The invention relates to the field of petroleum engineering and can be used during hydrocarbon production in directional, deviated, horizontal and complex-profile wells. A protective roller centralizer with a cable channel is provided, which comprises: a housing, inside which the cable channel extends longitudinally to the housing along the entire length of the housing; a clamping half-yoke made of at least two parts which are installed in a mirror-like manner and adjacent to each other. The at least two parts are pivotally connected to the housing on one side and are configured to be attached to each other on another side by means of a detachable fastening connection to form an inner cavity for accommodating a tubing pipe. The housing and the clamping half-yoke have ribs formed on their outer surface.

A system includes a flexi-string having a first lateral end, a second lateral end, and an outer diameter. The outer diameter defines an outer circumferential surface, and the outer diameter is smaller than an inner diameter of a casing shoe. The system further includes an anchor disposed on the outer circumferential surface of the first lateral end, where the anchor interacts with the casing shoe, or a last joint of casing, to hold the first lateral end of the flexi-string within the casing shoe. The system also has centralizers located between the first lateral end and the second lateral end of the flexi-string. The centralizers are configured to center the flexi-string within the casing shoe and the washout section. Finally, the system includes a roller guide for lowering the flexi-string inside the casing shoe and to a depth below the washout section of the well.

A wheel assembly configured to detachably connect to a downhole tool to thereby reduce friction between the downhole tool and a sidewall of a wellbore through which the downhole tool is conveyed. The wheel assembly may include an axle configured to contact a sidewall of the downhole tool, wherein the axle comprises a bore extending therethrough, a wheel rotatably connected to the axle such that the wheel extends around at least a portion of the axle and the bore, and a fastener configured to be disposed at least partially within the bore and extend out of the bore into the sidewall of the downhole tool to detachably connect the axle to the downhole tool.

An indexing valve system includes a tubular having an inner surface portion defining a passage portion, a first plurality of indexing components provided on the inner surface and a second plurality of indexing components provided on the inner surface portion. A valve sleeve is arranged in the passage portion. The valve sleeve includes a first plurality of indexing elements that selectively engage with the first plurality of indexing components, a second plurality of indexing elements that selectively engage with the second plurality of indexing components, and an inner surface section defining a passage section. The inner surface section includes a plurality of indexing step members. An insert extends into the passage section. The insert includes an outer surface supporting an indexer that selectively engages with the plurality of indexing step members to shift the valve sleeve between the first plurality of indexing components and the second plurality of indexing components.

Self-powered active sensing systems (SASS) for use in downhole drilling environments are disclosed. Sensor devices of the SASS can include a self-powered rotational speed sensor including a ring structure attached around a drill string. The ring rotates within a groove formed in an outer housing. Bearings on the ring are arranged to contact moveable members extending from the housing into the groove thereby causing the moveable member to generate an electrical signal representing rotational speed. The SASS can include a vibration sensor having a ring spring mounted within a housing. Spherical bearings on the outer surface of the ring are configured to contact screens that are mounted to the housing and that generate a signal representing movement of the bearing/ring from vibration. Multiple SASS units configured to wirelessly transmit sensor data can be placed along a drill string providing a distributed self-powered system for measuring downhole parameters.

The disclosure relates to a carriage apparatus for carrying a tool string down a wellbore in a wireline logging, and an orientation apparatus and hole finder device for a wireline logging tool string. In some embodiments the carriage includes a protection structure which extends longitudinally around a wheel of the apparatus to thereby prevent a side of the wheel from contacting a wall of the wellbore. In some embodiments an orientation apparatus and hole finder are arranged so that the orientation apparatus orientates the hole finder device in the wellbore so that a tip of a nose section of the hole finder is elevated above a low side of the wellbore by a height and offset from and above a longitudinal axis of the tool string.

A centralizer for use in high speed rotor dynamics applications includes a housing having a first end portion and a second end portion. The centralizer further includes a rotatable shaft positioned within a cavity of the housing. The centralizer also includes flexure springs that are each attached to and extend between the first end portion and the second end portion. The flexure springs are compressible toward a middle portion of the housing that is between the first end portion and the second end portion. The centralizer further includes roller wheels attached to the flexure springs.

An artificial lift system utilizing a downhole impeller-style pump and a motor at the surface. The system includes a centralizer for use with the rod string or tubing. The centralizer centralizes a rotating rod at intermediate points within the tubing string. The centralizer includes a plurality of flexure springs and bearings. A rod string tensioner induces a tension load on the rod string.

A device for centering a sensor assembly in a bore comprises a mandrel, a first support member and a second support member axially spaced apart along a central longitudinal axis of the device. A plurality of arm assemblies are spaced circumferentially apart around the central longitudinal axis of the device and connected between the first and second support members. Each arm assembly comprises a first arm pivotally connected to the first support member by a first pivot joint having a first pivot axis, a second arm pivotally connected to the second support member by a second pivot joint having a second pivot axis, and the first and second arms pivotally connected together via a third pivot joint having a third pivot axis. The mandrel comprises a plurality of facets spaced apart around an outer surface of the mandrel and the first and/or second support member has a corresponding plurality of facets spaced apart around an inner surface of the support member, to rotationally key the first and/or second support member to the mandrel.

Described herein is a perforating assembly and method of use. In one embodiment, the perforating assembly comprising an offset loading tube mounted within a gun carrier. A plurality of shaped charges are mounted within the loading tube and the loading tube is mounted within the gun carrier on one or more swivel mechanisms that enable the loading tube to rotate within the gun carrier.