A method for determining density and/or mass flow of a compressible medium with a measuring transducer of vibration-type having at least two oscillators, each including a pair of measuring tubes, wherein the pairs of measuring tubes are arranged for parallel flow, wherein the two oscillators have mutually independent oscillator oscillations with mutually differing eigenfrequencies for corresponding oscillation modes. The method includes steps of determining the values of the eigenfrequencies of at least two different oscillator oscillations, determining at least two preliminary density measured values based on the values of the eigenfrequencies, and determining a correction term for one of the preliminary density measured values and/or for a preliminary measured value of flow based on the preliminary density measured values and the values of the eigenfrequencies.

A vibratory cavity density meter (100-300) is provided. The vibratory cavity density meter (100-300) includes a pipe (110-310) extending from a first end (110a-310a) to a second end (110b-310b). The first end (110a-310a) includes an aperture (114-314) configured to receive a material from a container (10) and the second end (110b-310b) is self-enclosed so as to contain the material in the pipe (110-310). The vibratory cavity density meter (100-300) also includes at least one transducer (118, 218) coupled to the pipe (110-310), the at least one transducer (118, 218) configured to one of induce and sense a vibration in the pipe (110-310) to measure a property of the material.

Described is a device for measuring fluid density. The device is a flow meter including a housing with one side configured to mount to a flow conduit and define an outlet flow orifice near one end of the housing. The other side defines an inlet flow orifice near another end of the housing. The housing permits fluid to be introduced into the inlet flow orifice, flow through a flow cavity, and pass from the outlet flow orifice. The flow meter also includes a sensor head near the outlet flow orifice. The sensor head vibrates at a frequency upon introduction of electrical power while in contact with a fluid, detects the vibration frequency of the sensor head, and transmits the detected vibration frequency, which is associated with a density of the fluid. A system and method for determining a fluid density of a fluid using the described device is also disclosed.

A downhole formation fluid identification sensing module for measuring averaged gas molecular weight of wellbore formation fluid acquires simultaneous temperature, pressure, and density measurements. The sensing module includes two venturi-type gas sensors that both contain vibrating tubes. During operation, formation fluid flows through the vibrating tubes whereby resonant frequency measurements are acquired simultaneously with temperature and pressure measurements. Each measurement is then utilized to determine the gas molecular weight of the dry, wet or saturated formation fluid.

A method for determining density and/or mass flow of a compressible medium with a measuring transducer of vibration-type having at least two oscillators, each including a pair of measuring tubes, wherein the pairs of measuring tubes are arranged for parallel flow, wherein the two oscillators have mutually independent oscillator oscillations with mutually differing eigenfrequencies for corresponding oscillation modes. The method includes steps of determining the values of the eigenfrequencies of at least two different oscillator oscillations, determining at least two preliminary density measured values based on the values of the eigenfrequencies, and determining a correction term for one of the preliminary density measured values and/or for a preliminary measured value of flow based on the preliminary density measured values and the values of the eigenfrequencies.

A system is provided that can include a first tube for communicating a fluid through a wellbore. The system can also include a gap between the first tube and a first electromagnetic acoustic transducer (EMAT). The first EMAT can be positioned to magnetically couple with the first tube. The first EMAT can include a magnet and a wire coil positioned around the magnet. The first EMAT can coupled to a power source and positioned to, responsive to receiving a power from the power source, apply a first magnetic force to the first tube for determining a density or viscosity of the fluid.

Systems and Methods for controlling one or more mechanical resonators and determining information from resonant shift of the resonator(s) behavior, including at least one mechanical resonator, an excitation element for driving the resonator(s), a sensor for monitoring the motion of the resonator(s), at least one phase locked loop (PLL) in feedback between the excitation and monitoring elements, wherein each PLL is configured to operate at or near a different resonant mode of the resonator(s), and a processor for determining information from PLL internal signals indicative of a resonator frequency shift.

System, methods, and apparatuses for determining properties of a production fluid downhole are presented. In one instance, a system includes a sample-filled sensing device for vibrating a first suspended tube containing a sample of production fluid and producing a first response signal. The system also includes a reference-fluid sensing device with a second suspended tube containing a viscosity-tunable fluid therein. The system vibrates the second suspended tube to create a second response signal. The viscosity of the viscosity-tunable fluid is varied until it is deemed to match that of the sample production fluid. Other systems and methods are presented.

Systems and Methods for controlling one or more mechanical resonators and determining information from resonant shift of the reonator(s) behavior, including at least one mechanical resonator, an excitation element for driving the resonator(s), a sensor for monitoring the motion of the resonator(s), at least one phase locked loop (PLL) in feedback between the excitation and monitoring elements, wherein each PLL is configured to operate at or near a different resonant mode of the resonator(s), and a processor for determining information from PLL internal signals indicative of a resonator frequency shift.

A downhole formation fluid identification sensing module for measuring averaged gas molecular weight of wellbore formation fluid acquires simultaneous temperature, pressure, and density measurements. The sensing module includes two venturi-type gas sensors that both contain vibrating tubes. During operation, formation fluid flows through the vibrating tubes whereby resonant frequency measurements are acquired simultaneously with temperature and pressure measurements. Each measurement is then utilized to determine the gas molecular weight of the dry, wet or saturated formation fluid.