Abstract: A method of controlling flow in a well can include a device introduced into the well being conveyed by flow in the well, and the device having a plurality of fibers extending outwardly from a body, the fibers being retained by a retainer. A well system can include a flow conveyed device conveyed through a tubular string by flow in the tubular string, and the flow conveyed device including a body with a plurality of fibers extending outwardly from the body. A retainer can at least partially enclose the device. A flow conveyed device for use in a well can include a body, and a plurality of fibers joined to the body, each of the fibers having a lateral dimension that is substantially smaller than a size of the body.

Abstract: A method of restoring flow through an opening in a well, the opening being blocked by a plugging device, can include conveying a well tool into the well, contacting the plugging device with the well tool, and permitting flow through the opening as a result of the contacting step. Another method of restoring flow through an opening blocked by a plugging device in a well can include conveying a well tool into the well, reducing pressure in the well with the well tool, and permitting flow through the opening as a result of the pressure reducing step.

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 flow conveyed plugging device for use in a well, the device can include a body, and one or more lines extending outwardly from the body, each of the lines having a lateral dimension that is substantially smaller than a size of the body. A method of plugging an opening in a well can include deploying at least one flow conveyed plugging device into the well, the flow conveyed plugging device including a body and, extending outwardly from the body, at least one of the group consisting of: a) one or more fibers and b) one or more lines, the flow conveyed plugging device being conveyed by flow in the well into sealing engagement with the opening. Another flow conveyed plugging device can include a body, and fibers extending outwardly from the body. The flow conveyed plugging device degrades and thereby permits flow through an opening in the well.

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 vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path includes a switch, such as a bi-stable fluidic switch, for reversing the direction of the flow in the vortex chamber. The flow path may include multiple vortex chambers, and the device may include multiple flow paths. A hardened insert in the outlet of the vortex chamber resists erosion. This device generates backpressures of short duration and slower frequencies approaching the resonant frequency of the drill string, which maximizes axial motion in the drill sting and weight on the bit. Additionally, fluid pulses produced by the tool enhance debris removal ahead of the bit.

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 vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path is designed to produce alternating primary and secondary vortices—one clockwise and one counter-clockwise—where the primary vortex is stronger and produces higher backpressure than the secondary vortex. This in turn generates alternating weak and strong pressure pulses in the drill string. The weak pulses may be barely perceptible so that the effective frequency of the pulses is determined by the stronger primary vortices.

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 casing string is augmented with one or more variable flow resistance devices or “vibrating tools” to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out to open the casing string for further operations. The casing string assembly may include a vibrating tool at the end in place of a conventional float shoe or float collar. Multiple vibrating tools can be employed in the casing string, and they may be combined with conventional float shoes and collars. Additionally, vibrating tools in the form of plugs can be pumped down and landed inside the casing string.

Abstract: A method for use with a subterranean well can include releasing flow conveyed plugging devices into the well, each of the plugging devices including a body and, extending outwardly from the body, at least one of lines and fibers, and the plugging devices blocking flow through respective openings in the well. Another method can include perforating a zone, releasing a set of flow conveyed plugging devices into the well, each of the plugging devices including a body and, extending outwardly from the body, at least one of lines and fibers, the set of plugging devices blocking flow through respective perforations in the zone, perforating another zone, releasing another set of the flow conveyed plugging devices into the well, and the second set of plugging devices blocking flow through respective perforations in the second zone.

Abstract: A method of restoring flow through an opening in a well, the opening being blocked by a plugging device, can include conveying a well tool into the well, contacting the plugging device with the well tool, and permitting flow through the opening as a result of the contacting step. Another method of restoring flow through an opening blocked by a plugging device in a well can include conveying a well tool into the well, reducing pressure in the well with the well tool, and permitting flow through the opening as a result of the pressure reducing step.

Abstract: A method for use with a subterranean well can include releasing flow conveyed plugging devices into the well, each of the plugging devices including a body and, extending outwardly from the body, at least one of lines and fibers, and the plugging devices blocking flow through respective openings in the well. Another method can include perforating a zone, releasing a set of flow conveyed plugging devices into the well, each of the plugging devices including a body and, extending outwardly from the body, at least one of lines and fibers, the set of plugging devices blocking flow through respective perforations in the zone, perforating another zone, releasing another set of the flow conveyed plugging devices into the well, and the second set of plugging devices blocking flow through respective perforations in the second zone.

Abstract: A well system can include a well tool with a retarder chemical. The retarder chemical is released from the well tool into an annulus and retards setting of cement therein. A method of retarding setting of cement at a location in an annulus can include releasing a retarder chemical from a well tool connected in a casing string, after the cement is placed in the annulus. A well tool can include a valve that controls fluid communication via a port between an exterior of the tool and a flow passage extending through the tool, an annular recess, and a dispersible annular exterior component received in the recess. Another well tool can include a valve that controls fluid communication between an exterior of the tool and a flow passage extending through the well tool, an internal chamber, and a retarder chemical in the chamber.

Abstract: A method of restoring flow through an opening in a well, the opening being blocked by a plugging device, can include conveying a well tool into the well, contacting the plugging device with the well tool, and permitting flow through the opening as a result of the contacting step. Another method of restoring flow through an opening blocked by a plugging device in a well can include conveying a well tool into the well, reducing pressure in the well with the well tool, and permitting flow through the opening as a result of the pressure reducing step.

Abstract: A system for use with a well can include a perforating assembly with at least one perforator, the perforating assembly conveyed through a wellbore with fluid flow through the wellbore, and plugging devices spaced apart from the perforating assembly in the wellbore, the plugging devices conveyed through the wellbore with the fluid flow. A method of deploying plugging devices in a wellbore can include conveying a perforating assembly including a dispensing tool through the wellbore, the dispensing tool including a container, and then releasing the plugging devices from the container into the wellbore at a downhole location. Another method of deploying plugging devices in a wellbore can include conveying the plugging devices through the wellbore with fluid flow through the wellbore, and conveying a perforating assembly through the wellbore while the plugging devices are being conveyed through the wellbore.

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 vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path is designed to produce alternating primary and secondary vortices—one clockwise and one counter-clockwise—where the primary vortex is stronger and produces higher backpressure than the secondary vortex. This in turn generates alternating weak and strong pressure pulses in the drill string. The weak pulses may be barely perceptible so that the effective frequency of the pulses is determined by the stronger primary vortices.

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.