A system and method of determining a density of a drilling fluid in a wellbore. The system includes a drill string in the wellbore, the drill string including a downhole rotor. A drilling fluid flowing through the drill string in the wellbore causes the downhole rotor to rotate relative to the drill string. A brake is configured to apply a first brake torque to the downhole rotor to place the downhole rotor in a first state. A torque measurement system is configured to determine the applied first brake torque. A rotor speed measurement system is configured to measure a first downhole rotor speed of the downhole rotor having the drilling fluid flowing therethrough with the downhole rotor in the first state. A processor is configured to determine a density of the drilling fluid from the measured first downhole rotor speed, and the determined applied first brake torque.

A method for determining a measurement error caused by a filling error, in particular the presence of gas bubbles, during measurement of the density of a liquid by means of a densimeter having a flexural resonator containing the liquid to be measured. During a measuring operation, a period duration of an oscillation of the flexural resonator induced by an induction unit is measured by a measuring device and the density of the liquid is determined by an evaluation unit.

A method for determining a measurement error caused by a filling error, in particular the presence of gas bubbles, during measurement of the density of a liquid by means of a densimeter having a flexural resonator containing the liquid to be measured. During a measuring operation, a period duration of an oscillation of the flexural resonator induced by an induction unit is measured by a measuring device and the density of the liquid is determined by an evaluation unit.

A method for fills and/or cleans the measurement cell of a measuring instrument, namely a viscometer and/or density measuring instrument, in particular of a rotational viscometer. A sample is introduced via a sample line into the measurement cell by a pump, and wherein a dynamic viscosity and/or density of the sample is determined in the measurement cell. A funnel-shaped, reversibly openable receiving container, in particular a filling funnel, for the sample, is arranged in the sample line, between the pump and the measurement cell. The receiving container is opened and the sample is introduced into the receiving container. The receiving container is connected to the pump via a pressure line in such a way that, when pressure is applied into the receiving container, a proportion of the sample is dispensed out of the receiving container and introduced into the measurement cell.

A method for fills and/or cleans the measurement cell of a measuring instrument, namely a viscometer and/or density measuring instrument, in particular of a rotational viscometer. A sample is introduced via a sample line into the measurement cell by a pump, and wherein a dynamic viscosity and/or density of the sample is determined in the measurement cell. A funnel-shaped, reversibly openable receiving container, in particular a filling funnel, for the sample, is arranged in the sample line, between the pump and the measurement cell. The receiving container is opened and the sample is introduced into the receiving container. The receiving container is connected to the pump via a pressure line in such a way that, when pressure is applied into the receiving container, a proportion of the sample is dispensed out of the receiving container and introduced into the measurement cell.

Some aspects of what is described here relate to analyzing a well cement slurry. In some aspects, a well cement slurry is mixed in a mixer under a plurality of conditions. The plurality of conditions correspond to a plurality of distinct Reynolds number values for the well cement slurry in the mixer. Power number values associated with mixing the well cement slurry in the mixer under the plurality of conditions are identified. Each power number value is based on an amount of energy used to mix the well cement slurry under a respective one of the plurality of conditions. Values for parameters of a functional relationship between power number and Reynolds number are identified based on the power number values and the Reynolds number values for the plurality of conditions.

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 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 method for determining a measurement error caused by a filling error, in particular the presence of gas bubbles, during measurement of the density of a liquid by means of a densimeter having a flexural resonator containing the liquid to be measured. During a measuring operation, a period duration of an oscillation of the flexural resonator induced by an induction unit is measured by a measuring device and the density of the liquid is determined by an evaluation unit.

A method for determining a measurement error caused by a filling error, in particular the presence of gas bubbles, during measurement of the density of a liquid by means of a densimeter having a flexural resonator containing the liquid to be measured. During a measuring operation, a period duration of an oscillation of the flexural resonator induced by an induction unit is measured by a measuring device and the density of the liquid is determined by an evaluation unit.