A hydraulic fracking plug assembly comprises a mandrel, sealing element, upper and lower backup rings, upper and lower cones, upper and lower slips each having teeth configured to engage a well casing, and a shoe. At least one of these parts, and in a further example most or all of these parts, are soluble in a solvent such as a potassium chloride solution, an acid, or a base. In some such examples, the soluble parts comprise magnesium, a magnesium alloy, or a soluble polymer.

A cement plug is for plugging an annular region between a first casing and a second casing in a well. A method includes: perforating the first casing to open a flow path to the annular region; providing a magnetorheological cementitious slurry; inducing a magnetic field for affecting the physical properties of the magnetorheological cementitious slurry and for defining a lower boundary for the cement plug; feeding the magnetorheological cementitious slurry into the annular region through a perforation in the first casing; and impeding the mobility of the magnetorheological cementitious slurry in the annular region by exposing it to the magnetic field such that the magnetorheological cementitious slurry may consolidate substantially at the lower boundary without the need for a base device in the annular region.

A drillhole plug includes a frame or housing of a corrosion-resistant material and sized to fit within a milled portion of a directional drillhole that includes a hazardous waste repository; and a material that fills at least a portion of the frame or housing. The material exhibits creep such that the material fills one or more voids between the frame or housing and a subterranean formation adjacent the milled portion of the directional drillhole.

A cementing plug including a wiper portion, an engagement section attached to the wiper portion, the engagement section including an engagement feature configured to release at a selected threshold pressure related to cement forming an annular structure about a fracturing device.

A non-metallic tubular defines a central flow passage. Actuable rollers are actuable between an extended position and a retracted position. The actuable rollers are pivotally attached to the non-metallic tubular. The actuable rollers centralize the non-metallic tubular when in the extended position. The actuable rollers extend between the non-metallic tubular to an inner surface of the wellbore when in the extended position. A connector is attached to an uphole end of the non-metallic tubular. The connector is configured to attach to a downhole end of a work string.

A plug deployable into a wellbore having a casing string includes a sealing element including an outer sealing surface configured to extend outwardly from a central axis of the plug and sealingly press against a casing string when the plug is in the second configuration, and a slip including at least one slip body having a peripheral outer face oriented to face away from the central axis and towards the casing string, and one or more engagement members located on the outer face of the slip body wherein the one or more engagement members are configured to bite into the casing string when the plug is in the second configuration, wherein at least 40% of a total volume of the plug is formed from corrosion-selected materials and at least 30% of the total volume of the plug is formed from corrosion-resistant materials.

A chemical reaction heat source for use in heaters used in down-hole applications is provided. The heat source has a fuel composition that comprises thermite and a damping agent. The use of the thermite mix enables the heaters of the present invention to generate hotter temperatures down wells. This in turn allows the use of Bismuth/Germanium alloys, which have higher melting points, to enable the production of plugs for the abandonment of deeper wells where subterranean temperatures are higher.

A circulation test tool and method of performing a circulation test in a wellbore during single-trip casing cutting and removal. An anchor mechanism (20), a mechanical-set retrievable packer (22) and a cutting mechanism (18) allow gripping and cutting of casing (14) with the mechanical set-retrievable packer (22) being set after the cut to carry out the circulation test. The well is kept under control during the cut by application of tension on the drill string to set the packer (22) at any time. The arrangement provides full annulus flow pass at the packer during cutting. Embodiments describe additional features of a drill to dress a cement plug or a settable bridge plug.

A system and method to protect downhole tools and equipment used in transporting fluids with erosional and/or corrosive characteristics is disclosed according to one or more embodiments. The protection assembly engages with a latch coupling or other surface in need of protection to form a barrier between the latch coupling surface and any erosional or corrosive fluids. The protection assembly comprises a barrier sleeve portion and a support sleeve portion disposed in the barrier sleeve. The support sleeve is moveable between a first and second position within the barrier sleeve. In a first position of the support sleeve, collet fingers in the barrier sleeve may flex to allow movement through the latch coupling while in a second position of the support sleeve, the collet fingers may not flex and the barrier sleeve is engaged and protecting the latch coupling.

The present invention is a retrievable back pressure valve device and method of using the same that may be placed in tubing during well completion and retrieved as desired by dropping a ball down hole, which then interacts with the valve to shear the positioning points allowing for retrieval as the valve is allowed to move up the well to be removed from same.