Abstract: A monopole transmitter for a sonic well tool includes an axial tube, a piezoceramic cylinder surrounding the axial tube, an endcap disposed at each end of and firmly contacting the cylinder, and an apparatus for holding the endcaps firmly against the axial tube. The endcaps firmly contact the axial tube without simultaneously contacting an upper bulkhead. The apparatus may include spring washers disposed between the bulkhead and at least one endcap, or it may include a spring disposed between a nodal mount and each endcap. A nodal mounting tube may be disposed around the axial tube, a ring being disposed at each end of the nodal mounting tube, each ring being disposed outside of the cylinder, the apparatus including a spring disposed between each ring and an endcap outside of the cylinder for biasing the endcaps in tension against a ring thereby holding each endcap firmly in contact against the axial tube.

Abstract: A sonic well tool includes a transmitter array, including at least one monopole transmitter and at least one dipole transmitter, and a receiver array for receiving sonic pressure wave signals from a surrounding borehole formation. A first attenuation and delay apparatus is positioned above the receiver array and a second attenuation and delay apparatus is positioned below the receiver array in the sonic well tool. The first attenuation and delay apparatus includes an attenuation member comprising a plurality of interleaved rubber and metal like washers for attenuating compressional and flexural waves propagating along a metal, center support rod to the receiver array and an inner housing comprising a bellows section having a corrugated shape and a thin transverse dimension for delaying the propagation of compressional and flexural waves along the inner housing to the receiver array.

Abstract: A sonic isolation joint (SIJ) of a sonic well logging tool is disposed between a sonic transmitter section and a sonic receiver section of the tool and attenuates compressional and flexural waves which propagate longitudinally along an axis of the tool when the sonic transmitter transmits a pressure wave into a formation of a borehole. The SIJ comprises a first outer housing, a second outer housing, an inner housing disposed within the first and second outer housings, a first attenuation member disposed between the first outer housing and the inner housing and a second attenuation member disposed between the second outer housing and the inner housing, each of the attenuation members including a plurality of rubber isolating washers, and a plurality of steel washers interleaved with the plurality of rubber isolating washers.

Abstract: A transmitter for a sonic wall logging tool contains a piston, the plane of the piston being disposed along the longitudinal axis of the tool. The piston moves, in its entirety, transversely with respect to the tool when an alternating current flows in two coils disposed in magnetic fields created by two mangets. Sonic positive pressure waves are created on one side of the piston, and sonic negative pressure waves are created on the other side of the piston. Shear waves are created in the formation, a positive shear wave being created in the formation on one side of the tool, and a negative shear wave being created in the formation on the other side of the tool.

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: An exercise device which is adapted to provide resistance to ankle flexion about a plurality of spaced axes. The device can be quickly and easily adjusted to allow exercising of the anterior, posterior, medial, and lateral muscles of the ankle and lower leg. When attached to this device, all ankle movement takes place about a single pivot axis, the multidirectional quality being achieved by changing the orientation of the user's foot and ankle to the resistive movement about the pivot axis. A movable foot plate secures the user's foot and ankle in the desired orientation, parallel or perpendicular, to the pivot axis.