Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
  • G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material
  • G01N11/14—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material by using rotary bodies, e.g. vane
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
  • E21B49/008—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor

Definitions

• This invention relates, generally, to apparatus and methods used in measuring torque in a shaft.
• this invention relates to non-contact torsion measurement on a rotating shaft assembly, comprising two rigid shafts segments connected by a flexible torsion member.
• This invention relates to torque measurement in the following conditions while not compromising on performance and accuracy:
• this invention relates to testing apparatus and methods for monitoring mixing torque on liquids, gels, slurries or pastes enclosed under specific pressure and temperature conditions and, in particular, apparatus and methods for testing fluid mixtures and slurries for use in subterranean wellbores under simulated wellbore conditions.
• Two fluids are incompatible if undesirable physical or chemical interactions occur when the fluids are mixed. Incompatibility is characterized by undesirable changes in apparent viscosity and shear stresses. When apparent viscosity of the mixed fluids is greater than apparent viscosity of each individual fluid, they are said to be incompatible at the tested shear rate.
• An example of when compatibility of fluids is important may include the scenario below.
• Known prior art devices used to test fluids for these characteristics include viscometers, rheometers and consistometer. Examples include those illustrated and described in United States Patent Numbers 3,435,666, 4,668,911, 5,535,619 and 6,951,127, which are incorporated herein by reference for all purposes.
• Testing comprises filling a test chamber with a first mixture, bringing the chamber to pressure and temperature test conditions, and then conducting tests of the fluids characteristics.
• apparent viscosity is tested by measuring the torque required to rotate a paddle in a closed or sealed housing containing the test fluid.
• the tests are conducted at elevated temperatures and pressures. For instance rheology measurement applications in harsh conditions, requires an accurate but non-invasive measurement technique.
• these devices use a paddle rotated in a test fluid. The torque required to rotate the paddle in the fluid corresponds to the apparent viscosity of the fluid.
• Non-contact measurements have been previously carried out using optical encoders and non-offset magnetic systems.
• Optical encoders require clear fluids, and non-offset systems need the end of the shaft to be accessible to mount the sensor.
• Prior art systems have been deployed to measure angular displacement only, such as: Gear Tooth Detection Devices; Non-Offset Systems; and Systems with High Proximity between magnet and sensor.
• torque in a shaft can be measured accurately under difficult conditions using a magnetic- detector configuration.
• Permanent magnets placed along the shaft induce current or a voltage output in the detectors and, from the phase shift in the detector outputs, the torque can be calculated, knowing the properties of the shaft.
• the detectors can be used with Hall Effect sensors or other magnetic field sensors to detect magnet polarity.
• Figure 1 is a schematic diagram of the testing apparatus of the present inventions
• Figures 2 - 4, and 6 illustrate a magnet configuration and mounting for use in the present inventions.
• Figure 5 illustrates the non-contact torque measuring device of the present invention on a motor shaft.
• a fluid testing apparatus 10 embodying the method and apparatus of the present inventions.
• the apparatus 10 comprises a housing 12, enclosing a test chamber 14 containing the fluid 16 to be tested.
• the space in the housing 12 above the test chamber can be filled with an inert fluid.
• the housing and the test chamber are sealed enclosures that can be raised in pressure to perform tests on the fluid in the chamber 14.
• a shaft formed by two shaft segments SA and SB extends into housing 12. According to the present inventions, a paddle 18 mounted on shaft SB is rotated in the test chamber 14 while in contact with the test fluid 16 to measure the apparent viscosity of the test fluid.
• a resilient member embodied as a torsion spring 22 with the spring constant k, couples or connects shaft segment SA to shaft segment SB.
• the term "resilient member” refers to a member that has the ability to absorb energy when it is deformed elastically and release that energy upon unloading.
• Resilient members include springs and elastic items that are capable of returning to an original shape or position after having been deformed.
• the spring should be selected with a constant k that is linear (or within Hookean range) for the operating range of the apparatus.
• the spring embodiment could be a Flexural Pivot Bearing, such as the Cantilevered Single Ended Pivot Bearings or the Double Ended Pivot Bearings supplied in various sizes by Riverhawk Flexural Pivots Company of Hartford, New York.
• the shaft segment SA is, in turn, mechanically coupled at 22 to a driver 24.
• the driver 24 is an electrical motor which is coupled to the shaft segment SA through the wall of the housing 12, using a conventional a magnetic coupling 22.
• the magnet coupling has a driver magnet outside the housing coupled by magnetic forces to drive a follower magnet located inside the housing. Suitable bearings (not shown) can be used to maintain the shaft in position in the housing.
• the driver 24 could be mounted in whole or part inside the housing.
• Magnets MA and MB are mounted to rotate with shaft segments SA and SB with their magnetic field substantially perpendicular to the shaft, respectively.
• Detector DA is located outside the housing 12 in the proximity of (distance dl) magnet MA.
• Detector DB is located outside the housing 12 in the proximity of (distance d2) the magnet MB.
• Detectors DA and DB are connected to data processing unit 30 which, in the present embodiment, determines the phase shift between detectors DA and DB when torque is applied to the shaft segments.
• the Processing unit also includes a counter and clock to provide output data regarding the shaft speed and time.
• a display-data storage unit 40 is connected to the output of the unit 30 for recording data from detectors DA and DB and processed data from unit 30.
• Data acquisition can be carried out using the PX14330 card supplied by National Instruments.
• Waveform analysis can be carried out to extract information on phase shift, using standard Digital Signal Processing (DPS) techniques.
• phase detection can be carried out on the waveforms generated by the AMR sensors, using Model 7270 DPS Lock in amplifier and the SR810 or SR830 from Signalrecovery and Stanford Research Systems, respectively.
• test fluid 16 is added to test chamber 14, and the pressure and temperature test conditions are applied.
• Motor driver 24 is activated to rotate shaft A at a speed Omega as illustrated by arrow 26.
• Torsion spring 20 couples shaft segments SA and SB and transfers the rotation of shaft segment SA to shaft segment SB.
• the paddle 18 is rotated in the test fluid 16.
• Contact between the paddle 18 and the test fluid 16 retards the rotation shaft B which, in turn, causes twisting or relative rotation (angular deflection) between shaft segments SA and shaft SB due to the deflection in torsion spring 20.
• torque (measured in force multiplied by distance) is used herein to indicate applying a twisting force to an object to tend to cause rotation.
• Torsion is used herein to describe the shearing stress in a shaft or other object when torque is applied. Torsion, of course, varies from zero at the axis to a maximum at the outside surface of a shaft. By calibrating the device and measuring the relative rotation between shafts A and B, the apparent viscosity of the test fluid 16 can be determined.
• the detectors used in the apparatus of the present invention are Wheatstone bridge-type elements.
• Magnetic field detectors can comprise a coil wound with insulated conducting material.
• These detectors comprise resistive elements whose resistance changes with the orientation of the magnetic field and preferably are Anisotropic Magneto Resistance (AMR) effect sensors supplied by Honeywell Inc.
• AMR Anisotropic Magneto Resistance
• Sensors using this technology are classified as saturation mode or liner mode sensors.
• position sensors HMC1512 supplied by Honeywell Inc
• saturation mode sensors are classified as saturation mode sensors.
• the output of these sensors is an electrical signal and, in some sensors, is in the form of a sinusoidal wave, having twice the frequency of the rotation of the shaft.
• These sensors can be used with Hall Effect Sensors that act as polarity detectors as to which pole of the magnet is rotating.
• the phase shift between the detector outputs is measured to determine applied torque.
• the second kind of AMR detectors that can be used are supplied by Honeywell Inc.
• HMC 1512, 102X, 104X and 105X sensors offered by Honeywell, Inc could be used to infer magnetic field by measuring the voltage response.
• These sensors are available in single-axis, 2-axis and 3-axis configurations to measure the magnetic fields in space. These sensors work on the same principle as saturated mode sensors but provide a full 360-degree detection and exhibit a linear relationship between the output voltage and the magnetic field.
• Giant Magneto Resistance sensors from NVE Corporation may be used in some applications.
• GMR sensors may also use detectors made of multiple turns of coil wound using insulated metal wires such as insulated copper wire which generates induced voltage in the presence of the rotating magnets MA and MB.
• the preferred generally rectangular shape of the magnets A and B is illustrated in Figures 2 - 4.
• This shape is particularly suited to measuring the relative angular position of shafts rotating at high speeds.
• the magnet is identified, generally by reference numeral 30.
• the magnet body can best be described as having a generally rectangular cross section with two opposed, flat faces 32 formed by parallel straight lines and two opposed curved faces 34 formed by arcs.
• the arcs are preferably semicircular.
• the magnet is designed with bore 38 positioned to receive a shaft to be rotated about the geometric center of the generally rectangular cross section.
• the term "generally rectangular” refers to a shape that has sides and is elongated in the direction between its magnetic poles.
• the end faces 36 of the magnet are planar.
• the magnetic field orientation M is diametrical.
• a central bore 38 extends through the magnet between the ends 36.
• the magnet 32 is illustrated clamped onto the shaft SA by a mounting bracket M.
• the bore 38 is of a size to receive shafts A or B for mounting.
• the flat faces 32 are used to fix the magnets in an angular position on the shaft in bracket M.
• the bracket M is fixed to rotate with the shaft SA.
• Bracket M has a bifurcated portion forming a straight sided slot in which the magnet 32 is nested. The sides of the slot fit snugly against the faces 32 to prevent rotation of the magnet 32 with respect to the bracket and shaft.
• a set screw or the like is used to releasable hold the magnet in axial position in the bracket.
• the magnets By mounting the magnets in the manner the magnets can be easily changed out as required.
• the flat faces are replaced with planar faces, giving the magnet a rectangular, cross- sectional shape.
• the magnet is made from materials that can operate at high temperatures, for example, Sm5Col7 or Alnico.
• the size of the magnets are selected such that the minimal measurable magnetic field is at least in the order of the measuring range of the sensor.
• FIG. 5 An alternative application of the present invention is illustrated in Figure 5.
• Motor M drives shaft S which is connected to a load L.
• the motor is located outside a sealed enclosure or housing H (depicted as dotted lines), however, the system is useful in applications where no housing is present, such as where access to the shaft is limited.
• shaft S is twisted by the force applied by the motor to the shaft.
• the torque required to drive the load at a given speed can be measured by installing axially spaced magnets Ml and M2 to rotate with shaft S.
• Detectors-magnet pairs Dl-Ml and D2-M2 sense the position of the shaft at the detectors as shaft rotates.
• Torque in the shaft can be determined by measuring the twist in the shaft between the detectors.
• the two shaft segments are formed into a unitary shaft without the torsion spring used in the Figure 1 embodiment. The actual twist or distortion in the rotating shaft is used to determine the torque in the shaft.
• the housing itself can have an effect on the performance of the measurements.
• the housing which typically holds the pressure and temperature should be formed, at least in part, from non-magnetic materials.
• non magnetic is used to refer to materials that do not stick to magnets, such as materials like SS-316L, inconel 718, MP35N, etc.
• Non-magnetic materials will have a magnetic relative permeability value of about 1.
• the housing will be formed from non-metallic materials so that the magnetic field will be transmitted through the housing wall.
• it is preferable that a portion of the housing structure between the magnet and its sensor will be made out of a non-magnetic material.
• the position of magnet MA on shaft segment SA acts as a reference point against which the position of magnet MB on shaft segment SB is measured.
• the reference point may determined alternatively.
• the reference point may be determined at different locations in the system.
• magnet MA When driver 24 is a motor, magnet MA may be mounted on the motor shaft outside the housing, provided there is no material slippage between the motor and the shaft segment SA. If the driver is coupled to shaft segment SA by a belt, magnet MA may be mounted on the driven pulley shaft.
• the field lines of the magnetic coupling 22 can be sensed as a reference.
• the waveform from the coupling is of the type: Asin(wt+a)+Bsin(2wt+b).
• the primary frequency signal can still be processed on the fly by extracting the multitone information and digital signal processing to filter out the required reference signal [Asin(wt+a)] . Therefore, in one of the embodiments, more than one magnet may be disposed in the mounting location to provide measurements.

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Citations (7)

• 2013
  • 2013-05-22 CA CA2868847A patent/CA2868847A1/fr not_active Abandoned
  • 2013-05-22 WO PCT/US2013/042306 patent/WO2013177332A1/fr not_active Ceased
  • 2013-05-22 EP EP13726085.7A patent/EP2852826A1/fr not_active Withdrawn

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