Abstract: A nuclear magnetic resonance device for subterranean characterization includes a tool body, a peripheral measurement device, and a controller. The tool body includes a permanent magnet located therein, permanent magnet inducing a static magnetic field (B0) in a region of interest. The peripheral measurement device is coupled to the tool body. The measurement device includes a radio frequency coil controllable to generate a radio frequency magnetic field (B1) in the region of interest, receive a response signal, or both. The controller is communicatively coupled to the radio frequency coil and controllable to drive the radio frequency coil, process the response signal, or both.

Abstract: A side-looking Nuclear Magnetic Resonance (“NMR”) logging tool is designed to reduce and/or eliminate a borehole signal. The logging tool includes a magnet assembly having at least two magnets with magnetizations in different directions, thus resulting in a net magnetization that reduces the borehole signal.

Abstract: A method (and apparatus) for NMR relaxation measurements on borehole materials (e.g., drill cuttings, sidewall cores and whole cores) is based on combining an FID signal and spin-echo signals to obtain relaxation properties of a sample having fast relaxation components. The method comprises acquiring NMR signals from the sample, acquiring calibration NMR signals and acquiring a background signal (e.g., ringing after an excitation pulse). The background signal may be acquired using an additional static magnetic field to substantially spoil the NMR excitation volume in the sample. The acquired signals are processed to obtain a nuclear magnetic resonance relaxation property of the sample with at least one (first point) on the relaxation data produced from the FID and with the background data eliminated from the relaxation data.

Abstract: A side-looking Nuclear Magnetic Resonance (“NMR”) logging tool is designed to reduce and/or eliminate a borehole signal. The logging tool includes a magnetic assembly and a radio frequency (“RF”) transceiver antenna. The axial extent of the RF transceiver antenna has a length selected to reduce a borehole signal.

Abstract: NMR logging of hydrocarbon formations may be performed with a gradient multi-frequency NMR technique using an increased packing density of the sensitive volumes such that the radiofrequency (RF) pluses for adjacent sensitive volumes interfere. An exemplary method may include applying first and second sequences of RF pulses at first and second frequencies, respectively, the second sequence being applied at a time interval following the first sequence; acquiring the NMR relaxation data from first and second sensitive volumes corresponding to the first and second frequencies, respectively; and selecting the first and second frequencies and the time interval to allow for interference between the first sequence of RF pulses and the NMR relaxation data from the second sensitive volume in order to increase a signal-to-noise ratio and a signal-to-noise ratio per square root of time of the NMR relaxation data.

Abstract: A subterranean characterization and fluid sampling device includes a tool body, a probing module, and a permanent magnet. The tool body includes a fluid testing module configured to retain a fluid sample and an internal radio frequency coil disposed within the tool body and drivable to generate RF magnetic field B2. The probing module is coupled to the tool body and configured to withdraw the fluid sample from a formation and deliver the fluid sample to the fluid testing module. The probing module comprises an external antenna drivable to generate RF magnetic field B1. The permanent magnet induces static magnetic field B0. The permanent magnet is coupled to the tool body and external to the probing module.

Abstract: An apparatus (and method) for automated measurements on drill cuttings comprising a sample catcher to collect a portion of the drill cuttings directly from a shaker, an at least one pneumatic actuator to move the collected portion from the sample catcher into a measurement sensitivity area created by a measurement module. The measurement module has a hermetically sealed enclosure and placed near the sample catcher. The sensitivity area is formed outside the enclosure and surrounded by the measurement module. The measurement module and the pneumatic actuator are controlled by an external unit placed away from the shaker. The measurement module can be a nuclear magnetic resonance (NMR) measurement module or other measurement module that performs high-throughput bulk sensitive measurements.

Abstract: Nuclear magnetic resonance (NMR) logging tools may be configured for situation-dependent NMR logging operations by including two dissimilar coils that may function in four different modes of operation based on logging conditions including: a resistivity of the fluid, a diameter of the wellbore, a depth into the subterranean formation of the volume of investigation, or a combination thereof. For example, an NMR logging tool with a z-coil and a transversal coil may be useful in generating in a volume of investigation of a subterranean formation either (1) a transversal radiofrequency (RF) excitation with the transversal coil or (2) a quadrature RF excitation with both the z-coil and the transversal coil, where the choice of transversal or quadrature RF excitation is based on the logging conditions; and detecting an NMR signal from the subterranean formation with one of: (1) the transversal coil or (2) both the z-coil and the transversal coil.

Abstract: In some embodiments, an apparatus, system, and method may operate to transmit, using a first transceiver antenna, a common signal into a geological formation, and to receive in response to the transmitting, at the first transceiver antenna, a first corresponding nuclear magnetic resonance (NMR) signal from a first volume of the formation. Additional activity may include receiving, in response to the transmitting, at a second transceiver antenna spaced apart from the first transceiver antenna, the common signal transformed by the formation into a received resistivity signal, as well as transmitting, using the second transceiver antenna, a second corresponding NMR signal into a second volume of the formation different from the first volume of the formation. Additional apparatus, systems, and methods are disclosed.

Abstract: Nuclear magnetic resonance (NMR) tools, logging systems, and methods for measuring NMR properties of earth formations in a region of interest are provided. The NMR tool includes an antenna assembly, a magnet assembly, a compensating assembly, and a motion sensor. The antenna assembly is operable to generate a radio-frequency magnetic field and the magnet assembly is operable to generate a static magnetic field. The motion sensor is operable to generate readings for lateral motion of the antenna and magnet assemblies. The compensating assembly contains at least one electromagnet and is operable to reduce variation of the static magnetic field in the region of interest due to the lateral motion during NMR measurements based on the readings for the lateral motion.

Abstract: In some aspects, a downhole nuclear magnetic resonance (NMR) tool includes a magnet assembly and an antenna assembly. The NMR tool can operate in a wellbore in a subterranean region to obtain NMR data from the subterranean region. The magnet assembly produces a magnetic field in a volume about the wellbore. The magnet assembly includes a central magnet, a first end piece magnet spaced apart from a first axial end of the central magnet, and a second end piece magnet spaced apart from a second axial end of the central magnet. The antenna assembly includes a transversal-dipole antenna. In some cases, orthogonal transversal-dipole antennas produce circular-polarized excitation in the volume about the wellbore, and acquire a response from the volume by quadrature coil detection.

Abstract: An apparatus (and method) for automated NMR relaxation measurements on borehole materials (e.g., drill cuttings, sidewall cores and whole cores) includes a sample cassette and a sample transfer system operating synchronized with the NMR experiment. The apparatus implements an automatic calibration, adaptive data stacking and automated measurements of the sample volume for irregular shaped samples. The measurements throughput may be increased by creating more than one excitation/detection volume during a measurement cycle. The NMR surface data may be interpreted together with other bulk sensitive measurement data (e.g. natural gamma ray spectroscopy) or/and downhole data to evaluate earth formations while drilling an oil well.

Abstract: A subterranean characterization and fluid sampling device for analyzing a fluid from a subterranean formation includes a controller, a tool body, and a probing module. The tool body includes a fluid testing module configured to receive a sample of the fluid from the subterranean formation and a permanent magnet configured to induce a static magnetic field (B0). The probing module is coupled to the tool body and separate from the permanent magnet, and configured to withdraw the fluid from the formation and deliver the fluid to the testing module. The probing module comprises an antenna that generates a radio frequency magnetic field (B1) in response to a signal from the controller.

Abstract: Nuclear magnetic resonance (NMR) method, system, and sensing device for downhole measurements. The NMR device for characterizing a subterranean zone comprises a tool body, a magnetic element, and a radio frequency coil. The tool body comprises an uphole end and a downhole end, where a longitudinal axis extends through the uphole end and downhole end. The magnetic element is located within the tool body and generates a static magnetic field (B0) in a longitudinal direction at a region of the subterranean zone. The radio frequency coil is located within the tool body and generates a radio frequency magnetic field (B1). The magnetic element and the radio frequency coil enable a side-looking NMR mode.

Abstract: NMR properties of earth formations are determined using a logging device movable in a borehole. The logging device includes a magnet assembly to generate a static magnetic field and an antenna expandable from the surface of the magnet assembly into the borehole toward the borehole wall to increase the magnetic dipole moment of the antenna. The logging device can be lowered or raised through a drill pipe with the magnet assembly being configured to generate no magnetic field while the device is conveyed within the drill pipe. The logging device may also include a side-looking sensor to acquire fast relaxation component of the NMR signals.

Abstract: A nuclear magnetic resonance device for subterranean characterization includes a tool body, a peripheral measurement device, and a controller. The tool body includes a permanent magnet located therein, permanent magnet inducing a static magnetic field (B0) in a region of interest. The peripheral measurement device is coupled to the tool body. The measurement device includes a radio frequency coil controllable to generate a radio frequency magnetic field (B1) in the region of interest, receive a response signal, or both. The controller is communicatively coupled to the radio frequency coil and controllable to drive the radio frequency coil, process the response signal, or both.

Abstract: A nuclear magnetic resonance logging tool is provided. The tool includes a flexible or semi-flexible circuit board, at least one capacitor mounted on board, and a controller programmed to apply sequential pulses to the at least one capacitor of the tool with a spacing of less than 600 ?s between adjacent pulses. Ring down time induced by the at least one capacitor in response to pulses is less than about 200 ?s.

Abstract: NMR properties of earth formations are determined using a logging device movable in a borehole. The logging device includes a magnet assembly to generate a static magnetic field and an antenna expandable from the surface of the magnet assembly into the borehole toward the borehole wall to increase the magnetic dipole moment of the antenna. The logging device can be lowered or raised through a drill pipe with the magnet assembly being configured to generate no magnetic field while the device is conveyed within the drill pipe. The logging device may also include a side-looking sensor to acquire fast relaxation component of the NMR signals.

Abstract: A side-looking Nuclear Magnetic Resonance (“NMR”) logging tool is designed to reduce and/or eliminate a borehole signal. The flipping angle of an RF refocusing pulse or excitation pulse emitted by the logging tool is manipulated to reduce the borehole signal.

Abstract: A side-looking Nuclear Magnetic Resonance (“NMR”) logging tool is designed to reduce and/or eliminate a borehole signal. The logging tool includes a magnetic assembly and a radio frequency (“RF”) transceiver antenna. The axial extent of the RF transceiver antenna has a length selected to reduce a borehole signal.