In well bores with included tubulars, it is often desirable to segregate a portion of the wellbore's pressure-driven fluid flowpath in the conduit portion formed by included tubulars to permit work to be completed in a pressure-controlled portion of that flowpath. The subassembly and included frangible device provided here does so with minimal exposure of seals to well fluid environments, and provides a field-adjustable variability to the pressure differentials required to open the conduit by removal of the frangible sealing device from the flowpath into which the subassembly is installed or included.

A method of conditioning a well bore featuring an annulus (50) between a bore-lining tubing (20) and a surrounding bore wall (110) comprises pumping conditioning fluid through an inner tubing (10) located within the bore-lining tubing (20) and into a portion of the well bore containing the bore-lining tubing to affect the temperature of the portion of the well bore containing the bore-lining tubing. The annulus (50) between the bore-lining tubing (20) and the surrounding bore wall (110) is at least partially filled with settable material (54). The affected temperature of the portion of the well bore containing the bore-lining tubing influences the setting of the settable material. For example, heating the bore may accelerate setting of the material, while cooling the bore may retard setting of the material.

A non-explosive downhole tool for creating openings in tubulars and or earthen formations includes a carrier holding a non-explosive material, such as thermate, a head connected with the carrier and having a port to eject a product of the ignited material from the head and a communication path extending from the material to the port and a moveable member in a closed position blocking the communication path and in an open position opening the communication path.

A method of removing a wellbore isolation device comprising: causing or allowing at least a portion of the isolation device to undergo a phase transformation in the wellbore; and milling at least a portion of the isolation device that does not undergo the phase transformation.

A slow pressure triggered valve for a downhole tool may include an outer housing and a sliding sleeve. The sliding sleeve may slide within the outer housing such that apertures formed on the sliding sleeve do not align with fixed apertures of the outer housing until the sliding sleeve moves from a closed position into an open position. The sliding sleeve may be mechanically coupled to a damping piston. The damping piston may be positioned within a damping chamber and may have a flowpath formed therethrough such that as the damping piston moves with the sliding sleeve from the closed position to the open position, fluid within the damping chamber flows through the flowpath. The flowpath may include a low pressure relief valve and a flow restrictor. The sliding sleeve may be held in the closed position by a lock piston temporary retainer until a predetermined pressure is reached within the valve.

A well tool device (1) comprising a housing (10) having a through channel (11) with a first end (11a) and a second end (11b), said housing (10) further comprises a breakable ball seat (15), wherein a drop ball (17) received in the ball seat (15) partially or fully closes fluid communication in the through channel (11) of the housing (10). The breakable ball seat (15) is made of brittle and/or tempered glass, wherein the ball seat (15) is broken by a pressure build up in the housing (10) forcing the ball seat (15) against one or more disintegrating means (16), said disintegrating means (16) are provided as inside protrusions in the through channel (11).

A polymetaphosphate composition and method for temporarily sealing a perforation in a wellbore to facilitate a treatment therein and a well tool which can include a flow path, and a flow blocking device which selectively prevents flow through the flow path. The well tool can include a polymetaphosphate composition. A method of constructing a downhole well tool can include forming a structure of a solid mass comprising a polymetaphosphate composition, and incorporating the structure into the well tool.

A well tool device includes a housing having an axial through bore; a sleeve section axially displaceable relative to the housing; a fluid flow preventing frangible disc; and an axial fluid passage bypassing the frangible disc when the well tool device is in an initial state, thereby allowing a fluid flow between a first location above the frangible disc and a second location below the frangible disc. The sleeve section includes an axial through bore aligned with the axial through bore of the housing. The axial fluid passage is closed when the well tool device is in a intermediate state. The fluid flow preventing frangible disc is provided in the bore of the sleeve section in sealing engagement with the sleeve section. The well tool device further includes a disc supporting device for supporting the frangible disc in relation to the sleeve section. The disc supporting device is releasably connected inside the sleeve section by a releasable connection device. The well tool device further includes a disintegration device disintegration of the frangible disc. The well tool device is in a final state when the frangible disc has been disintegrated by the disintegration device. The frangible disc is configured to be pushed axially relative to the sleeve section towards the disintegration device after release of the disc supporting device.

A downhole gravel packing apparatus, comprising: a tubular assembly for being arranged within a wellbore to define an annulus between said tubular assembly and a wall of the wellbore; and a control valve provided within the tubular assembly to control flow of a gravel pack carrier fluid between external and internal regions of the tubular assembly, the control valve comprising a fluid reactant arrangement which reacts with a first fluid to reconfigure the control valve from a first configuration in which flow through the control valve is permitted during a gravel packing operation, and a second configuration in which flow through the control valve is restricted.

A method for operating a circulating sub in a well includes opening a port of the circulating sub, including: dropping a ball into a drill pipe containing a downhole fluid; and seating the ball on an actuator slidably disposed concentrically within the drill pipe, in which seating the ball on the actuator causes motion of the actuator relative to the drill pipe to open a port defined in a wall of the drill pipe. The method includes closing the port of the circulating sub, including: introducing a solvent different from the downhole fluid into the drill pipe, in which a solubility of the ball in the solvent is greater than a solubility of the ball in the downhole fluid; and degrading the ball in the solvent, in which the degrading of the ball causes motion of the actuator relative to the drill pipe to close the port.