Abstract: A mechanical stop arrangement includes a first coupler having a tool connection segment, and an arrangement connection segment, a second coupler having a first connection segment connectable with the arrangement connection section, and a frustoconical inside diameter surface, and a wedge having a radially outside surface angle that is complementary to the frustoconical inside diameter surface. A method for connecting a borehole tool to an outside surface of a tubular, including connecting the borehole tool to a first coupler either before or after disposing the coupler on the tubular, disposing the first coupler on the tubular, disposing a wedge on the tubular, disposing a second coupler on the tubular, interconnecting the first coupler and the second coupler, and jamming the wedge against the tubular with the interconnecting. A wellbore system, including a borehole, a string in the borehole, and an arrangement, disposed within or as a part of the string.

Abstract: A seal arrangement including a T-seal, a backup adjacent the T-seal, and a bullet seal adjacent the backup and responsive to the backup to splay a wing of the bullet seal. A method for sealing a system, including running a seal arrangement into a tubular structure, sealing the arrangement to the structure, and radially retaining the T-Seal with the backup. A borehole system, including a borehole in a subsurface formation, a string in the borehole, and a seal arrangement disposed within or as a part of the string.

Abstract: A seal arrangement including a mandrel, a T-seal having a flange disposed on the mandrel, and a first backup adjacent the T-seal, the backup having a notch of complementary geometry to the flange, the notch nesting with the flange to retain the T-seal to the mandrel. A method for sealing a system, including running a seal arrangement into a tubular structure, sealing the arrangement to the structure, and radially retaining the T-Seal with the first backup. A borehole system, including a borehole in a subsurface formation, a string in the borehole, and a seal arrangement disposed within or as a part of the string.

Abstract: A logging tool for performing resistivity measurements on the sidewall of a borehole in an earth formation is provided with a circumferential series of evenly-spaced measurement electrodes providing complete circumferential coverage of resistivity measurements. In one embodiment, the measurement electrodes are carried on a conductive pad circumferentially surrounding an elongate mandrel or tubular. The conductive pad is held at a voltage adapted to focus measurement current into the sidewall of the borehole. Preferably, the pad has dimensions relative to the measurement electrodes and a standoff distance between the measurement electrodes and said borehole wall to effectively focus the measurement current into the borehole wall. In accordance with one aspect of the invention, the measurement electrodes are spaced apart by a distance that is less than the width of each measurement electrode, thereby ensuring full circumferential resolution.

Abstract: An apparatus for controlling a fluid flow in a borehole may include a tool body that retrieves a fluid sample from a subsurface formation. The tool body has a fluid conduit having an inlet for receiving the fluid sample and an outlet for conveying the fluid sample to a selected location. A mandrel selectively blocks flow across the fluid conduit; and a seal disposed on the mandrel includes at least one chevron seal element that cooperates with the mandrel to selectively block flow across the fluid conduit.

Abstract: Roller standoff assemblies and devices facilitate disposal of an interior tubular member within an exterior tubular member. Roller standoff devices include a roller cage and at least one roller supported by the roller cage to contact and roll upon the exterior tubular member.

Abstract: An apparatus for controlling a fluid flow in a borehole may include a tool body that retrieves a fluid sample from a subsurface formation. The tool body has a fluid conduit having an inlet for receiving the fluid sample and an outlet for conveying the fluid sample to a selected location. A mandrel selectively blocks flow across the fluid conduit; and a seal disposed on the mandrel includes at least one chevron seal element that cooperates with the mandrel to selectively block flow across the fluid conduit.

Abstract: Roller standoff assemblies and devices facilitate disposal of an interior tubular member within an exterior tubular member. Roller standoff devices include a roller cage and at least one roller supported by the roller cage to contact and roll upon the exterior tubular member.

Abstract: A downhole tool having a body, a transducer within the body, and an opening formed through a sidewall of the body. The opening provides a port through which the transducer can communicate from within the body. An elastomeric boot in the body covers the opening and is a barrier that prevents fluid ingress into the downhole tool. An expandable sleeve envelopes the elastomeric boot and provides support that limits bulging of the elastomeric boot from within the body through adjacent openings in the body. An example sleeve is made from elongated members woven into a tubular.

Abstract: A logging tool for performing resistivity measurements on the sidewall of a borehole in an earth formation is provided with a circumferential series of evenly-spaced measurement electrodes providing complete circumferential coverage of resistivity measurements. In one embodiment, the measurement electrodes are carried on a conductive pad circumferentially surrounding an elongate mandrel or tubular. The conductive pad is held at a voltage adapted to focus measurement current into the sidewall of the borehole. Preferably, the pad has dimensions relative to the measurement electrodes and a standoff distance between the measurement electrodes and said borehole wall to effectively focus the measurement current into the borehole wall. In accordance with one aspect of the invention, the measurement electrodes are spaced apart by a distance that is less than the width of each measurement electrode, thereby ensuring full circumferential resolution.

Abstract: A measuring and transmitting apparatus for use in a drill string of a well drilling rig has an elongated tubular member functioning as a drill collar in a drill string. This apparatus includes an instrument having transducers that measure lithological and geophysical parameters in the borehole and derive from them data that is encoded into pressure pulsations of the mud flow of the drill string by a modulated signal generator. The modulated signal generator has a valve assembly that selectively restricts the mud flow to introduce the data. The valve is constructed with a movable valve element that is displaced into an orifice located in the mud flow stream. The movable valve element is mounted in a pressure balanced and an area balanced configuration in order that it can be displaced between extended and retracted positions by a valve actuator without regard to the mud pressure either within the drill string or in the borehole annulus around the drill string.

Abstract: A hydraulic power unit is provided for a downhole instrument of a measurement while drilling system for a well drilling. The hydraulic power unit is enclosed within a drill collar that is connected in the drill string of a rotary drilling rig. An outer body sleeve is rigidly mounted in the instrument drill collar. A fixed inner sleeve is connected to the outer body sleeve in a concentric relation with a longitudinally movable plunger assembly supported therebetween and movable in the telescopic fashion between an extended position and a retracted position to provide hydraulic power fluid for the hydraulically powered circuits of the instrument.