Abstract: An underwater signaling device being removably mounted to the strap commonly found in scuba diving tanks. The device includes two elongated members an one of them being removably secured to the strap while the other one, hingedly mounted to the first one, is urged towards the latter by the spring action of the wound common ends connecting each other. A solid mass is rigidly mounted to the movable elongated member and an impact receiving plate is mounted to the fixed elongated member so that when the movable member is released the impact is taken by the plate and not directly by the tank.

Abstract: The process consists in generating a primary tube wave, in using a reflecting element for the tube wave and in recording the times of emission of the induced waves radiated by the reflecting element, in receiving and recording at least part of the induced waves, then in processing the recorded signals so as to determine the characteristics of the medium to be explored. Application in particular to exploration between boreholes.

Abstract: The present invention comprises a multi-barrel seismic source air gun module for use in a marine environment, preferably comprising a plurality of air gun barrels symmetrically disposed in a single plane about and rigidly secured to a control head containing means for actuating said barrels.

Abstract: Amplifier gain is time ramped to increase amplification of the signal with increasing mud transit time and attenuation. Amplitude, ramp slope, and ramp onset time are independently controllable from the surface.

Abstract: An acoustic filter is provided for attenuating or suppressing the negative pressure half-waves of an elastic wave, comprising an enclosure containing a liquid whose saturating vapor tension is close to the atmospheric pressure. A pump causes the liquid to flow and a regulator fixes its temperature.

Abstract: The disclosure relates to a seismic vibrator having an airbag isolator, a transducer for monitoring the instantaneous air pressure within the airbags, a summer to add the pressures within each air bag and a calibrated weighting network to convert the composite pressure for display as holdown weight on a meter and for comparing the measured holdown against a preset threshold that is used to enable or disable sweep generation or operation of an inducer. The system also includes structure for comparing the measured holdown against a preset threshold that is used as a feedback signal to the lift system and for providing a signal proportional to holdown weight to the sweep generator for use as a feedback signal to modify the amplitude of the force generated by the actuator.

Abstract: An improved inclinable vibratory seismic source arranged to be vehicle mounted including a base plate mounted for movement relative to the vehicle frame and for engagement with the ground. Hydraulic cylinders are provided for raising and lowering the base plate. A shaft is connected to the base plate by a U-Joint and has a vibratory mass located thereon. Also, located on the shaft is a reaction mass that is resiliently coupled to the vibratory mass and tuned so that the reaction mass remains virtually vibration free. Control apparatus is connected to the reaction mass to position the shaft and vibratory mass at a preselected azimuth and inclination.

Abstract: Apparatus for generating a controlled parameter elliptically polarized shear wave into an earth medium. The apparatus consists of a baseplate for engagement with the earth medium in omni-directionally resistant manner and a reaction mass and actuator assembly affixed thereto and energizable to impart reciprocal lateral forces to the base-plate that exert a predetermined resultant force at a controlled rate of rotation.

Abstract: A housing for an acoustic logging tool apparatus for use in a well bore is disclosed. The logging tool comprises an acoustic transmitter and one or more acoustic receivers located a fixed distance from the transmitter and an elongated tubular housing having a transmitter area, an intermediate area and a receiving area. The tubular housing has a plurality of interruptions or holes in the longitudinal continuity of its wall to delay the acoustic energy passing from the transmitter to the receiver along the housing. The receiving area of the housing further having means for reducing secondary acoustic noise produced by acoustic scattering between the intermediate area and the receiving area.

Abstract: The microstructure of thinly laminated earth formations is acoustically determined with a logging tool having an acoustical transducer pad mounted for measuring while in contact with the borehole wall.

Abstract: Methods and apparatus are described utilizing low frequency tube waves in determining characteristics of formations traversed by a borehole. Data received from three spaced receiving transducers are utilized in formulating quantities representative of complex compressibility of formations as well as loss parameters attributed to formation characteristics. When these two factors are recorded as a function of depth, interpretation is made readily available as to the permeability and rigidity of subsurface earth formations. Data is also provided by way of the present invention to enable interpretation concerning the presence of fractures or cracks in the earth formations. The methods and apparatus may also be utilized to examine the condition of casing in a borehole.

Abstract: A marine seismic array wherein each air gun in the array is provided with an air supply valve that can be closed remotely to inactivate a particular air gun and then reopened upon command to reactivate the gun without retrieving the array. The valve is comprised of a housing having a ball valve therein which is rotated between an open and closed position by a reversible, electric motor in the housing upon the flowing of current to the motor in either a first direction or in an opposite direction. Limit means are provided in the housing to stop the motor when the ball valve rotates to either a full open or a full closed position.

Abstract: In an acoustic ground vibration detector for the detection of infrasound ground vibrations, comprising at least one three-component geophone probe, the three individual geophones of said geophone probe are electrically connected in series and act upon an operation amplifier whose output signal activates a Reed relay. The activated Reed relay switches on a sound signal transmitter which produces an audible acoustic signal for the duration of the ground vibration signal. The acoustic ground vibration detector is intended in particular for locating buried persons. Moreover, it serves to protect important objects by registering infrasound ground vibrations produced by footfall sound.

Abstract: Piezoelectric transducer for the production of, for example, hydrophones, with the transducer including a plurality of sensitive coaxial elements interconnected so as to compensate for the effects of accelerations and deflections.A transducer includes at least one pair of sensitive elements composed of sections of radially polarized coaxial piezoelectric cables having an opposing orientation, with an external armouring of one being connected with an internal armouring of the other, and vice versa. By increasing the number of parts of sensitive elements and selecting the relative disposition, it is possible to improve the immunity of the transducer to noise due to accelerations and deflections, regardless of the direction or the need to license a direction where the transducer is sensitive to such noise. A predetermined number of pairs of sensitive elements can be combined around a central column for accommodating connectors or cables.To be applied, for example, to the production of hydrophones.

Abstract: An automatic feedback control system for use with an off-road vehicle having an adjustable-elevation, ground-engaging implement, such as an agricultural tractor with a three-point hitch and a plough or cultivator, is disclosed. The automatic control system provides an engine-sensing draft control system which adjusts the height or elevation of the ground-engaging implement so as to maintain the draft or load forces experienced by the vehicle at a substantially constant level. The determination of the draft being produced by the ground-engaging implement is determined by the engine speed deviation from a target point speed which is indicated by an operator-set desired no-load engine speed and an operator-set engine lug-down value or load.

Abstract: An improved method and apparatus of transmitting data signals within a well bore having a string of tubular members suspended within it, employing an electromagnetic field producing means to transmit the signal to a magnetic field sensor, which is capable of detecting constant and time-varying fields, the signal then being conditioned so as to regenerate the data signals before transmission across the subsequent threaded junction by another electromagnetic field producing means and magnetic sensor pair; the method and apparatus also having a battery saving switch that extends the life of the battery carried by the tubular member in a compartment that shields the battery from the well bore environment.

Abstract: A flextensional sonar transducer assembly includes a stack of piezoelectric elements disposed along a linear axis, a plurality of electrodes disposed between the elements, end pieces disposed at each end of the piezoelectric stack, with the end pieces having outwardly facing, generally arcuate surfaces, a band of material formed into a loop to encircle the stack and end pieces, a flexural shell disposed to circumscribe the band of material to present a generally elliptical side cross-section, with the major axis thereof being generally coincident with the linear axis of the stack, and with the shell being reactively coupled to the arcuate end portions of the band of material so that a transverse movement of the long sides of the shell causes longitudinal compression or expansion of the elongate means and vice versa, and wedge elements positioned between the shell and the arcuate end portions of the band of material for maintaining driving contact between the shell and the end pieces.

Abstract: Method and apparatus for transmitting data uphole in a well to the top of the well. A string of electrically conductive tubing and a tool connected to the tubing are lowered down the well along the inside of tubular shaped electrically conductive casing for the well. The inside of the casing is electrically contacted with an electrical contact carried by the tool. A switch in the tool is operated for alternately electrically connecting and disconnecting the contact and thereby the casing and with respect to the conductive tubing for changing the electrical conductance between the tubing and the casing representative of data. The changing conductance is interrogated with an alternating current, formed at the top of the well, to recover the data.

Abstract: Disclosed is an apparatus for imparting only shear wave energy into the earth comprising a vibrating pad for connection to a mobile support, such as a wheeled vehicle, and means for vibrating the pad to impart at least two polarizations of shear wave energy into the earth. One such means includes azimuthally rotating the pad and/or the vibration energy generator.

Abstract: A method for controlling the firing times of a plurality of marine seismic sources which are towed as a seismic array behind a towing vessel is provided. The marine seismic sources are adapted to create seismic pulses after having been fired. The method measures and determines physical quantities representing the instantaneous operating depths of the individual seismic sources of the array and transmits the values of said quantities to a controling means for the seismic sources which compares the depth values thus obtained with predetermined depth values, and, if the measured depths are different from a preset depth, adjusts the firing times of the seismic sources of the seismic array in relation to the measured instantaneous depth values.Apparatus for carrying out the method is also provided.