Abstract: A method for predicting a stick-slip event includes measuring one or more surface properties using a sensor at the surface. The method also includes measuring one or more downhole properties using a downhole tool in a wellbore. The method also includes determining that the one or more surface properties and the one or more downhole properties match a distribution. The distribution occurs before two or more previously-detected stick-slip events. The method also includes determining a likelihood that a stick-slip event will occur based at least partially upon the distribution that the one or more surface properties and the one or more downhole properties match.

Abstract: Design parameters for PDC drill bit are correlated to instances of backward whirl, where backward whirl is detected along a lateral axis in the frequency domain during downhole drilling. Two regimes of backward whirl are described and detected—cutting-induced backward whirl and friction-induced backward whirl—where each regime has different characteristic frequencies, detection methods, and mitigation guidelines. Design parameters are quantified by gauge fullness, drilling efficiency (DE), and whirl index (WI). Design guidelines to mitigate backward whirl are generated by correlating design parameter quantifiers and instances of backward whirl, including both cutting-induced backward whirl and friction-induced backward whirl. Potential drill bit designs are then validated against the generated guidelines in order to mitigate backward whirl in future drilling runs.

Abstract: Embodiments of the present disclosure relate to a tangible, non-transitory, computer-readable medium that stores instructions executable by one or more processors, in which the instructions cause the one or more processors to determine a threshold value associated with an axial acceleration oscillation amplitude at a drill bit, in which the drill bit is a part of a drilling system. The instructions further cause the one or more processors to receive an operating parameter value of the drilling system, compare the operating parameter value with the threshold value, and adjust an operation of the drilling system in response to comparing the operating parameter value with the threshold value.

Abstract: 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.

Abstract: Systems and methods are disclosed for selecting a drill bit design that reduces or eliminates bit induced stick-slip. In some embodiments, each of a set of test drill bits is correlated with stick-slip events, wherein each of the test drill bits has a different design pattern comprising a combination of structural attributes. The design pattern stick-slip correlation includes, for each of the test drill bits, detecting variations in motion of the test drill bit during drilling operation. Stick-slip for each of the test drill bits is detected based on the detected variations in motion of the test drill bits during operation. The correlation further includes in response to detecting stick-slip, recording a stick-slip event in association with the corresponding test drill bit.

Abstract: An apparatus for drilling curved and straight sections of a wellbore is disclosed that in one non-limiting embodiment includes a drilling assembly configured to include a drill bit at an end thereof that can be rotated by a drive in the drilling assembly and by the rotation of the drilling assembly, and wherein the drilling assembly includes: a deflection device that (i) tilts a section of the drilling assembly within a selected plane when the drilling assembly is substantially rotationally stationary to allow drilling of a curved section of the wellbore by rotating the drill bit by the drive; and (ii) straightens the section of the drilling assembly when the drilling assembly is rotated to allow drilling of a straight section of the wellbore.

Abstract: A deviated or horizontal wellbore is drilled in a geologic formation with a multiphase fluid including a gas by a rotating drill bit positioned at a downhole end of a drill string. Portions of the gas are released into the wellbore during the drilling. During the drilling, soundwaves are emitted into the geologic formation from within the wellbore by a set of acoustic emitters attached to the drill string. The received reflected soundwaves are transmitted by the set of solid acoustic couplers to a set of acoustic sensors contacting the solid acoustic couplers. The reflected soundwaves are received by the acoustic sensors. Rock properties of the geologic formation are determined based on the less attenuated reflected soundwaves transmitted to the acoustic sensors by the solid acoustic couplers. A drilling direction of the wellbore is adjusted based on the determined rock properties.

Abstract: A method and apparatuses for testing the blowout preventer (BOP) piping system on a drilling rig for leaks. The method and apparatuses can be used in conjunction with a pressure or volumetric method to more accurately test the BOP for integrity and to shorten the total time of testing.

Abstract: An elongate battery pack for use in MWD drilling apparatus having torsion damping means at one or both ends thereof to reduce or eliminate “high g” rotational accelerations and decelerations being transmitted from the drill string to the battery pack within the MWD apparatus. In one embodiment the torsion damping means comprises torsion limiting means in the form of an electrical connector which allows electrical communication between the battery pack and remaining components of the MWD apparatus, but which allows relative rotational movement between (i) the MWD apparatus and its associated electrical leads connected to the battery pack, and (ii) the electrical leads in the battery pack connected to the battery therein.

Abstract: The operation of rotary equipment carried on elongate structure such as coiled tubing extending into a borehole from the Earth's surface is carried out by providing at least one optical fibre extending downhole to the rotary equipment from the surface, using optical time domain reflectometry to operating the optical fibre as a distributed vibration sensor while the rotary equipment is in operation, and thereby observing vibration created by the rotary equipment.

Abstract: Acoustic anisotropy of downhole formations is determined using statistical analysis. During operation of a downhole system, acoustic slowness measurements are acquired around a borehole extending along a formation. Statistical analysis is performed on the acquired slowness measurements, whereby the maximum and minimum slownesses of the formation are determined.

Abstract: Disclosed embodiments include a distributed nondestructive inspection method and system for slickline cable structural defect and mechanical strength degradation inspection. One method may include transmitting a light pulse along an optical fiber embedded in a slickline cable. A reflected light signal is received from the optical fiber in response to the local strain induced refractive index variation. Defects and mechanical strength degradation may be determined by time-dependent time-domain and frequency-domain data analyses of the dynamic strain signals and power spectral density variation as a function of time and cable location.

Abstract: 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.

Abstract: An apparatus for imaging a borehole wall includes an array of acoustic transducers and a controller. The controller scans a section of the borehole wall with first acoustic beams that are transmitted by a series of sets of acoustic transducers in the array to produce adjacent first acoustic measurements that are spaced a first distance D1 apart along the borehole wall, each set having at least one transducer that is different from an adjacent set, (ii) steers a second acoustic beam along the section of the borehole wall using one set of acoustic transducers in the array to produce adjacent second acoustic measurements that are a second distance D2 apart along the borehole wall, and (iii) images the borehole wall using the first acoustic measurements and the second acoustic measurement to generate a borehole wall image, wherein at least one second acoustic measurement is between adjacent first acoustic measurements.

Abstract: In one aspect, a method of determining the presence of whirl for a rotating tool is disclosed that in one embodiment includes obtaining measurements (ax) of a parameter relating to the whirl of the tool along a first axis and measurements (ay) of the parameter along a second axis of the tool, determining a first whirl in a time domain for the tool using ax and ay measurements, determining a second whirl rate for the tool in a frequency domain from ax and ay measurements and determining the presence of the whirl from the first whirl rate and second whirl rate. The method further quantifies the whirl of the tool from the first and second whirl rates.

Abstract: A method for determining stick slip conditions. The method may include disposing an operating apparatus in fluid communication with a pressure wave transmission medium. At least one pressure measurement device may be disposed at least partially within the pressure wave transmission medium and at some distance from the operating apparatus. One or more pressure waves generated by the operating apparatus may be measured within the pressure wave transmission medium with the at least one pressure measurement device and pressure measurement data may be generated therefrom. The pressure measurement data from the at least one pressure measurement device may be transmitted to a data acquisition system. The pressure measurement data may be analyzed to detect one or more stick slip conditions from one or more variations in the pressure measurement data.

Abstract: A cutting element for an earth-boring tool includes an elongated body having a longitudinal axis, a generally planar volume of hard material attached to the elongated body, and a sensor affixed to the elongated body. The sensor may be configured to sense at least one of stress and strain. An earth-boring tool includes a cutting element disposed at least partially within a pocket of a body. Methods of forming cutting elements comprise securing a generally planar volume of hard material to an elongated body, attaching a sensor to the elongated body, and configuring the sensor. Methods of forming earth-boring tools comprise forming a cutting element and securing the cutting element within a recess in a body of the earth-boring tool. Methods of forming wellbores comprise rotating an earth-boring tool comprising a cutting element and measuring at least one of stress and strain.

Abstract: A system, method and apparatus for determining wear on a component of a tool is disclosed. An oscillating member receives a particle freed from the component as a result of the wear on the component. A measuring device measures a change in a parameter of the oscillating member resulting from receiving the particle. A processor determines the wear on the component from the change in the parameter. In one embodiment, the component may include a component of a downhole tool.

Abstract: A system and method for monitoring underground drilling in which vibration is monitored by creating a model of the drill string using finite element techniques or finite difference techniques and (i) predicting vibration by inputting real time values of operating parameters into the model, and then adjusting the model to agree with measured vibration data, (ii) predicting the weight on bit and drill string and mud motor speeds at which resonance will occur, as well as when stick-slip will occur, so that the operator can avoid operating regimes that will result in high vibration, (iii) determining vibration and torque levels along the length of the drill string based on the measured vibration and torque at one or more locations, (iv) determining the remaining life of critical components of the drill string based on the history of the vibration to which the components have been subjected, and (v) determining the optimum drilling parameters that will avoid excessive vibration of the drill string.

Abstract: A pneumatic vibration isolating suspension is disclosed for supporting a payload on a moving carrier while suppressing the transmission of vibrations in the 1 to 50 Hz band between the carrier and the payload. The disclosed invention can be deployed in the air in a towed carrier or sonde, and operated from aircraft power, making it a suitable platform for airborne geophysical instrumentation. It also has particular application to airborne electromagnetic surveying operating in the same frequency band because the sensor vibrations that result in noise created by the modulation of the sensor coupling with the earth's magnetic field are suppressed. Furthermore, the invention can be constructed from resistive composite materials and non-magnetic metals, so it can be operated without producing significant modification to the ambient electromagnetic field being measured.

Abstract: Method to estimate severity of downhole vibration for a wellbore drill tool assembly, comprising: identifying a dataset comprising selected drill tool assembly parameters; selecting a reference downhole vibration index for the drill tool assembly; identifying a surface parameter and calculating a reference surface vibration attribute for the selected reference downhole vibration index; determining a surface vibration attribute derived from at least one surface measurement or observation obtained in a drilling operation, the determined surface vibration attribute corresponding to the identified surface parameter; and estimating a downhole vibration index by evaluating the determined surface vibration attribute with respect to the identified reference surface vibration attribute.

Abstract: An apparatus for estimating at least one of a dynamic motion of a portion of interest of a drill string and a static parameter associated with the portion of interest, the apparatus having: a plurality of sensors operatively associated with the drill string at at least one location other than the portion of interest; and a processing system coupled to the plurality of sensors, the processing system configured to estimate at least one of the dynamic motion and the static parameter using a measurement from the plurality of sensors as input.

Abstract: A system and method for monitoring underground drilling in which vibration is monitored by creating a model of the drill string using finite element techniques or finite difference techniques and (i) predicting vibration by inputting real time values of operating parameters into the model, and then adjusting the model to agree with measured vibration data, (ii) predicting the weight on bit and drill string and mud motor speeds at which resonance will occur, as well as when stick-slip will occur, so that the operator can avoid operating regimes that will result in high vibration, (iii) determining vibration and torque levels along the length of the drill string based on the measured vibration and torque at one or more locations, (iv) determining the remaining life of critical components of the drill string based on the history of the vibration to which the components have been subjected, and (v) determining the optimum drilling parameters that will avoid excessive vibration of the drill string.

Abstract: A system for imaging rock formations while drilling a wellbore includes a drill collar and a plurality of acoustic emitting transducers mounted in the drill collar at angularly spaced apart locations and oriented to emit acoustic energy at least one of laterally away from the drill collar and longitudinally away from the drill collar. A plurality of arrays of acoustic transducers arranged is longitudinally along the drill collar and angularly spaced apart from each other. Each transducer in the plurality of arrays is oriented normal to a longitudinal axis of the collar. Angular spacing between adjacent arrays is selected to provide lateral beam steered receiving response having a selected main lobe width and side lobe response for a plurality of rock formation acoustic velocities. A controller selectively actuates the emitting acoustic transducers at selected times.

Abstract: A system is disclosed that includes a pipe and a device for measuring and storing vibration data related to the use of the pipe and its remaining lifespan. The data can be collected wirelessly using a radio frequency device.

Abstract: An apparatus for measuring strain on a downhole component includes: at least one strain sensitive device disposed proximate to a surface of a component of a drilling assembly or disposed within a material forming the component; and a processor in operable communication with the at least one strain sensitive device, the processor configured to detect changes in the at least one strain sensitive device and detect at least one of erosion, crack formation and crack propagation in the component surface. An apparatus for measuring strain on a downhole component includes: at least one strain gauge deposited on a surface of a drive shaft or disposed within a material forming the drive shaft; and a processor in operable communication with the at least one strain gauge, the processor configured to detect changes in the at least one strain gauge and detect conditions affecting operation of the drive shaft.

Abstract: A stabilized field sensor apparatus collects field data, in particular magnetic field data, with reduced motion noise. The apparatus includes a tear drop shaped housing, a tow frame in the housing, a plurality of vibration isolating dampers spaced around the frame, a base assembly mounted to the dampers, a support pedestal having a bottom end fixed to the base assembly and an upper free end, a single spherical air bearing connected to the upper free end of the pedestal, an instrument platform with a lower hollow funnel having an upper inside apex supported on the air bearing for a one point support, principal and secondary gyro stabilizers for maintaining pivotal and rotational stability, and at least one field sensor mounted to the instrument platform for collecting the field data while being stabilized against motion noise including vibration, pivoting and rotation from the base assembly, from the tow frame and from the housing.

Abstract: Various micro-sonic density imaging-while-drilling systems and methods are disclosed. In at least some forms, the micro-sonic logging tool is embodied in a drill collar having at least one stabilizer blade. One or more acoustic transmitters are set in a distal face of the stabilizer blade to generate acoustic waves. One or more receivers can also be set in the distal face of the stabilizer blade to detect P-waves and S-waves that have propagated through the formation making up the borehole wall. Processing circuitry measures the velocity or slowness of the acoustic waves and optionally associates the measured values with a spot on the borehole wall as identified. Multiple transmitters can be used if it is desired to obtain compensated measurements. The tool can further include a fluid cell to measure acoustical properties of the borehole fluid, which can be used to convert the formation slowness measurements into density measurements.

Abstract: Determining constituent components of a fluid sample. At least some of the illustrative embodiments are methods including: creating electromagnetic energy with a wavelength in the infrared region; directing the electromagnetic energy into a fluid sample; modulating the electromagnetic energy at a modulation frequency; directing the electromagnetic energy that passes through the fluid sample to a first resonant chamber, the first resonant chamber has an acoustic resonant frequency substantially equal to the modulation frequency; absorbing at least a portion of the electromagnetic energy by a detector fluid within the first resonant chamber; detecting acoustic energy within the first resonant chamber; and determining a first constituent component of the fluid sample based on the acoustic energy within the first resonant chamber.

Abstract: Methods and related systems are described relating to a sealed acoustic transducer assembly for use in a wellbore is provided. A tool body is deployed in the wellbore, having a groove and a sealed acoustic transducer assembly removeably mounted therein. The transducer assembly includes an acoustic transducer element, and an elongated fluid filled sealed container housing the transducer element. The container includes flexible portions along the length of the container which allows for volume changes when exposed to changes in external pressure and/or temperature. Acoustic measurements downhole are made using the transducer element.

Abstract: Vibrating wire viscometers are described. Some example vibrating wire viscometer housings include a flowline through the housing to expose a first wire to a downhole fluid, a cavity in the housing to hold a magnet and to conduct one or more additional wires from the flowline to a signal generator, first and second electrically conductive posts mechanically coupled to the housing to hold the first wire in tension within the flowline, and a seal mechanically coupled to the housing to prevent access to the magnet by the downhole fluid.

Abstract: A system for imaging rock formations while drilling a wellbore includes a drill collar and a plurality of acoustic emitting transducers mounted in the drill collar at angularly spaced apart locations and oriented to emit acoustic energy at least one of laterally away from the drill collar and longitudinally away from the drill collar. A plurality of arrays of acoustic transducers arranged is longitudinally along the drill collar and angularly spaced apart from each other. Each transducer in the plurality of arrays is oriented normal to a longitudinal axis of the collar. Angular spacing between adjacent arrays is selected to provide lateral beam steered receiving response having a selected main lobe width and side lobe response for a plurality of rock formation acoustic velocities. A controller selectively actuates the emitting acoustic transducers at selected times.

Abstract: A downhole tool damage detection method includes transmitting ultrasonic energy through a downhole tool, receiving ultrasonic energy transmitting through the downhole tool, monitoring the received ultrasonic energy for changes over time and alerting that at least partial unthreading of a threaded connection in the downhole tool may exist in response to finding the changes.

Abstract: Stoneley-wave data acquired in the LWD environment are used to characterize/estimate formation permeability. Real-time Stoneley-wave time-delay/slowness and center-frequency/attenuation data are used to indicate/characterize formation permeability even during drilling. The use of stabilizers mounted at the tool ends helps maintain the tool position from severe decentralization, reducing ambiguities in the permeability characterization/estimation.

Abstract: Acoustic monitoring of a conduit, a wellbore or a reservoir associated with hydrocarbon production or transportation and/or carbon dioxide sequestration is carried out using a fibre optic cable extending along or appurtenant to it as a distributed interferometer. Coherent Raleigh noise generated by the transmission of the coherent beam of radiation through the fiber optic is detected and processed to identify an acoustic occurrence.

Abstract: The disclosure is directed to methods and apparatuses for estimating a response relating to a formation by stressing a wall of a borehole during either wireline or while drilling deployment. The response may be estimated by stressing the wall of a borehole formed in the formation; and estimating a response of the borehole wall to the stress. The response may be estimated using a force module configured to induce the stress around borehole and a tool configured to estimate the response of the borehole wall to the stress.

Abstract: A downhole tool includes circumferentially spaced and/or angled transducer elements. In one embodiment a standoff sensor has at least three piezoelectric transducer elements, at least a first element of which is configured to both transmit and receive ultrasonic energy. At least second and third of the elements are configured to receive ultrasonic energy transmitted by the first element in pitch catch mode. An electronic controller is configured to calculate a standoff distance from the ultrasonic waveforms received at the first, the second, and the third piezoelectric transducer elements. The controller may further be configured to estimate the eccentricity of a measurement tool in the borehole. Exemplary embodiments of the invention may improve borehole coverage and data quality and reliability in LWD caliper logging. In particular, the invention may advantageously reduce or even eliminate blind spots when logging eccentric bore holes.

Abstract: A distributed acoustic wave detection system and method is provided. The system may include a fiber optic cable deployed in a well and configured to react to pressure changes resulting from a propagating acoustic wave and an optical source configured to launch interrogating pulses into the fiber optic cable. In addition, the system may include a receiver configured to detect coherent Rayleigh noise produced in response to the interrogating pulses. The CRN signal may be use to track the propagation of the acoustic wave in the well.

Abstract: A method for preventing a downhole tool from getting stuck in a wellbore, includes: monitoring output of at least one friction sensor mounted on an external surface of the downhole tool; and if the output indicates a high friction condition, then reducing the friction to prevent the tool from getting stuck. A tool and a computer program product are provided.

Abstract: Methods and related systems are described relating to a sealed acoustic transducer assembly for use in a wellbore is provided. One or more acoustic transducer elements, which can be receivers or transmitters, are housed in an elongated fluid filled sealed container. The sealed container is adapted to be removeably mounted to a portion of a drill collar. The container, which for example can be made of thin corrugated metal or rubber, includes flexible portions along the length of the container which allows for volume changes when exposed to changes in external pressure and/or temperature.

Abstract: A multi-phase process fluid is passed through a vibratable flowtube. Motion is induced in the vibratable flowtube. A first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube is determined, and an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property is determined. A corrected intermediate value is determined based on a mapping between the intermediate value and the corrected intermediate value. A phase-specific property of a phase of the multi-phase process fluid is determined based on the corrected intermediate value.

Abstract: Apparatus and method for estimating a downhole parameter include a high-gain semiconductor device having a plurality of semiconductor layers forming an active region, the active region having a bandgap offset that provides device operation through at least the temperature environment of a downhole location, the high-gain semiconductor device being used at least in part to estimate a downhole parameter.

Abstract: Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

Abstract: A method of dynamically balancing a hole enlargement system is disclosed. The method includes modeling the hole enlargement system based on input parameters, simulating the hole enlargement system, adjusting one or more of the input parameters, and repeating the modeling, simulating, and adjusting until a balanced condition is met.

Abstract: A method and apparatus for estimating a property of a fluid downhole are disclosed. The apparatus includes a coated flexural resonator disposed in the downhole fluid. The resonator is coated to reduce effects of adhering surfactants suspended in the downhole fluid. The method uses the coated resonator to estimate a property of the downhole fluid.

Abstract: A method and apparatus for testing a hydrocarbon sample. The apparatus includes a sheath disposed about the hydrocarbon sample container and at least one set of acoustic sensors, wherein the at least one set of acoustic sensors is secured to the sheath, and further wherein at least one set of acoustic sensors produces an acoustic signal having a velocity through the hydrocarbon sample. In addition, the velocity is measured to provide information about the hydrocarbon sample. In other embodiments, the at least one set of acoustic sensors is disposed radially about the hydrocarbon sample.

Abstract: Methods and an apparatus for determining at least one characteristic of an environment are disclosed. A vibrational energy may be imparted into an environment and a magnitude of damping of the vibrational energy may be measured and at least one characteristic of the environment may be determined. Particularly, a vibratory source may be operated and coupled to an environment. At least one characteristic of the environment may be determined based on a shift in at least one steady-state frequency of oscillation of the vibratory source. An apparatus may include at least one vibratory source and a structure for positioning the at least one vibratory source proximate to an environment. Further, the apparatus may include an analysis device for determining at least one characteristic of the environment based at least partially upon shift in a steady-state oscillation frequency of the vibratory source for the given impetus.

Abstract: The present invention provides a chemometric equation to estimate fluid density, viscosity, dielectric constant and resistivity for a formation fluid sample downhole. The chemometric estimates can be used directly as estimated values for fluid density, viscosity, dielectric constant and resistivity for a formation fluid sample downhole. The chemometric estimates can also be plugged into a Levenberg-Marquardt (LM) non-linear least squares fit, as an initial estimate of the parameter to be estimated by the LM fit. If the initial parameter estimate is too far from the actual parameter values, the LM algorithm may take a long time to converge or even fail to converge entirely. The present invention estimates an initial value of a parameter that provides a high probability that the LM algorithm will converge to a global minimum.

Abstract: Embodiments of the present invention include a fiber optic seismic sensing system for permanent downhole installation. In one aspect, the present invention includes a multi-station, multi-component system for conducting seismic reservoir imaging and monitoring in a well. Permanent seismic surveys may be conducted with embodiments of the present invention, including time-lapse (4D) vertical seismic profiling (VSP) and extended micro-seismic monitoring. Embodiments of the present invention provide the ability to map fluid contacts in the reservoir using 4D VSP and to correlate micro-seismic events to gas injection and production activity.

Abstract: The present invention provides a downhole method and apparatus using a flexural mechanical resonator, for example, a tuning fork to provide real-time direct measurements and estimates of the viscosity, density and dielectric constant of formation fluid or filtrate in a hydrocarbon producing well. The present invention additionally provides a method and apparatus for monitoring cleanup from a leveling off of viscosity or density over time, measuring or estimating bubble point for formation fluid, measuring or estimating dew point for formation fluid, and determining the onset of asphaltene precipitation. The present invention also provides for intercalibration of plural pressure gauges used to determine a pressure differential downhole. A hard or inorganic coating is placed on the flexural mechanical resonator (such as a tuning fork) to reduce the effects of abrasion from sand particles suspended in the flowing fluid in which the flexural mechanical resonator is immersed.