Abstract: A stop collar for a tubular includes an inner ring configured to engage the tubular and having a waveform profile. The waveform profile includes a peak and a base. The stop collar includes an outer ring configured to be disposed around the inner ring and configured to compress the inner ring. A method for assembling a stop collar for a centralizer on a tubular includes positioning an inner ring around the tubular, the inner ring including a profile and compressing the profile against the tubular by disposing an outer ring around the inner ring.

Abstract: A device for forming bow springs in a one-piece centralizer includes a swing arm that is configured to receive the one-piece centralizer. The device and process using the device include mechanically applying, with a press, an external load onto an un-formed bow spring positioned on a form of the swing arm. When the load is applied with the device, the un-formed centralizer is forced downward to allow the bow spring to take the desired form/shape/geometry, length, and height of a formed bow spring.

Abstract: A centralizer having asymmetrical bow springs defining a more gradual lead-in angle and a steeper retreat angle to reduce the required insertion and running forces. The centralizer comprises two end bands and a plurality of bow springs connecting the two shaped to gradually contact the surrounding hole or well casing. The bow springs are arranged such that a least two of them are asymmetric and positioned such that the apex of each is the same distance from an end band.

Abstract: A system for maintaining a minimum clearance between a locomotive and a railway infrastructure is provided. The system includes at least one rollable and compressible device configured to be affixed or otherwise provided on a side of a locomotive or portion of a train. Each rollable and compressible device includes bi-directional rolling element and is configured to allow movement of the roller between a non-rolling state and a rolling state and between an uncompressed state and a predetermined maximum compressed state.

Abstract: A centralizer, a device and a system. An example centralizer includes: a longitudinal axis, and first and second opposing end collars positioned around the axis of the centralizer; and a plurality of spring bows extending from the first end collar via a generally convex curved portion to the second end collar. A radial distance from an outwardly facing portion of the first end collar to the axis is: greater than a radial distance from a first outwardly facing portion of a spring bow of the plurality of spring bows, at a longitudinal axial position where the spring bow extends from the first end collar, to the axis; and less than a radial distance from a second outwardly facing portion of the spring bow, at a longitudinal axial position between the first end collar and the second end collar that is farthest from the axis, to the axis.

Abstract: The invention relates to a device for rehabilitating pipelines, having a support structure (10) to which functional units of the device can be fastened, wherein the support structure (10) has at least two support structure elements (12, 16, 19) which reconnected to one another via at least one buckling mechanism (20). By means of the buckling mechanism (20), at least one support structure element (12, 16, 19) can be placed into a buckled position. Furthermore, an actuating device (30) is provided which is designed such that the buckling mechanism (20) can be placed into a buckling enable position and a buckling blocking position by means of the actuating device (30).

Abstract: In some embodiments, apparatus useful for cleaning at least part of the interior surface of a cylindrically-shaped member disposed in a subterranean well includes a housing and a plurality of retractable mill blades supported on the housing. The mill blades of such embodiments are capable of cleaning the entire circumference of the interior surface of at least a portion of the cylindrically-shaped member upon reciprocation of the housing.

Abstract: A cleaning apparatus for cleaning the inner surface of an oil or gas production tubing is disclosed. The cleaning apparatus includes a tubular body, one or more cleaning elements mounted on the outer surface of the body and an elastically deformable stabiliser. The elastically deformable stabiliser is rotatably mounted on the body to centralise the apparatus in the tubing whilst also allowing the body to pass though areas of reduced diameter in the production tubing. Preferably, there are a pair of spaced apart stabilisers having a web arrangement of spars with a flange at each end.

Abstract: A cleaning tool for cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighbouring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

Abstract: In some embodiments, apparatus useful for cleaning at least part of the interior surface of a cylindrically-shaped member disposed in a subterranean well includes a housing and a plurality of retractable mill blades supported on the housing. The mill blades of such embodiments are capable of cleaning the entire circumference of the interior surface of at least a portion of the cylindrically-shaped member upon reciprocation of the housing.

Abstract: An apparatus is provided for cleaning a drill string of drilling mud during tripping, the apparatus being provided with a mass and a volume such that it is able to float on a surface of the drilling mud in the drill string during the tripping operation. The apparatus includes a wiper device which is bellows-shaped, and a weight which is fastened to the top of the wiper device.

Abstract: A cleaning tool for cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighbouring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

Abstract: A cleaning tool and method of cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighboring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

Abstract: A limit clamp for securing a tool to a casing having a groove in its outer surface. The limit clamp comprises a block having a base and a flange. The base is positioned in the groove to contact at least one stop in the groove and the flange extends out of the groove. The limit clamp also comprise a lock ring encircling the block and the casing, wherein the lock ring engages the block.

Abstract: A centralizer for maintaining stand-off and/or centralizing a tubular member inside a larger diameter tubular member, for instance, in a wellbore. The centralizer is provided with bow springs that compress to a minimal diameter around the outer diameter of the sub to which the centralizer is concentrically mounted when compressive force is applied to the bow springs to facilitate insertion of the centralizer into restricted openings and/or flow control or wellhead equipment. The minimal diameter of the centralizer is provided by mounting the bow springs to a reduced diameter portion of the collar that is mounted to the sub, and even greater reduction in diameter is achieved by mounting the bow springs in notches formed in the reduced diameter portion of the collar.

Abstract: An automatic paraffin removal unit, including a scraper body, a tumbler, an arc spring leaf and a return torque spring, and the upper and lower commutators having a sleeve, an open spacing ring and a tower spring. In operation, the scraper is clamped on a pumping rod, while the upper, lower commutators are respectively connected to the upper, lower ends of the tubing section from the well head to the section having toe temperature lower than paraffin deposition temperature requiring paraffin removal. The scraper moves up and down following the pumping rod via unidirectional upward or downward movement, paraffin removal being performed to the inner wall of tubing and pumping rod unceasingly, and variations in direction being performed in the upper, lower commutators.

Abstract: A dual diameter centralizing sub for maintaining stand-off and/or centralizing a tubular member inside a larger diameter tubular member, for instance, in a wellbore. The centralizer is provided with bow springs that compress into grooves between radially outwardly-extending vanes that are spaced around the outer diameter of the sub when compressive force is applied to the bow springs. The vanes extend radially outwardly far enough that the effective diameter of the sub in the area of the vanes is greater than the diameter of the sub and/or the tubing to which it is mounted to provide stand-off even under conditions in which the bow springs are fully compressed while still maintaining fluid flow.

Abstract: A centralizer for laterally positioning an instrument in an opening larger in diameter than the diameter of an opening through which the centralizer can freely pass. The centralizer includes spring blades affixed at one end to an outer surface of the instrument and extending axially to a stop collar rotatably positioned on the outer surface of the instrument. A latch is operatively coupled to the stop collar and is adapted to enable rotation of the stop collar about the instrument upon release of the latch.

Abstract: A centralizer is disclosed for laterally positioning an instrument in an opening larger in diameter than the diameter of an opening through which the centralizer can freely pass. The centralizer includes spring blades affixed at one end to an outer surface of the instrument and extending axially to a stop collar rotatably positioned on the outer surface of the instrument. A latch is operatively coupled to the stop collar and is adapted to enable rotation of the stop collar about the instrument upon release of the latch.

Abstract: An apparatus and method for cementing a pipe in a well. A wiper is engaged with a pipe section as the pipe section is lowered into the wellbore. The wiper contacts the wellbore as the pipe section is reciprocated or rotated within the wiper. The wiper contacts and cleans the exterior surface of the pipe section as the pipe section is moved relative to the wiper. By cleaning the exterior of the pipe section before cement is placed between the pipe section and the wellbore, the potential for channeling in the microannulus between the pipe section exterior and the cement is substantially reduced.

Abstract: The centralizer comprises a main assembly suitable for centering a well tool in casing, and a removable adapter assembly (75) for use in the open hole portion of a borehole. The main assembly comprises a body (30), longitudinally spaced-apart supports (36, 41) slidably mounted on the body, and pairs of hinged arms (45.sub.1, 47.sub.1) disposed between the slidable supports. The central hinges (50.sub.1) of the pairs of arms carry wheels (51.sub.1) and are spaced apart laterally from the body under the effect of blade springs (52.sub.1, 53.sub.1). The adapter assembly (75) comprises curved spring blades (80.sub.1) hinged on link collars (77, 82) removably fixed on the sliding supports. The wheels are laterally spaced apart from the spring blades. The centralizer is easily modified to operate either in the case hole portion or in the open hole portion of a borehole.

Abstract: A roller arm centralizer to center a drill string in a well pipe. The arms of the roller arm centralizer include shoulders to limit movement of the arms in the direction of the centralizer body which prevents the arms from being locked in a straight line adjacent to the centralizer body. The shoulders also prevent the arms from being forced into an undesired configuration; wherein one arm is parallel to the body and the other two arms form a "V", by an abrupt decrease in the bore diameter. The roller arm centralizer remains operative when passing through relatively narrow sections of well pipe or through well pipe having abrupt changes in diameter.

Abstract: A conduit centralizer comprises segmented, sliding means connected by a plurality of axially extending, outwardly bowed leaf springs. Each sliding means is formed by the hinged connection of a plurality of double walled segments. The ends of the leaf springs are respectively inserted within the double walled segments and welded to both the inner and outer walls of the segments, thus providing an extremely rigid structure which is fabricated without machining operations.

Abstract: A centralizer for a well casing, and the method of producing a centralizer, for assembly in the field. The centralizer comprises two collars and a plurality of spring bows, with a bow receiving section in each collar for each bow. Aligned channels are formed in the collar defining a passage for receiving a bow end, and each bow end has a hat section for positioning in the aligned channels. After a bow end is inserted in a collar passage, one of the channels is compressed into the bow hat section to lock the bow in place.