Abstract: A method for predicting the formation pore-pressure ahead of the drill bit while drilling is disclosed. During the drilling process, the drill bit impacting the earth generates a seismic signal. The seismic signal propagate away from the drill bit in a radial fashion with some rays paths propagating directly towards the surface, while others propagating downward are reflected back towards the surface. The direct and reflected seismic signals are received by seismic sensors at one or more locations. The signals produced by the sensors are recorded for later processing. From the recorded signals an interval velocity for each formation behind the drill bit is determined much in the same way a vertical seismic profile is made. From the reflected seismic signals, an acoustic impedance for each formation ahead of the drill bit is determined.

Abstract: An acoustic transducer which can be made small in size, i.e., in width, length and thickness, so as to fit into a credit card size package. The transducer comprises a flat frame having an opening therethrough. A pair of diaphragms of a piezoelectric plastic material extend across the opening in the frame along opposite sides of the frame. The diaphragms are stretched in at least one direction and are bonded to the frame under tension in the direction of the stretch. The diaphragms are bonded together at a position within the opening in the frame. The diaphragms are coated in both surfaces with conductive metal films. The inner metal films on the diaphragms which are opposed to each other are electrically connected together and the outer metal films are electrically connected together.

Abstract: An underwater transducer system reproduces high-fidelity audio signals underwater, and detects and monitors low levels of sound activity, both adjacent to a body of water such as a swimming pool, and in the water. The system includes an underwater housing for a diaphragm that directly contacts the water, a coil assembly movable within the housing and rigidly connected to the center of the diaphragm by a tubular member of the coil assembly engaging a cylindrical boss portion of the diaphragm. The housing can be suspended by an elongated cord member from a wall coping, or mounted within a wall fixture structure. The system can have a source of illumination, a conduit from the source terminating in the housing on the coil axis proximate the diaphragm, and an optical element sealingly protrudes the diaphragm for transmitting light-amplified illumination into the water.

Abstract: An instrument probe contains a video camera and light source which is positioned in front of the camera for illuminating the passage being inspected, such as a bore or a casing. The power source for the instrument probe is located at the surface. A support cable contains an optical fiber for conducting camera signals to the surface and electrical conductors for conducting power from the surface to the instrument probe. The outer electrical conductor includes strands of copper alternating with and in electrical contact with strength member strands. The cable is enclosed in a stainless steel outer sheath. The support cable is coupled to the instrument probe by three fluid seals. The first seals the outer sheath in the probe. The second seals at the breakaway connection and the third seals at the probe bulkhead. The second and third seals include the use of adhesive caulking.

Abstract: A cylindrical metal end cap is formed over one end of a thermoplastic tubular casing. A pyrotechnic detonator is ohmically connected to the end cap via an aperture thereof and includes an electrically activated match. The detonator is soldered to the end cap with a solder ring simultaneously with the insertion of the detonator into the end cap aperture to form a hermetic seal. A thermoplastic end cap is heat welded to the other end of the casing to hermetically seal the pyrotechnic material within the casing. The heat welding occurs at the outer surface of the casing and at a temperature lower than the ignition temperature of the pyrotechnic material in the casing. The position of the match within the casing is selected to cause the pyrotechnic material to burn toward the metal end cap to enhance flash production, different length casings producing different flash intensities.

Abstract: An electrically insulative gap sub for inclusion in a drill string that consists of upper and lower threaded joint members, an inner sleeve connected to extend axially from the upper joint member, an outer sleeve connected to the lower joint member and extending in concentric spacing over the inner sleeve, and a plurality of differently configured, annular blocks of insulative gap material serially arrayed and filling the void in between inner and outer sleeves. The gap material is a high performance molded resin capable of transmitting the requisite torque, tensile and compressive forces encountered along the drill string.

Abstract: A seismic source for emitting vibrations through rotation of a set of eccentric weights. Two pairs of angularly out-of-phase weights (A1, A2 and C1, C2) rotate in the same direction. One pair of weight (B1, B2) of twice the mass of each of the first pairs of weights (A1, A2 or C1, C2), also angularly out of phase in relation to one another, rotates in the direction opposite to that of the first pairs of weights and at the same speed. All the weights are rotated by electric motors. An electronic set (ME1, ME2) receives control signals (cp1-cp6 and ac1-ac3) representative at any moment of the position of all the weights and out of direction of the generated resulting vibration, and produces electric currents (IMA1-IMA6) driving the motors, as well as currents (ICH, EV) necessary for controlling a hydraulic plant to secure the source against an application wall. The electronic set automatically controls the vibration in order to obtain the desired oscillation direction, frequency and intensity.

Abstract: A method and an apparatus for producing a large-caliber ammunition unit including a combustible or partially combustible propelling charge casing and compacted or partially compacted propelling charge powder, to increase internal ballistic performance. It is known to partially or completely compact or compress the propelling charge powder in a cartridge casing. However, such methods generally cannot be employed for ammunition including a combustible or at least partially combustible propelling charge casing because of the lower strength of the relatively thin-walled combustible casing material, as this would lead to deformation and/or to reduced loadability of such cartridges.

Abstract: Apparatus is described for placement in a borehole in the earth, which enables the generation of closely controlled seismic waves from the borehole. Pure torsional shear waves are generated by an apparatus which includes a stator element fixed to the borehole walls and a rotor element which is electrically driven to rapidly oscillate on the stator element to cause reaction forces transmitted through the borehole walls to the surrounding earth. Logitudinal shear waves are generated by an armature that is driven to rapidly oscillate along the axis of the borehole relative to a stator that is clamped to the borehole, to cause reaction forces transmitted to the surrounding earth. Pressure waves are generated by electrically driving pistons that press against opposite ends of a hydraulic reservoir that fills the borehole. High power is generated by energizing the elements at a power level that causes heating to over 150.degree. C.

Abstract: An electro-acoustic transducer comprises two transducer units each having first and second ends, a tubular supporting member disposed between the two transducer units, and a pair of oppositely disposed supporting components between which the transducer units and tubular member are disposed. One of the transducer units is compressively clamped between one of the supporting components and one end of the tubular member, and the other of the transducer elements is compressively clamped between the other of the supporting components and the other end of the tubular member.

Abstract: Self-contained, preprogrammable downhole well data recorder and method of use thereof, the recorder having the external configuration of a conventional sidepocket gas lift valve and being placeable and retrievable from a conventional gas lift sidepocket mandrel by a conventional valve positioning tool. The recorder monitors and collects fluid dynamics data downhole during well operations, such as stimulation, production and multi-zone well completions, without impeding fluid flow. Programming can involve selective actuation of one or more of the sensors intermittently for at least thirty days. After retrieval of the recorder, fluid dynamics data stored in memory is outputted to external equipment for analysis in a manner known per se.

Abstract: An apparatus for borehole electromagnetic telemetry is provided comprising a direct switching element to couple energy from a downhole energy source to the earth-drillstring system, a downhole energy source that may be adapted to a variety of voltage levels, a system to control the switching element in response to the desired information to be telemetered, a system to adapt the voltage level of the downhole energy source to the desired level for the conditions of usage, and an insulated joint so that the energy to be transmitted can be injected into the earth-drillstring system.

Abstract: The method and apparatus for providing elliptical polarized shear waves in a marine environment in which a shear wave source penetrates the surface sediment of a water bottom includes dual actuator/reaction mass system mounted inside a structural ring of a conical housing section. A cross shaped structure at the top of the apparatus serves as a passive reaction mass and as a moment arm support for reversibly motor driven propellers enclosed in shrouds at the outer ends of the cross shaped structure. A thruster system provides dynamic positioning. The cross shaped structure and housing section are connected by a structurally stiff member, such as a vertical tube. Pistons provide actuation of two reaction masses located within the housing structure, and the motions of the reaction masses generate shear waves which propagate in the subsurface formations.

Abstract: An acoustic field transducer (10) comprises an elastic membrane (15A) made of piezo-electric material and peripherally held in stretched condition with static strain. A major surface area of the membrane (15A) is free to move in response to acoustic field variations which are coupled to the membrane (15A). Electrical conductors (17) are connected to the membrane (15A) for collecting signals piezo-electrically generated by the membrane due to strain variations and which are a measure of the acoustic field variations. The acoustic field variations are coupled to the membrane (15A) in a variety of different arrangements.

Abstract: An ultrasound apparatus has a first group of transmission and reception channels that are respectively allocated to elementary transducer in the active aperture of a connectable transducer array. The central transmission location generated by a transmission channel and the reception location sampled by a reception channel coincide and lie on the allocated elementary transducer. In addition, a second group of transmission and/or reception channels is present, each being respectively simultaneously connectable to a plurality of elementary transducers via transmission and/or reception transfer stages for generating a virtual transmission and/or reception location that lies between the elementary transducers.

Abstract: An underwater acoustic projector including a Class IV flextension shell, preferably in the form of an ellipsoid, is connected to and driven by two substantially identical electromagnets having mutually opposing pole faces and having a common spatially uniform air gap which is centered between the pole faces. The coils of the two electromagnets are connected in series and when excited by a controlled current, generate a mutually attractive variable reluctance force which causes the pole faces to be attracted toward one another. The shell secured to the electromagnets elastically flexes along one of two mutually perpendicular axes resulting in a volumetric displacement of the outer surface of the shell.

Abstract: A metallic down hole seismic sensor cable for operating at temperatures up to about 400.degree. F. and pressures up to about 5000 psig is provided. The seismic sensor cable includes a flexible metallic conduit sized for receiving a seismic sensor, and means for transmitting output generated by the seismic sensor. The cable is preferably constructed of stainless steel. An inert curable heat resistant material substantially fills the unoccupied spaces of the assembled seismic sensor cable.

Abstract: An outer jacket (14), an inner jacket (15) and an explosive charge (16) are ach independently manufactured on one of three parallel production lines (1, 2, 3) and assembled on a contiguous assembly line (4). The jackets (14 and 15) are designed to have a sufficient shape stability to be handled as separate components, and obtain the required firing strength due to their assembly. By changing the inner jacket (15), the ammunition body manufactured in this way can be prepared with different active bodies as suited for the application intended.

Abstract: The invention relates to a frequency controlled motor driven low frequency sound generator. The low frequency sound generator consists of an open resonator (2) arranged as a sound emitter for generating standing gas-borne sound waves which produce a varying gas pressure inside the resonator, and a feeder unit (1) for a modulated supply of air pulses to the resonator. The feeder unit (1) comprises a motor driven piston (8) with an approximately sinusoidal volume velocity. The piston is mounted on a piston rod (7) which is connected to a flywheel (6). The flywheel, in its turn, is mounted on a shaft (5) which is driven by a motor (3). The motor speed and thereby the frequency of the piston is regulated by a special electronic control unit.

Abstract: A sonar transducer assembly is provided which is adapted to be mounted on the transom of a boat. The assembly includes a shaped transducer device comprising a housing having a base portion of substantially elliptical cross section and a nose of a flattened ellipsoidal shape. A connector stem having a faired leading edge connects the transducer housing to a mounting bracket assembly. The mounting bracket assembly includes a base member adapted to be connected to the transom and a pivotable member which supports the transducer device. A releasable connection between the members includes a pair of laterally spaced, outwardly extending projections on one member which engage ears formed on the other member. An elastomeric insert disposed between the arms controls the force necessary to cause release of the connection to provide "kick-up" when the transducer device strikes an object in the water.