Abstract: A transverse-wave logging tool consists of a plurality of sets of transducers mounted around a cylindrical mandrel. The transducer active faces are characterized by two orthogonal dimensions, one of which dimensions is a half-wavelength long relative to the acoustic excitation energy applied to a transmitter transducer and the transverse-wave formation velocity. Receiver transducers detect converted-compressional waves resulting from transverse waves that were generated by the acoustic excitation energy.

Abstract: A method for monitoring the relative goodness of a cement bond to a borehole casing by observing the relative change in amplitude of a converted-compressional wave as a function of depth in the borehole.

Abstract: A method and apparatus for obtaining improved measurements of shear waves in low-velocity lossy formations surrounding a borehole. The method comprises forming an interface between the borehole wall and a solid homogeneous material having a lower velocity than the formation. The geometry and velocity of the homogeneous material provide enhancement of the shear waves at the interface and thereby minimize the effect of interference from undesired compressional waves. Further improvement is obtained by using shear waves whose particles move perpendicular to the travel of the wave, parallel to the plane of the waves and perpendicular to the surface of the material. These are commonly referred to as SV shear waves.

Abstract: A method and apparatus for acoustical logging wherein a plurality of transducers are spaced circumferentially in a plane perpendicular to the borehole and in close proximity to the wall of the borehole. Numerous circumferential acoustic transmission paths are defined by using some of the transducers as transmitters and others as receivers. Ultrasound is transmitted and received separately along each of the paths and amplitudes of the received waves are separately recorded to provide a side-by-side comparison of the signals. The received waves may be comprised of shear waves and compressional waves, and the shear wave amplitude may be recorded to the exclusion of later arriving waves. Proper spacing of the transmitters and receivers will produce a complete circumferential acoustic log of the borehole that can be used to detect the presence of vertical fractures.

Abstract: An acoustical logging tool having a plurality of long, extendable, resilient arms, and means for remotely extending free ends of the arms into close proximity to the wall of a borehole. A cylindrical transducer is mounted on the free end of each arm, with some of the transducers being used as transmitters and the remainder as receivers. The signals from the receivers are separately recorded to provide a side-by-side comparison of the signals. The proper spacing of the transmitters and receivers will produce a complete circumferential acoustic log of the borehole that can be used to detect the presence of vertical fractures.

Abstract: An impoved game apparatus of the type employing sound producing pieces. A sonorous board is employed and the pieces are so constructed that certain ones will produce a concussion of the board by means of a hidden impactor. The concussion causes the board to vibrate, thus producing the sound. The pieces are of such form and appearance that those which will produce sound are not visually identifiable as such. In a first embodiment all the pieces have the same outward appearance but are of different colors on top and bottom faces. In a second embodiment the pieces display the same color on top and bottom but are constructed so as to produce sound in only one orientation, which is not visually identifiable. In a third embodiment each piece is colored on one face only and is supported upon the board by a compliant body. The impactor is concealed within the compliant body on certain pieces only.

Abstract: Method and apparatus for acoustically logging of a borehole wherein a beam of ultrasonic energy is transmitted from the borehole to the formation to produce substantially only shear waves in the formation. The shear waves are received at a position spaced from the point at which the acoustical waves were generated. The system includes means to measure the time required for the shear waves to travel from the transmitting point to the receiving point and/or the reduction in amplitude of the received shear waves.

Abstract: An acoustical logging tool having a plurality of long, extendable, resilient arms, and means for remotely extending free ends of the arms into close proximity to the wall of a borehole. A cylindrical transducer is mounted on the free end of each arm, with some of the transducers being used as transmitters and the remainder as receivers. The signals from the receivers are separately recorded to provide a side-by-side comparison of the signals. The proper spacing of the transmitters and receivers will produce a complete circumferential acoustic log of the borehole that can be used to detect the presence of vertical fractures.