In a dart for a downhole device according to the present invention, a ball is formed of a first degradable material having a first degradation rate, a mandrel is formed of a second degradable material having a second degradation rate lower than the first degradation rate, and a sleeve is formed of the second degradable material or a third degradable material having a third degradation rate lower than the second degradation rate.

The present invention relates to an apparatus (20) for clearing a plugged control line (12), in particular for clearing a plugged surface controlled sub-surface safety valve (11) control line (12), the apparatus (20) comprising a connecting means (27) configured to connect the apparatus (20) to an upstream end of the plugged control line (12); and a pumping means (21, 22) configured to pump a dissolvent (30) through the connecting means (27) into the control line (12) to build up dissolvent pressure in the control line (12). The invention further comprises a bore system and a method for clearing a plugged control line (12).

The present invention relates to an apparatus (20) for clearing a plugged control line (12), in particular for clearing a plugged surface controlled sub-surface safety valve (11) control line (12), the apparatus (20) comprising a connecting means (27) configured to connect the apparatus (20) to an upstream end of the plugged control line (12); and a pumping means (21, 22) configured to pump a dissolvent (30) through the connecting means (27) into the control line (12) to build up dissolvent pressure in the control line (12). The invention further comprises a bore system and a method for clearing a plugged control line (12).

A check valve may include a housing having a bore therethrough, the bore including an inner surface and a bearing face; a check seat adaptor coupled to the housing; a seal in the housing, the seal including a seat bore; and a dart disposed in the bore between the seal and the bearing face and axially moveable between closed and open positions. The dart may include a tail and a head that has at least one dart inlet and sealingly engages the seal when the valve is closed. The tail defines an inner chamber having an outlet that is in fluid communication with the bore. The dart inlet(s), the inner chamber, and the outlet may be in fluid communication and together define a dart flow path through the dart. A biasing device may urge the dart toward the seal.

A check valve may include a housing having a bore therethrough, the bore including an inner surface and a bearing face; a check seat adaptor coupled to the housing; a seal in the housing, the seal including a seat bore; and a dart disposed in the bore between the seal and the bearing face and axially moveable between closed and open positions. The dart may include a tail and a head that has at least one dart inlet and sealingly engages the seal when the valve is closed. The tail defines an inner chamber having an outlet that is in fluid communication with the bore. The dart inlet(s), the inner chamber, and the outlet may be in fluid communication and together define a dart flow path through the dart. A biasing device may urge the dart toward the seal.

Pressure-activated valve assemblies and methods to remotely activate a valve are disclosed. A pressure-activated valve assembly includes a valve, a latch mechanism configured to shift the valve to an open position, and a pressure-activated indexing mechanism that is initially engaged to the latch mechanism. The pressure-activated indexing mechanism is initially in an unarmed mode. After the pressure-activated indexing mechanism is in an armed mode, applying at least one cycle of threshold pressure to the pressure-activated indexing mechanism disengages the latch mechanism to shift the valve to the open position. The pressure-activated valve assembly also includes a remote-activated downhole system configured to receive an activation pressure signal having a signature profile, and in response to receiving the activation pressure signal, arm the pressure-activated indexing mechanism.

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.

The present invention relates to a downhole apparatus and a valve arrangement for a downhole apparatus having a tubular body having first and second ports in a wall thereof; and a method of operating a valve arrangement of a downhole apparatus. The valve arrangement has at least one locked configuration and the first port provides fluid communication with a tool or a device which is a sand control element having at least one fluid deformable device. The present invention also provides a method of setting a sand control completion, extending the sand control filter element thereof to a wellbore surface and isolating the reservoir from an upper portion of the wellbore.

A valve assembly for connection to an opening provided in a housing of a well tool device includes a fluid communication channel, a flapper valve device, a flapper element supporting device, and a securing device. The fluid communication channel provides fluid communication from an outside of the housing to a bore provided on the inside of the housing. The flapper valve device includes a flapper element configured to be in a closed position in which the fluid communication channel is closed and an open position in which the fluid communication channel is open. The flapper element is biased to the closed position. The flapper element supporting device supports the flapper element when the flapper element is in the open position. The securing device secures the flapper valve device and the flapper element supporting device to the opening. The securing device includes a through bore forming a first part of the fluid communication channel.

An injection valve including a housing having a port, an insert movably disposed in the housing, a seal and a diffuser disposed on the insert, the seal and diffuser being movable with the insert. A method for injecting in a borehole including pumping fluid into the borehole, pressurizing an inside diameter of an insert of an injection valve, moving the insert of the injection valve to a position that is not fully closed, diffusing fluid flowing from the inside diameter of the insert; and then flowing the diffused fluid past a seal on the insert.