The measuring system comprises a transducer apparatus with two tubes, each having a lumen surrounded by a wall. A fluid flows through each tube, while the tube is vibrated. An electromechanical-exciter mechanism maintains mechanical oscillations of each of the tubes, and a sensor arrangement registers mechanical oscillations of at least one of the tubes. The transducer apparatus includes two temperature sensors, each being mechanically and thermally conductively coupled with a wall of a respective one of the tubes and adapted to register a measuring point temperature and to convert such into a temperature measurement signal. A measuring- and operating electronics is adapted, with application of the temperature measurement signals, to generate a transducer temperature measured value, which represents a transducer apparatus temperature, which deviates both from each of the measuring point temperatures, such that a magnitude of the transducer temperature measured value is between the measuring point temperatures.

Techniques for determining rheological properties of a fluid include actuating a resonator disposed in a volume that contains a fluid sample to operate the resonator in the fluid sample at a predetermined actuation scheme; measuring at least one characteristic of the resonator based on the operation of the resonator in the fluid sample; comparing the at least one measured characteristic to a rheological model that associates characteristics of the fluid sample to one or more rheological properties; and based on the comparison, determining one or more rheological properties of the fluid sample.

An integrated hydraulic fracture design model that utilizes elastic fluids with high proppant suspension and low required power for injection into a hydrocarbon-bearing, subterranean formation. The integrated physics-based approach utilizes a hybrid friction model to compute viscous and elastic behavior to estimate pressure losses at different pumping conditions coupled with a novel geomechanical model capable of modeling proppant transport with elastic fluids in planar hydraulic fractures and natural fractures. An integrated process to optimize hydraulic fracture design evaluates and quantifies the proppant-carrying capacity of elastic fluids and its impact on the proppant transport process, and low water requirements.

An inline fluid properties measurement device that includes a tube defining an interior space that includes at least one non-cylindrical volume, and having a fluid entrance and exit, and capable of conducting fluid from the fluid entrance to the fluid exit, through the at least one non-cylindrical volume. An excitation and sensing transducer assembly is positioned to torsionally drive the tube and to sense torsional movement of the tube and a controller is programmed to drive the excitation and sensing transducer to drive the tube in torsion, thereby translating the fluid in the at least one non-cylindrical volume, and to sense torsional movement of the tube, thereby producing a sense signal. Finally, a signal analysis assembly responsive to the sense signal to form a measurement of at least one property of the fluid.

A model of the viscoplastic boundary layer of a yield stress fluid is described and, based on which, there is provided a method of estimating the yield stress of a flowing yield stress fluid using one or more vibratory transducers having a vibratory surface in contact with the yield stress fluid, the method comprising: vibrating a vibratory surface of a vibratory transducer to transmit a wave from a vibrating surface into a viscoplastic boundary layer of the flowing yield stress fluid, the wave propagating a distance into the viscoplastic boundary layer; making, using the vibrations of the vibratory transducer, one or more measurements of the degree of damping of vibration; and estimating the yield stress of the flowing yield stress fluid based on the one or more measurements of the degree of damping of vibration. There are disclosed single-frequency, dual-frequency and triple-frequency modes of operation.

A method for evaluating phase stability of an electrode mixture slurry, including the steps of: (S1) introducing the electrode mixture slurry to a rheometer; (S2) applying a first shear rate to the electrode mixture slurry; (S3) applying a second shear rate after applying the first shear rate to the electrode mixture slurry, wherein the second shear rate is higher than the first shear rate; (S4) applying a third shear rate after applying the second shear rate to the electrode mixture slurry, wherein the third shear rate is lower than the second shear rate; and (S5) comparing the shear viscosity at the first shear rate with the shear viscosity at the third shear rate. An apparatus for evaluating phase stability of the electrode mixture slurry is also provided.

A model of the viscoplastic boundary layer of a yield stress fluid is described and, based on which, there is provided a method comprises the steps of: vibrating a vibratory transducer at resonance at a first resonant mode in a yield stress fluid and making a first measurement of the resonant frequency; providing a vibration to liquefy at least a portion of the yield stress fluid around the one or more vibratory transducers; while said portion of the yield stress material is liquefied, vibrating a vibratory transducer at resonance at the first resonant mode in the yield stress fluid and making a second measurement of the resonant frequency; and estimating the yield stress of the yield stress fluid based on the first and second measurements. The vibration to liquefy yield stress fluid around the one or more transducers may be provided by the making of the second measurement at an increased amplitude of vibration relative to the first measurement.

An orthogonal superposition rotational rheometer that applies a rotational torque and an orthogonal axial oscillatory stress to a fluid. The rheometer uses a cylindrical bob in a double wall cup to apply shear rotational and axial forces to the fluid. Openings in the top section of the cylindrical bob reduce surface tension effects on the force measurement. Fluid pumping effects at the bottom of the rheometer's double wall cup are minimized by openings in the inner wall of the double wall cup that allow fluid to be displaced when the bob moves downwards.

A resonant sensor 1908 is used to determine fluid properties, the resonant sensor 1908 comprising a resonator 108 defining a lengthwise axis and having a central vibrational node (140), and a pair of opposed lengthwise end-portions (125); a support structure including a frame (115) and a set of flexible supports (110) extending from the frame to the central vibrational node and thereby supporting the resonator at the lengthwise midpoint; a driving and sensing assembly, adapted to drive the resonator to resonant motion and to sense resultant motion of the resonator and producing a motion sensed signal, responsive thereto; and a control and signal processing network adapted to control the driving and sensing assembly to drive the lengthwise end-portions in rotation about the lengthwise axis, in opposed rotational directions, and responsive to the motion sensed signal to determine at least one fluid property of a fluid under test in response to the motion sensed signal.

A process for evaluating rheological characteristics of an injectable gel including measuring the flexibility, wherein the flexibility is evaluated by measuring the strain at the crossover point of the amplitude sweep. The process may include subjecting an injectable gel to oscillating mechanical stresses to determine G and G as a function of strain () in an amplitude sweep, determining the crossover point as the point at which G and G have the same value, determining the strain .sub.cross at the crossover point, and determining the flexibility of the injectable gel as .sub.cross or proportional to .sub.cross. Further, a method of comparison of dermal fillers by measuring their flexibility and a method of evaluation of dermal filler behavior in human skin by measuring the flexibility.