Abstract: A method can include accessing a measurement model in memory of a downhole tool; determining an optimal parameter set using a processor of the downhole tool and the measurement model; and performing at least one measurement using at least one sensor of the downhole tool operated according to the optimal parameter set.

Abstract: A method can include performing an operation using a system where the operation depends on a decision made via a digital decision model stored in memory of the system; responsive to a decision state of the digital decision model, transmitting a request to update the digital decision model; and responsive to the request, receiving an updated digital decision model, where the updated digital decision model includes at least one new decision state that improves performance of the operation of the system.

Abstract: Systems and methods for monitoring a crude oil blending process use nuclear magnetic resonance (NMR) sensors which investigate properties of a plurality of crude oil streams that are mixed together to form a crude oil blend. An NMR sensor is also used to investigate the properties of the crude oil blend. The investigated properties may include viscosity. Resulting determinations may be used to control the input streams so that the output stream meets desired criteria. Additional sensors such as spectroscopy sensors, viscometers, and densitometers may be used in conjunction with the NMR sensors.

Abstract: An NMR sensor is configured to make NMR measurements of a fluid and includes a housing defining a chamber. A nonmagnetic cap is deployed in the chamber and divides the chamber into first and second regions. The cap is sized and shaped to define a fluid collector in the first region. A magnet assembly is deployed in the second region and is configured to generate a static magnetic field in the fluid collector. A radio frequency (RF) coil is interposed between the magnet assembly and the cap and is configured to generate an RF magnetic field in the fluid collector. Methods include using the sensor to make NMR measurements of multi-phase fluids such as drilling fluid.

Abstract: A method for evaluating drilling fluid includes making an NMR measurement of a sample of the drilling fluid and inverting the measurements to compute a corresponding T1T2 plot. The T1T2 plot is in turn evaluated to characterize the drilling fluid. In one embodiment, a stability index of the fluid may be computed from multiple NMR measurements made while aging the sample.

Abstract: An NMR well logging tool is provided that includes a sensor and associated electronic circuitry. The sensor includes an array of RF antenna elements. The electronic circuitry includes at least one low-power integrated circuit and a plurality of high-power modules corresponding the RF antenna elements of the array. Each high-power module is coupled to a corresponding RF antenna element of the array and includes an RF amplifier that is configured to amplify RF pulses generated by the at least one low-power integrated circuit and supplied thereto for transmission by the corresponding antenna element. In embodiments, the RF amplifier of each high-power module can include an H-bridge circuit or other suitable RF amplifier.

Abstract: Methods and systems are provided for optimizing well-logging using an optimized wait time determined by analysis nuclear magnetic resonance data to achieve faster and better quality borehole evaluation. The method comprises performing a nuclear magnetic resonance pre-log testing; identifying a wait time for a portion of a signal from the pre-log testing with a long T1 and T2, value at each depth of the pre-log testing, wherein T1 is defined as a longitudinal relaxation time and T2 is a transverse relaxation time ascertained from the nuclear magnetic resonance prelog testing; and constructing a logging program with a logging program wait time being consistent with the wait time identified.

Abstract: Magnet design is provided. A method customizes a magnetic field uniformity of a magnet by introducing one or more gaps between pieces of the magnet assembly.

Abstract: Nuclear magnetic resonance (NMR) relaxation and/or diffusion measurements are used to deduce fluid compositional information such as a chain-length distribution, which may then be used to predict the true boiling points (TBP) of a sample of a complex hydrocarbon fluid mixture, such as a crude oil. The NMR measurements may be considered a fast and portable proxy measurement in estimating fluid TBP distributions in lieu of distillation methods, or the simulated distillation by gas chromatography.

Abstract: An NMR sensor is configured to make NMR measurements of a fluid and includes a housing defining a chamber. A nonmagnetic cap is deployed in the chamber and divides the chamber into first and second regions. The cap is sized and shaped to define a fluid collector in the first region. A magnet assembly is deployed in the second region and is configured to generate a static magnetic field in the fluid collector. A radio frequency (RF) coil is interposed between the magnet assembly and the cap and is configured to generate an RF magnetic field in the fluid collector. Methods include using the sensor to make NMR measurements of multi-phase fluids such as drilling fluid.

Abstract: A method for evaluating drilling fluid includes making an NMR measurement of a sample of the drilling fluid and inverting the measurements to compute a corresponding T1T2 plot. The T1T2 plot is in turn evaluated to characterize the drilling fluid. In one embodiment, a stability index of the fluid may be computed from multiple NMR measurements made while aging the sample.

Abstract: An NMR well logging tool is provided that includes a sensor and associated electronic circuitry. The sensor includes an array of RF antenna elements. The electronic circuitry includes at least one low-power integrated circuit and a plurality of high-power modules corresponding the RF antenna elements of the array. Each high-power module is coupled to a corresponding RF antenna element of the array and includes an RF amplifier that is configured to amplify RF pulses generated by the at least one low-power integrated circuit and supplied thereto for transmission by the corresponding antenna element. In embodiments, the RF amplifier of each high-power module can include an H-bridge circuit or other suitable RF amplifier.

Abstract: A method for evaluating drilling fluid includes making an NMR measurement of a sample of the drilling fluid and inverting the measurements to compute a corresponding T1T2 plot. The T1T2 plot is in turn evaluated to characterize the drilling fluid. In one embodiment, a stability index of the fluid may be computed from multiple NMR measurements made while aging the sample.

Abstract: A method can include performing an operation using a system where the operation depends on a decision made via a digital decision model stored in memory of the system; responsive to a decision state of the digital decision model, transmitting a request to update the digital decision model; and responsive to the request, receiving an updated digital decision model, where the updated digital decision model includes at least one new decision state that improves performance of the operation of the system.

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 method can include accessing a measurement model in memory of a downhole tool; determining an optimal parameter set using a processor of the downhole tool and the measurement model; and performing at least one measurement using at least one sensor of the downhole tool operated according to the optimal parameter set.

Abstract: Nuclear magnetic resonance (NMR) relaxation and/or diffusion measurements are used to deduce fluid compositional information such as a chain-length distribution, which may then be used to predict the true boiling points (TBP) of a sample of a complex hydrocarbon fluid mixture, such as a crude oil. The NMR measurements may be considered a fast and portable proxy measurement in estimating fluid TBP distributions in lieu of distillation methods, or the simulated distillation by gas chromatography.

Abstract: Systems and methods for monitoring a crude oil blending process use nuclear magnetic resonance (NMR) sensors which investigate properties of a plurality of crude oil streams that are mixed together to form a crude oil blend. An NMR sensor is also used to investigate the properties of the crude oil blend. The investigated properties may include viscosity. Resulting determinations may be used to control the input streams so that the output stream meets desired criteria. Additional sensors such as spectroscopy sensors, viscometers, and densitometers may be used in conjunction with the NMR sensors.

Abstract: Small-sized flowlines are provided for use in NMR apparatus. The small-sized flowlines can have a channel with an inner diameter or maximum width of less than 0.2 inch and can be made of sapphire, yttria-stabilized zirconia (YSZ), or extruded polyether ether ketone (PEEK), which are useful in high temperature, high pressure environments such as downhole in a geological formation.

Abstract: A coaxial nuclear magnetic resonance (NMR) probe and related methods are described herein. The coaxial NMR probe includes a housing with a fluid inlet, a fluid outlet, a longitudinal axis, and an interior volume. The housing contains a fluid sample that is analyzed by the probe. The coaxial NMR probe also includes an elongated conductor disposed along the longitudinal axis of the housing. The elongated conductor generates an oscillating electromagnetic field within the interior volume of the housing. The oscillating electromagnetic field produces a NMR signal within the fluid sample. The elongated conductor may also be used to receive this NMR signal. The NMR signal is then analyzed to determine information about the fluid sample. Various NMR pulse sequences for use with this coaxial probe and other coaxial probes are also described herein.