Abstract: A method of performing a wellbore operation includes: circulating a doped wellbore fluid comprising a non-radioactive doped particulate material in a wellbore; and logging the wellbore with a logging-while-drilling tool to determine at least one characteristic of the doped wellbore fluid. A method of performing a wellbore operation includes: circulating a doped wellbore fluid comprising a non-radioactive doped particulate material in a wellbore; logging the wellbore with a logging tool; and determining a location of at least one fracture by elemental spectroscopy measurements.

Abstract: A gripping tool having a mandrel reciprocatable within a slide member, the mandrel having a top connector for connecting to a tubular string and a bottom connector for connecting to a cutting tool, the slide member having at least one radially outwardly biased friction member and a slip cage with at least one window through which a slip is deployable, by movement of the mandrel within the slide member, to engage and grip a section of casing to be removed from a well, the mandrel being rotatable by rotation of the tubular string to operate the cutting tool with the gripping tool in the gripping mode. After detachment of the section of casing by the cutting tool, the gripping tool and the gripped section of casing are pulled from the well. The gripping mode is restorable to a running position to reset the tool in the casing.

Abstract: A system includes an inner string assembly disposed within an outer casing. The inner string assembly includes a seal member in sealing engagement with the outer casing. An expansion sleeve is coupled to an end of the outer casing. An expandable liner is coupled to the expansion sleeve. A cone assembly is coupled to the inner string assembly and positioned proximate to the expansion sleeve when the inner string is in a running position.

Abstract: A system and method for positioning a tool within a tubular segment or a tubular tool, wherein the interior surface of the tubular segment or tubular tool is provided with one or more pluralities of grooves, each defining a selected profile. A downhole tool is lowered into the tubular segment or tubular tool, having a blade in communication therewith. The blade includes a plurality of protruding members thereon, which define a profile complementary to one of the selected profiles formed by one of the pluralities of grooves. A biasing member biases the blade toward the interior surface of the tubular segment or tubular tool to engage the protruding members of the blade within the complementary profile of the tubular segment or the tubular tool. The system and method further include a slip and wedge assembly usable to position a tubular segment or tubular tool within a tubular member or wellbore.

Abstract: A mill for use in a wellbore includes a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof and an arm disposed in each pocket. Each arm has a body portion and a blade portion extending from an outer surface of the body portion and is movable between an extended position and a retracted position. The mill further includes cutters disposed along each blade portion and a block disposed in each pocket and connected to the housing. Each block has a guide engaged with a mating guide of the respective body portion and an inner passage for providing fluid communication between the housing bore and the respective pocket. The mill further includes an actuator for extending the arms.

Abstract: Disclosed are systems and methods for removing components of a subsea well having a wellhead located on a seabed and multiple well casings connected to the wellhead and penetrating the seabed. A cutting tool is lowered from a floating vessel to a predetermined cut location in the subsea well. The cutting tool is at the end of a utility line connected to an actuator located on the floating vessel. The cutting tool is used to sever the multiple well casings at the predetermined cut location such that the multiple well casings are completely severed concurrently. The wellhead and the severed multiple well casings are raised together from the seabed to the floating vessel as a single assembly. Various forms of the cutting tool are disclosed. The methods disclosed can include an integrated procedure for dispensing cement to plug the well at the seabed as the well components are being removed.

Abstract: A method is for cutting of at least one line disposed along a pipe string in a well. The method includes (A), using a cutting tool for selective cutting activation and provided with at least one cut-forming means for cutting in a radial direction outward from the cutting tool; and (B) lowering the cutting tool to a longitudinal section where the cutting is to be carried out. In (A), a cutting tool is used for controlled cutting in a peripheral direction and distributed in an axial direction relative to the cutting tool. The method further includes (C), activating the cutting tool and cutting, in the radial direction through and past the wall of the pipe string, at least one peripherally extending hole collectively covering the entire circumference of the pipe string, and also distributing the hole in the axial direction.

Abstract: A settable down hole tool is of increased drillability and/or of increased expansibility. The improvement in drillability can be caused by fracturing cast iron slips into a large number of small pieces that can be circulated out of a well without further reduction in size. The improvement in expansibility can be partially caused by providing an expander cone of increased hardness thereby allowing an increased angle on the expander cone and slips. The improvement in expansibility can be partially caused by increasing the thickness of the slips.

Abstract: Casing removal operations may utilize an analytical model to the estimate the total force to (1) break bonding between a cut casing and the annular materials contained between the cut casing and the surrounding borehole and (2) pull the cut casing upward through the borehole while taking into account frictional forces inside and outside the cut casing, shear forces, and the like. Such models may further predict the casing overpull and total tension needed to extract the cut casing from the borehole. Using these models in conjunction with the specifications of the casing retrieval equipment may allow for determining the cutting depth for producing the cut casing with higher accuracy than previously available.

Abstract: There is disclosed herein a method and apparatus for using rupture pins to selectively open jets on a jet perforating tool. Rupture pins inserted in jets within a jet perforating tool are configured to rupture at pre-designed thresholds, thereby opening the jet to begin a perforating job, or to circulate fluid through the tool. Also disclosed are systems and methods for holding the rupture pins within the tool prior to rupture.

Abstract: A downhole tool and associated methods. The downhole tool includes a body with a throughbore; at least one extendable cutting member; and an actuation member. The actuation member is operatively associated with the extendable cutting member and movable relative to the body to extend the cutting member laterally from the body along an extension axis. The extension axis is offset from a radius of the body.

Abstract: Embodiments herein include a casing cutting tool comprising a top mandrel operatively coupled to a conveyance; a first retractable wedge operatively coupled to the top mandrel; a jetting tool operatively coupled to the retractable wedge, the retractable wedge thereby interposing the top mandrel and the jetting tool, wherein the jetting tool has one or more jetting nozzles arranged thereon; and a bottom terminal operatively coupled to the jetting tool, the jetting tool thereby interposing the retractable wedge and the bottom terminal.

Abstract: A window milling system can include a window mill having selectively retractable and extendable blades, and a whipstock assembly having a receptacle therein, the window mill being secured relative to the whipstock assembly the blades are received in the receptacle. A method of cutting a window through a wellbore lining can include cutting through the lining with a window mill, then retracting blades of the window mill, and then outwardly extending the blades in a whipstock assembly, thereby securing the whipstock assembly to the window mill. A window mill can include multiple blades adapted for cutting through a wellbore lining, the blades being outwardly extendable relative to a body of the window mill in a well. Another method of cutting a window through a wellbore lining can include a window mill drilling a wellbore outward a substantial distance from the window after the window mill cutting through the lining.

Abstract: A cutting element includes a body having two planes, each of the two planes defining a plurality of edges, and a support extending from a first of the two planes. The support and the body are configured such that when at least one of the plurality of edges and the support are in contact with the planar surface, edges of the plurality of edges on a second of the two planes form cutting edges and the second of the two planes forms an acute angle with the planar surface. The second of the two planes of the cutting element has a recess formed therein sized and positioned to be receptive to a support of a second cutting element similar to the cutting element when the first of the two planes of the second cutting element is butted against the second of the two planes of the cutting element.

Abstract: A remotely controlled pile cutter for insertion to a desired position within a tubular piling comprises an insertion cable attached to a lifting sub, radially extendable centralizer arms, an extendable rotatable cutter, a camera, and monitors and sensors in communication with a control panel and computer processor where information and control signals are received and generated. The radially extending centralizer arms hold the pile cutter in place at the internal piling wall. Radial extension of the rotatable cutter positions a fluid nozzle to direct high pressure cutting fluid against the internal piling wall as the cutter is rotated around the internal piling wall to sever the piling. The location and position of the rotatable cutter, the fluid steam, and the physical properties of the cutter environment may be continually and remotely monitored at the control panel.

Abstract: A method for separating a pipe comprising a pipe axis, a pipe wall, a pipe interior, an inside pipe circumference, an upper end to be separated, and a lower end, the pipe being anchored in the ground by the lower end, includes providing a cutting assembly comprising at least one water jet nozzle which produces a water jet. The cutting assembly is lowered into the pipe interior through the upper end to be separated down to a separation zone. The pipe is cut with the cutting assembly. The cutting assembly acts progressively against the inside pipe circumference. The water jet, when activated, produces a cut comprising a substantially constant cut width and two complementary conical cut surfaces. The water jet is directed at an angle (?) to a plane which runs perpendicular to the pipe axis so that the cut runs diagonally through the pipe wall.

Abstract: Downhole tools that have a housing and an actuation mechanism. The actuation mechanism is adapted to index in response to one or more balls being deployed into said tool and thereafter to actuate in response to another said ball being deployed into said tool. The indexing balls and the actuation ball are substantially identical. The actuation mechanism may comprise a member adapted for indexing from an initial position sequentially through one or more intermediate positions to a terminal position where the indexed member is mounted in an annular space between an outer wall and an inner wall. The tool may comprise a central conduit which is substantially uniform internal diameter substantially free of profiles. Methods are provided that include deploying an ancillary tool through the tool which has not been actuated or drilled out.

Abstract: A technique facilitates a perforation operation. A perforating gun carrier is combined with a pressure enhancement mechanism. The pressure enhancement mechanism provides a controlled increase in pressure within the perforating gun carrier as the perforating gun carrier is delivered into a higher pressure environment. The increase in internal pressure counters the buildup of a pressure differential to the degree desired for a given perforating gun carrier.

Abstract: An exemplary milling system includes a mill arranged within a shroud and configured to translate axially with respect to the shroud once detached therefrom, a guide block is coupled to a distal end of the mill and supports the mill while the mill forms the casing exit. A guide support arranged within the shroud defining one or more longitudinal channels configured to accumulate cuttings and debris. The shroud defines a plurality of perforations arranged as first and second axial perforation sets, and a sleeve is arranged therein and defines one or more piston guides that align one or more pistons with either the first or second axial perforation sets, depending on the amount of cuttings and debris.

Abstract: A method for removing a tubular from a wellbore can include repeatedly and sequentially using an upper gripping member of an upper section and a lower gripping member of a lower section to hydraulically grip the tubular, while repeatedly and sequentially extending and retracting the upper section relative to the lower section to raise the tubular from the wellbore to a predetermined height. At least one lifting hole can be formed in the tubular, and a lifting member can be installed in each lifting hole. A hoist can be connected with each lifting member. The tubular can be cut using a saw and removed from the wellbore using the hoist.

Abstract: An underreamer for increasing a diameter of a wellbore. The underreamer includes a body having an axial bore extending at least partially therethrough. A sleeve is arranged and designed to move a first axial distance within the body. A cutter block is movably coupled to the body. The cutter block is arranged and designed to move at least the first axial distance with respect to the body to contact the sleeve in response to hydraulic pressure in the bore. The cutter block moves from a first outer diameter to a second outer diameter as the cutter block moves the first axial distance.

Abstract: Tools and methods for abrasively cutting downhole pipes and casing. The tools and methods are ideally suited for situations where the pipe to be cut or perforated is positioned partly or wholly inside another pipe and damage to the outer pipe must be avoided. The jet nozzles are positioned at a non-normal angle to the target surface to reduce the jets' effective cutting distance. While pumping the abrasive fluid, the jets are supported at a selected radial distance from the target surface so that within a predetermined operating time the jets will cut or perforate the inner pipe but leave the outer pipe substantially intact. The tool may be rotated with a motor to perform cutoff operations or held in a fixed position for perforating.

Abstract: A cutting apparatus and method to facilitate milling of a casing window by improving the interaction between the mill and the casing. The cutting apparatus comprises a whipstock having a plurality of ramp sections which provide a ramp profile arranged and designed to cooperate with the cutting structure of a mill to achieve a desired loading on the mill cutting elements during milling of the casing window. The plurality of ramp sections, having specific lengths and oriented at specific angles, adjust the loading on the mill as the mill cuts through the casing during formation of the casing window. The improved whipstock maintains a more balanced loading across the cutting elements during milling operations. Additional mill cutting structures may also be selected and evaluated to further balance the cutting load during window milling.

Abstract: Systems for determining hydraulic fracture geometry and/or areal extent of an area of interest in a reservoir, are provided. An embodiment of a system can include downhole acoustic receiver equipment isolated from fracturing operations in a lower portion of a first wellbore, and fracturing equipment located in a second wellbore connected to the first wellbore. Communications between surface equipment in the downhole acoustic receiver equipment is provided through a communications conduit bypass that permits well operations in the second wellbore without interfering with communications between the surface equipment and the downhole acoustic receiver equipment.

Abstract: A reamer is designed to enhance operation of a bottom hole assembly in which it is included. One or more capabilities and/or characteristics of the cutters carried by the reamer blocks of the reamer may be varied even in the same profile portion to enhance the functionality and/or durability of the reamer.

Abstract: The present disclosure is directed to a downhole bypass tool that includes an inlet for receiving fluid into a housing of the bypass tool. The bypass tool also includes a flow directing apparatus disposed in the housing for directing fluid to flow into an operational flow path of a vibratory tool. The vibratory tool is at least partially disposed within the hosing of the bypass tool. The flow directing apparatus operates selectively bypass the operational flow path of the vibratory tool such that the fluid bypasses the operational flow path of the vibratory tool and flows out of an outlet of the bypass tool.

Abstract: Embodiments herein include a casing cutting tool comprising a top mandrel operatively coupled to a conveyance; a first retractable wedge operatively coupled to the top mandrel; a jetting tool operatively coupled to the retractable wedge, the retractable wedge thereby interposing the top mandrel and the jetting tool, wherein the jetting tool has one or more jetting nozzles arranged thereon; and a bottom terminal operatively coupled to the jetting tool, the jetting tool thereby interposing the retractable wedge and the bottom terminal.

Abstract: A technique facilitates forming cavities, e.g. perforations, into a geological formation. A jetting tool is moved downhole into a borehole, and an abrasive fluid is pumped down through the jetting tool. The abrasive fluid is discharged under pressure through a plurality of jetting nozzles to form jets of the abrasive fluid which act against a surrounding wall, e.g. a casing or other borehole wall. The jetting nozzles, and thus the jets, are oriented such that a rebound effect of the jets does not detrimentally impact the jetting tool. Consequently, the jets can be used to cut perforations through the surrounding wall and into the formation without eroding or otherwise detrimentally affecting components of the jetting tool.

Abstract: A cutting tool for cutting pipe or the like from the inside out includes a housing assembly. A first blade actuating wedge assembly is inside the housing assembly and is movable along a longitudinal axis. The first blade actuating wedge assembly has multiple first tapered blade actuating wedges. Each cutting blade is supported in a manner such that a position of the cutting blade relative to the housing assembly along the longitudinal axis is substantially fixed. Each cutting blade is coupled to a respective one of the first tapered blade actuating wedges such that movement of the first tapered blade actuating wedge assembly along the longitudinal axis causes each cutting blade in the first plurality of cutting blades to move perpendicular to the longitudinal axis.

Abstract: A method for enhanced degradation of a cutting structure on a drill shoe is provided. The cutting structure may be degraded at an accelerated rate after achieving a desired objective. Degradation of the cutting structures on the drill shoe may facilitate the eventual drill out of the drill shoe. In one embodiment, a method of degrading the cutting structure includes operating the drill shoe using a reduced flow rate of drilling fluid. In another embodiment, a method of degrading the cutting structure includes operating the drill shoe at an increased rotary speed. In yet another embodiment, a method of degrading the cutting structure includes operating the drill shoe with an increased weight on bit. In yet another embodiment, a method of degrading the cutting structure includes any combination of one or more of the enhanced degradation methods described herein.

Abstract: A method for milling a tubular cemented in a wellbore includes deploying a bottomhole assembly (BHA) into the wellbore through the tubular, the BHA comprising a window mill; and extending arms of the window mill and radially cutting through the tubular, thereby forming a window through the tubular, wherein a body portion of each window mill arm engages and stabilizes from an inner surface of the tubular after a blade portion of each window mill arm cuts through the tubular.

Abstract: Techniques for shearing a tubular of a wellbore penetrating a subterranean formation with a blowout preventer are provided. The blowout preventer has a housing with a hole therethrough for receiving the tubular. The techniques relate to a blade assembly including a ram block movable between a non-engagement position and an engagement position about the tubular, a blade carried by the ram block for cuttingly engaging the tubular, and a retractable guide carried by the ram block and slidably movable therealong. The restractable guide has a guide surface for urging the tubular into a desired location in the blowout preventer as the ram block moves to the engagement position.

Abstract: Re-treatment of a formation having a wellbore, which can be an open hole or a cased hole lined with casing, involves deploying a tubing string in the casing having tools disposed at intervals thereon. The tools position on the tubing string, and the tubing string with the tools thereon is inserted into the casing. Biasing rings of the tools passively engage with the casing. The annulus is accessed between the tubing string and the casing at the intervals between the tools. For example, sliding sleeves on the tubing string can be opened (selectively), or new plug and perforation operations can be used to create perforations in the tubing string at desired intervals between the tools. With access achieved, retreatment is pumped down the tubing string, out the access to the annulus, and at least partially sealed by the engaged rings in the intervals between the tools.

Abstract: An exemplary milling system includes a mill arranged within a shroud and configured to translate axially with respect to the shroud once detached therefrom, a guide block is coupled to a distal end of the mill and supports the mill while the mill forms the casing exit. A guide support is arranged within the shroud defining one or more longitudinal channels configured to accumulate cuttings and debris. The shroud defines a plurality of perforations arranged as first and second axial perforation sets, and a sleeve is arranged therein and defines one or more piston guides that align one or more pistons with either the first or second axial perforation sets, depending on the amount of cuttings and debris.

Abstract: A mill for use in a wellbore includes a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof and an arm disposed in each pocket. Each arm has a body portion and a blade portion extending from an outer surface of the body portion and is movable between an extended position and a retracted position. The mill further includes cutters disposed along each blade portion and a block disposed in each pocket and connected to the housing. Each block has a guide engaged with a mating guide of the respective body portion and an inner passage for providing fluid communication between the housing bore and the respective pocket. The mill further includes an actuator for extending the arms.

Abstract: This disclosure is directed to a method of using a packer having at least two areas of relative rotation. The disclosure is further directed toward a method of using a packer incorporating a jet port, a highly debossed mandrel and/or a J-pin rotatably disposed within a drag block assembly for continuously and redundantly engaging a J-slot area disposed in the mandrel.

Abstract: A casing cutting tool, to be disposed downhole in a casing string on a drillstring, for the cutting and/or milling of casing strings. The tool has a main body with a plurality of rotatable blades which can rotate between a first retracted position to a second position substantially at right angles to the main body. In this second position, cutting surfaces on the blades engage the casing wall, and rotation of the tool results in cutting of the casing. A plurality of stabilizing arms are rotatably attached to the main body. A link between the blades and the stabilizing arms forces the stabilizing arms to rotate outward when the blades rotate outward. The stabilizing arms are dimensioned to span the inner diameter of the casing string, while leaving clearance to rotate the tool. The outermost ends of the stabilizing arms are rounded to avoid cutting the casing and reduce drag.

Abstract: Proposed devices provide for a jetting process of formation critical areas after opening up a column, increasing a perforator's punch power and reliability, significantly preventing accidents. A hydro-mechanical piercing-type perforator includes a casing containing a hydraulic cylinder with a pusher, an operating tool radially movable and capable of interaction with the pusher. The tool is designed as a puncher, placed on a piston (plunger), mounted in a camera. The tool includes at least one through hydraulic channel and a jet. The camera is hydraulically connected with the cylinder. A proposed method for operating the perforator includes supplying a working fluid to the perforator through the column, creating pressure of the working fluid for an extension mechanism actuating the tool, extending the tool by applying the pressure through a piston rod system, to the piston with the puncher, and applying pressure to the piston through the hydraulic cylinder to the chamber.

Abstract: A firing head actuator for a well perforating system. The firing head actuator includes a housing assembly with a first impact piston initially secured thereto and slidably disposed therein. An electronic time delay assembly, a trigger assembly and an initiator are also disposed within the housing assembly. A second impact piston is initially secured within and slidably disposed within the housing assembly. In operation, a pressure signal of a predetermined threshold actuates the first impact piston, the first impact piston mechanically actuates the electronic time delay assembly, after a predetermined time period, the electronic time delay assembly electrically actuates the trigger assembly, the trigger assembly mechanically releases the second impact piston and pressure shifts the second impact piston into contact with the initiator.

Abstract: A method for forming lateral boreholes from an existing parent wellbore is provided. The wellbore has been completed with a string of production casing. The method generally comprises providing a downhole tool assembly having a whipstock. The method also includes running the assembly down into the parent wellbore. A force is applied to the assembly to cause the whipstock to rotate within the wellbore into an operating position. In this position, a curved face of the whipstock forms a bend-radius substantially across the inner diameter of the casing. A jetting hose is run into the wellbore. Upon contact with the curved face of the whipstock, the jetting hose is re-directed through a window in the production casing. Hydraulic fluid is injected under pressure through the hose to provide hydraulic jetting. The hose is directed through the window and into the formation to create a lateral borehole extending many feet outwardly into a subsurface formation.

Abstract: A system for injecting high pressure abrasive fluid into an abrasive jet tool in a wellbore comprises an abrasives hopper; a slurry tank connected to the abrasives hopper; a low pressure abrasive pump connected to the slurry tank; a first high pressure vessel connected to the low pressure pump through a first high pressure valve; a high pressure non-abrasive pump connected to the first high pressure vessel through a second high pressure valve; and an abrasive jet tool connected to the first high pressure vessel through a third high pressure valve.

Abstract: A method of severing at least a first object comprises: positioning a severing device adjacent to the first object, wherein the first object is a wireline or a tubular, and wherein the severing device comprises: a first reactant, and a second reactant; initiating a reaction, or allowing a reaction to occur, between the first reactant and the second reactant, wherein the reaction is an exothermic reaction, and wherein heat evolved from the reaction has a temperature greater than or equal to the melting point of the first object; and directing at least a portion of the heat from the outside of the first object through the first object.

Abstract: A technique facilitates removal of excess sand during a jet perforating operation without requiring that the perforating string be pulled out of hole. A jet perforating tool is provided with at least one perforating nozzle for creating perforations in a well via high-pressure fluid. The jet perforating tool also comprises at least one wash nozzle oriented to direct fluid under pressure against a sand plug to break loose excess sand. A pair of seats and plug members may be used in the jet perforating tool to control the flow of pressurized fluid through the perforating jet nozzle and/or the wash nozzle.

Abstract: Embodiments of a bottomhole assembly BHA for completion of a wellbore are deployed on electrically-enabled coiled tubing (CT) and permit components of the BHA to be independently electrically actuated from surface for completion of multiple zones in a single trip using a single BHA having at least two electrically-actuated variable diameter packers. One or both of the packers may be actuated to expand or retract for opening and closing off a variety of flowpaths between the BHA and the wellbore, in new wellbores, old wellbores, cased wellbores, wellbores with sleeves and in openhole wellbores. Additional components in the BHA, which may also be electrically-actuated or powered, permit perforating, locating of the BHA in the wellbore such as using casing collar locators and microseismic monitoring in real time or in memory mode.

Abstract: A system and method for jet perforating within a well are disclosed. A jet perforating tool configured to be lowered inside a production tubing string comprises a tool body with a passage, an inlet in the upper section, perforating jets in the lower section, and a stepped outer diameter configured to seat on a production tubing string restriction such as a seat nipple. The tool may be lowered into the production tubing string without the need to trip the production tubing string in and out of the wellbore.

Abstract: A cutting tool that inserts into a tubular for cutting the tubular from within. The cutting tool includes a motor, a cutting head, permanent anchor between the motor and cutting head, an electronics portion, and a modular anchoring sub that can be between the motor and electronics portion or on the upper end of the cutting tool. The modular anchoring sub provides flexibility in where anchoring elements are positioned so that depending on the application, the modular anchoring sub can be positioned so that it provides its maximum anchoring force for stabilizing the cutting tool during use.

Abstract: A rigless abandonment system including a surface vessel having an attached lifting device and a moonpool. The system further includes a cutting module configured to connect to a subsea wellhead, the cutting module having a wellhead connector having an actuatable lock and release mechanism, a motor assembly, and a cutter. An umbilical line connects the cutting module to the surface vessel, wherein the lifting device is used to raise and lower the cutting module connected to the surface vessel through the moonpool. A method for performing rigless casing cutting and wellhead removal operations, the method includes positioning a surface vessel above a subsea wellhead, where the surface vessel has a moonpool and a lifting device. The method further includes providing a cutting module, and deploying the cutting module through the moonpool, wherein the cutting module is connected to the surface vessel by an umbilical line.

Abstract: A method is for removing casing from a well. The method includes setting a first sealing element into fluid-sealing engagement with the inside of the casing, lowering a flow-through string into the well, a cutting tool and a second, reversibly expandable sealing element being connected to the string, forming perforations into the casing by means of said cutting tool, expanding the second, expandable sealing element into fluid-sealing engagement with the inside of the casing, passing a pressurized fluid through the string and into the annulus via the perforations, so that the viscous and/or solid mass is displaced up the annulus, cutting the casing around its entire circumference; and pulling a length of the casing up from the well.

Abstract: An assembly for minimizing damaging effects of pressure waves on devices in a wellbore. The assembly comprises a dynamic device disposed in the wellbore and generating pressure waves during actuation; a barrier device disposed in the wellbore and presenting an obstacle to the pressure waves generated by the dynamic device; and an occlusion disposed in the wellbore between the dynamic device and the barrier device which reduces the damaging effects of the pressure waves on the barrier device.

Abstract: A downhole magnetic latching tool includes at least one permanent magnet deployed on a non-magnetic tool body. A magnetically permeable housing is deployed about the permanent magnet. The magnetic latching tool provides an attractive magnetic force between a drill string and a cased target wellbore.