Abstract: A logging-tool assembly for generating both flexural wavefields and compressional wavefields in the sidewall formations encountered by a borehole. The assembly consists of a sonde constructed of a plurality of segments that are axially rotatable with respect to each other. Each one of two of the segments includes a compartment in which is mounted a dipole bender bar transmitting transducer. Two additional segments each contain one or more binaurally sensitive receiver transducers. Monopole transmitting and receiving transducers are also included in the respective appropriate segments. An acoustic isolator of novel construction acoustically separates the transmitting transducers from the receiving transducers.

Abstract: An acoustic isolator for use with a logging-tool assembly for generating both flexural wavefields and compressional wavefields in the sidewall formations encountered by a borehole. The acoustic isolator is sub-flexible and is composed of a plurality of individual vertebrate links. The links are made up of a plurality of spools laid out end-to-end in tandem. The spools have upset end portions. The upset end portions of each pair of adjacent spools are externally gripped by a split shells having internal recesses that fit over the upset end portions of the spools.

Abstract: An elongated body member adapted for coupling to a well logging or perforating instrument in a fixed rotational relation, and formed such that at least a portion of the mass is eccentrically disposed relative to the longitudinal axis of the body member. Located within the eccentric mass of the body member is a recess for retaining one or more magnets. When the orienting decentralizer is introduced into a borehole, virtually any deviation of the borehole from true vertical will cause the longitudinal axis of the body member to tilt and the eccentric mass will cause the decentralizer to rotate about its longitudinal axis and seek equilibrium with the eccentric mass uniformly disposed beneath the tilted axis of the body member, thus rotating the attached logging or perforating instrument to a predictable orientation relative to the lower side of the borehole.

Abstract: A system for orienting a well casing perforating gun for utilization in wells having multiple tubing strings wherein it is desired to perforate the well casing in a zone other than the deepest production zone of the well and includes a hoist and associated apparatus for moving the perforating apparatus through the well and actuating the perforating gun. The perforating apparatus includes an elongated housing supportable on a cable, rollers on the exterior of the housing to support it on the interior of the well casing and/or tubing, the casing perforating gun, an orienting apparatus operable to orient the perforating gun relative to a string of tubing within the casing, a swivel within the housing to permit rotating motion of the lower portion of the housing relative to an upper portion of the housing, and an eccentric weight below the swivel to assist in positioning and aligning the casing perforating gun to the desired position.