Abstract: An example includes performing near infra-red (NIR) spectrometry to provide NIR measurement data for a sample compound. The method also includes performing magnetic resonance (MR) spectrometry to provide MR measurement data for the sample compound. The method also includes analyzing, by a computing device, the MR measurement data in view of the NIR measurement data to characterize the sample compound.

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 method for measuring one or more properties of a formation includes applying a magnetic field to a subterranean formation using a downhole tool. A radiofrequency signal is transmitted into the subterranean formation that is exposed to the magnetic field. The radiofrequency signal induces a transverse magnetization in the subterranean formation, and the transverse magnetization induces an initial voltage signal in the downhole tool. The initial voltage signal is amplified using a first amplifier in the downhole tool such that the first amplifier outputs a first amplified voltage signal.

Abstract: A nuclear magnetic resonance (NMR) system includes a transmitter of an NMR tool to output a magnetic field pulse into a zone of interest, a receiver of the NMR tool to output an NMR echo data set produced from an interaction of the magnetic field pulse and the zone of interest, and an NMR echo processing module including a filter matched to a response of the NMR tool to output a filtered NMR echo data set from the NMR echo data set, wherein the filter is matched to an echo shape of the NMR echo data, is matched to an average of a selected signal spectra of the NMR echo data set, or dynamically changes in response to a measurement.

Abstract: Methods and systems for identifying a chemical species within a substance using nuclear quadrupole resonance (NQR) are described herein. One method includes applying a number of NQR perturbation-detection pulse sequences to the substance. Each perturbation-detection pulse sequence includes a perturbation segment applied at a perturbation frequency and a detection segment applied at a second different frequency. As the sequences are applied, the perturbation frequency, the second frequency, or both are varied for each pulse sequence. The method also includes applying a number of NQR reference pulse sequences to the substance at a reference frequency. The reference frequency is varied for each pulse sequence. A chemical species is identified within the substance by comparing (i) a set of NQR signals generated by the perturbation-detection pulse sequences with (ii) a reference set of NQR signals generated by the reference pulse sequences.

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: A method for applying a nuclear magnetic resonance (NMR) sequence is described herein. The method includes applying a series of refocusing pulses to a substance within an inhomogeneous static magnetic field. Each refocusing pulse in the series of refocusing pulses includes a central axis, a total pulse duration greater than t180, and at least five segments (e.g., 5, 7, 11, 20, and 21). The phase of each segment is substantially anti-symmetric about the central axis of the refocusing pulse. In a more particular embodiment, the phase of each segment is also symmetric about the central axis of the refocusing pulse and the five segments include a substantially constant amplitude.

Abstract: A method and system for applying nuclear quadrupole resonance (NQR) sequences to a substance and determining presence of a chemical species within the substance using the sequences are described herein. The method includes applying an NQR pulse sequence to the substance using a non-resonant transmitter circuit. The method further includes detecting a NQR signal within the substance and determining presence of a chemical species within the substance using the NQR signal.

Abstract: A hydrocarbon sample is subjected to a chemically selective J-editing nuclear magnetic resonance (NMR) pulse sequence. Resulting signals are analyzed in order to identify a coupling frequency present in at least one molecule of the hydrocarbon sample. A J-coupling frequency of approximately 150 Hz is indicative of a component having an internal double bonded carbon atom (i.e., an olefin). The presence of an olefin in a hydrocarbon sample can be indicative of the presence of a synthetic based mud (SBM) in the sample.

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: An apparatus, a system, and a chip are provided for improving RF system performance in MRI systems. The apparatus includes a radio-frequency (RF) coil array disposed at least partially in a coil housing, where the RF coil array may include at least one coil configured to receive magnetic resonance (MR) RF signals. The apparatus also includes a mixer disposed in the coil housing and electronically connected to the RF coil array, where the mixer converts MR RF signals from the RF coil array to intermediate-frequency (IF) signals. An electronic amplifier is disposed in the coil housing. The electronic amplifier is electronically connected to the mixer and is configured to amplify IF signals from the mixer to amplified IF signals.

Abstract: A formation fluid sample is analyzed using NMR spectroscopy to obtain a NMR spectrum. The NMR spectrum is then analyzed to find evidence of the amount of olefins present in the sample. The amount of olefins present in the sample can then be correlated to the level of contamination of the sample. In one embodiment, a 1H chemical shift of between substantially 4.5 and 6 ppm is used to identify olefins present in the sample. In another embodiment, a 1H chemical shift of substantially 1.9 to 2.1 ppm is used to identify olefins present in the sample. The NMR spectral equipment can be located uphole or downhole.

Abstract: An NMR system includes a radio frequency (RF) NMR application-specific integrated circuit (ASIC) chip configured to generate an RF output signal and a rectifier configured to receive the RF output signal and convert the RF output signal to (a) a direct current (DC) pulsed field gradient (PFG) signal or (b) a DC trigger signal for at least one of (i) activating at least one component of an NMR system external to the NMR RF ASIC chip and (ii) synchronizing at least one component of an NMR system external to the NMR RF ASIC chip.

Abstract: A non-resonant transmitter for a magnetic resonance (MR) system, such as a nuclear magnetic resonance (NMR) system, is described herein. The transmitter includes a coil for applying NMR pulse sequences to a substance. The coil is coupled to a circuit that includes a capacitor, a number of switches, and a power source. The transmitter operates in two modes. In a charging mode, the switches decouple the coil from the capacitor and the capacitor is charged by the power source. In a discharging mode, a radio frequency pulse is generated and the switches couple and decouple the coil from the capacitor so that the capacitor provides power to the coil. The addition of the capacitor improves the power factor of the circuit and reduces power draw from the power source.

Abstract: A 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 can include a transimpedance amplifier circuit with an input stage that includes a field effect transistor.

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: In one aspect, a nuclear magnetic resonance (NMR) system includes a transmitter of an NMR tool to output a magnetic field pulse into a zone of interest, a receiver of the NMR tool to output an NMR echo data set produced from an interaction of the magnetic field pulse and the zone of interest, and an NMR echo processing module including a filter matched to a response of the NMR tool to output a filtered NMR echo data set from the NMR echo data set. In another aspect, a method of processing an NMR echo data set includes providing from an NMR tool the NMR echo data set produced from an interaction of a magnetic field pulse and a zone of interest, matching a filter to a response of the NMR tool, and filtering the NMR echo data set with the filter to produce a filtered NMR echo data set.

Abstract: Methods and systems for identifying a chemical species within a substance using nuclear quadrupole resonance (NQR) are described herein. One method includes applying a number of NQR perturbation-detection pulse sequences to the substance. Each perturbation-detection pulse sequence includes a perturbation segment applied at a perturbation frequency and a detection segment applied at a second different frequency. As the sequences are applied, the perturbation frequency, the second frequency, or both are varied for each pulse sequence. The method also includes applying a number of NQR reference pulse sequences to the substance at a reference frequency. The reference frequency is varied for each pulse sequence. A chemical species is identified within the substance by comparing (i) a set of NQR signals generated by the perturbation-detection pulse sequences with (ii) a reference set of NQR signals generated by the reference pulse sequences.

Abstract: A method for applying a nuclear magnetic resonance (NMR) sequence is described herein. The method includes applying a series of refocusing pulses to a substance within an inhomogeneous static magnetic field. Each refocusing pulse in the series of refocusing pulses includes a central axis, a total pulse duration greater than t180, and at least five segments (e.g., 5, 7, 11, 20, and 21). The phase of each segment is substantially anti-symmetric about the central axis of the refocusing pulse. In a more particular embodiment, the phase of each segment is also symmetric about the central axis of the refocusing pulse and the five segments include a substantially constant amplitude.

Abstract: A 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 can include a transimpedance amplifier circuit with an input stage that includes a field effect transistor.