Disclosed is a pipeline pulling tool having an elongate housing. First and second roller wheel sections have at least two freely rotating roller wheels extending out from a sidewall of the housing. An attachment for a tool string is fixed to one of the roller wheel sections. A main section with a retractable propulsion wheel and at least one actuator for actuating the propulsion wheel between an extended position, out from the sidewall of the housing, and a retracted position, inside the housing, is located between the first roller wheel section and the second roller wheel section. A method of actuating a pipeline pulling tool is also disclosed.

Bottom hole assemblies with a combined roller-underreamer assembly can include: a body configured to be attached to a drill pipe; an uphole ring attached to the body; a downhole ring attached to the body between the uphole ring and the downhole end of the body; a sliding ring mounted around the body between the uphole ring and the downhole ring; a set tube slidably mounted around the body between the uphole ring and the sliding ring; a reamer assembly with at least one first articulated arm with extending between the uphole ring and the downhole end of the set tube; and a roller assembly with: at least one second articulated arm extending between the uphole end of the set tube and the sliding ring; and a rolling positioned at a joint of each second articulated arm.

An apparatus (10) includes a traction member in the form of a roller (24) configured for mounting on a body (12) so as to permit rotation of the roller (24) relative to the body (12). The roller (24) is mountable on the body (12) so as to define a skew angle relative to a longitudinal axis (26) of the body (12). In use, the roller (24) engages a wall of a borehole or bore-lining tubular and the roller (24) urges the apparatus (10) along the wall of the borehole or bore-lining tubular on rotation of the as the roller (24) rotates on the body (12).

A roller tool 1 that can be connected into a string for deployment into an oil or gas well includes at least two rollers or wheels 10 located on each side of the roller tool 1, with axes of rotation that are perpendicular to the axis of the roller tool 1. The roller tool further includes at least two interconnecting tubular portions, where one tubular portion 41 comprises a mandrel 45 that connects to another tubular portion 42. An annular hub 20 is fitted over the mandrel 45 and the rollers 10 are connected onto the hub 20. The tubular portions 41, 42 comprise circumferential sleeve sections 56a, 56b that partially extend over the rollers 10 and resist detachment of the rollers 10 from the roller tool 1. The roller tool 1 can aid passage of a string through a well by holding the string away from the walls of the well and reducing frictional contact.

A centralizer assembly replaces an existing centralizer of a wireline tool so the tool can be used with smaller casing, such as casing smaller than 6-in. The assembly includes first and second centralizer units that replace the existing centralizer on a mandrel. Each unit has a sleeve that fits in a recess of the mandrel, and each unit has slider blocks disposed together in the recess on opposing sides of a divider on the sleeve. Arms hingedly connected to the blocks on each unit connect together at a joint having a roller for engaging in the casing. On each unit, a common pin is disposed through the slider blocks, and biasing elements on the common pin bias the blocks toward one another with different amounts of bias.

A roller device for incorporation into a wireline tool string for use in an oil or gas well has a body with rollers comprising captive bearings arranged on the outer surface of the body to rotate around more than one axis relative to the body, and wherein the rollers are arranged in at least one or more helix around the body. Each helix completes at least one full circumferential turn around the body. The rollers circumferentially overlap one another on the body, so that when the body engages the inner wall of the wellbore, the entire circumference of the body is supported by at least one roller.

An apparatus for cutting into a subterranean formation includes a body and multiple cutting blades distributed around a circumference of the body. The cutting blades are configured to cut into the subterranean formation in response to being rotated. Each cutting blade includes a ball embedded in the respective cutting blade. At least a portion of the ball protrudes towards the subterranean formation from the respective cutting blade in which the ball is embedded. Each ball is configured to roll against the subterranean formation to reduce friction while the cutting blades are rotating.

Apparatus comprising a gripper operable to grip a cable extending between the Earth's surface and a downhole tool, wherein the downhole tool is suspended in a wellbore that extends from the Earth's surface to one or more subterranean formations. A body is assembled to the gripper. A plurality of rolling elements are each rotatably coupled to the body and operable to rotate relative to the body in response to contact with a sidewall of the wellbore as the body is translated along the wellbore. The body and the plurality of rolling elements collectively rotate relative to the gripper and, thus, the cable.

Systems and methods for optical communication in a downhole tool are disclosed. An optical communication system includes a rotation-varying outer housing that is at least partially rotationally decoupled from an inner member. The inner member is at least partially disposed within the rotation-varying outer housing. The optical communication system also includes one or more transceiver modules, one or more transmitting bulbs rotationally coupled to one of the outer housing or the inner member, and one or more optical sensors rotationally coupled to one of the outer housing or the inner member. The transmitting bulbs are configured to transmit light over at least a portion of a cavity between the transmitting bulbs and the optical sensors, and the optical sensors are configured to receive light over at least a portion of a cavity between the transmitting bulbs and the optical sensors.

A well tool apparatus for damping torsional vibration of a drill string comprises stabilizing members projecting radially outwards from a housing that is, in operation, rotationally integrated in the drill string, to stabilize the drill string by engagement with a borehole wall. The stabilizing members are displaceably mounted on the housing to permit limited angular movement thereof relative to the housing about its rotational axis. The well tool apparatus includes a hydraulic damping mechanism to damp angular displacement of the stabilizing members relative to the housing, thereby damping torsional vibration of the housing and the connected drill string, in use.