A downhole tool includes a bore isolation valve, a sensor configured to receive to a downlink signal, an annular pressure sensor, a valve actuation mechanism coupled to the bore isolation valve and responsive to the downlink signal, a pressure relief mechanism configured to provide a negative pressure pulse signal indicative of the annular pressure by venting fluid from a bore of the tool body, and a battery. A method includes drilling a well with a drill bit coupled to an on demand annular pressure tool initially in a deactivated mode, and activating the tool by a downlink signal when fluid flow out of the annulus drops below the fluid flow into the well to close a bore of the tool, pressurizing the drill string, holding pressure in the drill string, measuring annular pressure with the tool, and sending a negative pressure pulse signal indicative of the annular pressure.

A system and method for stall recovery of mud motors may be implemented in a steering control system. The stall recovery system and method may involve automatic detection of a stall of a mud motor during drilling controlled by the steering control system, and may respond to the stall in a rapid and controlled manner to avoid or minimize damage to the mud motor, such as by immediately reducing mud pressure and stopping rotary drilling, if used, faster than a typical human operator could perform. The stall recovery system and method may further take actions to automatically restart drilling.

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.

A downhole tool comprises a hollow body having a wall and a port in the wall, and a closing sleeve movable relative to the body to open and close the port. A seal is provided between the body and the sleeve and is configured to hold differential pressure. An isolation member may be deployed in the tool to isolate the seal from differential pressure and close the port. The isolation member may be deployed following initiation of a tool activation process, a successful outcome of the process being translating the closing sleeve and closing the port, and positioning the seal to hold a differential pressure. If it is detected that the outcome has not been achieved, the isolation member is deployed to isolate the seal from differential pressure and close the port.

A drill rod can include a body having an outer surface, an inner surface, a longitudinal axis aligned with a drilling axis, and at least one longitudinally extending groove extending radially outwardly from the longitudinal axis relative to the inner surface. The inner surface and the at least one longitudinally extending groove can cooperate to define an interior space through which an inner assembly can be received as the inner assembly is advanced and retracted relative to the drilling axis. The at least one longitudinally extending groove of the body of the drill rod can be configured to permit axial flow of fluid through the drill rod as portions of the inner assembly engage the inner surface of the body of the drill rod.

Methods, systems, and storage media are presented for operating a drill string within a well. Exemplary implementations may: detect, using one or more sensors, data representing an analog control command sequence; analyze the analog control command sequence; determine that the control command sequence represents a command to change an operational mode of the drill string from a first operational mode to a second operational mode; and transmit a signal to an actuator of the drill string, the signal representing an electronic command to activate the actuator in such a way as to change the drill string from the first operational mode to the second operational mode. In some embodiments, the analog control sequence may comprise a predetermined sequence of rotational inputs, vibrational inputs, pressure inputs, or a combination thereof.

A flow rate control system includes a housing and a valve assembly slidingly disposed within a housing inner bore. The housing includes bypass openings. The valve assembly includes a valve and an orifice disposed in a valve inner bore. The valve includes a plurality of valve bypass bores extending axially through a valve collar. The valve assembly slides between closed and fully open positions. A spring biases the valve assembly toward the closed position in which the valve closes the housing bypass openings. In the open position, a bypass fluid path is formed including the valve bypass bores and the housing bypass openings. The valve assembly is flow rate controlled in the closed position and pressure controlled in the open position. The valve assembly may slide within a sleeve assembly including sleeve bypass openings, which connect the valve bypass bores and housing bypass openings in the bypass fluid path.

A work string locatable in a borehole so as to form an annulus around the work string and a method of depressurizing the annulus are provided. The work string includes a packer expandable radially out from the work string to seal the annulus and a packer sub positioned below the packer including a sub body and a check valve in the body and operable to permit fluid in the annulus to flow into the work string and prevent fluid in the work string from flowing into the annulus. The check valve is operable to open and permit fluid in the annulus to flow into the work string upon exertion of a predetermined minimum pressure on the check valve by the fluid in the annulus. The method includes providing the work string in the borehole and depressurizing the annulus by permitting fluid in the annulus to flow through the check valve.

Fluid flows, such as slurries, conditioning fluids, spacer fluids, or the like, may be modified to carry materials having high magnetic permeability characteristics that can be detected by a magnetic permeability sensing apparatus positioned along the fluid flow path in wellbores or downhole tools. Sensed presence of the high magnetic permeability material by the sensing apparatus positioned in the fluid flow path may result in initiation of an operational event. The operational event may include, but not limited to closing or opening a valve, moving a component, conveying a signal, activating or deactivating a device, or the like.

A concentric valve positionable in a wellbore includes a valve body including an outer surface and a central passage, a receptacle disposed in the central passage and defining a chamber disposed therein, and a radial port extending between the receptacle and the outer surface to provide fluid communication between the chamber of the receptacle and an environment surrounding the concentric valve, an inner tubular member received in the receptacle of the valve body, wherein the inner tubular member includes a seal assembly configured to sealingly engage an inner surface of the receptacle, and a bypass passage extending around the receptacle of the valve body and circumferentially spaced from the radial port, wherein the bypass passage provides fluid communication between a first end of the central passage and a second end of the central passage opposite the first end.