A downhole tool for use in a wellbore tubular string comprises a housing having a bore therethrough forming part of a fluid flowpath through the wellbore tubular string, a sliding member operable to slide with respect to the housing, a plurality of magnetic pins, and a corresponding plurality of springs. A sliding line is formed by interfacing surfaces of the sliding member and the housing, and the plurality of pins comprise a locked position and an unlocked position whereby in the locked position at least one pin spans the sliding line to prevent the sliding member from sliding with respect to the housing and in the unlocked position no pins span the sliding line. The plurality of springs biases the pins towards the locked position.

A method of deploying a flexible cable in a wellbore includes carrying, by a tubular assembly, a cable spool cartridge into the wellbore. The cable spool cartridge is attached to an exterior of the tubular assembly and contains the flexible cable. A first end of the flexible cable is attached to a buoyancy device, and the buoyancy device is releasably attached to the cable spool cartridge. A fluid is flowed by the tubular assembly in a downhole direction through an interior of the tubular assembly and in an uphole direction within an annulus at least partially defined by the exterior of the tubular assembly. The fluid has a greater density than the buoyancy device. The buoyancy device is released by the cable spool cartridge, and the buoyancy device is configured to travel after release in the uphole direction with the fluid and thereby pull the flexible cable from the cable spool cartridge and into the annulus.

A subterranean tool can drop multiple objects to landing locations in a tubular string. The tool can keep at least one ball out of the fluid stream until ready for release. A dart or wiper plug can be kept in the fluid stream with an open bypass until axial mandrel movement allows release of the plug or dart. The tool is rotationally locked at a lower location for run in and then can rotationally lock at an upper location upon release of the dart or ball shifting relative rotation capabilities to different members. Axial movement that releases the dart also aligns a ball with a decreasing depth groove so that relative part rotation can cam the ball against a leaf spring detent and into the mandrel flow path.

A subterranean tool can drop multiple objects to landing locations in a tubular string. The tool can keep at least one ball out of the fluid stream until ready for release. A dart or wiper plug can be kept in the fluid stream with an open bypass until axial mandrel movement allows release of the plug or dart. The tool is rotationally locked at a lower location for run in and then can rotationally lock at an upper location upon release of the dart or ball shifting relative rotation capabilities to different members. Axial movement that releases the dart also aligns a ball with a decreasing depth groove so that relative part rotation can cam the ball against a leaf spring detent and into the mandrel flow path.

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly includes: holding moveable elements of the wellbore tool in an unactivated position using a shear pin; inserting one or more drop balls into a drilling fluid; and flowing the drilling fluid with the drop balls to a flow orifice located in or below the wellbore tool. The flow orifice is at least partially plugged with the drop balls to restrict fluid flow and correspondingly increases the hydraulic pressure of the drilling fluid. The hydraulic pressure is increased to a point beyond the rating of the shear pin, thereby causing the shear pin to shear and allowing the moveable elements of the tool to move to an activated position.

A plugging device can include a body configured to engage and substantially block flow through a passageway, and the body including a winding of at least one of fiber, line, rope, tube, filament, film, fabric, mesh and weave. A method of plugging a passageway can include releasing a plugging device into a fluid flow, thereby causing the plugging device to be carried by the fluid flow to the passageway, the plugging device including a body formed with at least one winding, and the plugging device engaging the passageway and thereby blocking the passageway. A well system can include a plugging device conveyed through a tubular string by fluid flow in the well, the plugging device including a body configured to engage and resist extrusion through a passageway in the well, the body including a winding, and in which the winding substantially blocks the fluid flow through the passageway.

A plugging device can include a body configured to engage and substantially block flow through a passageway, and the body including a winding of at least one of fiber, line, rope, tube, filament, film, fabric, mesh and weave. A method of plugging a passageway can include releasing a plugging device into a fluid flow, thereby causing the plugging device to be carried by the fluid flow to the passageway, the plugging device including a body formed with at least one winding, and the plugging device engaging the passageway and thereby blocking the passageway. A well system can include a plugging device conveyed through a tubular string by fluid flow in the well, the plugging device including a body configured to engage and resist extrusion through a passageway in the well, the body including a winding, and in which the winding substantially blocks the fluid flow through the passageway.

A technique facilitates downhole operations, e.g. gravel packing and cementing operations, in a borehole. According to an embodiment, a service tool is releasably coupled with respect to a casing. The casing is used to run the service tool downhole into a borehole. In some embodiments, the casing is connected with a downhole completion, e.g. a sand control completion. A work string may then be conveyed downhole to the service tool and connected to the service tool. While connected to the work string, the service tool may be operated to perform desired downhole operations.

Acid stimulation operations in a wellbore may be conducted using frac plugs constructed of a hydrolytically degradable polymer. The frac plugs may be constructed of an aliphatic polyester such as PGA and may be readily pumped into position in the wellbore due in part to their relatively low density. Once perforations have been created in the wellbore and a first frac plug is set in place, an acid solution may be pumped at a high-pressure acid against the frac plug and into the geologic formation. A second and/or any number of subsequent frac plugs may be pumped behind the acid, e.g., in brine solution, to be used in subsequent acid stimulation operations. After completing acid stimulation operations, the frac plugs may degrade in the wellbore to permit production within two weeks.

A pump down intervention tool may be pumped downhole through a work string after an installation of the work string. The pump down intervention tool may include a downhole tool that includes but is not limited to an agitator tool, including but not limited to a fluidic pulsation device, or a check valve. The pump down intervention tool may be pumped downhole in the work string, for example but not limited to in a coiled tubing or jointed pipes. The pump down intervention tool may be landed at a desired location along a length of the work string. The pump down intervention tool can allow for the addition of a downhole tool after the work string's initial deployment, providing a desired functionality downhole at time after the initial deployment of the work string downhole.