Embodiments described herein provide an expanding and collapsing apparatus and methods of use. The apparatus includes a plurality of elements assembled together to form a ring structure about a longitudinal axis. The ring structure is operable to be moved between an expanded condition and a collapsed condition by movement of the plurality of elements. At least one set of structural elements are operable to move between the expanded condition and the collapsed condition by movement of a first end in an axial direction, and by movement of a second end in a radial dimension. In certain embodiments, the plurality of elements includes at least one set of structural elements extending longitudinally on the apparatus and operable to slide with respect to one another. Applications of the embodiments described herein include oilfield devices, including anti-extrusion rings, plugs, packers, locks, patching tools, connection systems, and variable diameter tools run in a wellbore.

A buoyancy assist tool has an outer case and a rupture disk connected in the outer case. A sleeve is disposed in the outer case and movable from first to second position in the outer case. A rupture disk membrane of a rupture disk prevents the sleeve from moving to the second position prior to the rupture disk membrane rupturing. The outer case is configured to be connected in a well casing. A lock ring holds the sleeve in the first position

A sealing assembly for forming a seal within a subterranean well includes a sealing tool having a mandrel. Two or more seal members circumscribe the mandrel. The seal members are moveable between a retracted position and an extended position. A seal actuator can move the seal members between the retracted position and the extended position. A pressure communication port is located between adjacent of the two or more seal members, the pressure communication port extending from the central passage of the mandrel to an exterior of the sealing tool. A pressure communication valve is associated with the pressure communication port, the pressure communication valve operable to move between an open position where the pressure communication valve provides a path for flow of a fluid between the central passage and the exterior of the sealing tool between adjacent of the two or more seal members, and a closed position.

The disclosure provides a dual plug system, comprising a bottom plug, wherein the bottom plug comprises: a bottom plug mandrel; a plurality of first fins; and a first seat; wherein the plurality of first fins is disposed between a first end and a second end of the bottom plug mandrel, wherein the first seat is disposed at the second end; a top plug, wherein the top plug comprises a first end and a second end, wherein the top plug comprises: a top plug mandrel; a plurality of second fins; a collar; and a sleeve; wherein the plurality of second fins is disposed around the top plug mandrel covering at least a portion of the length of the top plug mandrel, wherein the collar is coupled to the top plug mandrel; and a connector, wherein the connector is coupled to the first end of the top plug.

A magnetic system for determining a position of an untethered dissolvable frac package for use in a hydraulic fracturing or stimulation operation. The system includes an array of magnets operable to produce a magnetic field that is operably associated with a position downhole along the string. A setting tool of the dissolvable frac package is configured to sense the magnetic fields and deploy a dissolvable frac plug at a predetermined position along the wellbore string.

Downhole assemblies and methods for isolating a wellbore. A downhole tool can include a body having a bore or flowpath formed therethrough, and one or more sealing members disposed therein. The one or more sealing members can include an annular base and a curved surface having an upper face and a lower face, wherein one or more first radii define the upper face, and one or more second radii define the lower face, and wherein, at any point on the curved surface, the first radius is greater than the second radius. The sealing members can be disposed within the bore of the tool using one or more annular sealing devices disposed about the one or more sealing members.

A frac plug with a flapper positioned within a shearable housing. More specifically, embodiments are directed towards an upper portion of the shearable housing that is configured to be separated from an insert responsive to flowing back through the frac plug.

A modular pressure cylinder for a downhole tool has an active mandrel tube that supports a modular pressure cylinder. Pistons of the modular pressure cylinder are respectively interconnected and cylinder walls of modular pressure cylinder are respectively interconnected. When fluid is pumped through a tubing string into the downhole tool, the pistons are urged in one direction while the cylinder walls are urged in an opposite direction along an axis of the active mandrel tube.

A petroleum well toolstring valve includes a drill pipe string conveyed J-slot running tool for a top stinger on a retrievable bridge plug. The J-slot running tool includes a J-slot sleeve with J-slots for disconnectably receiving the stinger. The top stinger includes a cylindrical stinger portion with J-slot connecting lugs. An internal plug is arranged between a central connector and stinger bores. A cylindrical neck on the stinger portion spans the internal plug in the axial direction. The cylindrical neck, when covered by the J-slot sleeve, forms an annular flow space connecting upper and lower radial ports and thus central bores. The stinger portion has a rotatable sleeve valve body arranged on a stinger valve stem portion. The sleeve valve body has a sleeve valve port arranged for being aligned with the lower stinger port when rotated into an open position. The rotatable sleeve valve body is connected to the lugs for being rotated by the drill pipe string for opening or closing the valve.

Downhole tools including a wellbore isolation device that provides a plurality of components including a mandrel, and a slip assembly comprising a plurality of slip elements including a slip wedge and a slip, wherein an element of the slip assembly is composed of a degradable metal material, and wherein the slip comprises a slip insert embedded therein, the slip insert having a compressive strength of greater than about 120,000 psi.