The disclosure provides an acoustic logging device comprising a first tubular member comprising a plurality of grooves disposed on an exterior of the first tubular member. The acoustic logging device further comprises a ring transmitter module disposed around an exterior of the first tubular member, which comprises a piezoelectric (PZT) ring transmitter, a transmitter sleeve, wherein the PZT ring transmitter is disposed within the transmitter sleeve, and a cage, wherein the transmitter sleeve is disposed between the cage and the exterior of the first tubular member, wherein the transmitter sleeve is disposed over the plurality of grooves. The acoustic logging device further comprises a plurality of dual bender transmitters, wherein there is a gap disposed the plurality of dual bender transmitters in the exterior of the first tubular member, wherein there is an array of holes connecting each of the gaps together and providing fluid communication between the gaps.

The disclosure provides an acoustic logging device comprising a first tubular member comprising a plurality of grooves disposed on an exterior of the first tubular member. The acoustic logging device further comprises a ring transmitter module disposed around an exterior of the first tubular member, which comprises a piezoelectric (PZT) ring transmitter, a transmitter sleeve, wherein the PZT ring transmitter is disposed within the transmitter sleeve, and a cage, wherein the transmitter sleeve is disposed between the cage and the exterior of the first tubular member, wherein the transmitter sleeve is disposed over the plurality of grooves. The acoustic logging device further comprises a plurality of dual bender transmitters, wherein there is a gap disposed the plurality of dual bender transmitters in the exterior of the first tubular member, wherein there is an array of holes connecting each of the gaps together and providing fluid communication between the gaps.

A tubular string includes a first tubular member with a pin end with pin threads and a pin external load shoulder. The tubular string also includes a second tubular member with a box end with a box external load shoulder and box threads, the pin threads being threadable into the box threads to form a connection, wherein the pin external load shoulder has an outer diameter (OD) that is different than an OD of the box external load shoulder. A load distribution sleeve is locatable between the first and second tubular members when threaded together and includes a first end facing the first tubular member and a second end facing the second tubular member, wherein the ODs of the load distribution sleeve first and second ends match the ODs of the pin and box external load shoulders respectively. The load distribution sleeve contacts the pin and box external load shoulders and distributes a make-up load between the pin and box external load shoulders when the connection is made up.

A tubular string includes a first tubular member with a pin end with pin threads and a pin external load shoulder. The tubular string also includes a second tubular member with a box end with a box external load shoulder and box threads, the pin threads being threadable into the box threads to form a connection, wherein the pin external load shoulder has an outer diameter (OD) that is different than an OD of the box external load shoulder. A load distribution sleeve is locatable between the first and second tubular members when threaded together and includes a first end facing the first tubular member and a second end facing the second tubular member, wherein the ODs of the load distribution sleeve first and second ends match the ODs of the pin and box external load shoulders respectively. The load distribution sleeve contacts the pin and box external load shoulders and distributes a make-up load between the pin and box external load shoulders when the connection is made up.

A stop collar for mounting to a downhole tubular includes: a cylindrical housing having a threaded inner surface and a tapered inner surface; a compressible slip ring having teeth formed in an inner surface thereof and a pair of tapered outer surfaces; a solid cam ring having a tapered inner surface; and a cylindrical bolt having a threaded outer surface. A natural outer diameter of each ring is greater than a minor diameter of the threaded surfaces. Screwing the threaded surfaces of the housing and the bolt is operable to drive the tapered surfaces together, thereby compressing the slip ring such that the teeth engage a periphery of the tubular.

A stop collar for mounting to a downhole tubular includes: a cylindrical housing having a threaded inner surface and a tapered inner surface; a compressible slip ring having teeth formed in an inner surface thereof and a pair of tapered outer surfaces; a solid cam ring having a tapered inner surface; and a cylindrical bolt having a threaded outer surface. A natural outer diameter of each ring is greater than a minor diameter of the threaded surfaces. Screwing the threaded surfaces of the housing and the bolt is operable to drive the tapered surfaces together, thereby compressing the slip ring such that the teeth engage a periphery of the tubular.

A retention system for attaching a collar to a pipe. The collar has an internally-disposed groove configured for placement of a ring. The ring is sized such that in one orientation, it can enter the collar between torque-transmitting features into the internally-disposed groove. Once in the groove, the ring may be adjusted such that its aperture is generally aligned with the axis of the collar. In this orientation, the features retain the ring within the groove. A bolt and a pipe may then be placed within the collar from opposite sides. The bolt is attached to the pipe through the ring. Once joined, the collar is joined to the pipe, forming its box end. Such a retention system may be used to join a series of inner pipe members of a dual-member pipe assembly, as in horizontal directional drilling.

A retention system for attaching a collar to a pipe. The collar has an internally-disposed groove configured for placement of a ring. The ring is sized such that in one orientation, it can enter the collar between torque-transmitting features into the internally-disposed groove. Once in the groove, the ring may be adjusted such that its aperture is generally aligned with the axis of the collar. In this orientation, the features retain the ring within the groove. A bolt and a pipe may then be placed within the collar from opposite sides. The bolt is attached to the pipe through the ring. Once joined, the collar is joined to the pipe, forming its box end. Such a retention system may be used to join a series of inner pipe members of a dual-member pipe assembly, as in horizontal directional drilling.

Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.