMR) signals from a particular substance within a sample includes: setting a frequency of RF pulses to be approximately equal to one of the NQR or LFMR frequencies of the substance; setting a set of parameters of the RF pulses to be optimal for the substance; setting a set of receiving parameters to be optimal for the substance; tuning the probe to maximum sensitivity for the signals detected at predetermined frequency and/or to maximum power transfer efficiency for RF pulses transmitted with the probe; transmitting the RF pulses with the probe at said optimal level during a transmitting period to irradiate the sample and excite an NQR or LFMR signal in the substance, if present; detecting and processing NQR or LFMR signals emitted by the substance; and calculating the concentration of the substance in the sample.

Abstract: A nuclear magnetic resonance (NMR) measurement, at two or more depths of investigation, of a subsurface formation containing formation water and a mud filtrate from a water-base mud is obtained, and the mud filtrate is distinguished from the formation water. A NMR logging tool is disposed in a wellbore penetrating the formation containing the mud filtrate and the formation water and NMR measurements at different radial depths of investigation into the formation are made. The mud filtrate is distinguished from the formation water by determining the relative salinities of the mud filtrate and the formation water. The relative salinities are determined by comparing distribution relaxation times across different depths of investigation or by comparing logarithmic mean values across different depths of investigation.

Abstract: Systems and methods for determining T2 cutoff are described. T2 cutoff can be derived from magnetic susceptibility measurements. By providing a depth curve of T2cutoff, improved permeability estimations from NMR can be generated. By combining a magnetic susceptibility tool and an NMR tool, a dynamic T2cutoff can then be provided, together with the standard NMR log, according to some embodiments. According to some embodiments the improved permeability estimations can be provided automatically and in real time at the wellsite.

Abstract: A method for estimating a property of an earth formation includes: conveying a carrier through a borehole penetrating the earth formation; performing nuclear magnetic resonance (NMR) measurements on a sensitive volume in the formation using an NMR tool disposed at the carrier to provide a distribution of relaxation times; identifying peaks in the distribution of relaxation times; selecting at least one peak based on a characteristic of the at least one peak; and estimating the property using a relaxation time associated with the at least one peak.

Abstract: Processing is described for magnetic resonance measurements of granular material in the reciprocal Fourier domain to determine grain size distribution and/or pore size distribution in the granular material. In some examples, the granular material is a rock from subterranean reservoir containing water, oil, gas or a combination thereof. The processing of the magnetic resonance data can include a Bayesian analysis and can be used to provide information on length scales below the resolution obtained practicably in conventional magnetic resonance imaging experiments.

Abstract: A method and system for performing speed correction on nuclear magnetic resonance logging data is provided. The speed correction performed can be done on a representation of echo data received by a logging tool, and then additively applied to the echo data. Such a process can reduce or remove the amplification of noise in the echo data that is common in conventional methods of speed correction.

Abstract: A method and system for applying nuclear magnetic resonance (NMR) sequences to a substance are described herein. The method includes applying an NMR pulse sequence to the substance using a non-resonant transmitter circuit. The NMR pulse sequence includes a first pulse sequence segment applied at a first frequency to a first shell within the substance and a second pulse sequence segment applied at a second frequency to a second shell. The second pulse sequence segment is initiated before the first shell reaches thermal equilibrium. In some cases, the first pulse sequence segment and the second pulse sequence segment are interposed within each other. Such NMR pulse sequences, with multiple pulse sequence segments, can also be applied to different atomic nuclei.

Abstract: A method and system for determining a nuclear magnetic resonance (NMR) property are described herein. The method includes applying a static magnetic field to a substance and applying an NMR pulse sequence to the substance. The NMR pulse sequence comprises a first pulse sequence segment applied at a first frequency to a shell and a second pulse sequence segment applied at a second frequency. The first pulse sequence segment generates a resonant signal in the shell and the second pulse sequence segment generates a characteristic within the resonant signal. The resonant signal is detected and an NMR property is determined using the characteristic within the detected resonant signal.

Abstract: A broadband magnetic resonance (MR) receiver is described herein. The MR receiver can be used to process nuclear magnetic resonance (NMR) signals. The MR receiver includes a transformer that amplifies the MR signals and a preamplifier that receives the MR signals from the transformer. The preamplifier includes a common-drain amplifier stage and a common-source amplifier stage.

Abstract: An apparatus is disclosed for identifying a fluid and locations of the fluid in a formation of shale having porous kerogen material and an inorganic matrix defining pores and micro-fractures. The apparatus includes: a carrier configured to be conveyed through a borehole penetrating the shale; a nuclear magnetic resonance (NMR) tool disposed at the carrier and configured to perform NMR measurements on the shale, the NMR measurements include a spectrum of transverse relaxation times; and a processor configured to receive NMR measurements on the shale performed by the NMR tool and to identify the fluid and locations of the fluid in the shale using the spectrum of transverse relaxation times.

Abstract: Pulse sequences are applied to a fluid in an earth formation with an external static magnetic field and NMR spin echo signals are obtained. The received NMR signals are affected by internal field gradients due to a contrast in magnetic susceptibility between the grains of the formation matrix and the fluid in the pore space. Processing of the data gives the relaxation time and diffusivity of the fluid.

Abstract: A system and method of characterizing a property of an earth formation penetrated by a borehole are described. The method includes conveying a carrier through the borehole. The method also includes performing an NMR measurement with an NMR tool disposed at the carrier and obtaining NMR data, compressing the NMR data to generate compressed NMR data, and telemetering the compressed NMR data to a surface processor for processing. The method further includes decompressing the compressed NMR data directly to T1 or T2 domain distribution data, and determining the property of the earth formation based on the T1 or T2 domain distribution data.

Abstract: A system and method estimate a property of an earth formation comprising hydrocarbon and non-hydrocarbon components. The method includes conveying a carrier down a borehole penetrating the earth formation, and performing a nuclear magnetic resonance (NMR) measurement on fluid in the earth formation with an NMR instrument disposed at the carrier to provide total NMR measurement data. The method also includes separating the total NMR measurement data into hydrocarbon-resultant NMR measurement data and non-hydrocarbon-resultant NMR measurement data, scaling a portion of the non-hydrocarbon-resultant NMR measurement data based on a correction factor to obtain scaled non-hydrocarbon-resultant NMR measurement data, and estimating the property based on the hydrocarbon-resultant NMR measurement data and the scaled non-hydrocarbon-resultant NMR measurement data.

Abstract: Method and apparatus for estimating a kerogen (organic) porosity of an earth formation. The method may include using at least one processor to estimate a kerogen porosity using NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation. The apparatus may include an NMR tool configured to acquire NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation.

Abstract: Method and apparatus for estimating a parameter of interest of an earth formation using a model based on NMR data, imaging data, and NMR tool response characteristics. The method may include constructing a model of the earth formation. The method may also include constructing a predictive model for estimating the parameter of interest. The apparatus may include an NMR tool and at least one processor configured to estimate the parameter of interest. The apparatus may also include an imaging tool configured to acquire the imaging data.

Abstract: A process using Nuclear Magnetic Resonance (NMR) with pre-determined oil specimens at the earth's surface by which to match the location and lateral boundaries of any and every producible oil reservoir responsive to NMR technology, to provide estimates to useable industry standards of porosity and permeability of said reservoirs for exploration purposes by NMR, to detect and identify depth and direction of faults in any given oil area by NMR, to provide mapping of surveyed areas prior to drilling either offset or wildcat ventures resulting from NMR testing, to evaluate reservoir and production potential in existing oil fields by NMR, to detect the existence of natural gas by NMR, and the ability to condemn any proposed drilling location in view of failure.

Abstract: A method for mineral analysis of a sample based on detection of NQR and/or Local Field Magnetic Resonance (LFMR) signals from a particular substance within a sample includes: setting a frequency of RF pulses to be approximately equal to one of the NQR or LFMR frequencies of the substance; setting a set of parameters of the RF pulses to be optimal for the substance; setting a set of receiving parameters to be optimal for the substance; tuning the probe to maximum sensitivity for the signals detected at predetermined frequency and/or to maximum power transfer efficiency for RF pulses transmitted with the probe; transmitting the RF pulses with the probe at said optimal level during a transmitting period to irradiate the sample and excite an NQR or LFMR signal in the substance, if present; detecting and processing NQR or LFMR signals emitted by the substance; and calculating the concentration of the substance in the sample.

Abstract: Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

Abstract: Estimating and displaying information about the size of molecules within a substance from nuclear magnetic resonance (NMR) maps and/or logs. Methods include utilizing a relationship between the molecular size (e.g., mean chain length), and either a moment of diffusion or a relaxation distribution, to create a scale on a two-dimensional map. In one case, applying the relationship between the molecular size, and either a moment of diffusion or a relaxation distribution, to one-dimensional diffusion or relaxation distributions for the purpose of estimating the mean chain length of molecules within the substance. In another case, a method includes determining mean chain lengths of molecules within a substance and providing a one-dimensional NMR log showing the mean chain lengths at a plurality of depths. In some cases, the NMR log includes actuatable regions for examining two-dimensional NMR maps or chain length distributions of the substance corresponding with distinct depths of the substance.

Abstract: An apparatus and method estimate a property of a fluid flow. The apparatus includes a nuclear magnetic resonance (NMR) tool performing an NMR measurement on the fluid in a sensitive volume. The apparatus also includes a processor receiving the NMR measurement from the NMR tool, determining a frequency or phase change of the spin echo signals from the NMR measurement, and estimating the property using the frequency or phase change.

Abstract: An apparatus detects a fluid flow. The apparatus includes a nuclear magnetic resonance (NMR) tool configured to perform an NMR measurement on the fluid in a sensitive volume by establishing a magnetic field in the sensitive volume and transmitting a sequence of refocus pulses, without a tipping pulse, the NMR measurement comprising spin echo signals. The apparatus also includes a processor configured to detect a presence of the fluid flow in the sensitive volume based on the spin echo signals.

Abstract: Illustrative embodiments are directed to applying a nuclear magnetic resonance sequence to a substance within an inhomogeneous static magnetic field. Various embodiments include applying a series of refocusing pulses to the substance, each refocusing pulse in the series of refocusing pulses having at least two segments, and a total pulse duration less than or equal to approximately 1.414 times T180. Various embodiments can further include applying an excitation pulse to the substance in the inhomogeneous static magnetic field, where the excitation pulse generates an initial magnetization that is aligned with a refocusing axis produced by a refocusing cycle that is performed after the excitation pulse.

Abstract: The present invention relates to making one or more measurements in a virgin formation using a downhole tool that includes a miniature logging tool. The downhole tool is disposed in a wellbore penetrating the formation, adjacent to the formation, and a sidetrack borehole is made into the formation. All or a portion of the miniature logging tool is deployed into the sidetrack borehole and measurements are made in the virgin formation using the miniature logging tool. The downhole tool may include a drilling/coring module, a pump module, and packers. The drilling/coring module is used to make the sidetrack borehole, and the packers and pump module can be used to create an underbalanced drilling condition in an isolated section of the wellbore.

Abstract: A method of correcting accelerometer and magnetometer measurements made in a well is provided. The method includes making a series of triaxial measurements with magnetometers and accelerometers in an interval of the well to derive measured values of gravitational acceleration g, magnetic filed intensity B, and the sine of the magnetic inclination sin I. The method also includes obtaining known values of g, B and sin I for the interval and determining values of a correction to be applied to the measured values by simultaneously minimizing the difference between the measured values and the known values of g, B and sin I for the interval. The method also includes applying the correction to the measured values to obtain in situ corrected values for g, B and sin I.

Abstract: A downhole micro MR analyzer for use in a wellbore, having a micro sample tube, a micro RF coil in close proximity to the micro sample tube, and one or more magnets disposed about the micro sample tube is disclosed. The micro MR analyzer can be used for nuclear magnetic resonance or electron spin resonance experiments to ascertain formation properties and chemical compositions.

Abstract: The present disclosure relates to an integrated nuclear magnetic resonance (NMR) transceiver array, the array including a plurality of integrated NMR transceiver circuits disposed on a single chip. At least one of the plurality of integrated NMR transceiver circuits includes a transmitter that receives and outputs a radio frequency (RF) pulse train and a receiver that receives an NMR signal.

Abstract: A device for ex situ magnetic resonance analysis is disclosed. The device comprises a static magnetic field unit (12) for generating a generally cylindrically symmetric static magnetic field outside the static magnetic field unit, and a radiofrequency unit (14) for generating a generally cylindrically symmetric radiofrequency field outside the radiofrequency unit. The radiofrequency field is perpendicular to the static magnetic field. A spatial inhomogeneity of the magnetic field substantially matches a spatial inhomogeneity of the radiofrequency field.

Abstract: A media displacement device has a body configured to be positioned radially outwards of a tool having an antenna for transmitting electromagnetic energy to or receiving electromagnetic energy from an earth formation. The body is made of materials causing less power loss to electromagnetic energy transmitted or received by the tool than the media the body is configured to displace.

Abstract: Percolation theory is applied to establish a connection between magnetization decay of nuclear magnetic resonance (NMR) measurements and residual carbon dioxide saturation (Scr). As a result, estimations of Scr are obtained through use of an NMR tool in a formation and appropriate processing. Data may be displayed as a log.

Abstract: The present disclosure relates to a method to determine a characteristic of a subsurface formation using a downhole logging tool. A downhole logging tool having the ability to make substantially concurrent disparate measurements on the subsurface formation is provided and substantially concurrent disparate measurements on the formation using the downhole logging tool are made. Those measurements are used to solve a system of equations simultaneously and the solution to the system of equations is used to determine the characteristic of the subsurface formation.

Abstract: Methods for the determination of the Total Gas in Place (TGiP) in gas-bearing formations are provided. Aspects of the subject disclosure also relate to the determination of the TGiP from nuclear magnetic resonance (NMR) logs alone or in combination other well logs.

Abstract: A method of calculating a porosity of a geological formation includes determining a bulk pore volume and a movable fluid pore volume in the geological formation in which drilling mud including a mud filtrate is introduced, calculating a porosity of the formation based on a bulk pore volume, and correcting the porosity based on the movable fluid volume in the geological formation.

Abstract: Methods for detecting a liquid under a surface and characterizing Ice are provided The liquid may be a liquid hydrocarbon such as crude oil or fuel oil or mineral oil The surface may be ice, snow, or water, and the method may be practiced in an arctic region to detect oil spills, leaks, or seepages The methods may be used with a range finder to characterize marine ice The methods may include a nuclear magnetic resonance (NMR) tool with antenna to send a radio-frequency (RF) excitation pulse or signal into volume of substances being detected, detect an NMR response signal to determine the presence of the liquid of interest The NMR response may include a relaxation time element and an intensity level and may include a free induction signal (T2*), a spin echo signal (T2), a train of spin echo signals (T2), or a thermal equilibrium signal (T 1).