Methods and apparatuses are provided for clearing a wellbore using a means for milling and a means for suctioning within a wellbore. Obstructions such as ball frac seats, bridge plugs, or formation material can be milled within a wellbore. As a result, larger, unrestricted, diameters can be obtained within the liner/wellbore. The cleared wellbore can allow for various remedial tools to be run into the liner/wellbore. In addition, the milled particles can be suctioned/vacuumed up and can be pumped/pushed to surface in an underbalanced fashion. In some embodiments, this can be achieved by incorporating a bottom-hole pump or a venturi component into the bottomhole assembly. The system can be deployed using a spoolable single or multi-conduit coiled tubing system and can be configured as a well intervention or work-over technology. In some embodiments, the clearing equipment can be temporary or mobile.

A wellbore plug isolation system and method for positioning plugs to isolate fracture zones in a horizontal, vertical, or deviated wellbore is disclosed. The system/method includes a wellbore casing laterally drilled into a hydrocarbon formation, a wellbore setting tool (WST) that sets a large inner diameter (ID) restriction sleeve member (RSM), and a restriction plug element (RPE). The WST is positioned along with the RSM at a desired wellbore location. After the WST sets and seals the RSM, a conforming seating surface (CSS) is formed in the RSM. The CSS is shaped to engage/receive RPE deployed into the wellbore casing. The engaged/seated RPE isolates heel ward and toe ward fluid communication of the RSM to create a fracture zone. The RPE's are removed or left behind prior to initiating well production without the need for a milling procedure. A large ID RSM diminishes flow constriction during oil production.

Apparatus and methods for penetrating a downhole target within a wellbore include providing a body with a longitudinal axis, a first end, and a second end into a wellbore, the body having a nozzle at the first end. The nozzle is adapted to project a medium in a direction generally parallel to the longitudinal axis to affect a downhole target. An actuator in communication with the medium is usable to initiate the apparatus. The nozzle can be provided with a geometry configured for projecting the medium in a pattern that separates the downhole target into at least two portions. The medium can include a ferromagnetic material that becomes associated with the downhole target to facilitate recovery of the target or portions thereof using a retrieval device having a magnetic element.

A well tool assembly includes a first well tool and a second well tool. The first well tool includes a first casing, a first drill bit and a drilling jar. The first drill bit is configured to drill through a subterranean zone to form a wellbore. The drilling jar is axially coupled to the casing uphole of the first drill bit. The drilling jar has an outer diameter that is greater than an outer diameter of the first casing. The second well tool has a second casing and a second drill bit. The second casing has an outer diameter that is smaller than an inner diameter of the drilling jar. The second drill bit has an outer diameter that is smaller than the inner diameter of the drilling jar.

Apparatus and adapter are usable for aligning downhole torch apparatuses and cutting devices, including axial pyro torches, circulating pyro torches, and radial cutting and perforating torches, within a wellbore for removal of one or more downhole obstructions. The torch and/or cutting apparatus comprises a body having a nozzle adapted to project a fuel load, such as molten thermite or molten thermite with a polymer, in a direction aligned with the obstruction. The adapter comprises protruding elements for eliminating or diminishing damage to the area surrounding the obstruction, including the inner walls of the wellbore and/or casing, and can further comprise centralizers for alignment of the apparatus with the obstruction, within the wellbore.

An automatic drilling apparatus having a tool body, a motive device connected to the tool body, and a drill bit connected to the tool body. The apparatus also includes a setting tool connected to the body, at least one sensor disposed on the tool body, and a computer disposed in the tool body, wherein the computer is configured to actuate the motive device, the drill bit, the setting tool, and the at least one sensor.

Methods of using a component in a subterranean wellbore include positioning a component including a degradable thermoset polymer material in a wellbore location, obstructing flow with the component, exposing the component to an acidic solution to degrade the selectively degradable thermoset polymer material and to remove the component from the wellbore location, and flowing a fluid through the wellbore location where the component was positioned. Methods of forming a component of a wellbore system include forming at least a portion of the component to comprise a degradable thermoset polymer material. Wellbore systems include at least one component including a selectively degradable thermoset polymer material. The selectively degradable thermoset polymer material may be a polyhexahydrotriazine (PHT) material.

A perforating tool includes a charge holder connected to a work string and a perforator fixed in a charge holder disposed along the work string. The perforator includes a cylindrical case, an explosive material, a metal cap, and a detonating cord. The case has a bulkhead at a first end, an open mouth at a second end, and an interior volume. The first end includes a post having a slot. The explosive material is disposed in the interior volume. The metal cap covers the open mouth of the case and has a disk section defined by a separator ring. The separator ring has a structurally weakened zone that encircles the disk section. The detonating cord is received in the slot of the post.

A well tool assembly includes a first well tool and a second well tool. The first well tool includes a first casing, a first drill bit and a drilling jar. The first drill bit is configured to drill through a subterranean zone to form a wellbore. The drilling jar is axially coupled to the casing uphole of the first drill bit. The drilling jar has an outer diameter that is greater than an outer diameter of the first casing. The second well tool has a second casing and a second drill bit. The second casing has an outer diameter that is smaller than an inner diameter of the drilling jar. The second drill bit has an outer diameter that is smaller than the inner diameter of the drilling jar.

A well tool assembly includes a first well tool and a second well tool. The first well tool includes a first casing, a first drill bit and a drilling jar. The first drill bit is configured to drill through a subterranean zone to form a wellbore. The drilling jar is axially coupled to the casing uphole of the first drill bit. The drilling jar has an outer diameter that is greater than an outer diameter of the first casing. The second well tool has a second casing and a second drill bit. The second casing has an outer diameter that is smaller than an inner diameter of the drilling jar. The second drill bit has an outer diameter that is smaller than the inner diameter of the drilling jar.