A downhole tool, multi-stage cementing tool, and method for cementing. The tool includes a body having a bore axially therethrough and an opening radially therethrough, and a first sleeve positioned in the bore of the body. The first sleeve has an opening radially therethrough that is axially aligned with the opening of the body when the downhole tool is in a first configuration. An inner surface of the first sleeve defines a first seat. The tool also includes a second sleeve positioned in the first sleeve, with the second sleeve being aligned with the opening of the first sleeve and preventing fluid flow therethrough when the tool is in the first configuration. The second sleeve is configured to move axially and engage the first seat of the first sleeve when the tool is in a second configuration, so as to resist relative rotation between the first and second sleeves.

The present invention relates to a downhole annular barrier to be expanded in an annulus between a well tubular structure and a wall of a borehole or another well tubular structure downhole in order to provide zone isolation between a first zone having a first pressure and a second zone having a second pressure of the borehole, the annular barrier comprising a tubular part adapted to be mounted as part of the well tubular structure, the tubular part having an outer face and an inside, an expandable metal sleeve surrounding the tubular part and having an inner sleeve face facing the tubular part and an outer sleeve face facing the wall of the borehole, each end of the expandable metal sleeve being connected with the tubular part, and an annular space between the inner sleeve face of the expandable metal sleeve and the tubular part, a first opening in fluid communication with the inside, a second opening in fluid communication with the annular space, a bore having a bore extension and comprising a first bore part having a first inner diameter and a second bore part having an inner diameter which is larger than that of the first bore part, wherein the first opening and the second opening are arranged in the first bore part and displaced along the bore extension, and the annular barrier further comprises a piston arranged in the bore, the piston comprising a first piston part having an outer diameter substantially corresponding to the inner diameter of the first bore part and comprising a second piston part having an outer diameter substantially corresponding to the inner diameter of the second bore part, and a rupture element preventing movement of the piston until a predetermined pressure in the bore is reached. Furthermore, the present invention relates to an annular barrier system.

A well tool device includes a housing with a through bore having a first end and a second end. A frangible obstruction device is provided inside the longitudinal bore, where fluid flow between the first end and the second end is prevented due to the frangible obstruction device. The frangible obstruction device includes a through opening. The well tool device further includes an actuation device extending fluid-tight at least into the through opening. The actuation device includes an actuation tool connection interface and a disintegration device. The disintegration device is configured to be at least partially moved into the frangible obstruction device and thereby provide disintegration of the frangible obstruction device, hence allowing fluid flow between the first end and the second end of the through bore.

A tool includes a housing between an outer wall and an inner wall that surrounds a longitudinal tool bore. First and second axially spaced ports connect the housing to the tool bore. An unlocking piston seals across the first port and an arming sleeve seats across the second port. A locking ring is held in place by a retaining ring and prevents the arming sleeve from sliding towards the unlocking piston to open the second port. An unlocking tool bore pressure at the first port moves the unlocking piston axially to displace the retaining ring and unlock the tool. A lower, arming tool bore pressure moves the arming sleeve in the unlocked tool to open the second port and arms the tool. An actuating tool bore pressure, which is less that the unlocking pressure, actuates a valve piston via the open second port.

Dual section mills are selectively sequentially operated by locking an actuator for the backup mill as the primary mill has blades extended with internal flow through a housing. When the primary mill is spent the support string is shifted to defeat a lock on an actuation piston for the backup mill so that its blades can extend and continue to mill to finish the job. The blades of the primary mill continue to rotate in the already milled portion of the window as the secondary mill enlarges the window. Another way the secondary mill is actuated is to open access to flow to the secondary mill by removing a pressure barrier such as a valve or a disappearing plug, for example.

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly includes: holding moveable elements of the wellbore tool in an unactivated position using a shear pin; inserting one or more drop balls into a drilling fluid; and flowing the drilling fluid with the drop balls to a flow orifice located in or below the wellbore tool. The flow orifice is at least partially plugged with the drop balls to restrict fluid flow and correspondingly increases the hydraulic pressure of the drilling fluid. The hydraulic pressure is increased to a point beyond the rating of the shear pin, thereby causing the shear pin to shear and allowing the moveable elements of the tool to move to an activated position.

A method of stimulating a subterranean formation using a tubular member with one or more burst disks therein.

A wellbore tubing string assembly comprises: a string including an inner bore having an inner diameter and a plurality of tools installed along the string including a first tool and a second tool axially offset from the first tool along the string; the first tool includes: a first sleeve in the inner bore having an inner surface, the inner surface defining a first restriction diameter smaller than the inner diameter; a first sensor mechanism in communication with the first sleeve and responsive to an application of force against the first sleeve; the second tool includes; a second sleeve in the inner bore having an inner wall surface, the inner wall surface defining a second restriction diameter smaller than the inner diameter; a second sensor mechanism in communication with the second sleeve and responsive to an application of force against the second sleeve; and a sealing device having a diameter greater than the second restriction diameter and being deformable to be pushable through the second restriction diameter to apply a force against the second sleeve.

A drilling motor provides rotational force within a wellbore and includes a power section within the interior of a housing, a rotor positioned within the power section, and a passage within the rotor. The passage is configured to bypass a portion of the drilling mud from above the power section within the interior of the housing to below the power section within the interior of the housing, and an interior valve at a downstream end of the passage, wherein the valve includes a rupture disc configured to close the passage when the pressure from the drilling mud is less than a threshold pressure, and to rupture to open the passage and pass the drilling mud through the valve when the pressure from the drilling mud is greater than the threshold pressure.

A method of performing a completion operation at a wellbore includes flowing a plug downhole within fluid through a pipe disposed within the wellbore, landing the plug on a platform carried on the pipe to close the pipe to fluid flow, flowing fluid downhole through the pipe against the plug positioned on the platform, and rupturing a disk of the plug with a pressure of the fluid to open the pipe to fluid flow through a channel of the plug.