Abstract: A passive array of acoustic sensors capture acoustic signals produced by sand movement. The array tool is deployed downhole where it passively listens for acoustic energy generated by sand movement in the well. Once acoustic signals are acquired, model-based frameworks are used to extract single and multiple sensor features from the acoustic signals. The extracted features are used as signatures to detect or classify the production of sand.

Abstract: A wireless communications system for a downhole drilling operation comprises surface communications equipment and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit an EM downlink transmission at a frequency between 0.01 Hz and 0.1 Hz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency greater than 0.5 Hz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission.

Abstract: Presented are methods and systems for regularizing content of multi-component seismic data. The method includes a step of receiving the seismic data, wherein the seismic data includes pressure and particle motion measurements and a step of regularizing and frequency optimizing the seismic data to desired positions based on Fresnel zones selected at various depths in a subsurface to obtain a regularized seismic dataset.

Abstract: A wireless communications system for a downhole drilling operation comprises surface communications equipment and a downhole telemetry tool. The surface communications equipment comprises a surface EM communications module with an EM downlink transmitter configured to transmit an EM downlink transmission at a frequency between 0.01 Hz and 0.1 Hz. The downhole telemetry tool is mountable to a drill string and has a downhole electromagnetic (EM) communications unit with an EM downlink receiver configured to receive the EM downlink transmission. The downhole EM communications unit can further comprise an EM uplink transmitter configured to transmit an EM uplink transmission at a frequency greater than 0.5 Hz, in which case the surface EM communications module further comprises an EM uplink receiver configured to receive the EM uplink transmission.

Abstract: An improved system for coupling a generated overpressure wave to a target media includes a coupling chamber and an interface between the coupling chamber and a target media. Pressure produced in the coupling chamber by a generated overpressure wave is applied to the interface thereby converting the pressure in the coupling chamber into a force that produces a conducted acoustic wave in the target media.

Abstract: The invention is an electric sweep type seismic vibrator source of the type used in seismic prospecting for hydrocarbons. The source uses an engine and generator combination to create electric power for all systems on the source such as driving a frame of linear electric motors that direct a rod or piston to contact the ground in a recurring fashion along with driving the source from location to location through a survey area. Preferably, a foot is arranged on the bottom end of the rod or piston for contact with the ground and by engaging the grid of motors to push down against the ground in a rapid progression, acoustic energy is created and delivered into the ground for geophones to sense and record.

Abstract: A probe assembly (1) suitable for use with apparatus for use in the investigation and/or analysis of an underwater floor of a body of water such as, for example, a seabed. The apparatus includes a depth penetration device (10), and an underwater floor testing tool (11, 12). The probe assembly (1) includes a first coupling for operatively connecting the probe to the depth penetration device (10) and a second coupling for operatively connecting the probe assembly (1) to the underwater floor testing tool (11, 12). The probe assembly (1) further includes a signal processing module (5) for processing information from the tool, a data transmission module (2) for the transmission of data from the signal processing module (5), a power source (3) for operating the data transmission module (2) and the signal processing module (5) and a switch module (4) for selectively connecting from the power source (3) to the data transmission module (2) and signal processing module (5).

Abstract: A probe assembly (1) suitable for use with apparatus for use in the investigation and/or analysis of an underwater floor of a body of water such as, for example, a seabed. The apparatus includes a depth penetration device (10), and an underwater floor testing tool (11, 12). The probe assembly (1) includes a first coupling for operatively connecting the probe to the depth penetration device (10) and a second coupling for operatively connecting the probe assembly (1) to the underwater floor testing tool (11, 12). The probe assembly (1) further includes a signal processing module (5) for processing information from the tool, a data transmission module (2) for the transmission of data from the signal processing module (5), a power source (3) for operating the data transmission module (2) and the signal processing module (5) and a switch module (4) for selectively connecting from the power source (3) to the data transmission module (2) and signal processing module (5).

Abstract: An exemplary system for managing the deployment of a seismic data acquisition system uses a module configured to execute a plurality of task in the field by receiving one or more seismic devices. The module may include a power source that provides electrical power to the seismic devices. The module may also include a processor programmed to retrieve data stored in the seismic devices, perform diagnostics, facilitate inventory and logistics control, configure seismic devices and update data or pre-programmed instructions in the seismic device.

Abstract: Embodiments of methods and systems for analysis of geological structures using seismic attributes are described. In some embodiments, a method includes computing a similarity function using one or more seismic attributes at a location within the geological structure along an I direction and a J direction; computing a total optimal similarity function in at least one plane defined by the I and J directions; computing a minimum possible value of the total similarity function for a defined range of rotations; and calculating a discontinuity measure based at least partially on the minimum possible value of the total similarity function.

Abstract: A high spatial resolution phase-sensitive technique employs a scanning near field ultrasound holography (SNFUH) methodology for imaging elastic as well as viscoelastic variations across a sample surface. SNFUH uses a near-field approach to measure time-resolved variations in ultrasonic oscillations at a sample surface. As such, it overcomes the spatial resolution limitations of conventional phase-resolved acoustic microscopy (i.e. holography) by eliminating the need for far-field acoustic lenses.

Abstract: A window image projection screen includes a transparent case, including a transparent front element and a transparent rear element. A thin inner space formed between the front and rear elements is filled with fine water drops produced by ultrasonic vibration of water in a reservoir to selectively crease a screen for a projected image.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end that may be directed away from, parallel to, or towards a target media. Recoil forces of the at least one overpressure wave generator, produced shear forces, or the forces of the plurality of overpressure waves are coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end. The at least one overpressure wave generator is oriented so the plurality of overpressure waves are not directed directly towards a target media. The recoil force of the at least one overpressure wave generator occurring during generation of the plurality of overpressure waves is coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: A technique includes providing a source in a first well and a seismic receiver in a second well to detect a seismic event that is caused by the source. The technique includes referencing clocks in the source and receiver to a common reference time frame and determining a time in the reference time frame at which the seismic source generates the seismic event.

Abstract: With a certain pipeline, either underground or deposited on a sea/lake bottom, the formation of critical faults is determined and localized, which arise in the walls of the pipeline, or the growth of an already localized fault is monitored, through a method which detects, by acoustic sensors regularly distributed along the pipeline, the ultrasounds diffused along the walls of the pipeline itself upon the formation of a critical fault, or when a controlled fault increases, and processing, by a remote processor, the digital signals associated with the sound waves to identify the position or evaluate the development of a critical fault.

Abstract: A method for marine seismic surveying includes towing seismic sensors in a plurality of streamers in the water, actuating a seismic energy source in the water at selected times and detecting seismic signals at the sensors resulting from the actuation of the source. A data trace is created for each of the detected signals. At least one Fresnel zone is determined for at least some of the seismic data traces. A contribution of each of the traces to each one of a plurality of bins defined in a predetermined pattern is computed, based on the Fresnel zone associated with each trace. Based on the computed contributions, a maximum lateral distance between corresponding seismic sensors is determined that will result in a contribution sum above a selected threshold.

Abstract: A transmission wave field imaging method, comprising the transmission of an incident wave field into an object, the incident wave field propagating into the object and, at least, partially scattering. Also includes the measuring of a wave field transmitted, at least in part, through an object to obtain a measured wave field, the measured wave field based, in part, on the incident wave field and the object. Additionally, the processing of the measured wave field utilizing a parabolic approximation reconstruction algorithm to generate an image data set representing at least one image of the object.

Abstract: One example of a seismic vibrator system includes a baseplate having a bottom surface and a coupling mechanism, the coupling mechanism being operable to a deployed position; a hold-down mass connected to the baseplate; a lifting mechanism in operational connection with the hold-down mass and the baseplate to apply a selected hold-down weight to the baseplate; and a driving mechanism functionally connected to the baseplate to transmit seismic energy through the baseplate into a ground surface to which the baseplate is coupled, wherein the coupling mechanism is urged outward from the bottom surface and into physical contact with the ground surface when operated to the deployed position.

Abstract: An apparatus for generating seismic body waves in a hydrocarbon reservoir includes a closed-loop borehole source having a resonant cavity for generating resonant energy, a drive source and a control unit. The drive source injects pressure pulses to the resonant cavity at a predetermined or selectable pressure and frequency. The fluid circulates between the cavity and the drive source in a closed-loop fashion. In another embodiment, the borehole source utilizes a smart or controllable material that is responsive to an applied excitation field. The cavity includes an excitation coil for providing an excitation field that changes a material property of the smart fluid. The control unit is programmed to adjust operating parameters to produce seismic waves having a selected frequency and amplitude. In one embodiment, a control unit adjusts operating parameters in response to measured parameters of interest or surface commands.

Abstract: A high spatial resolution phase-sensitive technique employs a scanning near field ultrasound holography (SNFUH) methodology for imaging elastic as well as viscoelastic variations across a sample surface. SNFUH uses a near-field approach to measure time-resolved variations in ultrasonic oscillations at a sample surface. As such, it overcomes the spatial resolution limitations of conventional phase-resolved acoustic microscopy (i.e. holography) by eliminating the need for far-field acoustic lenses.

Abstract: A Laplace transform system comprising a processor, a measured time domain wavefield, a velocity model, and Laplace damping constants, wherein the processor is programmed to calculate a substantially about zero frequency component of a Fourier transform of a time domain damped wavefield, wherein the time domain damped wavefield is damped by the Laplace damping constants to obtain long wavelength velocity information for deeper subsurface regions.

Abstract: A real-time signal processing technique for ultrasonic imaging of tissue vibrations for localizing the source of a bruit in a 2D image with respect to the anatomy and/or for obtaining simultaneous information about vibrations and the underlying blood flow. The bruit can be quantitatively assessed using an ensemble of ultrasound echoes. Signal processing enables estimation of wall displacement and the display of time-resolved vibration spectrum. Vibrations are detected and color-coded according to their amplitude and frequency and overlaid on the B-mode and/or color-flow image in real time. Proposed vibration imaging algorithms use data acquired during conventional ultrasonic color-flow imaging and the clutter signal, normally suppressed in color-flow imaging, to detect and characterize tissue vibrations. Three vibration imaging algorithms based on parametric modeling of vibrations and other criteria distinguish between clutter, blood flow, and vibrations.

Abstract: A transmission wave field imaging method, comprising the transmission of an incident wave field into an object, the incident wave field propagating into the object and, at least, partially scattering. Also includes the measuring of a wave field transmitted, at least in part, through an object to obtain a measured wave field, the measured wave field based, in part, on the incident wave field and the object. Additionally, the processing of the measured wave field utilizing a recursive reconstruction algorithm to generate an image data set representing at least one image of the object.

Abstract: Seismic data may be imaged using or recognizing substantially only primary reflections. Imaging seismic data may include for example integrating a plurality of seismic data points that have substantially similar arrival directions, for example, to a modeled primary ray. Seismic data points may be imaged that for example substantially meet a set of predetermined conditions, for example, conditions substantially unique to primaries, which may include for example arrival direction and angle of reflection.

Abstract: Waveforms for controlled source electromagnetic surveying. The waveforms have frequency spectra that include three or more frequencies spaced at substantially equal intervals on a logarithmic frequency scale and spanning a bandwidth of about one decade or more, at least three of which frequencies have approximately equal corresponding amplitudes.

Abstract: A high spatial resolution phase-sensitive technique employs a scanning near field ultrasound holography (SNFUH) methodology for imaging elastic as well as viscoelastic variations across a sample surface. SNFUH uses a near-field approach to measure time-resolved variations in ultrasonic oscillations at a sample surface. As such, it overcomes the spatial resolution limitations of conventional phase-resolved acoustic microscopy (i.e. holography) by eliminating the need for far-field acoustic lenses.

Abstract: A probe assembly (1) suitable for use with apparatus for use in the investigation and/or analysis of an underwater floor of a body of water such as, for example, a seabed. The apparatus includes a depth penetration device (10), and an underwater floor testing tool (11, 12). The probe assembly (1) includes a first coupling for operative Iy connecting the probe to the depth penetration device (10) and a second coupling for operatively connecting the probe assembly (1) to the underwater floor testing tool (11, 12). The probe assembly (1) further includes a signal processing module (5) for processing information from the tool, a data transmission module (2) for the transmission of data from the signal processing module (5), a power source (3) for operating the data transmission module (2) and the signal processing module (5) and a switch module (4) for selectively connecting from the power source (3) to the data transmission module (2) and signal processing module (5).

Abstract: The present invention provides a method and apparatus for seismic data acquisition. One embodiment of the method includes accessing data acquired by at least two particle motion sensors. The data includes a seismic signal and a noise signal and the at least two particle motion sensors being separated by a length determined based on a noise coherence length. The method may also include processing the accessed data to remove a portion of the noise signal.

Abstract: The present invention provides an accelerated weight drop for use as a seismic energy source, a method for operating an accelerated weight drop for use as a seismic energy source, and a seismic survey system including the accelerated weight drop. The accelerated weight drop, among other elements, includes a strike plate positionable on a surface, and a striker positionable over the strike plate. The accelerated weight drop further includes a compressed gas spring configured to drive the striker toward the strike plate thus creating seismic waves within the surface, wherein the striker is slidably coupled to the compressed gas spring and the striker and the compressed gas spring rotatably coupled to the strike plate about an axis.

Abstract: The present invention provides an accelerated weight drop for use as a seismic energy source, a method for operating an accelerated weight drop for use as a seismic energy source, and a seismic survey system including the accelerated weight drop. The accelerated weight drop, among other elements, may include a striker positionable over a surface, and a compressed gas spring configured to drive the striker toward the surface thus creating seismic waves within the surface. In this embodiment the striker is slidably coupled to the compressed gas spring.

Abstract: A method for generating acoustic waves, the method having the steps of: extending a tine from a support structure so that a proximal end of the tine is attached to the support structure and a distal end of the tine is uninhibited; positioning an oscillator so as to be supported by the support structure and to mechanically communicate with the tine; and oscillating the tine with the oscillator.

Abstract: An apparatus for generating acoustic waves, the apparatus having: a support structure; two tines extending from the support structure so that proximal ends of the two tines are attached to the support structure so that distal ends of the two tines are positioned with standoffs relative to a dimension of the support structure and the distal ends of the two tines are uninhibited, wherein the two tines each comprise a moment arm; and an oscillator in mechanical communication with the two tines.

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: An apparatus (10) and method are disclosed for eliminating a noise signal from at least one source during an acoustic measurement of a subsurface geological formation or borehole. The apparatus (10) includes a longitudinal body for positioning in the borehole and a transmitter (22) supported by the body for transmitting acoustic signals into the formation and borehole. A sensor (23), substantially isolated within the body, is used to detect one or more noise signals and a receiver (24) is carried by the body for receiving acoustic signals traversing the formation and borehole, and for receiving one or more noise signals.

Abstract: A shaftless acoustic source is disclosed having a solenoid, a bullet and driving electronics. The bullet, which is positioned inside the solenoid's coil, can be accelerated by a magnetic force generated when a current pulse is applied to the coil. Acoustic energies are generated upon the impact of the bullet with an object, such as a borehole wall. This impact force can be described by the Hertzian Contact Theory (also referred to herein as Hertzian Theory) as a point of normal force with a time function similar to a half period sine function. A retraction device may be used to retract the bullet back into the solenoid after firing.

Abstract: A measuring device for measuring the elastic properties of a surface structure (3), comprising a probe (2) arranged within a housing (1), a transmitter and at least one receiver, the transmitter transmitting acoustic pulses and the receiver picking up the propagation behavior of the acoustic pulses in the surface structure (3), a control means (16) for generating acoustic pulses and an evaluating means (18) for the measuring signals received by the receiver, at least two adjacent measuring tips (4, 6) being connected as transmitting and receiving elements, the measuring tips being adapted to be set onto the surface structure (3) and having strip-shaped bi-morph elements (12, 14) carried by a holder (8, 10), wherein the measuring tips (4,6) are formed by the holders (8, 10) of the bi-morph elements (12, 14) and the strip-shaped elements (12, 14) have one side of one of their ends fastened to the holder (8, 10).

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: The present invention discloses a buried object detection system. The detection system has an acoustic emitter capable of generating a non-linear acoustic impulse or a continuous acoustic signal of variable amplitude and frequency. Sensors are deployed on an appropriate surface or surfaces of a granular medium, which are capable of detecting the backscattered and, if possible, forward scattered signals of the original impulse or wave from a buried inclusion or inclusions. The information received by the sensors may be transmitted to a computer for further manipulation and analysis.

Abstract: The present invention provides a method for forming wellbores. In one method, one or more wellbores are drilled along preplanned paths based in part upon seismic surveys performed from the surface. An acoustic transmitter conveyed in such wellbores transmits acoustic signals at a one or more frequencies within a range of frequencies at a plurality of spaced locations. A plurality of substantially serially spaced receivers in the wellbores and/or at surface receive signals reflected by the subsurface formations. The sensors may be permanently installed in the boreholes and could be fiber optic devices. The receiver signals are processed by conventional geophysical processing methods to obtain information about the subsurface formations. This information is utilized to update any prior seismographs to obtain higher resolution seismographs. The improved seismographs are then used to determine the profiles of the production wellbores to be drilled.

Abstract: A well tool in accordance with the invention comprises an attenuation device which attenuates tube waves associated with an elastic wave emission and/or reception set (1, 12). The attenuation device comprises a bubble generator (2) which releases into the well a gas not readily soluble in the well fluid, slightly overpressured in relation to the hydrostatic pressure, in the form of calibrated bubbles which greatly attenuate the parasitic tube waves. The attenuation device is placed above or below the elastic wave emission and/or reception set having a plurality of pickups whose signals are acquired by a local electronic module (14) and/or a source of elastic waves such as a vibrator. A bubble trap (17) is preferably associated with the bubble generator (2) in order to limit the volume of gas to be generated in situ. The invention is applicable to VSP type seismic prospecting and acoustic logging.

Abstract: A marine seismic source for generating acoustic source energy. A housing has a continuous exterior perimeter which is moveable to displace water. Movement of the housing can be accomplished by providing alternating convex and concave exterior surfaces connected with inflection points. The composite shape provides movement inwardly or outwardly, and can be moved with different types of actuators. Piezoelectric elements can be activated to move the housing surfaces and to change the internal housing volume. The resulting pressure pulse provides acoustic source energy useful for the evaluation of subterranean geologic formations and for other purposes.

Abstract: There is provided an acoustic source especially for use in seismic studies at sea. The acoustic source has a longitudinal axis and sound emitting surfaces adapted to be put into sound emitting movements towards and away from each other by use of a drive unit. The sound emitting surfaces comprise two curved plate members having upper and lower ends essentially symmetrically positioned in relation to the longitudinal axis of the acoustic source, and forming a convex cross section with their respective upper and lower edges converging towards each other. The upper and lower edges of the sound emitting surfaces, respectively, are connected to each other with two corresponding side elements, the side elements each being connected to at least one hinge stretching along at least a part of the length of the source.

Abstract: The present invention provides a method for forming wellbores. In one method, one or more wellbores are drilled along preplanned paths based in part upon seismic surveys performed from the surface. An acoustic transmitter conveyed in such wellbores transmits acoustic signals at a one or more frequencies within a range of frequencies at a plurality of spaced locations. A plurality of substantially serially spaced receivers in the wellbores and/or at surface receive signals reflected by the subsurface formations. The sensors may be permanently installed in the boreholes and could be fiber optic devices. The receiver signals are processed by conventional geophysical processing methods to obtain information about the subsurface formations. This information is utilized to update any prior seismographs to obtain higher resolution seismographs. The improved seismographs are then used to determine the profiles of the production wellbores to be drilled.

Abstract: A seismic vibrator system for imparting compressional and shear wave vibrations into the earth has an earth contacting base with a vertical post. A tubular hub is slidably received on the post in a piston/cylinder relationship. Spaced apart horizontal top and bottom plates are secured to the hub. A mass is slidably supported between the plates. Pistons interconnect the hub and the mass. Hydraulic energy is used to reciprocate the mass vertically on the post and horizontally between the plates.

Abstract: Acoustic source, especially for use in seismic studies at sea, with sound emitting surfaces adapted to be put into sound emitting movements toward and away from each other by use of a drive unit in a known manner, in which the sound emitting surfaces comprise two curved plate members essentially symmetrically positioned in relation to the longitudinal axis of the source, forming a convex cross section with their respective upper and lower edges converging towards each other, and the respective upper and lower edges of the sound emitting surfaces are flexibly connected to two corresponding side elements positioned between them, and that the source comprises a rigid frame for supporting the drive unit, comprising at least two rigid slide rods stretching through the side elements, and that rigid covers are mounted on the slide rods, covering at least the whole side elements, thus forming rigid, covering surfaces with a constant distance between the covers.

Abstract: An interactive sand box or sand table for use in tactical training includes an automated control system and image generator so that infinitely variable visual images may be projected onto the contoured surface of the sand for training and preparation for action in the military field and disaster control, industrial planning, environmental protection, and similar situations.

Abstract: An apparatus for placing geophones beneath the surface of the earth includes a machine frame that supports an elongated probe rod. The probe rod is dimensioned to reach a selected subterranean earth layer. The rod has upper and lower end portions. A geophone holder is positioned at the lower end of the rod for holding a geophone and its cable. A plurality of drive wheels carried by the frame transport the rod between the upper and lower positions. The drive rollers include at least an opposed pair of upper wheels and an opposed pair of lower wheels. The wheels are loaded with an adjustable spring pusher so that extensive pressure can be applied from the drive wheels to the pipe for gripping and driving the pipe even when muddy. A gear train interconnects all of the driving wheels so that all of the wheels rotate at the same rotational speed. A gear train preferably includes six gears including a pair of upper gears, a pair of lower gears, and a pair of intermediate drive gears.

Abstract: An attenuator for use in attenuating tube waves in a borehole includes a body formed from a permeable material having a rigid matrix which can be saturated with fluid. In its simplest form, the attenuator is one or more cylindrical bodies as part of a borehole acoustic logging system. Alternatively, the shape, particularly at the end regions, can be modified to reduce the amount of reflection of tube waves in the borehole. Another attenuator includes a body for placement in a borehole formed from an attenuating material, the shape of the body being selected such that the change in impedance experienced by acoustic waves in the borehole is gradual rather than abrupt. One particularly preferred shape for the body comprises one in which the diameter is greatest towards the center of the body, for example the shape formed by two cones placed base to base, or a cylinder having conically tapered ends. A number of bodies can be used where appropriate.

Abstract: A method and system for using sonography to image the internal structure of geophysical and geologic models are disclosed. The sonography system includes a wand having a plurality of piezoelectric elements at an active surface thereof, each coupled to driver/receiver circuitry. Certain of the piezoelectric elements are selected as ultrasonic sources and receivers; the source/receiver designation may vary over time, as each of the elements may either generate or receive acoustic energy. A computer system, connected to the wand, receives signals from the receivers corresponding to reflected and refracted ultrasonic energy, and generates a zero offset trace image therefrom. In the geophysical case, the scale model is formed of materials such as plastics and rubbers having the desired properties for simulating the response of a portion or layer in the earth to ultrasonic vibrations.