Abstract: A downhole seismic signal source (vibrational or impulsive) capable of producing a signal of sufficiently high energy to permit the tool to be used in a deep wellbore (exceeding 4000 feet). A piston rod having two pistons reciprocates in an elongated cylindrical housing. An electrohydraulic valve controls the flow of hydraulic fluid to opposite sides of a first piston to control the piston rod's vertical movement. The second piston is positioned between a fluidic spring which balances the pressure of the wellbore fluid and a reservoir of hydraulic fluid which inflates a flexible bladder to produce the seismic signal in the wellbore fluid.

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: Vibrator apparatus having adjustable cylinder volume by means of a continuously adjustable end sleeve that varies the axial limit of the cylinder. A reaction mass with an axial cylinder bore reciprocates on a double rod piston. Frist and second end sleeves define the cylinder volume and one end sleeve is threaded and axially translatable relative to the piston to vary volume while a position sensing device continually maintains centering of the piston in the cylinder.

Abstract: A seismic signal generator with a self-adjusting footprint base plate. A signal generator for use on paved or other hard surfaces, has a pair of tread members (preferably urethane) that are laterally slidable with respect to the reaction mass. The tread members are biased outwardly away from the reaction mass. Should slippage from the point of initial placement occur during signal generation, the biasing force will continue to move the tread members outwardly to a more stable position, thereby achieving optimum intimate contact between the generator and the surface of the ground maximizing signal transfer into and through that surface.

Abstract: This invention is an improved type of shear wave vibrator are carried by a support vehicle and utilizing telescoping tubes for energy engagement within an underlying earth medium. A shear wave vibrator so constructed is particularly desirable for use over marshy or soft surface earth areas. The device consists of a jack assembly supporting a shear wave vibrator relative to a suitable carrier vehicle in vibrationally isolated manner. The vibrator structure consists of a pair of parallel, elongatable telescoping blades for earth penetration and engagement with a passive reaction mass pivotally secured across the top portion of the telescoping blades and an active mass/vibrator system pivotally secured across the lower portion of the telescoping blades adjacent the earth surface.

Abstract: An orbital vibratory mass is used for generating seismic signals and the like. An annular reaction mass is mounted on a crank by means of bearing. The reaction mass orbitally oscillates relative to the axis of the crank shaft without rotating. This reduces the internal forces created in the reaction mass by centrifugal force and enables less exotic, less expensive materials to be used in its construction.

Abstract: An apparatus for incremental cylinder length control in a hydraulic vibrator of the type having a reaction mass with a cylinder bore disposed therein, first and second end sleeves disposed in sealed movable position in the ends of the cylinder, a piston rod sealed and slidably disposed through the first and second sleeves with a piston attached to the piston rods where the improvement comprises threading the ends of the cylinder bore and forming mating threads on the first and second sleeves with means for rotating the sleeves with respect to the cylinder so that the sleeves move toward or away from the piston thereby reducing the volume of hydraulic oil between the end of the piston and the end sleeves.

Abstract: The density of the fluid flowing through a tubular member may be measured by a device comprising a rotor assembly suspended within the tubular member, a fluid bearing medium for the rotor assembly shaft, independent fluid flow lines to each bearing chamber, and a scheme for detection of any difference between the upstream and downstream bearing fluid pressures. The rotor assembly reacts to fluid flow both by rotation and axial displacement; therefore concurrent measurements may be made of the velocity of blade rotation and also bearing pressure changes, where the pressure changes may be equated to the fluid momentum flux imparted to the rotor blades. From these parameters the flow velocity and density of the fluid may be deduced.

Abstract: A device for measuring the fluid density of a two-phase mixture flowing through a tubular member. A rotor assembly is rotatively supported within the tubular member so that it can also move axially within the tubular member. The rotor assembly is balanced against a pair of springs which exert an axial force in the opposite direction upon the rotor assembly. As a two-phase mixture flows through the tubular member it contacts the rotor assembly causing it to rotate about its axis. The rotor assembly is forced against and partially compresses the springs. Means are provided to measure the rotational speed of the rotor assembly and the linear displacement of the rotor assembly. From these measurements the fluid density of the two-phase mixture is calculated.