Abstract: A screen to be expanded when placed downhole is disclosed. The screen is delivered to the location with a cover that blocks access to the screen from well fluids. Circulation or reverse circulation can be undertaken with no appreciable flow through the screen due to placement of the cover. In one embodiment the cover has slits that open to be diamond shapes upon expansion of the underlying screen. In another embodiment, the openings are created by shapes that have a weakened edge that, as a result of expansion break off to create available openings for flow.

Abstract: A method of treating a subterranean formation surrounding a wellbore, according to which a tool inserted into the wellbore for performing a function in the wellbore is fabricated of a material that breaks up upon detonation of an explosive mounted on the tool, thus allowing the pieces of the tool to fall to the bottom of the wellbore.

Abstract: A sealed multilateral junction system provides fluid isolation between intersecting wellbores in a subterranean well. In a described embodiment, a method of forming a wellbore junction includes the steps of sealing a tubular string in a branch wellbore to a tubular structure in a parent wellbore. The tubular string may be secured to the tubular structure utilizing a flange which is larger in size than a window formed in the tubular structure. The flange may be sealed to the tubular structure about the window by a metal to metal seal or by adhering the flange to the tubular structure.

Abstract: Coatings for well screens that protect the screens from damage as they are inserted into the wellbore and once in the well, release reactive materials to react with and degrade potentially plugging materials such as drill solids, fluid filtercakes, fluid loss additives, and drilling fluids. The coatings can be specifically designed for individual well conditions and are comprised of a binder that either melts or dissolves within the wellbore and one or more reactive materials such as acids, enzymes, surfactants, chelants, oxidizers or free radical generators and the like which are released into the screen and the near wellbore area and which are effective in degrading or dissolving materials which could potentially plug the screen.

Abstract: The present invention relates to methods and equipment for recovering use of a well-bore in circumstances where the well bore has become blocked by downhole equipment. The invention provides a method comprising the steps of separating, at a release joint, a portion of equipment from a jammed portion (6) of equipment; running the separated portion of equipment uphole out of the wellbore (100); running a deflector assembly (60) downhole into the wellbore (100); and deflecting a milling tool (64) from the wellbore into surrounding formation. The method is characterised by restricting relative movement between the deflector assembly (60) and the wellbore (100) by engaging, prior to deflecting the milling tool (64), the deflector assembly (60) with said jammed portion (6) of equipment.

Abstract: A method of the preparation and utilization of polymerized alpha-hydroxycarboxylic-acid-coated proppants for gravel pack and removal of filter cake that was deposited by reservoir drilling fluid. In a preferred example, polyglycolic-acid-coated sand is used to replace conventional gravel pack sand typically used for gravel packing. Under downhole conditions, the acidic by-product generated from the hydration of polyglycolic-acid-coated sand can break down acid-soluble and/or acid-breakable components embedded in the filter cake. This reaction enhances the filter cake removal and the flow of hydrocarbon from the producing formation. The polyglycolic-acid-coated sand may be produced by polymerizing a glycolic acid with a natural or synthetic proppant like 20-40 mesh commercial sand, at temperatures of about 210° F. or higher.

Abstract: The present invention generally relates to a method for recovering productivity of an existing well. First, an assembly is inserted into a wellbore, the assembly includes a tubular member for transporting drilling fluid downhole and an under-reamer disposed at the end of the tubular member. Upon insertion of the assembly, an annulus is created between the assembly and the wellbore. Next, the assembly is positioned near a zone of interest and drilling fluid is pumped down the tubular member. The drilling fluid is used to create an underbalanced condition where a hydrostatic pressure in the annulus is below a zone of interest pressure. The under-reamer is activated to enlarge the wellbore diameter and remove a layer of skin for a predetermined length. During the under-reaming operation, the hydrostatic pressure is maintained below the zone of interest pressure, thereby allowing wellbore fluid to migrate up the annulus and out of the wellbore.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.

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 method of removing a gravel packed screen to reach another zone is described. The method involves a bottom hole assembly comprising an isolation device for the screen and a tool to latch on to it. A perforating gun is shot off to put holes in the screen to allow gravel to come through. A flow through a reversing valve is initiated to urge the gravel into the newly perforated screen while a vibrator shakes the screen and stimulates gravel flow through the screen. Alternatively, the screen is not isolated and a reverse circulation from the surface in conjunction with vibration urges the gravel to flow through the screen and out through the tubing supporting the bottom hole assembly.

Abstract: A tool for making a cut inside a downhole tool, including a housing adapted to move in the downhole tool, a plurality of openings in a wall of the housing that provides a passage from inside the housing to an exterior of the housing, a plurality of cutters disposed in the housing that are adapted to protrude from the plurality of openings to the exterior of the housing, wherein the plurality of cutters provides 360 degree cutting regardless of the orientation of the tool, and an actuation mechanism adapted to force the plurality of cutters to protrude through the plurality of openings.

Abstract: A packer retriever having a grapple body rotatably and slideably coupled to a mandrel directly attached to a milling tool can engage a packer (or extension thereof) having a substantially smooth I.D. in a wellbore while the packer is milled. The mandrel rotates in a central opening through the grapple body. The grapple body does not rotate when released from teeth of a nut on the mandrel and can remain engaged to the packer (or the extension) as milling proceeds. The mandrel includes a specially designed shoulder and the grapple body includes a specially designed bearing, both casehardened, which allow the mandrel to rotate constantly while reducing the effects of wear. The packer retriever remains in the engaged position to prevent the packer from falling if it breaks loose while milling. The packer retriever can transfer torque to the packer and can be engaged and released multiple times.

Abstract: Various techniques for holding open an SSSV using expansion technology are disclosed. A sleeve is delivered to the SSSV and expanded mechanically or hydraulically to deposit the deformed sleeve in position over a flapper or against a flow tube holding the flapper in the open position.

Abstract: A method and a device for testing of a well, such as in a well liner, a newly drilled hole, and the like, is disclosed. The method is characterised in that a plug is directed down into the well, that the plug is fixed towards the wall of the well the sealing means of the plug is activated to seal against the wall of the well, and after the testing has ceased the sealing function is removed by disintegrating the plug. Preferably a plug of a disintegratable material is used, such as a ceramic material, glass or the like.

Abstract: Method and composition for sealing a borehole. A chemically bonded phosphate ceramic sealant for sealing, stabilizing, or plugging boreholes is prepared by combining an oxide or hydroxide and a phosphate with water to form slurry. The slurry is introduced into the borehole where the seal, stabilization or plug is desired, and then allowed to set up to form the high strength, minimally porous sealant, which binds strongly to itself and to underground formations, steel and ceramics.

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: An improved dump valve assembly (22) is provided for use as a part of an elongated, sectionalized, tubular downhole pipe string (18). The assembly (22) includes a tubular pipe section (24) having endmost threading (34, 38) and a rupture disc fitting (26); the fitting (26) includes a metallic, preferably concavo-convex disc (50) with performed lines of weakness (52, 54) on one face thereof. The section (24) is interconnected between a pair of lower pipe sections (20a, 20b). In operation when it is desired to elevate the string (18) from the well, the fluid within the string (18) is pressurized sufficiently to rupture the disc (50), thereby allowing fluid within the string (18) to drain. The string (18) and other well components can then be removed from the well without contamination owing to spillage from the tubular string (18).

Abstract: An apparatus (38) and method for progressively gravel packing an interval of a wellbore (32) is disclosed. The apparatus (38) comprises a sand control screen (52) that is positioned within the wellbore (32) and a tubular member (42) that is disposed within the wellbore (32) forming a first annulus (56) with the sand control screen (52) and a second annulus (58) with the wellbore (32). The tubular member (42) initially prevents fluid communication between the first annulus (56) and the second annulus (58). Once the gravel packing operation begins, however, the tubular member (42) selectively allows fluid communication from the first annulus (56) to the second annulus (58) by progressively establishing fluid communication between the first annulus (56) and the second annulus (58) from a first end of the interval (48) to a second end of the interval (48).

Abstract: A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

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 one trip method for drilling a wellbore below a cemented casing is disclosed. An apparatus for use in performing the method is also disclosed. The method comprises lowering a drill bit into a casing cemented in the wellbore. The casing has float equipment connected therein. The drill bit is rotated in the casing above the float equipment so that it expands radially outwardly to a diameter greater than the inner diameter of the casing. The float equipment, which can be a float shoe or a float collar or any other type of float equipment known in the art, includes an outer case with a valve connected therein. The outer case is comprised of a drillable material. Thus, the drill bit utilized to drill the wellbore can begin its drilling operation above the float equipment and successfully drill a wellbore below the casing having a diameter greater than the inner diameter of the casing.

Abstract: A modified casing coupling that includes a receptacle, or receptacles, for a modular burst disk assembly. The burst disk assembly is retained by threads or a snap ring and is sealed by the retaining threads, or an integral o-ring seal. The. The disk fails at pressure specified by the user but before trapped annular pressure threatens the integrity of the outer casing. The design allows for the burst disk assembly to be installed on location or before pipe shipment.

Abstract: A method and apparatus for use in a subterranean well is described. The apparatus typically includes a subterranean plug including a mandrel having an outer surface and a non-circular cross-section and a packing element arranged about the mandrel, the packing element having a non-circular inner surface matching the mandrel outer surface such that concentric rotation between the mandrel and the packing element is precluded. The apparatus may include slips having cavities to facilitate quick drill-out of the plug. The apparatus may include a valve for controlling fluid flow through a hollow mandrel. The apparatus may include a composite mandrel having radial vents that establish fluid communication from within to without the mandrel. Also, the apparatus may include a wire line adapter kit for running the apparatus in a well bore.

Abstract: A downhole tool for sealing a wellbore. The downhole tool includes a packer with a ball seat defined therein. A sealing ball is carried with the packer into the well. The movement of the sealing ball away from the ball seat is limited by a ball cage which is attached to the upper end of the packer. The ball cage has a plurality of ports therethrough for allowing flow into the ball cage and through the packer at certain flow rates. A spring is disposed in a longitudinal opening of the packer and engages the sealing ball to prevent the sealing ball from engaging the ball seat until a predetermined flow rate is reached. When the packer is set in the hole, flow through the frac plug below a predetermined flow rate is permitted. Once a predetermined flow rate in the well is reached, a spring force of the spring will be overcome and the sealing ball will engage the ball seat so that no flow through the frac plug is permitted.

Abstract: A device for introducing high-pressure fluid through a well having a vertical passage with at least one valve and into a well having a well tubing into said vertical passage, has a lower part removably attachable to the well tubing, a hollow mandrel adapted to extend through the inner passage of the lower part and having a passage through which a high pressure fluid can be introduced, an upper part firmly connected with the mandrel to hold the mandrel and movable relative to the lower part between a distal position in which the upper part is spaced from the lower part and the mandrel is not introduced into the well tubing and a proximal position in which the upper part is located close to the lower part and the mandrel is introduced into the well tubing and passes through an area of the well tubing provided with the valve, so that when the high pressure fluid is introduced through the mandrel it can not affect the valve, the upper part having a port communicating the inner passage of the upper part with an ou

Abstract: Method and apparatus for producing multiple zones from a single wellbore wherein a hollow whipstock is used to complete a lateral into an upper zone which lies above a lower producing zone. The whipstock has openings through its tapered face which, in turn, are sealed by dissolvable plugs (e.g. aluminum). Once the lateral has been completed, a reagent (e.g. hydrochloric acid) is pumped down the wellbore to dissolve the plugs and open the openings through the face of the whipstock thereby allowing the flow from the lower zone to pass through the whipstock to be produced up through the wellbore along with the flow from the upper production zone.

Abstract: A one trip method for drilling a wellbore below a cemented casing is disclosed. An apparatus for use in performing the method is also disclosed. The method comprises lowering a drill bit into a casing cemented in the wellbore. The casing has float equipment connected therein. The drill bit is rotated in the casing above the float equipment so that it expands radially outwardly to a diameter greater than the inner diameter of the casing.

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: An assembly for formation and completion of deviated wellbores is disclosed which includes a toolguide and a casing section which can be used together or separately. The toolguide includes a lower orienting section and a whipstock having a sloping face, commonly known as the directional portion of a whipstock. The toolguide is coated with a material such as epoxy or polyurethane to provide a repairable surface and one which can be removed to facilitate removal of the toolguide from the well bore. The lower orienting section has a latch which extends radially outwardly from the section and can be locked in the outwardly biased position.

Abstract: An apparatus for disconnecting a bottom hole assembly from a work string, having an upper tool body, a piston biased away from a slidable collet, locking dogs held in engagement with a lower tool body by the slidable collet, and one or more collet fingers holding the collet in place, relative to the upper body. The piston can be hydraulically displaced against the biasing spring, thereby releasing the collet finger, followed by further displacement of the piston to contact the collet, then displacement of the piston and the collet to release the locking dogs from engagement with the lower tool body. A shear pin in the collet can provide a positive pressure indication of release of the disconnect device.

Abstract: An apparatus and method for removing a frangible rupture disc or other frangible device from a wellbore casing. The casing has a special casing section defining a plurality of holes therethrough. Rupturable glass ceramic discs or inserts are disposed in the holes and retained therein. The glass ceramic discs or inserts are adapted to withstand fluid differential pressure normally present in the wellbore but are rupturable in response to impingement by a pressure wave thereon. The pressure wave is provided by a pressure wave generating device positionable in the casing string adjacent to the holes in the special casing section. The pressure generative device may generate a pressure pulse or an acoustical wave. Methods of perforating a well casing using a pressure pulse or an acoustical wave are also disclosed.

Abstract: Coatings for well screens that protect the screens from damage as they are inserted into the wellbore and once in the well, release reactive materials to react with and degrade potentially plugging materials such as drill solids, fluid filtercakes, fluid loss additives, and drilling fluids. The coatings can be specifically designed for individual well conditions and are comprised of a binder that either melts or dissolves within the wellbore and one or more reactive materials such as acids, enzymes, surfactants, chelants, oxidizers or free radical generators and the like which are released into the screen and the near wellbore area and which are effective in degrading or dissolving materials which could potentially plug the screen.

Abstract: The present invention provides a drop ball sub that may be used to drop a large ball having an outer diameter larger than the inner diameter of a restriction in the wellbore such as the running tool used to run a first casing string through a second casing string. A smaller ball is used to control dropping of the large ball. The smaller ball has an outer diameter smaller than the restriction. The drop ball sub of the present invention may be used to operate any downhole tool that would benefit by receipt of a large ball. By dropping a larger ball, in one use of the invention larger valves can be controlled in the float equipment that provide a larger fluid flow path. A larger fluid flow path reduces surge pressure and enables the system to handle more debris. The present invention provides a system that preferably provides for a diverter tool above the running tool and a diverter tool below the running tool.

Abstract: Methods and compositions for forming permeable cement sand screens in well bores are provided. The compositions are basically comprised of a hydraulic cement, a particulate cross-linked gel containing an internal breaker which after time causes the gel to break into a liquid and water present in an amount sufficient to form a slurry.

Abstract: A separation method and apparatus for separating components used in downhole well development activity, whilst in position down the well. Method and apparatus are characterized in that they do not make use of external mechanical forces, or internal fluid pressure, applied through the development apparatus to render the components in a separable state. The release is achieved through the use of a fusible metal element.

Abstract: A junk basket comprises a sleeve sized to fit within a well bore. The sleeve has a bore therethrough, an internal latch at its top end for connection to a complementary retrieval tool having an external latch. A basket floor is movable axially in the bore between a first position intermediate the axial length of the sleeve, and a second position resting on a retaining shoulder at the bottom of the sleeve. In a well bore, the basket floor is supported at the first position, preferably on a retrievable bridge plug, and debris is collected in the defined volume above the floor. When the basket is lifted during retrieval, the basket floor falls to the second position, increasing the collection volume, loosening the debris and loosening the basket in the well bore for ease of retrieval. Further, a novel method of jointly deploying a junk basket and bridge plug results. The basket is connected to the plug and a setting/insertion tool passes through the basket's bore and through a port in the basket floor.

Abstract: Process for destroying a rigid thermal insulator obtained in particular by a process of the sol-gel type and positioned in a confined space, the process comprising the stage of introducing a dissolving liquid into the confined space in order to convert the insulator into a liquid phase. The process applies in particular to destroying an insulating jacket positioned in the annular space of an oil well.

Abstract: Methods, apparatus and tools to be used with tubular expansion apparatus. In one aspect of the invention, tools are actuated or operated within a well by selectively expanding the tool wall. To actuate the tool, the tool wall is urged outward past its elastic limits. The expanding wall physically unlocks a locking ring which then unlocks a piston. Thereafter, hydraulic pressure differences are employed to move the piston to operate the downhole tool. In another aspect of the invention, a first piece of casing is joined to a second, larger diameter casing. By expanding the diameter of the first piece of casing into contact with the second piece of casing, the two are joined together. The joint is formed with helical formations in a manner that provides flow paths around the intersection of the two members for the passage of cement or other fluid.

Abstract: A packer for use inside a casing of a subterranean well includes a resilient element, a housing and a rupture disc. The resilient element is adapted to seal off an annulus of the well when compressed, and the housing is adapted to compress the resilient element in response to a pressure exerted by fluid of the annulus of a piston head of the housing. The housing includes a port for establishing fluid communication with the annulus. The rupture disc is adapted to prevent the fluid in the annulus from entering the port and contacting the piston head until the pressure exerted by the fluid exceeds a predefined threshold and ruptures the rupture disc.

Abstract: A method for locating a drill bit when drilling out cementing equipment from a casing of a wellbore. A first step involves placing in the casing of the wellbore at the time of placing cementing equipment, at least one coloured marker member. A second step involves monitoring cuttings during drilling for traces of colour. Penetration of a drill bit into the cementing equipment is indicated by coloured cuttings from the at least one coloured marker member.

Abstract: The invention is the method of treating of a well, a formation, or both, with the solids, liquids, or apparatuses, by 1) encasing the solids, liquids, or apparatuses in a water-soluble shell, 2) conveying the encased solids, liquids, or gases to the predetermined location in the well, and then 3) allowing the water-soluble shell to dissolve in the aqueous phase in the wellbore. The shell is preferably made of water-soluble polymers such as collagen, a crosslinking agent such as zolidine, optionally a hydrophobic compound such as a processed oil, and water used in processing. Other modifying or conditioning compounds, for example glycerin and other polymeric additives, may be incorporated to extend the strength or temperature range of the shell. The shell encases a variety of solids, liquids, or combinations thereof, where the solids or liquids are useful in the treatment of the well or of the producing formation.

Abstract: The bottom end of a coil tubing string is secured to the bottom end of a primary tubing string at ground surface. Usually the primary tubing string will be of larger diameter and is therefore stronger and stiffer than the coil tubing string. The strings are secured together with a locking assembly. This assembly comprises two interlocking members, one connected with each string. One of the interlocking members is meltable when exposed to elevated temperature. The primary tubing string and the coil tubing string are run together into the desired position in the wellbore. The primary tubing string acts to drag the coil tubing string along with it. Heat is then used to melt the interlocking member so that the strings can be separated. The heat can be provided by circulating steam or hot water or oil down to the assembly. Alternatively the downhole formation temperature may be sufficient to induce melting. Once separated, each string can be pulled or moved independently.

Abstract: An apparatus and method for drawing small milling debris into a combination milling and debris retrieval tool, during the performance of the milling operation. A milling tool has a fluid intake port near its lower end, where debris-laden fluid is drawn into the milling tool and subsequently into a separator section. The separator section has a debris deflection tube and a screen for separating the debris from the fluid. Fluid is drawn into the tool by either a set of eductor nozzles or a downhole motor and pump.

Abstract: In a broad aspect, the invention relates to a method and apparatus for downhole safety valve remediation using a measured, controlled, explosion to remove scale and/or other debris from within or around the downhole safety valve or for explosively locking out the safety valve in an open position.

Abstract: A tubular casing section for a subterranean well has side wall apertures therein which are temporally sealed with plug structures. The plugged casing section is positioned within a wellbore at a selected subterranean formation and cemented in place within the wellbore. The plugs are removed, such as by melting, fracturing, shearing or corrosion, and a stimulation tool is lowered into the casing and operated to pierce through the cement lining at the unplugged casing side wall apertures and into the surrounding subterranean formation to establish communication between the formation and the interior of the casing.

Abstract: The present invention provides separation method and apparatus for separating components used in downhole well development activity, whilst in position down the well. Method and apparatus are characterized in that they do not make use of external mechanical forces, or internal fluid pressure, applied through the development apparatus to render the components in a separable state. The release is achieved through the use of a fusible metal element.

Abstract: Apparatus for use in operations performed in conjunction with a subterranean well is provided by the present invention. In one described embodiment, a plug apparatus includes a soluble polymer material, which is utilized in a plug member for blocking flow through a fluid passage. In another described embodiment, a soluble polymer material is utilized in a blocking member for blocking displacement of a displacement member of an apparatus.

Abstract: A connector permits separation of a submergible pumping system from its deployment system. The connector includes an upper assembly and a lower assembly that are connected by shear screws. A hydraulic separation mechanism is used to shear the shear screws and separate the upper and lower assemblies from a remote location.

Abstract: Multiple wellbores are interconnected utilizing a deflection device having a guide layer of lower hardness than the body of the deflection device, and a cutting tool having a guide portion and being operative to cut through the deflection device guide layer and a tubular structure lining a wellbore.

Abstract: A well perforating apparatus has a first perforating gun section, a second perforating gun section, and a longitudinally collapsible unitary section connected between the first and second perforating gun sections. The unitary section can include a deformable member, or a frangible member, or a flexible member. One specific such member is a cable, such as implemented with a length of wireline material or slickline material. In a method of perforating a well having a plurality of zones to be perforated, a well perforating apparatus is lowered into the well. This includes separating a first perforating gun section from a second perforating gun section such that one gun section is adjacent one zone to be perforated and such that the other perforating gun section is adjacent another zone to be perforated.