A bit saver assembly having an inner valve sleeve that actuates upon the weight-on-bit (WOB) of the drill bit exceeding a threshold value to overcome the countervailing force provided by a spring contained within the bit saver assembly and the internal flow pressure of the drilling fluid at the area of the inner valve sleeve. Actuation of the inner valve sleeve opens a fluid passage to the wellbore annulus resulting in a reduction of drilling fluid flow pressure and the stretch of the drill string thereby reducing WOB of the drill bit without operator assistance.

A surge flow mitigation tool can include a surge flow valve that permits one-way fluid flow through a flow passage, and a bypass flow path that opens when a differential pressure across the surge flow valve is greater than a predetermined level. A method of mitigating surge flow in a well can include producing fluid through a tubular string with a bottom hole assembly including a surge flow mitigation tool connected downhole of a packer, the surge flow mitigation tool including a surge flow valve that permits the fluid to flow toward surface via the tubular string, but prevents the fluid from flowing into the well via the tubular string, and increasing a differential pressure across the surge flow valve to greater than a predetermined level, thereby opening a bypass flow path that permits injection flow from the tubular string into the well downhole of the packer.

A method can include directing fluid flow longitudinally through a well tool connected in a tubular string downstream of a longitudinally compressed circulating valve assembly, thereby causing the well tool to operate, and longitudinally elongating the circulating valve assembly while the fluid flow is ceased, and then increasing the fluid flow, thereby causing the fluid flow after the elongating to pass outwardly through a housing of the circulating valve assembly to an external annulus. Another method can include directing a fluid flow through a well tool connected in a tubular string downstream of a circulating valve assembly, thereby causing the well tool to operate, and decreasing then increasing a flow rate of the fluid flow, thereby causing the fluid flow to pass outwardly through a housing assembly of the circulating valve assembly to an external annulus. Circulating valve assemblies are also disclosed.

Disclosed is an actuator capable of imparting a linear, rotary, or combined roto-linear force. In one embodiment, the actuator has a rotor and a stator, each having helical grooves with a thrust ball occupying the grooves. A nose piece is situated at the end of the actuator and can be attached to other equipment. The actuator is electrically controlled and can be used in applications requiring high forces or other specialized environments.

A one-trip screen installation and cleaning system includes a tubular supporting a screen. The tubular has an inner surface defining a flow bore positioned radially inwardly of the screen. At least one actuator extends radially inwardly from the inner surface and is positioned axially offset relative to the screen. The at least one actuator includes at least one actuator surface. A wash pipe is arranged in the flow bore. The wash pipe includes a bypass valve including a selectively openable outlet port, a spray cleaning device arranged axially outwardly of the selectively openable outlet port, and an inflow control valve arranged between the selectively openable outlet port and the spray cleaning device.

A method for modifying a return fluid in a wellbore comprising disposing at least one valve along a drill pipe section of a drill string in the wellbore. At least one parameter of interest is determined at at least one location along the wellbore. At least one valve is controllably actuated to discharge at least a portion of at least one fluid from inside the drill string to an annulus in the wellbore to modify a local property of the return fluid in the annulus based at least in part on the measured parameter of interest.

A method and a downhole apparatus for clearing a wellbore are disclosed. The method locates a mill in the wellbore about the obstructions, introduces a driving fluid flow along a driving flow path from surface to the mill, and introduces a circulation fluid flow along a circulation flow path from surface into a wellbore annulus at a location in the wellbore above the mill. Then the mill is driven by the introduced driving fluid flow to mill the obstructions; and milled obstructions are circulated to the surface via the wellbore annulus using the introduced circulation fluid and gas flow. At least a portion of the circulation flow path is within the driving flow path.

A circulation tool includes a tubular outer body having a main bore and at least one flow port in a wall thereof, and a valve seat assembly including a valve body, a valve member, and locking elements are movably mounted within the outer body main bore. The valve seat assembly is biased towards a first position in which flow through the outer body flow port is prevented and the locking element is in the extended position, restricting passage of the valve member along the valve body bore and out of the valve body. The valve seat assembly is movable to a second position in which the locking element is in the retracted position, permitting passage of the valve member along the body bore and out of the body. The valve seat is also movable to a third position in which flow through the outer body flow port is permitted.

Disclosed are check valve assemblies operable to inject treatment fluids during stimulation operations. One check valve assembly includes a valve body defining an inlet, one or more discharge ports, and a cylindrical passageway that fluidly communicates the inlet with the one or more discharge ports, the valve body further providing a cylindrical section in which the one or more discharge ports are defined, a valve cap disposed about an exterior of the cylindrical section and defining an opening that fluidly communicates with the cylindrical passageway, and a spherical piston disposed within the passageway and movable between a closed configuration, where the spherical piston prevents fluid communication between the inlet and the one or more discharge ports, and an open configuration, where fluid communication is allowed between the inlet and the one or more discharge ports.

A method of controlling fluid flow between two tubulars includes disposing a sealing member in an annular area between two tubulars, wherein the two tubulars partially overlap; moving the sealing member to a lower position where it is not in contact with one of the tubulars, thereby allowing fluid flow through the annular area; and moving the sealing member to an upper position where it is in contact with both of the tubulars, thereby preventing fluid flow through the annular area.