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: An expanding wellbore junction system, apparatus and methods are provided for forming a sealed wellbore intersection in a subterranean well. In one. described method, an expandable wellbore junction is expanded within an under-reamed cavity in a wellbore. Intersecting tubular legs of the wellbore junction are then drifted using a drifting apparatus. A deflection device may be used to direct a drift of the drifting apparatus into a selected one of the wellbore junction legs.

Abstract: A system for forming a patch in a well at a location along a tubular string which has lost sealing integrity includes a central patch body 60, an upper expander body 52 carrying an upper seal 50 or 56, and a lower expander body 98 carrying a lower seal 102, 104. The running tool includes an inner mandrel 14 axially moveable relative to the central patch body, and one or more pistons 20, 30, 20A axially moveable relative to the inner mandrel in response to fluid pressure within the running tool. Top expander 48 is axially moveable downward relative to the upper expander body in response to movement of the one or more pistons, and a bottom expander 120 is axially moveable upward relative to a lower expander body. After the upper expander body and a lower expander body have been moved radially outward into sealing engagement with a downhole tubular string, the running tool is retrieved to the surface.

Abstract: The present invention concerns a cement slurry with high permeability and good compressive strength, comprising a solid fraction constituted by: 35% to 80% (by volume) of particles with a mean size in the range 100 microns (&mgr;) to 800 &mgr;; 0% to 15% (by volume) of particles with a mean particle diameter in the range 0.1 microns to 10 microns; and 10% to 40% (by volume) of particles with a mean particle diameter in the range 20 &mgr; to 50 &mgr;; a fraction of said-solid particles being constituted by a cement, and preferably a further fraction by self-destructive particles; a liquid fraction in a water/solid ratio in the range 38% to 50% by volume; and a percentage of cells, provided by a gas or a liquid which is not miscible with water, in the range 30% to 60% of the final volume of the slurry.

Abstract: The present invention includes a method and apparatus for setting a liner in a wellbore and then expanding a screen in the wellbore in a single trip. In one aspect of the invention, a liner and expandable screen is provided with a slip assembly to fix the liner in the wellbore. An expansion tool and work sting is run into the wellbore in the liner. After the liner is set, the expansion tool is used to expand the screen. In another embodiment, an annular area between the expansion tool and work string is utilized in order to set the slips. Thereafter, cup packers used in forming the annulus are lifted from the liner prior to expanding the screen.

Abstract: A method of isolating a section of downhole tubing comprises: running a length of expandable tubing (20) into a tubing-lined borehole (12, 14) and positioning the expandable tubing (20) across a section of tubing to be isolated; deforming at least portions of the expandable tubing (36, 40) to increase the diameter of the portions to sealingly engage the tubing (14) and to isolate the tubing section.

Abstract: A method and apparatus is provided for drilling and lining a wellbore in one downhole trip. The method comprises mounting a drill bit on a drill string including a section of expandable tubing and providing a tubing expander in the string, then rotating the drill bit and advancing the drill string through a bore, then passing the expander through the expandable tubing to expand the tubing, wherein the expandable tubing is deformed by compressive plastic deformation of the tubing with a localised reduction in wall thickness, resulting in a subsequent increase in tubing diameter, and then retrieving the drill bit from the bore through the expanded tubing.

Abstract: A method of removing lining from a tubing in a well includes: reaming at least a portion of the lining material; cutting at least a segment of the lining along a spiral path; engaging the lining for applying a pulling force to the lining; and applying a pulling force to lift the engaged lining out of the tubing. Individual aspects of this also form parts of the present invention, such as a lining reamer, a method of excavating material of a lining in tubing in a well, a spiral-cut cutting tool, a method of spiral cutting lining in a tubing in a well, various inner engagement members to navigate through a bent lining segment in a lining in tubing in a well, a lining removal tool in which the components are rotationally fixed so that all rotate together, a lining removal tool in which an inner engagement member (such as a flat cutting blade or a plurality of resilient but stiff wires) is connected to an inner surface of the outer engagement member, and lining removal methods.

Abstract: A method to deliver an expandable casing string to an uncased borehole coaxially upon a composite coiled tubing drilling string is presented. Once the drilling operation is completed, the casing string is expanded by supplying pressure between the coaxially positioned strings to expand the casing string to the borehole. Preferably, the outer diameter of the casing string contains an adhesive agent designed to be activated by the expansion of the casing string against the borehole wall. Alternatively, the mechanical structure of the casing string itself may be configured to prevent the casing string from collapsing once it has been expanded. Once expanded, the casing string is left behind to isolate the well formation from drilling and production fluids that may subsequently flow therethrough.

Abstract: A system for forming a patch in a well at a location along a tubular string which has lost sealing integrity includes a central patch body 60, an upper expander body 52 carrying an upper seal 50 or 56, and a lower expander body 98 carrying a lower seal 102, 104. The running tool includes an inner mandrel 14 axially moveable relative to the central patch body, and one or more pistons 20, 30, 20A axially moveable relative to the inner mandrel in response to fluid pressure within the running tool. Top expander 48 is axially moveable downward relative to the upper expander body in response to movement of the one or more pistons. In one embodiment, a bottom expander sleeve 210 is axially moveable upward relative to a lower expander body, and a top expander sleeve 230 is axially moved downward relative to an upper expander body. The expander sleeves may remain downhole to radially support the downhole tubular.

Abstract: A technique for facilitating the use of a variety of completion elements in a wellbore environment. The technique utilizes an insertion guide disposed within an open-hole section of a wellbore. The insertion guide may be radially expanded towards the surrounding formation to remove excess annular space. The expansion of the insertion guide further allows the use of a completion element having a greater diameter than would otherwise be afforded.

Abstract: A method and apparatus is provided for drilling and lining a wellbore in one downhole trip. The method comprises mounting a drill bit on a drill string including a section of expandable tubing and providing a tubing expander in the string, then rotating the drill bit and advancing the drill string through a bore, then passing the expander through the expandable tubing to expand the tubing, wherein the expandable tubing is deformed by compressive plastic deformation of the tubing with a localised reduction in wall thickness, resulting in a subsequent increase in tubing diameter, and then retrieving the drill bit from the bore through the expanded tubing.

Abstract: An apparatus and method of creating a seal between two coaxial tubulars so as to create a hanger and a packer. A first tubular is disposed coaxially within a portion of a second, larger tubular. A portion of the first tubular is expanded into frictional contact with the second tubular, thereby creating a liner and a hanger. In one embodiment, a pattern of grooves and profile cuts are formed in the surface of a portion of the first tubular body. The grooves in one aspect define a continuous pattern about the circumference of the tubular body which intersect to form a plurality of substantially identical shapes, such as diamonds. The grooves and profile cuts serve to improve the tensile strength of the tubular body. At the same time, the grooves and profile cuts allow for expansion of the tubular body by use of less radial force.

Abstract: A method and apparatus for creating a seal between two coaxial strings of pipe are provided. The method and apparatus have utility in one embodiment for sealing the annulus between the tubing and the casing within a hydrocarbon wellbore. According to the method of the present invention, an expander tool is positioned at a selected depth within the tubing, and then actuated in order to expand the tubing against the inner wall of the casing wall. Multiple configurations of the expander tool are disclosed. The expander tool is rotated in order to provide a fluid seal in the annulus. In this way, the tubing string becomes its own packer. In one embodiment, a seal ring is provided around the outer surface of the tubing to enhance the fluid seal. Further, a slip ring is provided around the outer surface of the tubing to provide a gripping means between the tubing and the casing.

Abstract: A method of isolating a section of downhole tubing comprises: running a length of expandable tubing (20) into a tubing-lined borehole (12, 14) and positioning the expandable tubing (20) across a section of tubing to be isolated; deforming at least portions of the expandable tubing (36, 40) to increase the diameter of the portions to sealingly engage the tubing (14) and to isolate the tubing section.

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: Methods and apparatus for forming metal or metal alloy casings in well bores are provided. A method of the invention comprises the steps of providing and pumping a fluid suspension of a particulate metal or metal alloy into a pipe string within a well bore having a casing forming tool connected thereto. The casing forming tool includes an internal passageway sealingly communicated with the pipe string and with a plurality of radial openings in the tool positioned around the periphery thereof. An internal heater for heating the fluid suspension and melting the particulate metal or metal alloy and an internal rotating impeller for imparting centrifugal force to the fluid suspension are provided in the casing forming tool. Centrifugal force is imparted to the fluid suspension by the rotating impeller whereby the melted particulate metal or metal alloy forms a casing which solidifies on the walls of the well bore.

Abstract: A scrolled resilient sheet is installed against the inner surface of a fluid conduit using a carrier tool from which a resilient sheet having an average thickness more than 2 mm and an elastic or pseudoelastic recoverable strain of at least 0.6% is released so that the sheet expands with an expansion force which is sufficiently high to allow the sheet to press itself into place alongside the inner surface of the conduit and to remain in place after installation.

Abstract: A method of providing a downhole seal, such as a packer, in a drilled bore between inner tubing and outer tubing comprises: providing an intermediate tubing section defining a seal arrangement for engaging with the inner tubing; and radially plastically deforming the intermediate tubing section downhole to form an annular extension. The extension creates a sealing contact with the outer tubing.

Abstract: A tubing coupling method is provided. In one aspect, the method comprises providing a length of expandable tubing and a length of larger diameter non-expanding tubing, connecting an end portion of the expandable tubing to an end portion of the non-expanding tubing, running the tubing into a bore, and expanding the expandable tubing. The expandable tubing may form part of an expandable well or sand screen, or may be an expandable bore liner.

Abstract: A downhole apparatus and method for depositing metal at a desired area in a well casing. In one embodiment the apparatus comprises an oxygen tank filled with oxygen, a fuel tank filled with fuel, and a metal depositing device. An inert gas, such as nitrogen, may be supplied to dampen the heat generated by the metal depositing device. In an alternate embodiment, the apparatus comprises a gas tank with nitrous oxide therein and a sparking device to initiate a decomposition reaction to separate the nitrous oxide into its oxygen and nitrogen components. The metal depositing device may be adapted for flame spraying, plasma spraying or welding. A steering head is provided to reciprocate and rotate the apparatus so that the metal depositing device may be directed to the desired area in the casing. A camera and light are disposed at the bottom of the apparatus so that the interior of a well casing is illuminated and an image is transmitted to the operator for proper actuation of the steering sub.

Abstract: The present invention relates to methods and apparatus for expanding tubulars in a wellbore. In one aspect of the invention, an expansion tool with hydraulically actuated, radially expandable members is disposed on a string of coil tubing. In another aspect of the invention the apparatus is utilized to expand a tubular lining a lateral wellbore into contact with a window of a larger tubular lining a central wellbore.

Abstract: An improved expansion assembly for an expander tool is provided. The expander tool is used to expand a surrounding tubular body within a wellbore. The expansion assembly first comprises a piston disposed within a recess of the expander tool. The top surface of the piston defines a bearing cavity configured to closely receive a roller. A shoe is further disposed on the top surface of the piston to receive a lower portion of the roller. In one arrangement, the roller is a tapered cylindrical roller actuated by hydraulic pressure applied from within the bore of the expander tool. Actuation of the tool forces the pistons to radially extend away from the body of the tool within the recesses. This, in turn, causes the roller members to engage the inner surface of the surrounding tubular body to be expanded. Rotation of the expander tool causes the rollers to at least partially rotate within the bearing cavity.

Abstract: A molten metal plug which expands upon solidification can be used to form a pressure resistant seal in a tubular such as is used in oil and gas exploration and production.

Abstract: A method and apparatus to provide a large bore hook hanger system incorporating sand exclusion at a junction in a multilateral wellbore includes the running of a lateral liner having an expandable sleeve positioned thereon to bridge a milled window from the lateral borehole to the primary borehole, expandable sleeve including a pre-machined window and a hook to hang the liner from the primary borehole. The hook further acts to center the pre-machined window in the expandable sleeve to provide access to the primary wellbore. The expandable sleeve is preferably covered on its outer surface with an elastomeric material and is outwardly concentric to an expandable packer for run-in. Once the expandable sleeve is positioned at the appropriate location in the junction, the expandable packer is inflated thus permanently deforming the expandable sleeve into contact with the open hole of the lateral borehole thereby preventing sand or gravel ingress to the primary borehole.

Abstract: A method of isolating a section of downhole tubing comprises: running a length of expandable tubing (20) into a tubing-lined borehole (12, 14) and positioning the expandable tubing (20) across a section of tubing to be isolated; deforming at least portions of the expandable tubing (32, 40) to increase the diameter of the portions to sealingly engage the tubing (14) and to isolate the tubing section.

Abstract: The present invention provides apparatus and methods for expanding tubulars in a wellbore. In one aspect, a process of sealing an annular area in a wellbore is provided in which a tubular having perforations at a predetermined location and a sleeve concentrically covering substantially all of the perforations is expanded into substantial contact with an inner diameter of a tubular, such as a casing or a liner. In another aspect, a process of sealing an annular area in a wellbore is provided in which a tubular having perforation at a predetermined location and a sleeve concentrically coving substantially all of the perforations is expanded into substantial contact with a junction between two tubulars, such as a liner and a casing, or between two liners.

Abstract: A downhole apparatus and method for depositing metal at a desired area in a well casing. In one embodiment the apparatus comprises an oxygen tank filled with oxygen, a fuel tank filled with fuel, and a metal depositing device. An inert gas, such as nitrogen, may be supplied to dampen the hear generated by the metal depositing device. In an alternate embodiment, the apparatus comprises a gas tank with nitrous oxide therein and a sparking device to initiate a decomposition reaction to separate the nitrous oxide into its oxygen and nitrogen components. The metal depositing device may be adapted for flame spraying, plasma spraying or welding. A steering head is provided to reciprocate and rotate the apparatus so that the metal depositing device may be directed to the desired area in the casing. A camera and light are disposed at the bottom of the apparatus so that the interior of a well casing is illuminated and an image is transmitted to the operator for proper actuation of the steering sub.

Abstract: Herein is described a method of consolidating a subterranean formation or repairing a gravel pack, comprising (i) providing a consolidating fluid, wherein the consolidating fluid comprises a gel component and a gel-forming agent; and (ii) injecting the consolidating fluid into the formation or gravel pack, under conditions wherein the gel component forms a flexible gel, thereby consolidating the formation.

Abstract: A swedge assembly is disclosed which has the capability of allowing for a sealing connection between an inner tubular and an outer tubular where the outer tubular has significant out of roundness. A resilient segment or segments is disposed on the swedge in contact with the inner tubular to be expanded so as to fill any voids created by out of roundness of the outer tubular. The resilient material may be an elastomer or any pliable metallic or any other material compatible with the applicable well bore conditions.

Abstract: A method of selective plastic expansion of sections of a tubing to create one or more recesses in the tubing with a larger diameter than that of the original tubing in which the tubing is radially symmetrically or asymmetrically expanded at one or more locations by application of a radial force to the interior of the tubing thereby inducing a plastic radial deformation of the tubing and removing said radial force from the interior of the tubing.

Abstract: An apparatus for connecting a main casing section to a lateral casing section using thermoset plastic molding. The apparatus is used to set a flexible sock made of a hardenable material at a location adjacent to an intersection between the main and lateral casing sections. The sock is inflated so that it conforms to the inner surfaces of the main and lateral casing sections. Heat is applied to the hardenable material so that the sock is cured in the inflated, operating position. Heat may be applied by releasing chemicals which provide an exothermic reaction and/or by using a heater positioned within the sock.

Abstract: Circulation flow apertures in a wellbore pipe, tubing, casing or casing liner screen may be selectively closed by an internal pipe sleeve that is formed of a thin, malleable material. One axial end of the sleeve is flared and secured to the inner bore surface of the pipe as by welding or by clamping between the ends of axially adjacent pipe joints joined by a threaded coupling. The remaining length of the sleeve extends along the pipe and over any pipe apertures to form an annular space between the outer cylinder surface of the sleeve and the inner bore surface of the pipe. A perimeter seal element such as an O-ring is placed around the sleeve outer perimeter beyond the apertures in a direction opposite from the sleeve flare. The flow aperture in the pipe is closed by a swaging tool that expands the sleeve against the pipe bore wall sufficiently to close the annulus and compress the O-ring seal against the pipe borewall.

Abstract: A method of providing a downhole seal, such as a packer (12), in a drilled bore between inner tubing (11) and outer tubing (16) comprises: providing an intermediate tubing section (18) defining a seal arrangement for engaging with the inner tubing; and radially plastically deforming the intermediate tubing section downhole to form an annular extension (40a, 40b). The extension creates a sealing contact with the outer tubing (16).

Abstract: A wellbore casing is formed simultaneously with the drilling out of the wellbore.

Abstract: A wellbore casing is formed simultaneously with the drilling out of the wellbore.

Abstract: An apparatus suitable for use in a wellbore comprises an expandable bistable device. An exemplary device has a plurality of bistable cells formed into a tubular shape. Each bistable cell comprises at least two elongated members that are connected to each other at their ends. The device is stable in a first configuration and a second configuration.

Abstract: A method of creating a weld to connect a first element to a second element, said elements being arranged in a wellbore containing a wellbore fluid, is provided. The method comprises selecting a welding path along which the weld is to be created, selecting a volume portion of the wellbore, in which selected volume portion said path is located and sealing said selected volume portion from the remainder of the wellbore volume, and providing pressure control means for controlling the fluid pressure in said selected volume portion. The pressure control means is then operated so as to reduce the fluid pressure in said selected volume portion to a selected pressure at which the weld can be created, and the weld is created along the selected welding path.

Abstract: An expandable tubing (12) for a well bore hole (14) in which selected length portions (24, 26, 28) are weakened by a slot configuration (FIGS. 2, 3, 4) to obtain predetermined expansion characteristics. The slot configurations are tailored or selected for a predetermined bore hole length and may be expanded to different radial diameters to conform generally to the peripheral contour of the bore hole. Tubing portions (29) between the slotted length potions (24, 26, 28) are unweakened.

Abstract: A flexible swage comprises a swage cup and a support receivable in a swage cup. The swage cup and support are separable in order to promote distinct purposes. The first purpose is to allow the swage to act as such and reform a deformed junction when the support is engaged with the swage cup thus supporting it against deflection. The second purpose is to remove the swage from the deformed junction at which time deflection in the swage cup is beneficial. Thus, the support is removed from engagement with the swage cup thereby allowing the swage cup to deform and be removed from the reformed junction more easily.

Abstract: A wellbore casing formed by extruding a tubular liner off of a mandrel. The tubular liner and mandrel are positioned within a new section of a wellbore with the tubular liner in an overlapping relationship with an existing casing. A hardenable fluidic material is injected into the new section of the wellbore below the level of the mandrel and into the annular region between the tubular liner and the new section of the wellbore. The inner and outer regions of the tubular liner are then fluidicly isolated. A non hardenable fluidic material is then injected into a portion of an interior region of the tubular liner to pressurize the portion of the interior region of the tubular liner below the mandrel. The tubular liner is then extruded off of the mandrel.

Abstract: A tubing connector for joining the ends of two lengths of expandable tubing including two expandable tubular portions for mounting on the ends of the lengths of expandable tubing. Each portion includes a plurality of circumferentially spaced couplings for engaging corresponding couplings on the other portion. The engaging parts of the couplings are located on parts of the tubular portions which define an upset following expansion.

Abstract: A method for lining a portion of a casing affixed within a well bore a distance below an upper end of the well bore with a viscoelastic pipe having an upper end, a lower end, and an outer diameter greater than the inner diameter of the casing is provided. The outer diameter of the pipe is reduced so that the outer diameter of the pipe is less than the inner diameter of the casing. The reduced pipe is then lowered into the casing to a predetermined depth where the upper end of the reduced pipe is positioned a distance below the upper end of the well bore. The reduced pipe is then allowed to expand against the internal wall of the casing, thereby forming a fluid tight seal with the casing and effectively sealing any breaches in the casing. So that the outer diameter of the reduced pipe remains less than the inner diameter of the casing as the viscoelastic pipe is being passed down the casing, the reduced pipe is maintained in tension as the reduced pipe is being passed down the casing.

Abstract: Selective isolation of a zone within a slotted liner completion of a wellbore is accomplished by expanding the original slotted liner to the full inner diameter of the wellbore into the annular area normally found around slotted liners. At least one solid tubular is run into the expanded area of the slotted liner and expanded at least in that section of the wellbore to be isolated. A custom expandable slotted liner can be run and expanded within the existing expanded slotted liner if excessive splits or rips should occur in the existing slotted liner due to expansion. Epoxies, rubber, or other sealing materials can also be utilized to better effect a seal between the liners.

Abstract: A method for replacing an old drive pipe in a slot on an offshore platform. The old drive pipe is first cut to provide an upper portion and a stub portion which remains firmly embedded in said marine bottom. Next, a guide cable is affixed to the stub portion of the old drive pipe and extends to the platform. The upper portion is then retrieved to the surface. A new drive pipe which carries a whipstock at its lower end is then made-up and lowered over the guide cable until the whipstock engages the stub portion where the new drive pipe is then diverted by the whipstock into a different path from that of the old drive pipe.

Abstract: A cutting tool and a rotatable removal tool can be used together in a system and method for removing lining from tubing in a well. A particular cutting tool includes a mandrel, a sleeve mounted on the mandrel, and a cutting member connected to the sleeve. The cutting member has a width and a cutting edge of angular disposition to form a beveled cut through the lining. Setoff members can be used to space the sleeve from the lining and to engage the lining to enable relative rotation between the mandrel and the sleeve when the cutting tool is in the lining. A particular removal tool includes an inner engagement member and an outer engagement member. The two engagement members are connected such that lining is drawn into and held between them in response to rotating at least the inner engagement member within the lining. A particular engagement member includes a bulbous body adapted to twist into lining in response to rotating the bulbous body in the lining.

Abstract: A wellbore tubular patch for patching a hole in a wellbore has been invented, the tubular patch in certain aspects having an expandable top member having a hollow tubular body and a top end and a bottom end, an expandable bottom member having a hollow tubular body and a top end and a bottom end, an expandable outer sleeve in which is secured a portion of the bottom end of the expandable top member, and a portion of the top end of the expandable bottom member inserted into and held within expandable outer sleeve. A method for making a tubular patch for patching a hole in a tubular in an earth wellbore has been invented, the method in certain aspects including securing a portion of a bottom end of an expandable top member in an expandable outer sleeve, the expandable top member having a hollow tubular body and a top end, and securing a portion of a top end of an expandable bottom member within the expandable outer sleeve, the expandable bottom emmber having a hollow tubular body.

Abstract: A system of patching single and multiple casing leaks that occur in an injection well annulus, where there is direct communication from an outermost casing string to an original open-hole wellbore and adjacent earth strata. Preferred in this pumping system is a four-stage pump process employing four separate types of fluids. The first Injection Stage utilizes either H.sub.2 SiO.sub.3, Na.sub.2 in a solution of water forming Na.sub.2 SiO.sub.3 +H.sub.2 O (Sodium Metasilicate) or Na.sub.2 O*SiO.sub.2 (Sodium Silicate) in water. The second Injection Stage utilizes CaCl.sub.2 solution in water. These two solutions react in a double replacement chemical reaction to yield an aqueous phase and a solid phase. The third Injection Stage is then implemented, the same including a bentonite/high-density, high-solids, concentrated slurry additionally containing large plugging materials suspended therein. The Fourth Stage utilizes covalently bonded N.sub.2 in a gaseous state. After injection of the first Three Stages, N.

Abstract: An apparatus and method for sealing an inner wall of a portion of a casing positioned in a well employs an inflatable sleeve having an outer surface and a conformable composite sleeve of curable composition extending around the outer surface of the inflatable sleeve. The inflatable sleeve is inflated to compress the composite sleeve against the surface of the inner casing wall. A local, activatable energy source, positioned downhole to deliver heat to the composite sleeve, is activated to cure the composite sleeve to form a hardened sleeve. The hardened sleeve presses against the inner wall of the casing portion to create a fluid seal. The embodiments shown have a number of preferred features. The local energy source includes an exothermic heat energy source for generating heat energy to cure the composite sleeve. The composite sleeve includes a mixture of resin and a curing agent, and the exothermic heat source includes thermite. The thermite includes a composition having a metal oxide and a reductant.

Abstract: A method of cementing a well permitting a reduction in the degree of diameter reduction of casing or liners required, and not requiring excessively large initial conductor casing, is described. The method is characterized by provision of an enlarged wellbore and a novel liner structure which is adapted for expansion of a reduced diameter section thereof downhole, providing, before expansion of the section, unimpeded flow of fluid from the enlarged wellbore during cementing and close fit of the expanded section with the casing or preceding liner, after cementing is completed and expansion of the section. A novel well liner structure and novel well liner expansion means are disclosed.