Abstract: A system can include a disconnect tool connected as part of a tubular string, the disconnect tool including an outer housing, and an inner mandrel in the outer housing, in which an abrasive slurry is directed to flow through the tubular string and from the inner mandrel to an annulus between the inner mandrel and the outer housing, and the abrasive slurry erodes through the outer housing. A method can include installing a tubular string in a well, then deploying a disconnect assembly into the tubular string, and flowing an abrasive slurry through the disconnect assembly, thereby parting the tubular string. A disconnect tool can include a rotational flow structure configured to induce rotational flow, and an inner diameter decrease downstream of the rotational flow structure.

Abstract: 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.

Abstract: A method of plugging at least one undesired opening in a fluid conduit can include introducing one or more plugging devices into the conduit, conveying the plugging devices by flow to the opening, and blocking the flow through the opening with the plugging devices. A system for plugging at least one undesired opening in a fluid conduit can include a deployment apparatus configured to introduce one or more plugging devices into the conduit, a sensor that measures a physical parameter indicative of leakage from the conduit, and a controller that activates an actuator of the deployment apparatus in response to receipt from the sensor of an indication of leakage from the conduit.

Abstract: A plugging device, well system and method. In one example, a wrap, band or other type of binding is utilized to secure together multiple fibers, tubes, filaments, films, fabrics or lines of the plugging device. In another example, fibers, tubes, filaments, films, fabrics or lines are fused, adhered or bonded to an outer surface of a body of the plugging device. In other examples, a material of the plugging device may become more rigid or swell in a well. A plugging device may comprise a body loosely enclosed in a bag, wrapper or other enclosure.

Abstract: A jarring tool can include a longitudinally displaceable piston, a first fluid chamber having a volume that decreases in response to displacement of the piston, a flow controller that controls flow of fluid between the first fluid chamber and a second fluid chamber, and a plug seat secured to the piston. A method of applying a jarring force can include applying a pressure differential across a plug in a jarring tool, the plug restricting flow from a first flow passage section to a second flow passage section, then increasing a flow rate of fluid from the first flow passage section. Another jarring tool can include an outer housing with a longitudinal flow passage and seal surfaces at opposite ends of the outer housing, and a flow obstruction, fluid flow through the flow passage being increased in response to application of a pressure differential across the obstruction.

Abstract: A method of treating each of multiple formation zones in a subterranean well can include isolating two of the zones from each other in the wellbore with a plug assembly positioned in the wellbore; treating one of the zones by flowing a treatment fluid through openings that provide fluid communication between the wellbore and one of the zones; then blocking flow through the openings; increasing pressure in the wellbore in response to the blocking; and opening the plug assembly in response to the pressure increasing. A well treatment system for treating each of multiple zones intersected by a wellbore can include multiple plug assemblies in the wellbore, each of the plug assemblies isolating a respective adjacent pair of the zones from each other in the wellbore. Each of the plug assemblies opens in response to a respective predetermined pressure differential applied across the plug assembly.

Abstract: A fluid pulse generator can include a fluid motor and a bypass flow path in fluid communication with an inlet and an outlet, and a flow control device configured to permit flow through the bypass flow path in response to a predetermined pressure differential applied across the flow control device. A method of generating fluid pulses can include flowing a fluid through a fluid pulse generator, thereby generating fluid pulses, and then applying a predetermined pressure differential from an inlet to an outlet of the fluid pulse generator, thereby permitting flow of the fluid through the fluid pulse generator without generating the fluid pulses. A fluid pulse generation system can include a fluid pulse generator with a fluid motor, a variable flow restrictor, and a bypass flow path. A predetermined pressure differential applied across the fluid motor permits the flow of the fluid through the bypass flow path.

Abstract: A fluid pulse generator can include a fluid motor including a rotor that rotates in response to fluid flow, a variable flow restrictor positioned upstream of the fluid motor and including a restrictor member rotatable relative to a ported member and longitudinally displaceable relative to the rotor. Another fluid pulse generator can include a flex joint or a constant velocity joint connected between the restrictor member and the rotor. In another fluid pulse generator, the variable flow restrictor can include a valve and a fluidic restrictor element, the valve being operable in response to rotation of the rotor, the fluidic restrictor element being configured to generate fluid pulses in response to the fluid flow through a flow path, and the valve being configured to control the fluid flow through another flow path connected in parallel with the first flow path.

Abstract: A system can include a disconnect tool connected as part of a tubular string, the disconnect tool including an outer housing, and an inner mandrel in the outer housing, in which an abrasive slurry is directed to flow through the tubular string and from the inner mandrel to an annulus between the inner mandrel and the outer housing, and the abrasive slurry erodes through the outer housing. A method can include installing a tubular string in a well, then deploying a disconnect assembly into the tubular string, and flowing an abrasive slurry through the disconnect assembly, thereby parting the tubular string. A disconnect tool can include a rotational flow structure configured to induce rotational flow, and an inner diameter decrease downstream of the rotational flow structure.

Abstract: A system can include an annular restrictor connected in a tubular string. The annular restrictor restricts flow through an annulus formed between the tubular string and a wellbore. Restriction to the flow through the annulus biases the tubular string into the wellbore, and fluid in the wellbore displaces into the tubular string and/or a formation penetrated by the wellbore. A method can include connecting an annular restrictor in a tubular string, and flowing a fluid through an annulus formed between the tubular string and a wellbore, thereby causing a differential pressure across the annular restrictor, the differential pressure biasing the tubular string into the wellbore. Another method can include connecting an annular restrictor in a tubular string, flowing a fluid through an annulus, thereby biasing the tubular string into a wellbore, and then causing the annular restrictor to no longer restrict flow through the annulus.

Abstract: A method of plugging at least one undesired opening in a fluid vessel can include introducing one or more plugging devices into the vessel, conveying the plugging devices by flow to the opening, and blocking the flow through the opening with the plugging devices. A system for plugging at least one undesired opening in a fluid vessel can include a deployment apparatus configured to introduce one or more plugging devices into the vessel, a sensor that measures a physical parameter indicative of leakage from the vessel, and a controller that activates an actuator of the deployment apparatus in response to receipt from the sensor of an indication of leakage from the vessel.

Abstract: A method of releasing plugging devices into a wellbore can include conveying a dispensing tool to a desired downhole location in the wellbore, the dispensing tool including a container, and then releasing the plugging devices from the container into the wellbore at the downhole location. A plugging device dispensing system for use with a subterranean well can include a dispensing tool having a container configured for containing multiple plugging devices, and an actuator operable to release the plugging devices from the container at a downhole location in the well.

Abstract: A well completion method can comprise, in a single trip into a wellbore, the following steps being performed for each of multiple zones penetrated by the wellbore: abrasively perforating the zone with a tubing deployed perforating assembly, fracturing the perforated zone with flow from surface via a well annulus, and then plugging the fractured zone with a removable plug substance, the perforating assembly displacing in the wellbore while the fractured zone is being plugged. Another well completion method can comprise, in a single trip into a wellbore, the following steps being performed for each of multiple zones penetrated by the wellbore: perforating the zone using an abrasive perforator, then displacing the perforator in the wellbore away from the earth's surface, then fracturing the zone, and plugging the fractured zone with a flowable plug substance.

Abstract: A system can include a disconnect tool connected as part of a tubular string, the disconnect tool including an outer housing, and an inner mandrel in the outer housing, in which an abrasive slurry is directed to flow through the tubular string and from the inner mandrel to an annulus between the inner mandrel and the outer housing, and the abrasive slurry erodes through the outer housing. A method can include installing a tubular string in a well, then deploying a disconnect assembly into the tubular string, and flowing an abrasive slurry through the disconnect assembly, thereby parting the tubular string. A disconnect tool can include a rotational flow structure configured to induce rotational flow, and an inner diameter decrease downstream of the rotational flow structure.

Abstract: A method can include deploying a diverter plug into a well, the diverter plug comprising a group of particles that are prevented from dispersing, flowing fluid, thereby conveying the diverter plug into engagement with a fluid passageway, the particles conforming to a shape of the fluid passageway as the diverter plug blocks fluid flow through the fluid passageway, and the particles being prevented from dispersing while the diverter plug blocks the fluid flow through the fluid passageway. The diverter plug can include a group of particles disposed within an outer enclosure. The particles in the enclosure can conform to a shape of the fluid passageway as the diverter plug blocks fluid flow through the fluid passageway. In another method, the enclosure can sealingly engage the fluid passageway while the particles remain disposed within the enclosure.

Abstract: A well completion system can include fluid flow through a flow passage, and one or more diverters deployed into the flow passage downhole of a perforating assembly, the diverters and the perforating assembly being concurrently displaced by the fluid flow. A perforating assembly can include a perforator, and a control module including a memory, a motion sensor, a timer, and a controller that causes the perforator to fire in response to a lack of motion for a predetermined period of time. A well completion method can include flowing fluid through a flow passage, deploying a perforating assembly into the flow passage, and displacing the perforating assembly through the flow passage by the fluid flow at a predetermined flow rate for a predetermined flow time, and ceasing the fluid flow at an end of the predetermined flow time, thereby placing the perforating assembly at a desired location for forming perforations.

Abstract: A method can include deploying a plugging device into a well, the plugging device including a body, and an outer material enveloping the body and having a greater flexibility than a material of the body, and conveying the plugging device by fluid flow into engagement with the opening, the body preventing the plugging device from extruding through the opening, and the outer material blocking the fluid flow between the body and the opening. In another method, the plugging device can include at least two bodies, and a washer element connected between the bodies, the washer element being generally disk-shaped and comprising a hole, a line extending through the hole and connected to the bodies on respective opposite sides of the washer element, the washer element preventing the plugging device from being conveyed through the opening, and the washer element blocking the fluid flow through the opening.

Abstract: A method can include deploying a plugging device into a well, the plugging device including a body, and an outer material enveloping the body and having a greater flexibility than a material of the body, and conveying the plugging device by fluid flow into engagement with the opening, the body preventing the plugging device from extruding through the opening, and the outer material blocking the fluid flow between the body and the opening. In another method, the plugging device can include at least two bodies, and a washer element connected between the bodies, the washer element being generally disk-shaped and comprising a hole, a line extending through the hole and connected to the bodies on respective opposite sides of the washer element, the washer element preventing the plugging device from being conveyed through the opening, and the washer element blocking the fluid flow through the opening.

Abstract: A method of dislodging a tubular string or well equipment connected to the tubular string can include connecting a dislodging tool in the tubular string, so that a flow passage of the dislodging tool extends through the tubular string, deploying a plug into the dislodging tool, applying a pressure differential across the plug, thereby displacing the plug through a seat of the dislodging tool, and dislodging the tubular string or the component in response to the displacing. A dislodging system can include a dislodging tool connected as part of a tubular string, the dislodging tool including a flow passage and a seat configured to sealingly engage a plug deployed into the tubular string, and at least one of a jarring force, load, impact, shock wave, elastic strain release and pressure pulse being generated in the tubular string in response to displacement of the plug through the seat.

Abstract: A downhole well tool assembly can include a perforator and a selectively openable and closable perforation plug discharge port. A method of perforating and treating multiple formation zones of a well in a single trip of a downhole well tool assembly into the well can include positioning the downhole well tool assembly at a zone, closing a perforation plug discharge port of the downhole well tool assembly, perforating the zone, treating the zone, opening the perforation plug discharge port, deploying perforation plugs into the well via the perforation plug discharge port, plugging perforations in the zone with the perforation plugs, positioning the downhole well tool assembly at a subsequent zone, closing the perforation plug discharge port, perforating the subsequent zone, and treating the subsequent zone.