Abstract: A tandem seal adapter for a perforating gun assembly includes a housing having a first end adapted to be connected to a first perforating gun and a second end adapted to be connected to a second perforating gun. A port extends through a wall of the housing and is in communication with an interior of the first perforating gun. A tracer material is arranged in the port, and a retainer secures the tracer material in the port. Upon detonation of the first perforating gun, the retainer is displaced and the tracer material is expelled from the port by gas pressure produced by the detonation. A corresponding method of using a tandem seal adapter to disperse tracer material into a wellbore and a tool string employing such a tandem seal adapter are also provided.

Abstract: A method and apparatus for detonating a power charge in downhole wellbore using a heating element embedded within the energetic material of the power charge.

Abstract: A downhole tool for transmitting rotation to a casing string includes a tool body having a bore extending from a first end to a second end. The downhole tool also includes a cam positioned within the tool body, the cam being axially translatable along an axis of the bore. The downhole tool further includes a recess, formed in an outer diameter of the cam. The downhole tool includes a locking mechanism, positioned at least partially within the tool body. The locking mechanism includes a tool key. The locking mechanism also includes a biasing member, the biasing member driving the tool key toward the retracted position.

Abstract: A tubing string release apparatus includes a first mandrel configured to be fixed to an inner wall of a tubing string extended within a wellbore, the first mandrel defining a telescope chamber and a first port that facilitates fluid communication into the telescope chamber, a second mandrel slidably arranged against the first mandrel and defining a second port, and a telescoping cylinder arranged within the telescope chamber and including a telescoping base releasably coupled to the tubing string at an aperture defined in the tubing string, and a telescoping piston releasably coupled to the telescoping base. The telescoping base is advanced radially outward through the aperture when a pressure within the tubing string is increased to a first pressure, and the telescoping piston is advanced radially outward through the telescoping base when the pressure within the tubing string is increased to a second pressure greater than the first pressure.

Abstract: A wellbore isolation assembly includes an outer component and an inner component. The outer component is disposed at a first location in a wellbore. The inner component is disposed at a second location in the wellbore. The inner component is moved from the second location into engagement with the outer component at the first location to form a barrier within the wellbore. The wellbore isolation assembly is retrievable from the wellbore.

Abstract: A setting tool includes a barrel piston that is configured to couple to a setting sleeve and defines a working surface and a vent port. An upper mandrel is disposed within the barrel piston and defines a power charge chamber that is configured to receive a power charge and includes an upper threaded portion, a lower internal thread, and a plurality of axial discharge ports disposed circumferentially around the lower internal thread. The plurality of axial discharge ports are in fluid communication at one end with the power charge chamber and at the other end with the working surface of the barrel piston. A lower mandrel has an upper end and a lower end, with the upper end in threaded engagement with the lower internal thread of the upper mandrel, and the lower end configured to couple to a frac plug. The power charge chamber includes an upper chamber and a lower chamber, with the lower chamber shaped to open to be in fluid communication with each of the plurality of axial discharge ports.

Abstract: A downhole shock absorbing sub which includes a tubular main stem extending through a sub housing and a lateral shock absorbing assembly positioned within the sub housing. The lateral shock absorbing assembly includes an activator ring positioned around the main stem, the activator ring including a plurality of wedge inserts positioned around a perimeter of the activator ring. A reaction collar is positioned on each side of the activator ring with the reaction collars including ramp surfaces engaged by the wedge inserts. A spring system is positioned to resist movement of the reaction collars away from the activator ring, whereby lateral movement of the main stem causes the wedge inserts to move the reaction collars against the spring system.

Abstract: A tubing hanger assembly includes a tubing hanger body, a downward facing load shoulder axially displaceable relative to the body, an annular load member rotatably supported on the body, and a torque member operatively engaged between the load member. The load shoulder and load member are arranged such that rotation of the load member relative to the body results in axial displacement of the load shoulder relative to the body. In use, the torque member rotates the load member to thereby displace the load shoulder axially relative to the body.

Abstract: A tool to remove portions of casing from a wellbore. A tool may include a bottom sub-assembly and casing that selectively detach from a sub-assembly. This may allow for tools and casing within the wellbore to be efficiently and effectively removed from the wellbore without having to cut tools down well.

Abstract: A downhole anchor mechanism for use in downhole tools. The downhole anchor mechanism generally consists of a plurality of sliders that pivot outwardly from a downhole tool body to engage distal ends thereof against a well casing. The sliders are operatively engaged within faceted cavities associated with the tool body, which creates load components that act in a tangential direction, allowing a thin-walled tool body to withstand increased holding force.

Abstract: An pneumatic plug for sealing a pipeline. The pneumatic plug includes a tubular member that extends in an axial direction from a first end to a second end. The tubular member includes a rubber layer and an elastomeric band. The rubber layer extends from the first end to the second end of the tubular member. The elastomeric band is disposed on a top of the rubber layer. The elastomeric band is positioned between the first end and the second end of the tubular member.

Abstract: A downhole tool comprises a hollow body having a wall and a port in the wall, and a closing sleeve movable relative to the body to open and close the port. A seal is provided between the body and the sleeve and is configured to hold differential pressure. An isolation member may be deployed in the tool to isolate the seal from differential pressure and close the port. The isolation member may be deployed following initiation of a tool activation process, a successful outcome of the process being translating the closing sleeve and closing the port, and positioning the seal to hold a differential pressure. If it is detected that the outcome has not been achieved, the isolation member is deployed to isolate the seal from differential pressure and close the port.

Abstract: A casing patch system comprising a base tubular with two anchor/seals coupled to the base tubular and an expansion tool comprising two expansion devices positioned such that upon expansion of the first anchor/seal, the second expansion device engages the second anchor/seal. In another embodiment, the expansion device comprises two swages coupled to a shaft at a distance between them approximately equal to the length of the anchor/seal. The swage diameters are selected such that the expansion forces of the anchor/seal by front and back swages are approximately equal.

Abstract: A downhole oil level detection device includes a mounting housing (1) and a balance cylinder (2) installed on the mounting housing (1). The balance cylinder (2) includes a cylinder body (25) and a moving piston (21), a piston tension spring (22), a moving rod (23), a moving rod compression spring (24) and a displacement sensor (3) installed in the cylinder body (25). One end of the piston tension spring (22) is fixed to one end of the cylinder body (25), the other end thereof is connected to one side of the moving piston (21); one side of the moving piston (21) is also connected to one end of the moving rod compression spring (24), the other end of the moving rod compression spring (24) is connected to one end of the moving rod (23), the other end of the moving rod (23) is provided with the displacement sensor (3).

Abstract: A gravel pack system includes a liner assembly and a deployment assembly. The liner assembly includes a sand control screen. The deployment assembly facilitates rotation of the liner assembly and circulation through the liner assembly while running the liner assembly into a wellbore using a work string. The deployment assembly includes a crossover tool that is operated to facilitate gravel packing without manipulation of the work string. The deployment assembly also includes a setting tool for setting a packer and/or a sand barrier at the top of the liner assembly.

Abstract: A drill string connect tool comprises a housing having first and second sections. The first section has a first recess, and the second section has a second recess. The tool and the first and sections may be in a connected configuration or a disconnected configuration. The connect tool comprises at least one tension member placeable within, and suitable to transfer tensile forces between, the first and second sections when in the connected configuration. A retaining member can retain the tension member within the first and second recesses. The retaining member is selectively dissolvable by a dissolving fluid, while the remaining components of the tool can withstand the dissolving fluid. When exposed to a dissolving fluid, the retaining member dissolves, allowing the tension member to exit the first and second recesses, thereby actuating the tool to the disconnected configuration.

Abstract: A piston for use in a rotary steerable system includes a body formed from a first material. A sealing surface extends around the circumferential wall of the body. The sealing surface is formed from a plurality of layers of a second material. The second material is harder than the first material. The piston can be within a downhole piston assembly that also includes a housing, and the piston being longitudinally movable in a bore in the housing. A method for producing a piston includes preparing a piston formed from a first material, with the piston including a first end. A sealing surface is applied to the piston using laser cladding, with the sealing surface including a second material harder than the first material. The sealing surface is finished to a sealing surface diameter.

Abstract: A technique facilitates connection of tubulars along a tubing string via a linear motion. A first tubular is provided with a first connector end having a non-circular transverse cross-section, and a second tubular is provided with a second connector end having a corresponding non-circular transverse cross-section. The non-circular cross-section and the corresponding non-circular cross-section are designed to matingly engage when the first and second tubulars are moved linearly toward each other to form a tubing string. A seal is provided to seal the first connector end with the second connector end once linearly engaged. A locking mechanism may be employed to linearly lock the first connector end with the second connector end.

Abstract: A braking and setting device is configured to slow down a movement of a tool in a well and to fix the tool relative to the well. The braking and setting device includes two or more arms configured to extend from the tool, toward the well, to brake the movement of the tool along a longitudinal axis X; a movable piston configured to be hosted fully within the tool and to move only when a well fluid acts on a base portion of the movable piston, while a tip portion of the movable piston pushes away the two or more arms; and an actuation mechanism configured to establish a fluid communication between the well fluid and the base portion of the movable piston. The movable piston moves exclusively due to a force exerted by the well fluid on the movable piston.

Abstract: A resource exploration and recovery system includes a first system and a second system extending into a wellbore. The second system includes a completion having a casing defining a wellbore internal diameter. A chemical injection tubing extends from the first system into the completion. The chemical injection tubing includes a terminal end portion. A chemical introduction system is arranged at the first system and is fluidically connected to the chemical injection tubing. The chemical introduction system is operable to deliver a chemical into the chemical injection tubing. A chemical injector assembly is mounted to the terminal end portion. The chemical injection system includes an anchor and a chemical injector valve.

Abstract: A setting tool having a tool body, a chamber configured to contain a non-explosive fuel configured to generate gas and plasma, a cavity, a bleed sub located between the chamber and the cavity. The bleed sub is configured to bleed pressure from the chamber to the cavity after the non-explosive fuel has been initiated. The setting tool also includes a piston disposed within the cavity oriented to stroke in a first direction after the non-explosive fuel has been initiated. The piston may divide the cavity into an upper volume that may receive the pressure increase from the bleed sub and a lower volume. The setting tool may also include a shaft mechanically connected to the piston within the lower volume of the cavity. The shaft may include a dampening conduit configured to drain a fluid from the lower volume after the non-explosive fuel has been initiated.

Abstract: A liner hanger running system including a liner hanger having a body including a wall defined by an outer surface and an inner surface. The body includes an opening that extends through the outer surface and the inner surface. A piston housing including a wall portion defined by an outer surface portion and an inner surface portion is spaced from the outer surface of the body to define a piston Chamber exposed to the opening. A piston is arranged in the piston chamber. A liner hanger running tool including a dog key extends into the opening and engages the piston. The dog key is selectively shiftable relative to the liner hanger to release the piston and expose the opening to a setting pressure.

Abstract: A downhole tool for transmitting rotation to a casing string includes a tool body having a bore extending from a first end to a second end. The downhole tool also includes a cam positioned within the tool body, the cam being axially translatable along an axis of the bore. The downhole tool further includes a recess, formed in an outer diameter of the cam. The downhole tool includes a locking mechanism, positioned at least partially within the tool body. The locking mechanism includes a tool key. The locking mechanism also includes a biasing member, the biasing member driving the tool key toward the retracted position.

Abstract: An enhanced geometry receiving element for a downhole tool, such as an enhanced geometry receiving element for a plunger downhole tool used in the oil and gas industry. In one embodiment, the enhanced geometry receiving element includes a set of axial grooves disposed in the interior of a fishing neck portion of a bypass plunger.

Abstract: A work string locatable in a borehole so as to form an annulus around the work string and a method of depressurizing the annulus are provided. The work string includes a packer expandable radially out from the work string to seal the annulus and a packer sub positioned below the packer including a sub body and a check valve in the body and operable to permit fluid in the annulus to flow into the work string and prevent fluid in the work string from flowing into the annulus. The check valve is operable to open and permit fluid in the annulus to flow into the work string upon exertion of a predetermined minimum pressure on the check valve by the fluid in the annulus. The method includes providing the work string in the borehole and depressurizing the annulus by permitting fluid in the annulus to flow through the check valve.

Abstract: An alternative chemical injection path system that includes a conduit and a manifold. The conduit has a first injection point configured at a first distance from a first end of the conduit and a second injection point configured at a second distance from the first end, with the second distance being different than the first distance. The manifold has an inlet and first and second outlets. The inlet is configured for receiving a chemical, while the first outlet is fluidly coupled to the first injection point, and the second outlet is fluidly coupled to the second injection point. The manifold is configured to distribute the chemical to the first injection point and the second injection point according to a location of a clog in the conduit.

Abstract: The present invention relates to a drill pipe expansion assembly (1) for expansion of a completion component (3) located at a fixed position in a well (4) having a longitudinal axis (5), the drill pipe expansion assembly comprising an expansion unit (6) which is moveable in relation to the completion component comprising a tubular element (7) comprising a first end (8) and a second end (10) and a wall (11) having an outer face (12) and an outlet (14) for ejection of pressurised fluid, and a first sealing element (15,15a) and a second sealing element (15, 15b) arranged on the outer face on each side of the outlet, and a positioning unit (20) comprising a body (21) and a first fixation element (22) movable between a projected position and a retracted position in relation to the body, the positioning unit being connected with the tubular element in order to maintain the expansion unit in a fixed position in relation to the completion component (3) during expansion.

Abstract: A method of detecting an event within a wellbore includes obtaining a sample data set, determining a plurality of frequency domain features of the sample data set, comparing the plurality of frequency domain features with an event signature, determining that the plurality of frequency domain features matches the thresholds, ranges, or both of the event signature, and determining the presence of the event within the wellbore based on determining that the plurality of frequency domain features match the thresholds, ranges, or both of the event signature. The sample data set is a sample of an acoustic signal originating within a wellbore including a fluid. The sample data set is representative of the acoustic signal across a frequency spectrum. The event signature includes a plurality of thresholds, ranges, or both corresponding to the plurality of frequency domain features.

Abstract: A downhole tool for projecting a projectable element downhole includes a tool body having a radial bore, a projectable element forming a piston in the radial bore, the projectable element having first and second element parts. In the retracted position the projectable element and the second bore part define an annular cavity, a hollow base part having an open end and a closed end, the open end extending into the open first end of the projectable element forming a chamber. The open end of the hollow base part has at least one spring element arranged in the chamber and connected to the closed first end of the projectable element and to the closed end of the hollow base part for retraction of the projectable element, and a pump configured to pump fluid into the chamber via a fluid channel to project the projectable element.

Abstract: A method and apparatus for detonating a power charge in downhole wellbore using a heating element embedded within the energetic material of the power charge.

Abstract: A submersible downhole pump (1) includes an elongate pump unit (3) defining a longitudinal pump axis (L) and a pump unit diameter (D), and at least one cable lug (13) for attaching a cable. The at least one cable lug (13) is connected to the pump unit (3) and pivotable around a pivot axis (P) perpendicular to the longitudinal axis (L) between a defined first position and a defined second position. The at least one cable lug (13) is positioned, in the first position, fully within the pump unit diameter (D). In the second position, the at least one cable lug (13) is positioned at least partially protruding outside the pump unit diameter (D).

Abstract: A downhole centralizer operable to be coupled with a tool string and conveyed within a downhole passage, wherein the downhole passage is a wellbore or a tubular member disposed in the wellbore. The downhole centralizer may have a plurality of arms that are operable to move against a sidewall of the downhole passage to centralize at least a portion of the tool string within the downhole passage, impart an intended force against the sidewall of the downhole passage, and maintain the intended force substantially constant while the tool string is conveyed along the downhole passage and an inner diameter of the downhole passage changes.

Abstract: The present invention relates to a downhole plug and abandonment system (100) for a well (105), comprising a first well tubular metal structure (101a) having a wall, a second well tubular metal structure (101b) having a wall, the second well tubular metal structure being arranged inside the first well tubular metal structure, the well tubular metal structures having longitudinal extensions and being arranged in a borehole (104) of a well, a packer (350) arranged between the first well tubular metal structure and the second well tubular metal structure defining an annular space (351) above the packer, a first plug (106) arranged in the second well tubular metal structure dividing the second well tubular metal structure into a first part (107) and a second part (108), the first part being closest to a top of the well, and a cement plug (270) arranged in the first part on top of the packer and the plug. Furthermore, the present invention relates to a downhole plug and abandonment method.

Abstract: Downhole component support systems and methods including a housing having a housing cavity therein, the housing cavity configured to contain a hydraulic frame and a hydraulic frame configured to support at least one component package removably disposed within the housing cavity. At least one master hydraulic assembly is in hydraulic communication with the hydraulic frame and at least one slave hydraulic assembly is coupled to the hydraulic frame and hydraulically coupled to the at least one master hydraulic assembly. Adjustment of the at least one master hydraulic assembly urges the at least one slave hydraulic assembly between a first position and a second position, and, when in the second position, the hydraulic frame is secured to an interior surface of the housing.

Abstract: A well tool for sensing seismic activity at a downhole location has an anchoring mechanism for mechanically coupling the tool to a formation by contact engagement with a wall of a subterranean cavity in which the well tool is located. The anchoring mechanism is deployable by a pressure-triggered hydraulic actuator incorporated in the tool. The actuator is configured for pressure-triggered activation and for hydraulic actuation by agency of borehole fluids (e.g., drilling mud). The actuator can provide a persistent contacting force urging the anchoring mechanism into contact with the cavity wall, to promote firm coupling with the formation for seismic sensoring purposes.

Abstract: 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.

Abstract: A flushable well screen or filter assembly for placement within a tubular. The assembly includes a well screen or filter having an inlet end and an outlet end; and a velocity fuse positioned downstream of the outlet end of the well screen or filter, the velocity fuse in fluid communication with the well screen or filter. A system for removing fluids from a well and a method for back-flushing an upstream well screen or filter installed within a tubular are also provided.

Abstract: A pulling tool deploys on a workstring to retrieving a well component, such as casing or a liner, stuck downhole. The tool has an anchor, a puller, and an implement. The implement is supported on the end of the puller and engages the component. Hydraulic pressure supplied downhole moves at least one puller piston coupled to the implement along a piston mandrel to pull the implement and component. An anchor mandrel coupled to the workstring and the piston mandrel anchors the pulling tool downhole. The anchor has slips disposed on the anchor mandrel that engage in surrounding casing when an anchor piston disposed on the anchor mandrel is hydraulically actuated with the communicated pressure.

Abstract: A hydraulic setting tool apparatus and method for drilling operations providing one-trip setting of a cement-retainer assembly and pumping of cement without excessive pulling, pushing, or twisting of the workstring, using hydraulic drilling fluid pressure and internal movement in the tool.

Abstract: A setting tool for deploying a downhole tool within a wellbore is described herein. The setting tool uses an in situ non-explosive gas-generating power source to generate high-pressure gas, which drives a mechanical linkage to actuate the deployment of the downhole tool. According to certain embodiments the non-explosive gas-generating setting tool contains no hydraulic stages and may contain only a single piston. The setting tool may be fitted to provide different stroke lengths and can provide usable power over a greater percentage of its stroke length, compared to setting tools using explosive/pyrotechnic power sources. Methods of using a non-explosive gas-generating setting tool to deploy a downhole tool within a wellbore are also disclosed.

Abstract: This invention relates to a method for recovering a tubular structure (3) from a well (1), wherein a so-called free point is defined as the location where the tubular structure is stuck in the well. The method comprising providing a downhole tool string comprising a pipe-severing tool and an upper part of the downhole tool string; lowering the downhole tool string into the tubular structure to release the free pipe. Before the step of triggering the pipe-severing tool to sever the tubular structure, the method includes releasing the pipe-severing tool and subsequent withdrawing the upper part, of the downhole tool string away from the free point towards the surface over at least a predefined distance. The invention relates to a downhole tool string for use in such method.

Abstract: A wellhead hanger assembly is provided. In one embodiment, a system includes a wellhead hanger, a running tool coupled to the wellhead hanger, and a torque sleeve positioned to transmit torque from the running tool to the wellhead hanger. The running tool can be in castellated engagement with the torque sleeve via a first set of castellations and mating slots, and the wellhead hanger can be in castellated engagement with the torque sleeve via a second set of castellations and mating slots. Additional systems, devices, and methods are also disclosed.

Abstract: A self-contained module for actuating an element of an earth-boring tool comprises a drive unit configured to be coupled to at least one actuatable element of the earth-boring tool. The drive unit is configured to be disposed at least partially within a compartment of a body of the earth-boring tool. The compartment is radially decentralized within the earth-boring tool. The drive unit includes a drive element configured to be coupled to the at least one actuatable element. The drive unit is configured to move the drive element in a manner moving the at least one actuatable element from a first position to a second position in a direction having a component parallel with a longitudinal axis of the earth-boring tool. The self-contained module is configured to be repeatedly attached to and detached from the earth-boring tool. Such a module may be attached to a tool body carrying extendable elements to form an earth-boring tool for borehole enlargement or stabilization within an enlarged section of the borehole.

Abstract: A centralizer for centralizing a pipe is provided which collaborates the spring force of its bow springs. The centralizer includes a pair of end collars, and at least one center collar. Each of the collars has a center hole for coaxially receiving a pipe. In addition, the centralizer includes a plurality of longitudinally extending and arcuate bow springs having ends which affix to the end collars. The centralizer includes linkage arms which connect the center collar to the bow springs. The linkage arms may provide additional outward spring force against the bow springs. Preferably, the centralizer includes a mechanism for forcing the bow springs radially inward from their at rest position.

Abstract: There is provided a locator configured for coupling to a workstring for locating a wellbore feature, The locator includes a protrusible member, a chamber, a hydraulic fluid supplying passage, and a hydraulic fluid supply source. The protrusible member is moveable, relative to the workstring, and biased for disposition, relative to the workstring, in an extended position. In the extended position, the protrusible member is engageable with the wellbore feature. The first chamber is disposed in fluid pressure communication with the protrusible member, and has a volume configured to change correspondingly with a change in position of the protrusible member such that expansion of the first chamber corresponds with an extension of the protrusible member and such that contraction of the first chamber corresponds with a retraction of the protrusible member. The hydraulic fluid supply source is fluidly coupled to the first chamber via the hydraulic fluid supplying passage.

Abstract: A pressure actuated module associated with a subterranean tool is set with pressure in the well annulus supplemented by added pressure. The addition of pressure to the hydrostatic opens access to a setting piston that is referenced to a low pressure chamber. The piston strokes to a travel stop reducing the volume of the atmospheric chamber while setting the tool. After the tool is set the annulus is communicated to the low pressure reference chamber for the actuating piston to remove a residual net force on the setting piston after the set. One way to do this is to sequentially break multiple rupture discs at different pressures. Another is to have a degradable member in the atmospheric chamber. A piston is fixed in place during setting, and shifts with the application of additional pressure allowing pressure to pass through a port between the annulus and the atmospheric chamber.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A surface handling tool for casing employs slips to grab the casing internally and a lock that operates mechanically in conjunction with the setting of the slips. The slips rub on the inside wall to hold an outer housing against rotation. The top sub and mandrel are rotated in tandem relative to the outer housing that is held by the rubbing of the slips on insertion. The mandrel rises when rotated to extend the slips while lock segments ratchet over a series of protrusions that are shaped to resist downward movement of the mandrel. Once slips and lock are set, subsequent rotation will not release the lock or slips. When the casing is supported on the rig floor weight can be set down and a spring compressed as the leading ramp of the top sub retracts the lock segments such that rotation to the right can then retract the slips.

Abstract: A clad is expanded with a variable swage or other ways to create a seat for an object to obstruct the passage therethrough while at the same time expanding at least a part of the clad into a surrounding tubular for support and sealing. The exterior of the clad can have grit to enhance the grip. A perforating gun can be delivered in the same trip with the clad. After the swage passes through the clad the gun is positioned and fired, the bottom hole assembly is retrieved and the ball is dropped from the surface onto the seat formed in the clad with expansion or with some other means. A treating operation against the clad and into the surrounding formation can then take place. The process can be repeated preferably in a bottom up direction until the formation is fully treated. The clads and objects landed on the clads disintegrate with time or borehole exposure.

Abstract: An erosion device and a corresponding method are disclosed for machining a hollow-cylindrical workpiece, wherein the device is elongated and/or formed in the manner of a tube or cylinder and is characterized in that at least two rotationally acting drives (A1, A2), each with a drive shaft (AW1, AW2), and also an erosion electrode (E), interacting with the drives (A1, A2) and formed in the manner of a ring or disc, are provided. The drives (A1, A2) and the electrode (E) are adapted in size and extent to the internal diameter of the workpiece (W) to be machined, so that the device can be introduced into the respective hollow-cylindrical workpiece (W) and can be positioned at the location respectively to be machined or the region to be machined in the workpiece (W), and the erosion electrode (E) can be pivoted or can be rotated by a coupled pivoting or rotating movement of the at least two drives (A1, A2).