A downhole tool may include a first end collar configured to be positioned at least partially around a tubular, a second end collar configured to be positioned at least partially around the tubular, a plurality of elongate members extending between and connected to the first and second end collars, and a dissolvable retention member coupled to the second end collar. The dissolvable retention member is configured to maintain a position of the second end collar relative to the first end collar until the dissolvable retention member at least partially dissolves in a downhole fluid. When the dissolvable retention member at least partially dissolves, the second end collar is configured to move with respect to the first end collar, and the plurality of elongate members expand radially outwards.

A chemical reaction heat source for use in heaters used in down-hole applications is provided. The heat source has a fuel composition that comprises thermite and a damping agent. The use of the thermite mix enables the heaters of the present invention to generate hotter temperatures down wells. This in turn allows the use of Bismuth/Germanium alloys, which have higher melting points, to enable the production of plugs for the abandonment of deeper wells where subterranean temperatures are higher.

A method for manufacturing a centralizer assembly includes reducing a diameter of a mandrel such that a turned-down region is formed in the mandrel, positioning a first stop segment in the turned-down region, and positioning a centralizer at least partially in the turned-down region, wherein the first stop segment is positioned intermediate of axial extents of the centralizer, such that the first stop segment at least partially limits a range of motion of the centralizer relative to the mandrel.

A downhole tool may include a first end collar configured to be positioned at least partially around a tubular, a second end collar configured to be positioned at least partially around the tubular, a plurality of elongate members extending between and connected to the first and second end collars, and a dissolvable retention member coupled to the second end collar. The dissolvable retention member is configured to maintain a position of the second end collar relative to the first end collar until the dissolvable retention member at least partially dissolves in a downhole fluid. When the dissolvable retention member at least partially dissolves, the second end collar is configured to move with respect to the first end collar, and the plurality of elongate members expand radially outwards.

A centraliser for use in a wellbore includes: first and second collars, at least one resilient device extending between the first and second collars, and a locking ring for receiving a tubular in a position radially inside the resilient device and axially between the first and second collars; the resilient device being resiliently biased in a radial direction away from the locking ring; the locking ring having at least one catch device adapted to engage with the at least one resilient device in a radially restricted configuration and the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; and at least one fixing between the at least one catch device and the locking ring and made from a sacrificial material adapted to degrade in wellbore conditions.

A centraliser includes a number of members extending between two collars for mounting the centraliser on a casing. The members are configured to contact a wall of the bore and centraliser the casing in the bore. The members are radially moveable between the casing and the bore wall. The members further include an intermediate portion and end portions, the end portions being relatively more flexible than the intermediate portion.

A method of connecting an end part of a pipe attachment device to a part of a function element, includes: aligning longitudinal axes of a substantially tubular end part of a pipe attachment device and a substantially tubular part of a function element; applying a force that moves the end part of the pipe attachment device relatively towards the part of the function element along the longitudinal axis. Contact between the end part of the pipe attachment device and the part of the function element causes each of a plurality of fingers on the end part to elastically deflect. Applying the force so that each of the plurality of fingers on the end part returns from their deflected position and is retained in one or more holes in the part of the function element.

Spring systems for subsea applications and equipment projects for the oil and gas industry are preferably manufactured from composite materials and include at least one pair of springs consisting of a first spring component and a second spring component, mounted so as to offer a first central contact region and double curvature and rebound areas forming a coupling. The pair of springs are thus, self-centering.

A wellbore radial positioning apparatus includes a tool body and a motor that actuates a traction wheel. The tool body is configured to be positioned within a wellbore. The motor driving the traction wheel is connected to the tool body and is configured to rotate the tool body in the wellbore. The traction tool is configured to frictionally contact or attach to the wellbore. The tool body is rotated in the wellbore by the action of the motor actuating the traction wheel.

Systems and methods for cementing an annular space radially outward of a casing of a subterranean well include a float shoe located at a downhole end of the casing. A float valve is located within the float shoe and within a fluid flow path extending through the float shoe from an internal bore of the casing to an exterior surface of the float shoe. At least two wing members are located on an outer diameter surface of the casing, each of the wing members extending from the float shoe to an uphole end of the casing. The wing members are sized to define two or more separate sections of the annular space. A downhole splitter is located on a downhole surface of the float shoe. The downhole splitter is sized to seal between the downhole surface of the float shoe and an end surface of the subterranean well.