A thrust bearing is described comprising first and second bearing assemblies (15, 17) rotatable relative to each and a plurality of axially arranged bearing stages (14a, 14b) formed between the first and second bearing assemblies (15, 17). Each bearing stage comprises a first load shoulder (16) provided on the first bearing assembly (15), a second load shoulder (18) provided on the second bearing assembly (17), a bearing structure (30) defined between the first and second load shoulders; and an extrudable component (32) forming part of the bearing structure. Wherein axial load applied between the first and second bearing assemblies (15, 17) in a first relative axial direction is transmitted between respective pairs of first and second load shoulders via the extrudable components (32) of respective bearing structures (30). The extrudable components (30) provide for load balancing between each bearing stage (14a, 14b).

A release device for a jarring tool includes a collet positioned between the mandrel of the jarring tool and a trigger sleeve. At least one end of the collet is in contact with a precompressed spring via a bushing. In order for the jarring tool to operate, a force greater than the precompressed force of the spring must be applied to the mandrel so that the collet can move in axial direction against the spring thereby releasing the mandrel.

A release device for a jarring tool includes a collet positioned between the mandrel of the jarring tool and a trigger sleeve. At least one end of the collet is in contact with a precompressed spring via a bushing. In order for the jarring tool to operate, a force greater than the precompressed force of the spring must be applied to the mandrel so that the collet can move in axial direction against the spring thereby releasing the mandrel.

A mechanical service tool that may include one or more anchors, a cutter, a communication and control system, and one or more sensors, as well as methods for operating the mechanical service tool, are provided. The one or more anchors may extend radially from the mechanical service tool and the cutter may move relative to the mechanical service tool. The cutter may include a drilling bit. The communication and control system may obtain remote commands that control the cutter, the one or more anchors, or both. The one or more sensors may detect operational conditions of the mechanical service tool and may be operatively coupled to the communication and control system.

The present invention relates to a downhole tool for removing a restriction in a well tubular metal structure having a wall and an inner diameter, the restriction partly blocking the inner diameter, creating an opening defined at least partly by a rim section of the restriction, the downhole tool having a tool axis and comprising a tool body having a first part and a second part, an electrical motor arranged in the first part for rotating a rotatable shaft, a core bit arranged in the second part and having a first end connected with the rotatable shaft and a second end having a cutting edge, wherein the second part of the downhole tool further comprises a locator for locating the rim section, a collecting means for collecting part of the restriction to be cut out by the cutting edge, the locator and the collecting means are rotating with the core bit until the locator locates the rim section and a threshold value is reached.

The present invention relates to a downhole tool for removing a restriction in a well tubular metal structure having a wall and an inner diameter, the restriction partly blocking the inner diameter, creating an opening defined at least partly by a rim section of the restriction, the downhole tool having a tool axis and comprising a tool body having a first part and a second part, an electrical motor arranged in the first part for rotating a rotatable shaft, a core bit arranged in the second part and having a first end connected with the rotatable shaft and a second end having a cutting edge, wherein the second part of the downhole tool further comprises a locator for locating the rim section, a collecting means for collecting part of the restriction to be cut out by the cutting edge, the locator and the collecting means are rotating with the core bit until the locator locates the rim section and a threshold value is reached.

Techniques for removing a tubular from a wellbore include running a downhole tool on a downhole conveyance into a wellbore formed from a terranean surface into a subterranean formation; activating a piston sub-assembly to repeatedly move pistons to contact a portion of a casing installed in the wellbore to at least de-bond a cement layer installed between the portion of the casing and the subterranean formation from the portion of the casing; activating a cutting sub-assembly to move a cutting blade to cut through the portion of the casing adjacent the de-bonded portion of the cement layer; activating a hanger sub-assembly to move a set of slips into contacting engagement with the cut portion of the casing; and running the downhole tool on the downhole conveyance out of the wellbore with the cut portion of the casing engaged with the set of slips.

Techniques for removing a tubular from a wellbore include running a downhole tool on a downhole conveyance into a wellbore formed from a terranean surface into a subterranean formation; activating a piston sub-assembly to repeatedly move pistons to contact a portion of a casing installed in the wellbore to at least de-bond a cement layer installed between the portion of the casing and the subterranean formation from the portion of the casing; activating a cutting sub-assembly to move a cutting blade to cut through the portion of the casing adjacent the de-bonded portion of the cement layer; activating a hanger sub-assembly to move a set of slips into contacting engagement with the cut portion of the casing; and running the downhole tool on the downhole conveyance out of the wellbore with the cut portion of the casing engaged with the set of slips.

A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections have either different widths or are separated by varying distances and releaseably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel. The release lugs may be supported by an annular ring member.

A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections have either different widths or are separated by varying distances and releaseably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel. The release lugs may be supported by an annular ring member.