A method and microfluidic device to perform reservoir simulations using pressure-volume-temperature (“PVT”) analysis of wellbore fluids.

In some embodiments, a method includes generating at least a first pulse sub-sequence comprising a number of refocusing pulses at a first flip angle and generating at least a second pulse sub-sequence comprising a number of refocusing pulses at a second, lower flip angle. The method further includes detecting, by a nuclear magnetic resonance (NMR) sensor of a logging tool positioned in a wellbore formed in a subsurface formation, NMR spin-echo signals generated in response to at least the first pulse sub-sequence to acquire a first dataset of transversal NMR relaxation data, detecting, by the NMR sensor, NMR spin-echo signals generated in response to at least the second pulse sub-sequence to acquire a second dataset of transversal NMR relaxation data, and determining a property of the subsurface formation based on the first and second datasets of transversal NMR relaxation data.

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.

Methods and systems are provided that employ a combination of dielectric dispersion measurement(s) and Nuclear Magnetic Resonance (NMR) measurement(s) to determine data that characterizes tortuosity of rock and data that characterizes tortuosity of fluid phases in the rock independently from one another.

A device for generating oscillating signals includes an energy transfer device configured to apply an oscillating signal to a sensitive volume, and a resonant tuning circuit including the energy transfer device. The tuning circuit includes a tuning capacitor configured to cause the tuning circuit to resonate at a selected frequency, and an energy storage device. The transmitting device also includes a controller configured to apply a pulse sequence to the tuning circuit having a series of pulses, the energy storage device configured to retain electrical energy at an end of a first pulse, and discharge the electrical energy to the tuning circuit at an onset of a next pulse of the pulse sequence.

System and methods for nuclear magnetic resonance (NMR) fluid substitution are provided. NMR logging measurements of a reservoir rock formation are acquired. Fluid zones within the reservoir rock formation are identified based on the acquired measurements. The fluid zones include water zones comprising water-saturated rock and at least one oil zone comprising rock saturated with multiphase fluids. Water zones having petrophysical characteristics matching those of the oil zone(s) within the formation are selected. NMR responses to multiphase fluids resulting from a displacement of water by hydrocarbon in the selected water zones are simulated. A synthetic dataset including NMR T2 distributions of multiphase fluids is generated based on the simulation. The synthetic dataset is used to train a machine learning (ML) model to substitute NMR T2 distributions of multiphase fluids with those of water. The trained ML model is applied to the NMR logging measurements acquired for the oil zone(s).

A method and system for transmitting an electromagnetic (EM) signal in a wellbore to improve an open loop system. The method comprises measuring a parameter indicative of a property of a transmitter using a sensor in the wellbore and generating an input signal for the transmitter based at least in part on the measured parameter to correct distortions exhibited by the output signal of the transmitter. The method comprises also comprises applying the input signal to the transmitter to transmit the EM signal corrected for distortions. The system comprises an antenna, a transmitter, a sensor, and a controller. The controller is configured and operable to generate an input signal for the transmitter based at least in part on the measured parameter to correct distortions exhibited by an output signal of the transmitter; and apply the input signal to the transmitter to transmit the EM signal corrected for the distortions.

A method for determining the porosity of a core sample can include: saturating a core sample with a nuclear magnetic resonance (NMR) saturation fluid, wherein the core sample has a permeability of 100 milliDarcy (mD) or less, to achieve a saturated core sample; taking a NMR measurement of fluids in the saturated core sample; determining a porosity of the core sample based on a correlation between the NMR measurement and a NMR signal to fluid volume calibration.

Disclosed is a system and method for sorting copper-bearing ore to select portions having a target copper content. The system includes an analysis and selection station including first magnetic resonance analyzer measuring the copper content of input ore and a controlled diverter to divert portions of the input ore to a collection path when the copper content meets or exceeds a predetermined cut-off value. The predetermined cut-off is adjusted by a controller in response to the first magnetic resonance analyzer. A second magnetic resonance analyzer measures the copper content of the ore in a product path. That measurement is fed back to the controller to fine tune the adjusted cut-off value above, up or down, to optimize the yield of ore having the targeted copper content. The system may include a station for sizing the input ore, a station for sizing the output ore, and a station for sizing waste produced by the system.

A method for NMR measurements on borehole materials, e.g., sidewall cores, is based on performing a standard measurement in substantially homogeneous magnetic fields with a sensitivity volume covering an entire sample and a measurement on a fragment of the sample (local measurement), the fragment having a predetermined volume independent of the irregularities of the sample shape (e.g., irregular shaped edges). The fragment of the sample is selected using a switchable static magnetic field gradient or a localized radio-frequency magnetic field. The homogeneous and the local measurement data are processed jointly to obtain volume normalized NMR relaxation data (in porosity units), the processing also using a calibration sample data. A measurement apparatus with an automated sample transfer can be used to implement the method in order to perform high-throughput NMR relaxation measurements that do not require independent measurement of the sample volume.