Abstract: An ultrasonic flowmeter having a measuring tube, a control unit, at least one first ultrasonic measuring unit and a second ultrasonic measuring unit, the measuring tube having a measuring tube interior and a measuring tube longitudinal axis, wherein each of the ultrasonic measuring units is arranged on the measuring tube, wherein each ultrasonic measuring unit has a first ultrasonic transducer and a second ultrasonic transducer, the first and the second ultrasonic transducers spanning a sound measuring section with a sound axis. The sound measuring section and the sound axis penetrate the measuring tube interior for carrying out ultrasonic measurements. To provide an ultrasonic flowmeter for reliable measurement of a multi-phase medium, the sound axis of the first ultrasonic measuring unit and the sound axis of the second ultrasonic measuring unit span a sound measuring plane which extends substantially parallel to the longitudinal axis of the measuring tube.

Abstract: An ultrasonic flowmeter having a measuring tube, a control unit, at least one first ultrasonic measuring unit and a second ultrasonic measuring unit, the measuring tube having a measuring tube interior and a measuring tube longitudinal axis, wherein each of the ultrasonic measuring units is arranged on the measuring tube, wherein each ultrasonic measuring unit has a first ultrasonic transducer and a second ultrasonic transducer, the first and the second ultrasonic transducers spanning a sound measuring section with a sound axis. The sound measuring section and the sound axis penetrate the measuring tube interior for carrying out ultrasonic measurements. To provide an ultrasonic flowmeter for reliable measurement of a multi-phase medium, the sound axis of the first ultrasonic measuring unit and the sound axis of the second ultrasonic measuring unit span a sound measuring plane which extends substantially parallel to the longitudinal axis of the measuring tube.

Abstract: A method for operating a flowmeter for determining the flow of a multiphase medium flowing through a measuring tube using a first and a second measuring device, one of which operates on a tomographic measuring principle and one of which uses a measuring principle based on nuclear magnetic resonance. The first measuring device operates in a different manner from the second measuring device, e.g., using a measuring device operating on the measuring principle of pre-magnetization contrast measurement and having a pre-magnetization section with a constant magnetic field. The magnetic field has at least one component perpendicular to the direction of flow of the multi-phase medium and is generated by using magnetic field generating elements, which are arranged around the measuring tube. Additionally, an assembly for exciting nuclear spin by a RF excitation pulse or a RF excitation pulse sequence is part of the measuring device.

Abstract: A method for operating a nuclear-magnetic flowmeter in which, when determining a velocity of the medium through a measuring tube, the dependency on properties or the state of a medium is at least reduced. The method exciting a first volume of the magnetized medium flowing at a first velocity within a first measuring section to nuclear-magnetic resonances and a first signal sequence is formed characterizing the nuclear-magnetic resonances of the medium in the first volume, and then, exciting a second volume of the magnetized medium flowing at a second velocity within the first measuring section is excited to nuclear-magnetic resonances and a second signal sequence is formed characterizing the nuclear-magnetic resonances of the medium in the second volume. A quotient sequence is determined from each of the first and second signal sequences, and the first velocity and/or the second velocity is/are determined using the quotient sequence.

Abstract: 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.

Abstract: 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.

Abstract: A flowmeter for determining the flow of a multi-phase medium through a measuring tube has a first and a second measuring device, one of which operates on a tomographic measuring principle and one of uses a measuring principle based on nuclear magnetic resonance. The first measuring device operates in a different manner from the second measuring device, e.g., using a measuring device operating on the measuring principle of pre-magnetization contrast measurement and having a pre-magnetization section with a constant magnetic field. The magnetic field has at least one component perpendicular to the direction of flow of the multi-phase medium and is generated by using magnetic field generating elements, which are arranged around the measuring tube. Additionally, an assembly for exciting nuclear spin by a RF excitation pulse or a RF excitation pulse sequence is part of the measuring device.

Abstract: A method for operating a flowmeter for determining the flow of a multiphase medium flowing through a measuring tube using a first and a second measuring device, one of which operates on a tomographic measuring principle and one of which uses a measuring principle based on nuclear magnetic resonance. The first measuring device operates in a different manner from the second measuring device, e.g., using a measuring device operating on the measuring principle of pre-magnetization contrast measurement and having a pre-magnetization section with a constant magnetic field. The magnetic field has at least one component perpendicular to the direction of flow of the multi-phase medium and is generated by using magnetic field generating elements, which are arranged around the measuring tube. Additionally, an assembly for exciting nuclear spin by a RF excitation pulse or a RF excitation pulse sequence is part of the measuring device.

Abstract: A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2), having a magnetic field generator (3) having permanent magnets for generating a magnetic field interfusing the medium over a magnetic field section LM, having a pre-magnetization section LVM located within the magnetic field section LM and having a measuring device also located in the magnetic field section LM including a coil-shaped antenna (4) with the length L1 serving as a measuring antenna. At least one coil-shaped antenna (5) is provided in the pre-magnetization section LVM for generating a pulse or pulse sequence spoiling the magnetization of the medium in the direction of the magnetic field.

Abstract: A method for operating a nuclear-magnetic flowmeter in which, when determining a velocity of the medium through a measuring tube, the dependency on properties or the state of a medium is at least reduced. The method exciting a first volume of the magnetized medium flowing at a first velocity within a first measuring section to nuclear-magnetic resonances and a first signal sequence is formed characterizing the nuclear-magnetic resonances of the medium in the first volume, and then, exciting a second volume of the magnetized medium flowing at a second velocity within the first measuring section is excited to nuclear-magnetic resonances and a second signal sequence is formed characterizing the nuclear-magnetic resonances of the medium in the second volume. A quotient sequence is determined from each of the first and second signal sequences, and the first velocity and/or the second velocity is/are determined using the quotient sequence.

Abstract: 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.

Abstract: A nuclear magnetic flowmeter with a measuring tube through which a multiphase medium can flow and which can be connected to an inlet tube which is located in the flow direction of the medium upstream of the measuring tube and to an outlet tube which is located in the flow direction downstream of the measuring tube. The nuclear magnetic flowmeter is, first of all, characterized essentially in that a medium bypass is assigned to the measuring tube, that the medium bypass includes a bypass tube, an inlet valve and/or an outlet valve and that, for a calibration operation, the bypass tube, on the one hand, can be connected to the inlet tube, and on the other hand, to the outlet tube, specifically via the inlet valve, via the outlet valve or via the inlet valve and via the outlet valve.

Abstract: A magnetization device with a magnetic field which is generated by permanent magnets for variable magnetization of a medium flowing through a tube over a magnetization distance along the longitudinal axis of the tube. The magnetization device improves the quality of the results relative to known nuclear magnetic resonance measurement and analysis methods in that the magnetic field in the medium has a single direction over the magnetization distance.

Abstract: 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.

Abstract: A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2), having a magnetic field generator (3) having permanent magnets for generating a magnetic field interfusing the medium over a magnetic field section LM, having a pre-magnetization section LM located within the magnetic field section LM and having a measuring device also located in the magnetic field section LM including a coil-shaped antenna (4) with the length L1 serving as a measuring antenna. At least one coil-shaped antenna (5) is provided in the pre-magnetization section LVM for generating a pulse or pulse sequence spoiling the magnetization of the medium in the direction of the magnetic field.

Abstract: A flowmeter for determining the flow of a multi-phase medium through a measuring tube has a first and a second measuring device, one of which operates on a tomographic measuring principle and one of uses a measuring principle based on nuclear magnetic resonance. The first measuring device operates in a different manner from the second measuring device, e.g., using a measuring device operating on the measuring principle of pre-magnetization contrast measurement and having a pre-magnetization section with a constant magnetic field. The magnetic field has at least one component perpendicular to the direction of flow of the multi-phase medium and is generated by using magnetic field generating elements, which are arranged around the measuring tube. Additionally, an assembly for exciting nuclear spin by a RF excitation pulse or a RF excitation pulse sequence is part of the measuring device.

Abstract: A magnetization device with a magnetic field which is generated by permanent magnets for variable magnetization of a medium flowing through a tube over a magnetization distance along the longitudinal axis of the tube. The magnetization device improves the quality of the results relative to known nuclear magnetic resonance measurement and analysis methods in that the magnetic field in the medium has a single direction over the magnetization distance.

Abstract: A nuclear magnetic flowmeter with a measuring tube through which a multiphase medium can flow and which can be connected to an inlet tube which is located in the flow direction of the medium upstream of the measuring tube and to an outlet tube which is located in the flow direction downstream of the measuring tube. The nuclear magnetic flowmeter is, first of all, characterized essentially in that a medium bypass is assigned to the measuring tube, that the medium bypass includes a bypass tube, an inlet valve and/or an outlet valve and that, for a calibration operation, the bypass tube, on the one hand, can be connected to the inlet tube, and on the other hand, to the outlet tube, specifically via the inlet valve, via the outlet valve or via the inlet valve and via the outlet valve.

Abstract: A method for reducing longitudinal flow of fluids through an annular space surrounding a permeable well tubular, such as a slotted liner or a sandscreen, in an inflow region of an oil and/or gas production well having: arranging a series of collapsed resilient sealing rings at regular longitudinal intervals around the permeable tubular before lowering the tubular into the well by means of tape and/or a binder which dissolves downhole; placing the tubular in the inflow region of the well; and allowing the tape and/or binder to dissolve, thereby allowing the resilient sealing rings to expand radially in the annular space surrounding the permeable tubular.

Abstract: A method for determining a dimension in a motor is described. By applying Fourier analysis, a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave. Based upon the above, a determination of an angle &dgr; (22) is described, wherein the fifth harmonic term of the sequence of terms is minimized. An electronic motor having a rotor (26) and a set of slot on said rotor surface (36) having a set of magnets (46) with a width &dgr; (22) along the circumference (30) of said rotor surface (36) is described. The width &dgr; (22) is determined by a method that includes applying Fourier analysis thereby a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave.