Abstract: Drill string sections are provided comprising internal passages that may be used to facilitate the electrical or hydraulic connection of multiple devices, such as sensors, arranged at spaced apart positions along the length of the drill sections. Methods of manufacturing the drill string sections are also provided, wherein the internal passages are formed by a first passage, a second passage, and a connecting passage therebetween.

Abstract: The present invention provides methods and apparatus for cutting tubulars in a wellbore. In one aspect of the invention, a cutting tool having radially disposed rolling element cutters is provided for insertion into a wellbore to a predetermined depth where a tubular therearound will be cut into an upper and lower portion. The cutting tool is constructed and arranged to be rotated while the actuated cutters exert a force on the inside wall of the tubular, thereby severing the tubular therearound. In one aspect, the apparatus is run into the well on wireline which is capable of bearing the weight of the apparatus while supplying a source of electrical power to at least one downhole motor which operates at least one hydraulic pump. The hydraulic pump operates a slip assembly to fix the downhole apparatus within the wellbore prior to operation of the cutting tool. Thereafter, the pump operates a downhole motor to rotate the cutting tool while the cutters are actuated.

Abstract: A well abandonment process for cutting and retrieving an offshore well casing, the process comprising: making a trip to the well wherein all of the following steps are performed, the steps comprising: pulling a seal assembly from the wellhead, cutting the casing, griping the casing, and retrieving the seal assembly and cut casing.

Abstract: A one-trip through tubing window milling system is disclosed. The whipstock is delivered with the mill and downhole motor in a downhole assembly which further includes MWD equipment for proper whipstock orientation. The entire assembly is run through tubing and the MWD equipment orients the whipstock. A motor lock prevents the downhole motor from turning as fluid pressure is applied to properly anchor the whipstock below the production tubing. The motor lock is defeated and the milling commenced using the downhole motor. At the conclusion of the window milling, the bottom hole assembly, including the mill, is removed and a retrieving tool releases the whipstock for retrieval through the production tubing.

Abstract: A structure is positioned on the outer surface of a casing or liner to enable cutting the casing in substantially any azimuth over a given length of casing without damaging the structure. After placing the casing in a wellbore, the position of the structure on the casing may be determined with reference to an orienting slot in an indexing coupling. Thereafter, a non-colliding region on the casing may be identified for cutting the casing.

Abstract: Method and apparatus are presented for perforating a subterranean formation so as to establish fluid communication between the formation and a wellbore, the wellbore having casing cemented therein, the casing having a cement sheath therearound. The casing is perforated with a mechanical perforator and thereafter a propellant material is ignited within the casing thereby perforating the cement sheath. The formation may thereafter be stimulated with an acid stimulator. The mechanical perforator may include use of a toothed wheel, or a needle-punch perforator. The propellant may be deployed in a sleeve and may comprise an abrasive material.

Abstract: A tool string for use in a well includes a filter sub (or trapped pressure regulator sub) that is used with other components to reduce trapped pressure. The filter sub filters out debris that may occur from various types of downhole operations, such as perforating operations. By filtering out larger debris, only gases, liquids, and smaller particles are allowed to enter various components of the tool string. Without the presence of larger solid debris inside certain components of the tool string, the likelihood of plugs being formed is reduced so that gases and liquids can more readily pass out of the tool string as the tool string is retrieved to the surface of the well and the well hydrostatic pressure decreases.

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurized-fluid operable actuator mechanism 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-side engagement positions. The guide device 14 includes pressurized fluid supply mechanism 28, 18 formed and arranged for controlling the supply of pressurized fluid to the actuator mechanism 24, for operation thereof.

Abstract: A method and apparatus for horizontally drilling in wells utilizing a shoe assembly at the down hole end of upset tubing. The shoe assembly includes a fixed section and a rotatable section suspended below the fixed section. An electric motor and associated batteries and a gyroscope carried on the rotatable section enable an operator on the surface to selectively rotate and position the rotatable section to any desired angular location for drilling a hole in the well casing. After one or more holes have been cut in the casing, a drill assembly can be removed from the upset tubing and be replaced by a high pressure blaster nozzle to bore into the formation zones. The gyroscope enables the operator to accurately position the rotatable section to the same locations at which the holes have been cut. The drill assembly includes an electric motor with an associated battery, flexible drive shaft, and a hole saw.

Abstract: Methods and apparatus are described for forming a window of optimum dimensions in casing wall. A window of maximum width is cut when the center line of the mill tool is located inside of the inner diameter of the casing where a maximum amount of casing is drilled away by the mill tool. A whipstock is described which deviates the mill tool outwardly so that the center line of the mill tool is in approximately this position. The whipstock then maintains the mill tool at this approximate location until a window of desired length is cut having a substantially maximum width. The whipstock then deviates the mill tool such that the centerline is outside of the casing to drill a rathole into the formation.

Abstract: A pipe bursting system of the invention operates by compaction rather than by reaming. The system includes a conventional directional boring machine, a drill string, and a pipe burster attached to the terminal end of the drill string. A pipe burster according to the invention includes a frame having a front connecting portion configured for connection to a drill string that can pull and rotate the frame about an axis of rotation, at least two axles mounted on the frame, and rollers mounted on each axle. Each roller has a curved outer surface forwardly inclined towards the axis of rotation of the frame, whereby rotation of the frame about its axis of rotation results in rotation of the rollers when the curved outer surfaces of the rollers engage a cylindrical inner surface of a pipe being burst.

Abstract: A fluid cutting tool and method for perforating or severing tubular members from inside. The tool is especially suited for use with a rotational drive system, such as a downhole motor, to separate downhole structures, such as stuck production tubing. The cutting tool preferably takes the form of an elongate metal body with an open first end connectable to the end of a downhole motor. The downhole end of the tool may be conical. A fluid conduit within the body of the tool communicates with the fluid channel in the downhole motor. Ports in the sides of the tool body direct jets of cutting fluid out the side of the tool. The tool attached to the motor is fed downhole until the tool is at the desired location in the well. Then the motor is operated to rotate the tool while cutting fluid is pumped through it. This causes the jets of fluid to be directed at the inner surface of the production tubing (or other tubular structure). This process is continued until the tubing is perforated or severed, as needed.

Abstract: A method and apparatus for milling a window in a downhole structure, such as a casing or a liner, includes a mandrel that supports milling elements arranged in a predetermined pattern. In one example, the milling elements are arranged in one or more continuous channels each having a generally helical pattern. The milling elements are able to cut the window in the downhole structure substantially continuously to the desired size.

Abstract: A method of cutting a well casing located beneath a subsea wellhead wherein a cutting assembly is made and lowered into an operative position. A mounting device is secured to the wellhead and the cutter is radially expanded into engagement with the casing. The motor is operated so as to rotate the tubing string and thereby rotate the cutter to cut the casing. A cutting assembly is used to cut a well casing. The cutting assembly has a motor mounting device, a motor, an output shaft, a radially expandable cutter and a tubing string. The tubing string connects the cutter to the output shaft of the motor and clamp members secure the mounting device to the wellhead so that the rotary reaction forces from the mounting device are transmitted to the wellhead. Axial reaction forces are also transmitted from the mounting device to a radially extending surface of the wellhead.

Abstract: A coalbed methane borehole pipe liner perforation system comprises a plastic pipe punch that slips down inside a coalbed methane production borehole lined with a non-perforated plastic pipe. A ground-penetrating radar is used inside the plastic-pipe lined borehole to determine which sections of the pipe are in contact with groundwater. The punch is then operated along the length of the plastic-pipe lined borehole to perforate it for methane-gas collection wherever such groundwater is not present. A radar survey to determine groundwater contact can be made simultaneously in combination with the punching of liner pipe perforations, or earlier in a separate operation.

Abstract: The apparatus is used for cutting an opening through the wall of a conduit located in a borehole traversing the subsurface formations. The apparatus includes a body adapted to be lowered into the conduit to a desired level. The body is formed by a cylindrical wall defining an elongated chamber having a combustible charge receiving portion and an ignition means portion located close to the combustible charge receiving portion. A plurality of spaced apart apertures are formed through the wall defining a given pattern which may be at least one elongated row of apertures generally parallel with the axis of the cylindrical wall or a line which encloses a given configuration on one side of the axis.

Abstract: Method and apparatus are presented for perforating a subterranean formation so as to establish fluid communication between the formation and a wellbore, the wellbore having casing cemented therein, the casing having a cement sheath therearound. The casing is perforated with a mechanical perforator and thereafter a propellant material is ignited within the casing thereby perforating the cement sheath. The formation may thereafter be stimulated with an acid stimulator. The mechanical perforator may include use of a toothed wheel, or a needle-punch perforator. The propellant may be deployed in a sleeve and may comprise an abrasive material.

Abstract: Wellbore apparatus has been invented which, in at least certain aspects, includes a wellbore apparatus having a tubular member with a top end, a bottom end, a hollow portion, and a window therethrough, a sleeve positioned within the hollow portion of the tubular member, the sleeve having a top end and a bottom end, a diverter apparatus within or outside the tubular member amd, optionally, below the bottom end of the sleeve, the sleeve movable so that the diverter, and the diverter directs the sleeve to the window and through the window into a bore extending beyond the window, and the window having an edge therearound to which the top end of the sleeve is weldable to sealingly secure the sleeve at the window.

Abstract: The present invention provides a method and apparatus for plugging a wellbore in a trip saving manner. In one aspect, the invention includes a cement retainer disposed on a run-in string and a radially expanded perforating assembly disposed below the cement retainer. In a single run, the apparatus provides for perforating a wellbore and squeezing cement through the perforations and into the formation therearound. In another aspect, a method of plugging the wellbore includes running a cement retainer and a radially expanded perforating assembly into a wellbore on a run-in string. After the cement retainer is set, a firing head is actuated to cause the perforating gun to discharge. After perforations are formed, cement is introduced from the cement retainer into the isolated area and squeezed through the perforations. Thereafter, the run-in string disengages from the cement retainer leaving behind the plug formed.

Abstract: In completing a well bore in a underground formation, the well bore being closed off by a closing structure for blocking flow of pressurized fluid through the well bore, a substantially tubular element having a tube wall surrounding an axial bore is passed through the closing structure. The tube wall having passed the closing structure is processed along at least a portion of its axial dimension from a first condition into a second, processed condition. In the first condition, the tube wall is substantially impermeable in radial direction to pressurized fluid for precluding a flow of pressurized fluid from passing the penetrated closing structure. In the second condition the tube wall is radially permeable to pressurized fluid along at least a processed portion of its axial dimension. A tubular element to be used in such an application is described as well.

Abstract: The present invention discloses apparatus and methods for replacing a BOP with a gate valve to thereby save space, initial costs, and maintenance costs that is especially beneficial for use in offshore subsea riser packages. The method provides a gate valve capable of reliably cutting tubing utilizing a cutting edge with an inclined surface that wedges the cut portion of the tubing out of the gave valve body. A method and apparatus is provided for determining the actuator force needed to cut the particular size tubing.

Abstract: The present invention provides an apparatus and method for severing casing as it is pulled from a wellbore. An apparatus is first provided, comprising a clamping assembly, a drilling assembly and a cutting assembly. In one aspect, the apparatus is disposed at the end of a telescopic arm, with the components being remotely operated by personnel using a control panel. The apparatus can be positioned adjacent casing and clamped thereto. Thereafter, the apparatus can drill a hole completely through the casing for the insertion of a retention pin. The apparatus can then severe the casing into manageable lengths to facilitate disposal, such as during a plugging and abandonment procedure.

Abstract: A downhole system includes a deflector with a reaction surface that is engageable to a mill. The deflector is coupled to a motion mechanism that is activable to move the deflector generally along a longitudinal direction. During operation, the mill is engaged to a surrounding downhole structure, and the mill is rotated. As the mill cuts an opening in the downhole structure, the motion mechanism moves the deflector, which allows the mill to move with the deflector. A smooth motion is provided by the motion mechanism to enable a more accurate cutting of the downhole structure (e.g., casing or liner).

Abstract: A pipe bursting system of the invention operates by compaction rather than by reaming. The system includes a conventional directional boring machine, a drill string, and a pipe burster attached to the terminal end of the drill string. A pipe burster according to the invention includes a frame having a front connecting portion configured for connection to a drill string that can pull and rotate the frame about an axis of rotation, at least two axles mounted on the frame, and rollers mounted on each axle. Each roller has a curved outer surface forwardly inclined towards the axis of rotation of the frame, whereby rotation of the frame about its axis of rotation results in rotation of the rollers when the curved outer surfaces of the rollers engage a cylindrical inner surface of a pipe being burst.

Abstract: A method and apparatus for predictable downhole milling of a casing window having predetermined location, orientation, dimension and contour geometry. An elongate substantially rigid milling shaft has at least one casing window milling element in fixed relation therewith and has a pilot mill in articulated and rotary driven connection with the milling shaft. The milling shaft is in articulated and rotary driven connection with a rotary drive mechanism. The articulated connection of the pilot mill and milling shaft may incorporate an articulation control system to permit the pilot mill to be maintained substantially coaxial with the milling shaft so that its trajectory at a predetermined stage of window milling can be controlled by the milling shaft when positive guiding by a deflecting tool can no longer be ensured.

Abstract: The present invention discloses and claims a system for forming an opening, or window, in a downhole tubular for the subsequent formation of a lateral wellbore. In the system of the present invention, an apparatus is run into the parent wellbore which includes at least a tubular having a drill bit, a diverter such as a whipstock releasably connected to the drill bit, an anchoring device such as a packer, and a milling device. This apparatus allows for the milling of a window in the parent wellbore, and the drilling of a lateral wellbore through that window, in a single trip.

Abstract: The invention relates to a method for the formation of a plug (1) in a petroleum well (2) extending from the earth's surface or the sea floor to a petroleum reservoir, which well is lined with casing (3, 3′). At least one opening (4) is formed in the casing (3) at a distance from the earth's surface, and a liquid curable resin is provided in at least a portion of the opening (4) and an adjacent area of the well (2), whereby the resin after curing forms a plug (1) in the well. The invention also relates to a tool (9) for milling an opening (4) in a casing (3) of a petroleum well (2), and a plug (1) for plugging casing (3) of a petroleum well (2).

Abstract: The present invention generally provides an apparatus and method for forming a pilot hole in a formation. In one aspect of the present invention, the apparatus may comprise a starter mill connected to a bearing mill by a body joint. The apparatus may further comprise a lead bearing connected to a starter mill by a lead joint. Preferably, an outer diameter of the bearing mill is about the same as an inner diameter of a wellbore. As the lead bearing travels along the concave, the apparatus will bend between the bearing mill and the lead bearing. The bend urges the starter mill into contact with the wellbore wall. In another aspect of the present invention, a method for forming a pilot hole in a wellbore includes running a tool into the wellbore, the tool comprising a starter mill disposed between a first bearing and a second bearing. While running the tool along a concave of a whipstock, the tool bends between the first and second bearing and urges the starter mill to form the pilot hole.

Abstract: A method and apparatus for milling a section of casing in an upward direction, utilizing a downhole hydraulic thrusting mechanism for pulling a section mill upwardly. A downhole motor and torque anchor can be used to rotate the section mill, or the mill can be rotated by a work string. A stabilizer above the section mill can be used to stabilize the mill relative to the casing being milled. A spiral auger below the section mill can be used to move the cuttings downwardly.

Abstract: A packer and method for sealing an annulus in a wellbore is provided. In one aspect the packer comprises a body having one or more conduits formed there-through; a chamber disposed within the body, wherein the chamber is in fluid communication with each of the one or more conduits; and an aperture for pressurizing the chamber. In another aspect, the packer comprises a body having one or more conduits formed there-through; a lock body disposed on a first end of the body; a collapsible member threadably engaged to the body at a first end and shouldered against the lock body at a second end; and a slideable member disposed within the collapsible member. In yet another aspect, the packer comprises a body having one or more conduits formed there-through, wherein the one or more conduits comprises an enlarged first end; and a cutting member disposed with the enlarged first end.

Abstract: A downhole tool (10) comprises a body (12) defining a fluid chamber (14), a fluid outlet (16) for directing fluid outwardly of the chamber (14), and an arrangement for producing a rapid reduction in the volume of the chamber, such that fluid in the chamber is displaced rapidly through the outlet. The fluid may be utilised to deform or perforate a surrounding tubular (46).

Abstract: A communication tool (100) for communicating hydraulic fluid through a tubing retrievable safety valve (50) is disclosed. The tool (100) has a first section (102) and a second section (132) that are initially coupled together. A set of axial locating keys (112) is operably attached to the first section (102) and is engagably positionable within a profile (62). A radial cutting device (148) is radially extendable through a window (152) of the second section (132). A circumferential locating key (140) is operably attached to the second section (132) and is engagably positionable within a pocket (66) of the safety valve (50) when the first and second sections (102, 132) are decoupled, thereby circumferentially aligning the radial cutting device (148) with the non annular hydraulic chamber (60).

Abstract: A method and apparatus for severing the mandrel of an anchor device such as a packer to release the packer and remove it from a well. A cutter locator profile above the packer assembly and a cutter locator element on the cutting tool are located so as to precisely position the cutting element at a desired location on the packer mandrel. Once the mandrel is severed, the packer assembly can elongate to release the expansion mechanism. Then, the packer assembly can be pulled upwardly to release the packer, and to remove it from the well. A cutting tool can be lowered through production tubing to sever the mandrel, followed by pulling the packer with the production tubing. Alternatively, a cutting tool can be lowered on a workstring and latched to the upper end of the packer assembly, followed by severing the mandrel and pulling the packer with the workstring.

Abstract: A system and method for setting an anchor and/or whipstock attached to a downhole motor having a cutting tool attached to a tubular member, such as coiled tubing. In one aspect, the motor allows flow therethrough sufficient to actuate an upstream MWD or other position measuring tool, and an orienter if so equipped, and retain the orientation of the motor with the attached whipstock. An increased flow rate or pressure actuates the motor once the whipstock is set and rotation of the cutting tool or other equipment can begin.

Abstract: A method and apparatus for initiating an azimuth controlled vertical hydraulic fracture in unconsolidated and weakly cemented soils and sediments using active resistivity to monitor and control the fracture initiation and propagation. Separate or overlapping treatment walls and containment barriers can be created by controlling and monitoring the propagation of fractures in the subsurface. A fracture fluid is injected into a well bore to initiate and propagate a vertical azimuth controlled fracture. The fracture fluid is energized to conduct electrical current while the fracture propagates through the ground. A series of electrical resistivity monitors measure the electrical conductivity of the fracture fluid in real time against the background conductivity of the formation.

Abstract: A method of machining a workpiece in a subterranean wellbore comprises the steps of: (a) providing a workpiece that comprises (1) a first section that comprises a first material, and (2) a second section that comprises a second material, the second section forming at least one surface of the workpiece; (b) placing the workpiece in a subterranean wellbore that is surrounded by a geologic formation; and (c) machining the workpiece to remove at least part of the second material in the second section, whereby at least one surface of the workpiece is formed into a desired configuration. This method allows, for example, a landing nipple to be installed in a wellbore, and customized locking recesses to be formed in the inner surface of the nipple at a later time.

Abstract: Apparatus for boring a hole from an inside of a tube outwardly perpendicular to a longitudinal axis of the tube comprises a drill shoe having a longitudinal axis and being positionable in the tube, the shoe having an inlet, an outlet perpendicular to the shoe longitudinal axis and a passageway connecting the inlet and outlet, a torsional load transmitting element having no torsional flexibility in relation to its bending flexibility, having a longitudinal axis and being disposed in the passageway, the torsional load transmitting element being movable relative to itself with no resistance about first and second perpendicular axes both of which are perpendicular to the longitudinal axis of the torsional load transmitting element, a hole saw connected to one end of the torsional load transmitting element and a motor rotatably connected to the other end of the torsional load transmitting element.

Abstract: The invention discloses methods of, as well as apparatus and systems for, perforating and treating multiple intervals of one or more subterranean formations intersected by a wellbore by deploying a bottom-hole assembly (“BHA”) having a perforating device and a sealing mechanism within said wellbore. In one embodiment, the perforating device has no washing fluid flow passage provided therethrough. In another embodiment, an erosive jet device is used to perforate at least one interval of said one or more subterranean formations. In yet another embodiment, the BHA has at least one pressure equalization means that establishes pressure communication between the portions of the wellbore above and below the sealing mechanism. In another embodiment, the BHA comprises a perforating device and a sealing mechanism, wherein the perforating device is positioned below the sealing mechanism.

Abstract: A method and apparatus for determining whether a tubing conveyed perforating (TCP) gun has fired by detecting a change in characteristics of the flow of an oil well. A method and apparatus detects the presence of fluorescent tracer dye to determine whether or not a TCP gun has fired. The method and apparatus detects a change is capacitance, or fiber optic electrical properties to determine whether or not a TCP gun has fired. The method and apparatus detects the number of charges fired to determine whether or not all TCP guns have fired and also provides a method and apparatus for determining the contributions of injection wells to producing wells by introducing fluorescent tracers into injection wells and detecting the presence of the fluorescent tracers at production wells. A method and apparatus is provided for placing fluorescent dye particles in a gravel pack to sense when a gravel pack is deteriorating by detecting the tracer dye particles in the well flow.

Abstract: For an apparatus and method to shut down pipelines, an apparatus frame is supported by the pipe to be shut down, and includes a pointed drill and a drill cylinder to drill a hole, essentially similar in diameter size with the plug cylinder or, when in the same temperature, essentially smaller in diameter size than the plug cylinder, through the pipe to be shut down. The apparatus includes a plug cylinder and equipment for installing the plug cylinder in the drill hole. There is a channel inside the drill cylinder and/or plug cylinder and/or shaft to feed a coolant, a flowing substance, preferably hydrogen, carbonic acid, or other such substance, cooling and at the same time reducing the size of the plug cylinder until it is inserted in the drilled hole. After the plug cylinder has been inserted, the flow of the coolant stops. As a result, the temperature of the plug cylinder increases, and the size of the plug cylinder increases as well.

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurized-fluid operable actuator means 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-side engagement positions. The guide device 14 includes pressurized fluid supply means 28, 18 formed and arranged for controlling the supply of pressurized fluid to the actuator means 28, 18 for operation thereof.

Abstract: A safety valve of the type where two valve elements (4) in a bore (3) can be moved towards each other for closing a flow path (2). Each valve element comprises two parts (10,20), each of which is connected to an actuator (5,6), thus enabling them to be moved independently of each other.

Abstract: A tool containing a solid combustible material is used to provide a pipe-cutting flame and to direct a pipe-cutting flame against a casing or tubular. The nozzles can be configured in any desired array and intensity. In the preferred embodiment, a rectangular window is burned away completely if the nozzles are sufficiently intense or the window is formed in segments if other distributions are used. The device can be anchored by a packer or anchor and can be run in the wellbore on tubing, wireline or electric line. The window can be produced in a single trip. The tool can be removed and a kick-off diverter installed adjacent the window for milling the lateral.

Abstract: The side tracking system includes a window mill having a full diameter cutting surface and a reduced diameter tapered cutting surface and a whipstock having a ramp engaging the reduced diameter cutting surface. The materials of the whipstock have a first cutablity and the materials of the casing have a second cutability. The reduced diameter cutting surface contacts the whipstock ramp at a first contact area and the full diameter cutting surface contacts the wall of the casing at a second contact area. As weight is applied to the mill, there is a first contact stress at the first contact area and a second contact stress at the second contact area. A cutability ratio is the first cutability divided by the second cutability and a contact stress ratio is the first contact stress divided by the second contact stress. The mill cuts the casing rather than the whipstock by maintaining the product of the cutability ratio and the contact stress ratio less than one.

Abstract: A process and apparatus for completing a subterranean well bore in at least one subterranean formation. At least one perforating gun assembly is positioned on the outside of casing in a subterranean well bore. A suitable signal, such as a hydraulic, electric or wave signal, is transported to the perforating gun assembly so as to detonate one or more explosive charges in the perforating gun assembly which are aimed toward the casing. At least one wall in the casing is perforated thereby establishing fluid communication through the wall of the casing. Usually, cement surrounding the casing and a subterranean formation surrounding the casing are also perforated to establish fluid communication between the formation and the interior of the casing.

Abstract: The present invention generally provides a system and method for stiffening a cutting tool assembly used in cutting laterally relative to a wellbore axis to reduce stresses and cyclical bending of the cutting tool assembly during cutting. The system includes a cutting tool attached to a shaft such as an output shaft of a motor or a drill string. A sleeve is disposed in an annular space, known as a box relief, defined between the shaft and a peripheral wall of the cutting tool. The sleeve is preferably fixed in the annular space by a sleeve ring surrounding a recess in the shaft, but can be coupled to the peripheral wall and/or shaft by, for example, a threaded engagement.

Abstract: A one-trip system for removing casing from a wellhead is described. The string includes a cutting device spaced at the required depth and a grappling device above it at the appropriate location. A swivel tool, such as a marine swivel, is used in conjunction with a seal-pulling assembly so that after cutting the casing, the seal assembly can be pulled without an additional trip into the well. The grappling device or spear can be hydraulically actuated to grab the casing for removal from the wellbore. The spear features a drop-in restrictor which allows sufficient flow during cutting operations with a mechanical cutter without actuating the spear, while at the same time allowing actuation of the spear by circulation after dropping in the restrictor after the casing section has been cut.

Abstract: Apparatus and method for drilling into strata adjacent to a well casing through an existing hole in a side of the well casing at a desired elevation therein, including a flexible tube for passage through the hole having a first end, an opposite second end, and an internal cavity extending therethrough between the first end and the second end, a nozzle for passage through the hole on the first end of the flexible tube, the nozzle having at least one aperture therethrough in communication with the internal cavity of the flexible tube, and structure suspendable in the well casing and connected to the second end of the flexible tube for supporting the flexible tube and the nozzle in the well casing at the desired elevation for passage through the hole, the structure including an element for rotating the flexible tube and the nozzle when extending through the hole relative to the structure, and the structure including an internal passage connected in communication with the internal cavity of the flexible tube and

Abstract: Apparatus for boring a hole from an inside of a casing outwardly at an angle relative to a longitudinal axis of the casing comprises a drill shoe having a longitudinal axis and being positionable in the casing, the shoe having first and second passageways which converge into a third passageway exiting the shoe, a torsional load transmitting element and a cutting element connecting to one end of the torsional load transmitting element, the torsional load transmitting element and cutting element being positioned in the first passageway during non-use and in the third passageway during use, and a fluid conduit and a nozzle connected to one end of the fluid conduit, the fluid conduit and nozzle being positioned in the second passageway during non-use and in the third passageway during use.

Abstract: A method and apparatus for improving reservoir communication includes, in one arrangement, use of one or more chambers to create an underbalance condition and/or a fluid surge in the wellbore. In another arrangement, a tool string comprises a packer, a circulating valve, and an atmospheric chamber, in which the circulating valve, when open, is adapted to vent a lower wellbore region below the packer when the packer is set, and the atmospheric chamber is capable of being operated to create an underbalance condition below the packer. In yet another arrangement, an apparatus comprises a subsea wellhead equipment including a blow-out preventer, choke line filled with a low density fluid, and a kill line filled with a heavy fluid. The choke line is adapted to be opened to create an underbalance condition in the wellbore.