Abstract: The position of a droppable object (e.g., a cementing plug or drillpipe dart) in a cased wellbore may be determined in real time during a cementing operation. A pressure data acquisition system is installed at a wellsite and a pressure transducer is installed at the cementing head. As the droppable object travels through casing it encounters regions with a positive or a negative change of inner cross-sectional dimension. The droppable object generates a pressure pulse as it passes through the regions. The pressure pulse and associated reflections are detected by the pressure transducer, and the signals are processed mathematically by a Kalman filter to determine the current position of the droppable object.

Abstract: A device and method for imaging, measuring and identifying multiphase fluid flow in wellbores using phased array Doppler ultrasound. The device includes a radially-configured or ring-shaped ultrasound transducer that when deployed in a well in Doppler mode can measure the velocity of radially flowing fluids in the wellbore and generate a 3D image of radial flow in the wellbore, including flowback into the wellbore after fracturing operations, or flow leaving the wellbore during water injection operations. The ring-shaped ultrasound transducer can also simultaneously operate in a B-mode to generate a B-mode image of the wellbore liner upon which the Doppler image can be overlaid. The device may also include a forward facing ultrasound transducer either instead of or in place of the ring-shaped transducer for obtaining information and images on axial flow in the wellbore in Doppler mode, and the location of phase boundaries and phase locations in B-mode.

Abstract: A non-addressable switch device that is part of a chain of switch devices in a gun string, the non-addressable switch device including a first switch configured to make an electrical connection between an electrical line and another non-addressable switch device of the chain of switch devices; a second switch configured to make an electrical connection between a detonator and the electrical line; and a processor PA connected to the first and second switches and configured to close and open the first and second switches. The processor PA is configured to not use a digital address, and the processor PA is configured to perform one of plural functions based on a corresponding pulse received along the electrical line.

Abstract: A technique facilitates monitoring of parameters related to a downhole operation, e.g. a water injection operation. A completion string may be deployed in a borehole with at least one water injection mandrel combined with a side pocket. A sensor tool is constructed for conveyance down through the completion string and into sealing engagement with the interior surface of the side pocket. The sensor tool comprises at least one sensor for sensing a desired parameter or parameters, e.g. pressure and/or temperature. Additionally, the sensor tool comprises a nose which is positioned to mechanically open a check valve coupled to the side pocket so as to enable monitoring of the desired parameter or parameters via the at least one sensor.

Abstract: An electro-acoustic transducer includes a tubular body extending a longitudinal direction and having two end portions, opposing each other longitudinally, and internally having a first chamber, sending with the first end portion and a second chamber, on one side adjacent to and in fluidic communication with the first chamber and on the other side ending with the second end portion. The first end portion is closed towards the outside by a membrane applied to the tubular body. The second end portion has openings that put it in fluidic communication to the outside of the tubular body. The first chamber containing electrical windings arranged in succession to each other in the longitudinal direction. The second chamber is filled with a liquid. A movable element is housed in the first chamber and has a permanent magnets packaged and arranged one above the other, with the magnetization alternating and separated.

Abstract: Included are cement compositions and methods and systems for locating the cement compositions in a wellbore. An example method comprises deploying a sensing system in the wellbore and introducing the cement composition into the wellbore. The cement composition comprises a cement and hollow beads having a crush pressure and configured to emit an acoustic signal when imploded. The method further comprises pumping the cement composition through the wellbore to a depth with a wellbore pressure exceeding the crush pressure of the hollow beads to induce implosion of the hollow beads and the emission of the acoustic signal. The method further comprises sensing the emitted acoustic signal and determining the location of the cement composition in the wellbore from the sensed emitted acoustic signal.

Abstract: In a first aspect, a method for monitoring a material and/or a device in a borehole using a fiber optic measurement cable is provided, and, in a second aspect, a system for carrying out the method is provided. The system includes a fiber optic measurement cable which is present introduced into a borehole, wherein a material and a device are present in the borehole.

Abstract: A method and system for generating arbitrary ultrasonic waveforms using a tri-state transmitter. Three variants of the device are described to provide functionality in three usage scenarios.

Abstract: Methods and apparatus for detecting nearby conductors such as pipes, well casing, etc., from within a borehole. A nearby casing string can be detected by transmitting an electromagnetic signal from a transmit antenna on a downhole logging tool and measuring a parallel response signal with a first receive antenna parallel to the transmit antenna and a perpendicular response signal with a second receive antenna perpendicular to the transmit antenna, both receive antennas on the downhole logging tool. As the tool rotates, the transmitting and measuring are repeated to determine the azimuthal dependence of the parallel and perpendicular response signals. The azimuthal dependence is analyzed to determine a diagonal component of said azimuthal dependence for each response signal. Distance to a casing string can be estimated using the diagonal component of each response signal. At least one of the antennas is preferably tilted.

Abstract: Various embodiments include apparatus and methods to process acoustic signals according to joint time-frequency processing. The joint time-frequency processing can combine features of both time-based processing and frequency-based processing. This processing may be based on delay calculation from amplitude phases generated from the acoustic signals. The joint time-frequency processing may be applied to a variety of applications to evaluate properties associated with a borehole or surrounding formations. Additional apparatus, systems, and methods are disclosed.

Abstract: A method and apparatus for packaging surface acoustic wave transponders for use in down-hole or other extreme environmental applications is provided. An exemplary ID tag transponder may include a surface acoustic wave (SAW) piezoelectric device, wire bonds, antennae structure, an antenna reflector, a radome, and a base constructed of a conductive, non-magnetic metal or metal alloy adapted to withstand an extreme environment encountered in down-hole applications. The metallic base may have a notched lip or flange about its periphery that is adapted for pressure fitting into the milled cylindrical orifice located on the exterior surface of a tool asset. In some embodiments, an exemplary SAW piezoelectric device may be attached directly onto an antenna substrate and wire bonded directly to an antenna. An RF reflector is created inside an exemplary transponder tag device.

Abstract: A stacked-ring, slow-wave acoustic telemetry isolation system and method for use with tubular assemblies such as drillpipe or production tubing comprising an acoustic wave transmitter, the acoustic isolator behaving such that a “down” wave propagated toward the isolator is reflected back substantially in phase with an “up” wave propagated from the acoustic wave source away from the isolator. The acoustic isolator is similarly effective in reflecting “up” propagating waves originating from below the isolator, hence further protecting the acoustic wave source from possible deleterious interference. It causes substantially all of the emitted wave energy to travel in a chosen direction along the drill pipe, thus aiding the efficiency of acoustic telemetry said pipe.

Abstract: An acoustic logging while drilling tool includes an acoustic transmitter and a linear array of acoustic receivers. At least one of the transmitter and the linear array of receivers is deployed on a blade having an outer diameter greater than that of the tool body. In preferred embodiments the transmitter and linear array are each deployed on a distinct blade. Deployment of the transmitter and/or the receivers on a blade reduces the standoff distance to the borehole wall which tends to improve the signal strength of received guided waves without an increase in transmitter power or receiver sensitivity.

Abstract: A sonde for installation in a well including a clamp (2) for engaging with the inner wall of a well casing (3) and securing device for securing the clamp to inner tubing of the well, whereby the securing device includes an attachment device (5, 6) for connection to the inner tubing and a rod (4) connected between the clamp and the attachment device.

Abstract: An acoustic telemetry isolation system and method for use with tubular assemblies such as drillpipe and production tubing includes an acoustic wave transmitter and an acoustic isolator. A “down” wave propagated toward the isolator is reflected back substantially in phase with an “up” wave propagated from the acoustic wave source away from the isolator. Furthermore, the acoustic isolator is similarly effective in reflecting “up” propagating waves originating from below the isolator, hence further protecting the acoustic wave source from possible deleterious interference. The construction of the isolator utilizes a specified combination of waves traveling in parallel in materials whose properties aid the beneficial combination of reflected and transmitted waves. The design of the isolator is to generally provide a bandstop filter function, thereby aiding the frequency isolation of an acoustic transmitter over a passband that may be constrained by the geometry of drill pipe or components of production tubing.

Abstract: A method of detecting motion in components that form part of a structure. The method includes flooding a first component with transmitted radio frequency signals and receiving reflected radio frequency signals from the first component with an antenna. The method further includes generating a first set of intermediate frequency signals based on differences between the transmitted radio frequency signals and the reflected radio frequency signals and measuring the first set of intermediate frequency signals. The method further includes flooding a second component with transmitted radio frequency signals and receiving reflected radio frequency signals from the second component with an antenna. The method further includes generating a second set of intermediate frequency signals based on differences between the transmitted radio frequency signals and the additional reflected radio frequency signals and measuring the second set of intermediate frequency.

Abstract: An improved energy efficient intelligent pulser driver used for generating a mud pulse in a MWD (measurement while drilling) application. In the pulser driver, a direct current (DC) powered control circuit activates a three-phase DC brushless motor that operates a servo-valve. Opening of the servo-valve equalizes pressure in a plenum causing the operation of a main valve reducing flow area and causing a pressure spike in the mud column. Closing of the servo-valve creates a reduction in mud pressure that operates the main valve and increases the flow area causing an end to the pressure spike. The servo-valve is powered both in opening and closing operations by the motor.

Abstract: A method and apparatus for packaging surface acoustic wave transponders for use in down-hole or other extreme environmental applications is provided. An exemplary ID tag transponder may include a surface acoustic wave (SAW) piezoelectric device, wire bonds, antennae structure, an antenna reflector, a radome, and a base constructed of a conductive, non-magnetic metal or metal alloy adapted to withstand an extreme environment encountered in down-hole applications. The metallic base may have a notched lip or flange about its periphery that is adapted for pressure fitting into the milled cylindrical orifice located on the exterior surface of a tool asset. In some embodiments, an exemplary SAW piezoelectric device may be attached directly onto an antenna substrate and wire bonded directly to an antenna. An RF reflector is created inside an exemplary transponder tag device.

Abstract: Measurements made with at least two sensors (flow rate or pressure) during generation of a message concurrently with operation of a noise source are used to estimate a channel transfer function. The estimated transfer function is then used to attenuate pump noise in a mud pulse telemetry system. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, placing the wellbore composition in the wellbore, obtaining data from the MEMS sensors using a plurality of data interrogation units spaced along a length of the wellbore, and telemetrically transmitting the data from an interior of the wellbore to an exterior of the wellbore using a conduit positioned in the wellbore. A system, comprising a wellbore extending the earth's surface, a conduit positioned in the wellbore, a wellbore composition positioned in the wellbore, the wellbore composition comprising a plurality of Micro-Electro-Mechanical System (MEMS) sensors, and a plurality of data interrogation units spaced along a length of the wellbore and adapted to obtain data from the MEMS sensors and telemetrically transmit the data from an interior of the wellbore to an entrance of the wellbore via the conduit.

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: This invention applies to the means whereby capacitance changes due to varying temperature and/or pressure in a piezoelectric transducer used for acoustic telemetry in a drilling environment is dynamically offset by modifying one or more parameters associated with the drive or control circuitry of said transducer. The object of the invention is to closely maintain the transducer in a resonant mode, thereby ensuring optimum energy consumption.

Abstract: A system or corresponding method provides for communicating data in confined waveguides containing a fluid. The system includes processing and transmitter/receiver operations at nodes in or alone the confined waveguides and transducers to produce a propagation signal that transmits modulated data via the fluid in the confined waveguide. Applications include sensing information about the fluid, such as the pressure, pH, or other parameter(s), and transmitting that data via the fluid in the confined waveguide. For example, the system may be distributed about an oil pipeline or network of oil pipelines. Nodes in the system may include turbines that generate power for use by the nodes at levels sufficient to support the node for its activities. Signal processing and multiple transducers at each node may be employed to extend distances up to kilometers between nodes for low-cost operation of the system.

Abstract: In some embodiments, a method includes receiving a data signal from a sensor that is positioned within a well bore, during a hydraulic fracturing operation. The method further comprising detecting a microseismic event, that is caused by the hydraulic fracturing operation, wherein the detecting comprises performing a noise canceling operation on the data signal.

Abstract: In one general implementation, a method for identifying fluids in a wellbore includes generating light in a visible spectrum from a light source in a production wellbore; generating light in an ultraviolet spectrum from the light source in the production wellbore; receiving a first fluid in the production wellbore from a subterranean zone; receiving a second fluid in the production wellbore from the subterranean zone; capturing at least one image of a combined flow of the first fluid and the second fluid in at least one of the visible spectrum and the ultraviolet spectrum with an optical receiver in the production wellbore; and distinguishing, at least in part through the image, the first fluid from the second fluid in either or both the visible and ultraviolet spectrums.

Abstract: The present invention involves methods and apparatus for permanent downhole deployment of optical sensors. Specifically, optical sensors may be permanently deployed within a wellbore using a casing string. In one aspect, one or more optical sensors are disposed on, in, or within the casing string. The optical sensors may be attached to an outer surface of the casing string or to an inner surface of the casing string, as well as embedded within a wall of the casing string. The optical sensors are capable of measuring wellbore parameters during wellbore operations, including completion, production, and intervention operations.

Abstract: The present invention relates to a direction guide vibration system of a vehicle operating with a navigation and control method thereof, which applies vibration to a driver's seat on which a driver sits at the spot where a left turn or a right turn and a U turn are expected, on a path to move to a driver's intended destination, informs a driver thereof in advance for people and the hearing impaired using a navigation and informs the driver thereof before an enforcement area in which an over-speed camera is installed, thereby securing a safe driving of a vehicle.

Abstract: An integrated framework is described for automating some or all of mud slowness estimation for both fast and slow formations. An estimation of fluid slowness based on monopole radial profiling is calculated if conditions permit. Alternatively, an estimation of fluid slowness based on Scholte wave slowness is estimated if conditions do not permit calculation based on monopole radial profiling. Tool standoff may also be estimated based on monopole radial profiling.

Abstract: A seismic and/or acoustic while drilling configuration includes a high speed telemetry arrangement; at least one seismic and/or acoustic energy sensor in communication with the high speed telemetry arrangement; at least one seismic and/or acoustic energy source capable of producing at least one seismic and/or acoustic energy signal receivable by the at least one seismic and/or acoustic energy sensor and methods.

Abstract: A marine port monitoring system including an inspection apparatus, either fixed or mobile, for intercepting cargo vessels entering the port. The system includes sensors placed in a shipping channel for examination of a hull of a passing vessel to detect externally mounted weapons or explosives. The inspection apparatus includes devices for removing cargo containers from vessels, non-intrusively inspecting the containers and isolating containers having suspect cargo. The apparatus includes explosive containment including a separable containment system for protecting the apparatus.

Abstract: A method and system for conducting a seismic survey by lowering a string of intelligent clampable sensor pods with 3-C sensors into a borehole. The string of pods is serially interconnected by a cable having a conductor pair which provides both power and data connectivity. The uppermost sensor pod is connected to a downhole telemetry and control module. The cables and pods use connectors to allow assembly, customization, repair, and disassembly on site. Each pod has an upper and a lower connector, a processor, and memory which is coupled to both the upper and the lower connectors. Each pod is capable of simultaneous and independent serial communications at each connector with the memory. The telemetry and control module is designed to query the pods to determine the system configuration. The telemetry and control module then simultaneously triggers all pods to acquire data, the pods storing the collected data locally in the memory.

Abstract: A rotary pulser for transmitting information to the surface from down hole in a well by generating pressure pulses encoded to contain information. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes housing containing a stator forming passages through which drilling fluid flows on its way to the drill bit, a rotor, and a replaceable wear sleeve enclosing the rotor. The rotor has blades that are capable of imparting a varying obstruction to the flow of drilling fluid through the stator passages depending on the circumferential orientation of the rotor, so that rotation of the rotor by a motor generates the encoded pressure pulses.

Abstract: A plurality of actuators are provided at predetermined intervals on the reverse surface of a predetermined side wall of a swimming pool. When an electric signal corresponding to a sound to be propagated in the water is given to the actuators, the electric signal is converted by the actuators into a mechanical vibration signal to cause vibrations. The actuators are secured directly to the reverse surface of the predetermined side wall by an adhesive or otherwise, and thus the vibrations of the actuators are radiated as a sound in the water of the pool through the side wall.

Abstract: A telemetry system having: a pipe; a SCADA box acoustically coupled to the pipe; and a gauge inserted in the pipe, the gauge comprising: an acoustic wave generator; a coupler mechanically connected to the acoustic wave generator, wherein the coupler is engageable and disengageable with the pipe, wherein the coupler defines an acoustic transmission path between the acoustic wave generator and the pipe when engaged with the pipe; and a signal controller in communication with the acoustic wave generator. A method for communicating information in a wellbore from a downhole location to the surface, the method having the following steps: running a downhole gauge into a pipe within the wellbore, wherein the downhole gauge comprise an acoustic wave generator; setting the downhole gauge in the pipe; and communicating an acoustic signal between the downhole gauge and the pipe.

Abstract: The invention consists of a pressure transducer based air velocity sensor that has been optimized for use in metal ducts. The fluid flow velocity is determined by measuring the propagation delay of a direct path pressure wave signal transmitted through the fluid as a function of a frequency difference rather than as a phase delay measurement. This system electronically removes multi-path signals from the measured signal, thereby obviating the requirement for installation calibration.

Abstract: A mud pulse telemetry system comprises a surface located fluid supply line having a drilling fluid flowing therein. A non-venting pulser is disposed in the drilling fluid in the supply line, and the non-venting pulser is adapted to generate pressure fluctuations in the flowing drilling fluid. A downhole receiver in hydraulic communication with the non-venting pulser is adapted to detect the pressure fluctuations in the drilling fluid. A method for transmitting pressure signals from a surface location to a downhole location in a wellbore, comprises disposing a non-venting pulser in a surface located fluid supply line having a drilling fluid flowing therein. The non-venting pulser is actuated to generate pressure fluctuations in the flowing drilling fluid according to a predetermined encoding scheme. The pressure fluctuations are detected with a downhole receiver in hydraulic communication with the non-venting pulser.

Abstract: The apparatus includes a pump for circulating pressurized fluid in a wellbore. A control device controls the pump which a conduit interconnects to the wellbore. A downhole transducer detects changes in fluid pressure at a downhole location and generates signals accordingly. A processor generates actuator commands based on the signals. Actuators activate a downhole tool based on the actuator command. A modulating valve modulates the fluid pressure. A remote transducer detects the pressure remotely from the downhole transducer. The control device causes the pump to generate acoustic signals in the fluid via wave forms which the downhole transducer detects. The modulating valve generates wave forms in the fluid. The control device sends control signals via the fluid to the downhole transducer. Consequently the processor actuates the tools. Following correct actuation the modulating valve generates signals via pressure changes which the remote transducer receives to indicate successful tool deployment.

Abstract: A casing sensor and methods for sensing using a casing sensor are disclosed. The casing sensor includes a casing shoe and a sensor coupled to the casing shoe. A casing data relay includes a downhole receiver coupled to a well casing and a transmitter coupled to the receiver. The casing sensor may be coupled to the transmitter. A drill string actuator may be controllable through the downhole receiver.

Abstract: A plurality of heavy mass irregularities attached to an inner wall of the drill collar attenuate waves traveling through the collar. The plurality of heavy mass irregularities are spaced and sized for the maximum attenuation of acoustic pulses in a predetermined frequency range. The mass irregularities may be rings firmly coupled to the outer surface of the collar. Alternatively, the mass irregularities may be rings firmly coupled to the outer collar surface by neck pieces, extending inwardly from the inner circumference of the ring. The mass irregularities may be made of steel or tungsten. In another preferred embodiment, the mass irregularities are asymmetrically coupled to an outer collar wall for providing preferential directional attenuation.

Abstract: System, apparatus, and method of telemetering downhole sensor information to the surface while operations are performed in an oil or gas well using coiled tubing. Data are transmitted on coiled tubing as digital signals encoded in acoustic signals. In one implementation, a stripper packer through which coiled tubing is moved into a well is operated between at least a first state and a second state; and an acoustic communication device responds to operation of the stripper packer such that when the stripper packer is in the first state, the acoustic communication device is decoupled from acoustic communication with the coiled tubing, but when the stripper packer is in the second state, the acoustic communication device is coupled for acoustic communication with the coiled tubing.

Abstract: A method and apparatus for notifying a user of an incoming cellular telephone call are provided. The apparatus includes a cellular telephone body having at least a back surface, a first transducer positioned within said cellular telephone body perpendicular to the back surface and adapted to generate a first acoustic field, and a second transducer positioned coaxially to the first transducer and adapted to generate a second acoustic field. A first frequency generator is coupled with the first transducer to drive the first transducer to generate the first acoustic field and a second frequency generator is coupled with the second transducer to drive the second transducer to generate the second acoustic field in response to an indication that an incoming cellular telephone call has been received. The first and second acoustic fields overlap. The overlapping fields generate a vibrational sensation from a difference of frequency from unequal frequencies generated by the first and second transducers.

Abstract: An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Improved sensors provide noise channels with reduced signal content. Motion sensors are used to detect noise and provide a noise channel free of signal content. The motion sensors are shielded from electromagnetic signals to prevent detection of the telemetry signal.

Abstract: A method and apparatus for transmitting information to the surface from down hole in a well in which a pulser is incorporated into the bottom hole assembly of a drill string that generates pressure pulses encoded to contain information concerning the drilling operation. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes a stator forming passages through which drilling fluid flows on its way to the drill bit. The rotor has blades that obstruct the flow of drilling fluid through the passages when the rotor is rotated into a first orientation and that relieve the obstruction when rotated into a second orientation, so that oscillation of the rotor generates the encoded pressure pulses. An electric motor, under the operation of a controller, drives a drive train that oscillates the rotor between the first and second orientations.

Abstract: A communication system is disclosed enabling communication from a surface location to a downhole location where instructions communicated are executed. The system employs accelerometers to sense vibrations traveling within the annulus fluid or the tubing string. The accelerators provide signals representative of the vibration generated at the surface of the well to a microcontroller. The microcontroller is programmed to energize a nichrome element to actuate the downhole tool in response to a user-defined vibration sequence. The vibration sequence includes a defined number of vibration cycles. Each cycle includes alternating periods of vibration and no vibrations with each period lasting for a defined length of time. The user may program the parameters of the sequence and arm the vibration receiving unit on site through a handheld terminal that interfaces with the microcontroller.

Abstract: A method for improving ROP and reducing hazards in drilling subterranean wells by using an acoustical system 15 to look ahead of the drill bit 14, detects and analyzes geologic features ahead of the bit 14 which may be qualified as drilling hazards 17. Detection of such hazards 17 may facilitate use of more aggressively penetrating bits 14 such as PDC bits as opposed to roller cone bits. In addition, other drilling parameters may be adjusted to improve ROP due to the ability to timely respond to identified hazards 17 before they may be detrimentally encountered by the bit 14. The acoustic system 15 may look ahead of the bit 14 by at least 100 meters, using propagated acoustic waves 19 to locate changes in acoustic impedance which may represent drilling hazards 17. In addition, bulk resistivity ahead of the bit 14 may also be measured and used to locate drilling hazards 17.

Abstract: A subsea communication system is used to communicate between a position that is proximal to a surface of the sea and an apparatus of the seabed. The subsea communication system includes an umbilicalless communication system.

Abstract: A two-conductor bidirectional digital telemetry interface between a seismic sensor acquisition/conversion module and a seismic data collection module. The data collection module is configured as a master electronics device and the sensor acquisition/conversion module is configured as a slave electronics device in the telemetry system. The master device provides power to the slave device over the two conductors. The master device transmits portions of commands to the slave device at a first time and the slave device transmits portions of a digital seismic data packet to the master at a different second time in a fixed-duration frame. The frames are transmitted at regular intervals. The outbound commands and inbound data are encoded by block codes. A phase-locked loop in the slave is locked to a master clock in the master by deriving a clock and a sync point from the block-coded commands it receives from the master.

Abstract: The logging tool of this invention includes a transmitter conveyed on a drilling collar for exciting a quadrupole signal in a borehole being drilled by a drill bit and a receiver for receiving the signal. The transmitter is operated at a frequency below the cut-off frequency of the quadrupole collar mode. The received signal consists primarily of the formation quadrupole mode which, at low frequencies, has a velocity that approaches the formation shear velocity. The transmitter, in one embodiment, consists of eight equal sectors of a piezoelectric cylinder mounted on the rim of the drilling collar. The value of the cut-off frequency is primarily dependent on the thickness of the drilling collar. Alternatively, the transmitter may be operated to produce both the collar mode and the formation mode and a processor may be used to filter out the collar mode.

Abstract: A water leakage detecting apparatus is capable of detecting water leakage of a water pipe precisely and at low cost. The water leakage monitoring apparatus includes vibration/electric converter for converting an acoustic vibration transmitted to a water pipe into an electrical signal. A signal discriminator processes an output signal of the vibration/electric converter to detect a signal of a predetermined band being held below a predetermined level continuously beyond a continuing condition to generate a sound interruption detection signal. A counter counts the number of occurrences of the sound interruption detection signal.

Abstract: A communication system is disclosed enabling communication from a surface location to a downhole location where instructions communicated are executed. The system employs accelerometers to sense vibrations traveling within the annulus fluid or the tubing string. The accelerators provide signals representative of the vibration generated at the surface of the well to a microcontroller. The microcontroller is programmed to energize a nichrome element to actuate the downhole tool in response to a user-defined vibration sequence. The vibration sequence includes a defined number of vibration cycles. Each cycle includes alternating periods of vibration and no vibrations with each period lasting for a defined length of time. The user may program the parameters of the sequence and arm the vibration receiving unit on site through a handheld terminal that interfaces with the microcontroller.