Shear thinning fluids may be useful as calibration fluids for calibrating rheometers with bob/rotor eccentricity and at lower shear rates, which may be particularly useful for calibrating rheometers at well sites that are used for measuring the rheological properties of complex fluids (e.g., wellbore fluids like drilling fluids, cementing fluids, fracturing fluids, completion fluids, and workover fluids). Additionally, high shear rate calibrations may also be performed with shear thinning calibration fluids. Newtonian fluids may be used for high shear rate calibrations in alternate of or in addition to the shear thinning calibration fluid.

The invention relates to a compensation device for the compensation of a phase shift caused a component of an electronic system unit of a vibronic sensor. The compensation device includes a bridging unit for the electrical bridging of at least the electromechanical converter; a signal generator for generating a test excitation signal; a phase detection unit for determining the phase shift between the test excitation signal and a test receive signal that passes through the bridging unit and the component of the electronic system unit; and a computer unit which determines a phase compensation instruction from the first phase shift.

A method is provided for monitoring a flow behavior of mixed components without requiring additional instrumentation or sampling. The method is carried out by determining ratios of the power required to rotate a mixing impeller at different rotational speeds and then comparing the ratios. Characteristics about the mixed components are determined based on differences between the ratios.

An apparatus for checking a need for maintenance of a viscometer measuring consistency of suspension comprises a rigid rod and an elongated cavity in a measuring arm of the viscometer. The rigid rod is matched with the cavity for the rod to be movable in the cavity. The cavity is configured to become mismatched with respect to the rod in response to a bending of the measuring arm, the mismatch indicating a need for maintenance of the viscometer.

A capillary bridge viscometer, comprises an input port (flow in) an output port (flow out) a first capillary tubing arm (R1) in a first hydraulic path between the input port and a first differential detection point (DP+), a second capillary tubing arm (R3) in a second hydraulic path between the first differential detection point (DP+) and the output port (flow out), a third capillary tubing arm (R2) in a third hydraulic path between the input port (flow in) and a second differential detection point (DP−), a fourth capillary tubing arm (R4) in a fourth hydraulic path between the second differential detection point (DP−) and the output port (flow out), an adjustable mechanical flow restrictor (20) in one of the first, second, third, and fourth hydraulic paths, wherein the adjustable mechanical flow restrictor (20) is operative to mechanically adjust a resistance to flow of a fluid while the fluid flows through the adjustable mechanical flow restrictor.

A method for measuring a rheological property of a drilling fluid by using a curved pipe on site includes: step 1: deriving relationship constants between friction coefficients of a drilling fluid through offline checking; step 2: calculating R.sub.ei according to f.sub.ci; step 3: calculating an actual shear stress τw.sub.i and a shear rate γ.sub.i of the drilling fluid in the on-site curved pipe according to the relationship constants and R.sub.ei; step 4: establishing a plurality of on-site models according to τw.sub.i and γ.sub.i; step 5: determining an optimal on-site model according to correlations between τw.sub.i and predicted shear stresses of the plurality of on-site models; and step 6: performing on-site measurement on the rheological property of the drilling fluid according to the optimal on-site model. The method avoids inaccurate rheological measurement due to different types of drilling fluids and improves the measurement accuracy for different types of drilling fluids.

The invention relates to a measuring device and a method for determining rheological properties of a viscous, polymeric mass, wherein the measuring device comprises a rheometer with a container containing the mass and a rotation element that is positionable inside the container, wherein the measuring device provides a relative between the rotation element and the container about an rotation axis that defines an axial direction parallel to the rotation axis and a radial direction perpendicular to the rotation axis, wherein the measuring device comprises one or more normal force sensors for detecting at least a component of the normal force that is exerted onto the container or the rotation element in the axial direction and a radial force sensor for detecting a radial force exerted onto the container in the radial direction.

An apparatus for measuring a viscosity of a fluid is disclosed. The apparatus includes a Parylene coated quartz tuning fork for immersion in the fluid and an electronic circuit to excite a vibration of the Parylene coated quartz tuning fork and measure one or more vibrational parameters of the Parylene coated quartz tuning fork. A computer processor is configured to determine a non-Newtonian viscosity from the vibration of the Parylene coated quartz tuning fork based, at least in part, on a Stokes flow hydrodynamic model. The computer processor is coupled to a memory for storing a calibration curve to determine a Newtonian viscosity of the fluid from the non-Newtonian viscosity of the fluid.

Described is a measuring drive for a measuring instrument, in particular a rheometer. The measuring drive has: i) a motor, ii) a shaft, which is coupled to the motor in such a way that the shaft is drivable by the motor, and iii) an ultrasonic device, which is configured to provide ultrasound to the shaft in such a way that at least a part of the shaft is bearable substantially without contact by the ultrasound. Furthermore, the measuring instrument, a method, and a using are described.

The invention relates to a measuring device and a method for determining rheological properties of a viscous, polymeric mass, wherein the measuring device comprises a rheometer with a container containing the mass and a rotation element that is positionable inside the container, wherein the measuring device provides a relative between the rotation element and the container about an rotation axis that defines an axial direction parallel to the rotation axis and a radial direction perpendicular to the rotation axis, wherein the measuring device comprises one or more normal force sensors for detecting at least a component of the normal force that is exerted onto the container or the rotation element in the axial direction and a radial force sensor for detecting a radial force exerted onto the container in the radial direction.