A method for operating a nuclear magnetic flowmeter for determining the flow of a slug flow medium flowing through a measuring tube, with which tuning parameters and matching parameters are set for a slug zone a film zone, reflected power is measured over time. If the reflected power in a system set for slug zone is low for the slug zone and high for the film zone and if the reflected power in a system set for film zone is low for the film zone and high for the slug zone, relative dwell time of the slug zone and the film zone in the RF coil and the relative frequency of the slug zones and film zones in the flowing medium are determined using the reflected power with a jump in the value of the reflected power from a high value to a lower value used to trigger measurement initiation.

A method for operating a nuclear magnetic flowmeter for determining the flow of a slug flow medium flowing through a measuring tube, with which tuning parameters and matching parameters are set for a slug zone a film zone, reflected power is measured over time. If the reflected power in a system set for slug zone is low for the slug zone and high for the film zone and if the reflected power in a system set for film zone is low for the film zone and high for the slug zone, relative dwell time of the slug zone and the film zone in the RF coil and the relative frequency of the slug zones and film zones in the flowing medium are determined using the reflected power with a jump in the value of the reflected power from a high value to a lower value used to trigger measurement initiation.

A method for measuring the flow rate of a multi-phase medium flowing through a measuring tube using a nuclear magnetic resonance flow meter can be used to measure the flow rate of a multi-phase medium in a simplified manner. For this purpose, a measuring device is used which implements, at the end of each pre-magnetization path, 2D tomography in the measurement tube cross-sectional plane with stratification in the z direction; the measurement tube cross-sectional plane is subdivided into layers that are thin compared to the measurement tube diameter; nuclear magnetic resonance measurements are carried out in every layer to determine measurement signals, using pre-magnetization paths of different lengths; the flow rates are measured in every layer based on the measurement signals; and the time is determined from the signal ratios of the amplitudes of the measurement signals in every layer.

A method for measuring the flow rate of a multi-phase medium flowing through a measuring tube using a nuclear magnetic resonance flow meter can be used to measure the flow rate of a multi-phase medium in a simplified manner. For this purpose, a measuring device is used which implements, at the end of each pre-magnetization path, 2D tomography in the measurement tube cross-sectional plane with stratification in the z direction; the measurement tube cross-sectional plane is subdivided into layers that are thin compared to the measurement tube diameter; nuclear magnetic resonance measurements are carried out in every layer to determine measurement signals, using pre-magnetization paths of different lengths; the flow rates are measured in every layer based on the measurement signals; and the time is determined from the signal ratios of the amplitudes of the measurement signals in every layer.

A method for operating a nuclear magnetic flowmeter in which the necessary time for determining a longitudinal relaxation time constant of the medium is reduced in comparison to the prior art by at least one nuclear-magnetic measuring process being carried out on a magnetized medium in the measuring tube. The at least one nuclear-magnetic measuring process includes an inversion pulse and acquisition sequences, each acquisition sequence beginning at a starting point in time in respect to the at least one nuclear-magnetic measuring process and has an activating pulse, a first waiting interval, a first refocusing pulse, an echo interval with a duration, a second refocusing pulse, a second waiting interval and a deactivating pulse. An echo signal is measured in the echo interval, and a longitudinal relaxation time constant of the medium is determined using the echo signals.

A method for operating a nuclear magnetic flowmeter in which the necessary time for determining a longitudinal relaxation time constant of the medium is reduced in comparison to the prior art by at least one nuclear-magnetic measuring process being carried out on a magnetized medium in the measuring tube. The at least one nuclear-magnetic measuring process includes an inversion pulse and acquisition sequences, each acquisition sequence beginning at a starting point in time in respect to the at least one nuclear-magnetic measuring process and has an activating pulse, a first waiting interval, a first refocusing pulse, an echo interval with a duration, a second refocusing pulse, a second waiting interval and a deactivating pulse. An echo signal is measured in the echo interval, and a longitudinal relaxation time constant of the medium is determined using the echo signals.

The embodiments of the present application disclose a method and an apparatus for determining flow rates of components of multiphase fluid. The method comprises: performing a first magnetization treatment and a second magnetization treatment on multiphase fluid in a pipeline in a target oil and gas well, respectively, to obtain first magnetized multiphase fluid and second magnetized multiphase fluid; determining a first echo train signal set and a second echo train signal set corresponding to the first magnetized multiphase fluid and the second magnetized multiphase fluid, respectively; determining contents of an oil phase component, a water phase component, and a gas phase component of the multiphase fluid at a specified horizon position, and determining a flow velocity of the multiphase fluid at the specified horizon position; and determining flow rates of the oil phase component, the water phase component and the gas phase component in the multiphase fluid. The technical solutions provided by the embodiments of the present application can improve the accuracy of the determined flow rate of each component of the multiphase fluid.

The embodiments of the present application disclose a method and an apparatus for determining flow rates of components of multiphase fluid. The method comprises: performing a first magnetization treatment and a second magnetization treatment on multiphase fluid in a pipeline in a target oil and gas well, respectively, to obtain first magnetized multiphase fluid and second magnetized multiphase fluid; determining a first echo train signal set and a second echo train signal set corresponding to the first magnetized multiphase fluid and the second magnetized multiphase fluid, respectively; determining contents of an oil phase component, a water phase component, and a gas phase component of the multiphase fluid at a specified horizon position, and determining a flow velocity of the multiphase fluid at the specified horizon position; and determining flow rates of the oil phase component, the water phase component and the gas phase component in the multiphase fluid. The technical solutions provided by the embodiments of the present application can improve the accuracy of the determined flow rate of each component of the multiphase fluid.

A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2) having a magnetic field generator (4), a measuring unit (5) and an antennae unit (6) with an antenna (7). wherein the antennae unit (6) has at least one further antenna (11, 12), that is designed as a coil and is designed for transmitting the excitation signal to the magnetized medium (3) and for detecting the measuring signal over a further measuring section (13, 14) aligned parallel to the longitudinal axis (8) of the measuring tube and located in the magnetic field path (9), and the measuring section (10) and the further measuring section (13, 14) are different.

A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2) having a magnetic field generator (4), a measuring unit (5) and an antennae unit (6) with an antenna (7). wherein the antennae unit (6) has at least one further antenna (11, 12), that is designed as a coil and is designed for transmitting the excitation signal to the magnetized medium (3) and for detecting the measuring signal over a further measuring section (13, 14) aligned parallel to the longitudinal axis (8) of the measuring tube and located in the magnetic field path (9), and the measuring section (10) and the further measuring section (13, 14) are different.