Abstract: A method for cementing a casing in a wellbore, the method having the following steps: attaching a valve to a casing; locking the valve in an open configuration; running the casing and the valve into the wellbore; reverse circulating a cement composition down an annulus defined between the casing and the wellbore; injecting a plurality of plugs into the annulus; unlocking the valve with the plurality of plugs; and closing the valve.

Abstract: A by-pass tool for incorporation in a drillstring is adjustable between an inactive mode in which it allows fluid flow lengthwise of the drillstring during normal drilling operation, and an active by-pass mode when drilling is to be interrupted. The tool includes an outer casing, an axially displaceable sleeve within the casing, a valve seat associated with the sleeve and arranged to receive an activating ball, and by-pass port means in the casing. The valve seat receives the activating ball when the ball is launched from the surface and down the drillstring. The valve seat displaces the sleeve axially to adjust the tool from the inactive mode to the active by-pass mode. The by-pass port means allows a locking ball to partially block the port means and thereby initiate flushing-out of any drillstring fluid debris above the valve seat via the port means.

Abstract: A circulation tool 10 for use downhole in a well includes a housing 12 having one or more bypass ports 16 for circulation between a bore in the housing and an annulus surrounding the housing. A sleeve 68 is axially movable within the housing, and axially spaced seals 70, 74 seal between the sleeve and the housing when the sleeve is in the closed position. A ball 52 is rotatably mounted to the sleeve, and includes a seat 54 about a central bore 55 in the ball for engagement with a plug. When the sleeve closes off the circulation ports 16, the ball is rotated to the open position with a substantially full bore diameter.

Abstract: The present invention generally relates to a wellbore tool for selectively isolating a portion of a wellbore from another portion of the wellbore. In one aspect, a method of selectively isolating a zone in a wellbore is provided. The method includes the step of positioning a downhole tool in the wellbore. The downhole tool includes a bore with a first flapper member and a second flapper member disposed therein, whereby each flapper member is initially in an open position. The method also includes the step of moving the first flapper member to a closed position by rotating the first flapper member in one direction. Further, the method includes the step of moving the second flapper member to a closed position by rotating the second flapper member in an opposite direction, whereby each flapper member is movable between the open position and the closed position multiple times. In another aspect, an apparatus for isolating a zone in a wellbore is provided.

Abstract: The present invention comprises a drilling tool assembly for drilling oil comprising a bit release subassembly, a test sleeve that is removable to open and close flow ports, and a profile nipple.

Abstract: One or more flapper valve assemblies are placed in a casing string extending through one or more hydrocarbon bearing intervals. The flapper valve assemblies are placed between some of the hydrocarbon bearing intervals. In an open or inoperative position, the flapper valve assemblies are full opening compared to the casing string. The hydrocarbon bearing intervals are stimulated, typically by fracing, starting with the bottom zone. The flapper valve assembly immediately above the stimulated interval is manipulated to allow it to close, preventing downward flow in the well and thereby isolating the lower stimulated interval so an upper interval can be stimulated. The well is easy to put on production because the flapper valves will normally open simply by opening the well at the surface.

Abstract: A fluid actuated packer 10 and collar 36 assembly is provided for positioning on a tubular member 12. The collar 36 is moveable by a running tool 110 positioned within the tubular member and has a closed position and a packer activate position, fluidly connects the collar 36 to the packer element 14 when in the packer activate position, and closes off the flow path 26 when in the closed position. According to a method of the invention, the flow path 26 extends from the collar to the expandable packer element 14 and is open to activate the packer element 14 and closes off the flow path 26 when in the closed position.

Abstract: A system and method for actuating a shut-off valve in a wellbore wherein the shut-off valve element can be positively closed before the pump is removed from the well. A hydraulic actuator component is operably associated with the shut-off valve to provide for selective isolation of the well by positive closing of the valve prior to removal of the pump and opening of the valve after replacement of a pump within the wellbore. The hydraulic actuator component has a balanced hydraulic design wherein the valve closure element may be moved toward an open or closed position by flow of hydraulic fluid through first and second hydraulic lines. When a repaired pump or replacement pump is placed into the well, the actuator is stabbed into a packer element to seat it. The hydraulic actuator assembly is then operated to open the shut-off valve, thereby reestablishing well operation.

Abstract: An isolation string having an upper packer and an isolation pipe in mechanical communication with the upper packer, the isolation pipe comprises an operable valve and an object activated valve. An object holding service tool is adapted to release an object to activate the object activated valve. A method of running-in an isolation string, comprising an operable valve and an object activated valve, with an object holding service tool having an object held therewith; setting the isolation string in the casing adjacent perforations; pressurizing the object to cause a release from the object holding service tool, whereby the object travels to the object activated valve; closing the object activated valve with the released object; and withdrawing the object holding service tool from the well.

Abstract: A valve apparatus. The valve apparatus is disposed within a well so that an annulus is formed between an outer portion of the valve and an inner portion of the well. In one preferred embodiment, the valve apparatus comprises an outer mandrel containing an annulus port; an inner mandrel slidably disposed within the outer mandrel, and wherein the inner mandrel contains a production and equalizing port. The valve contains a seal assembly so that pressure from the annulus is isolated from the inner portion of the inner mandrel. In one preferred embodiment, the seal assembly comprises: a first header seal; a first seal ring, abutting the header seal, for sealing with the outer portion of the inner mandrel; a follower seal abutting the seal ring; a second seal ring, abutting the follower seal, for sealing with the outer portion of the inner mandrel; a second header seal; and an equalizing seal abutting the second seal ring.

Abstract: A positioning tool for moving an element in a flow path of a down hole system without actuating a pressure actuated device in the system. The positioning device includes a choke for restricting flow of fluid between the positioning device and the down hole system, a flow diversion path from the upper end of the positioning device to a lower end of the positioning device, and a valve allowing fluid to flow through the diversion path when the choke is proximate the pressure actuated device and blocking flow of through the diversion path when the choke is displaced from the pressure actuated device. The down hole system may be a flapper type fluid loss device with a pressure actuated opening prop.

Abstract: An isolation string having: an upper packer; and an isolation pipe in mechanical communication with the upper packer, wherein the isolation pipe comprises a pressure activated valve and an object activated valve. A method having: running-in an isolation string on a service tool, wherein the isolation string comprises a pressure activated valve and a object activated valve; setting the isolation string in the casing adjacent perforations in the casing; releasing an object from the service tool, whereby the object travels to the object activated valve; closing the object activated valve with the released object; and withdrawing the service tool from the well.

Abstract: A tubing string assembly for fluid treatment of a wellbore includes substantially pressure holding closures spaced along the tubing string, which each close at least one port through the tubing string wall. The closures are openable by a sleeve drivable through the tubing string inner bore.

Abstract: A method and system allows periodic access the wrong way through one or more one-way valves installed in a fluid flow stream. Fluid can flow through the bypassed valves or through the tools used to bypass the valves such as those of a reciprocating production pump. A stab tool cooperates with a valve to unseat a ball from a ball seat so as to bypass the ball and pass through the ball seat. The stab tool can be conveyed by tubing for discharge of fluid through ports in the stab tool. In another aspect of the invention, a rod installed within a pump between a reciprocating uphole valve and a downhole valve is arranged so that when the pump is closed, the stab tool at the rod's lower end passes through the downhole valve and a projection at the rod's upper end passed though the uphole valve the pump is partially closed. Fluid can be pumped in reverse through the pump fluidize debris.

Abstract: A lockout tool dimensioned to be received within a housing of a subsurface safety valve (SSV). The lockout tool generally comprises an elongated housing, and an expander mandrel slidably received within the housing. Together, the elongated housing and expander mandrel are run into the wellbore and landed into the housing of the SSV such that the end of the expander mandrel opens the flapper valve. A portion of the lookout tool housing shoulders against the flow tube in the SSV to drive the flow tube downward, thereby maintaining the flapper of the SSV in its open position. As the expander mandrel moves downward through the hard scat of the SSV, the mandrel engages the flow tube and expands it against the hard seat. In this manner, the flow tube is expanded into permanent, frictional engagement with the hard seat. This, in turn, looks the flapper member of the SSV in its open position.

Abstract: A valve assembly to control the intake of fluid. The valve assembly has a valve body and a valve choke disposed therein. The valve choke has a choke bore through the interior of the valve choke. The valve choke has a plurality of orifices to the choke bore spaced at intervals along the valve choke. A seal is disposed between the valve body and valve choke. The valve system is operable to position the valve choke so that the seal is positioned between the valve body and the valve choke at the intervals between the plurality of orifices.

Abstract: Equipment and methods which may be used in conjunction with an underbalanced well completion. In a described embodiment, a valve for use in a subterranean well in conjunction with a tool conveyed through the valve in a container is provided. The valve includes a passage formed longitudinally through the valve, a closure assembly which selectively permits and prevents flow through the passage, and an engagement device which engages the container as the tool is conveyed through the passage. The closure assembly permits flow through the passage when the container is conveyed into the passage, and the closure assembly prevents flow through the passage when the container is removed from the passage. Engagement between the container and the engagement device separates the tool from the container.

Abstract: A ball drop tool for dropping an actuating ball to a ball seat located in a tool or tool string therebelow. The ball drop tool includes a housing with a ball drop cage positioned therein. The ball drop cage has a rocker arm pivotably attached thereto. In a first position, the rocker arm retains the actuating ball in the housing and in the second position releases the actuating ball so that it is displaced downwardly to engage the ball seat therebelow in the tool string. The ball drop cage may be connected to a releasing seat sleeve thereabove. Downward movement of the releasing seat sleeve from a first position to a second position after landing a releasing ball on the releasing sleeve moves the ball drop cage from the first position to the second position to release the actuating ball.

Abstract: A drop ball catcher apparatus for use with downhole tools in oil well drilling and installation operations. A drop ball catcher apparatus is used to receive and stow a drop ball ejected from a ball-actuated downhole tool.

Abstract: A system is provided for unloading accumulated liquids and enhancing the recovery of gas from a reservoir having diminished pressure. An annulus between a tubing string and casing is isolated by a packer and continually pressurized with a slipstream of compressed gas while the well continues to produce. A unique valve positioned in the tubing string is shuttled between a production position in which production fluids are permitted to bypass the valve to the surface and a lift position in which the bypass is blocked and an unloading port is opened to vent high pressure annulus gas to the tubing string above the valve, lifting accumulated liquids with it. Preferably, the valve is actuated to the lift position by the impact of a plunger dropped from a lubricator at the wellhead, when the pressure in the annulus has reached a predetermined threshold.

Abstract: An improved control system, particularly useful for SSVs, is disclosed. It is responsive to a rupture of the tubing and control line to equalize pressure on an operating piston to allow the SSV to go to its failsafe position. The annulus pressure-sensing feature can be employed with a variety of control systems, a particular one is used as an example.

Abstract: An apparatus for reducing pressure surges in a wellbore comprising a body having a bore therethrough, the bore providing a fluid path for wellbore fluid between a first and second end of the body, at least one fluid path permitting the wellbore fluid to pass between the bore and an annular area formed between an outer surface of the body and the walls of a wellbore therearound, and a number of closure mechanisms whereby the at least one fluid path is selectively closable to the flow of fluid.

Abstract: A fluid flow switching device for a drill string comprises a tubular member having a port (4). A sleeve member is slidable within the tubular member between a first position in which a port (3) thereof is in alignment with the port (4) and a second position in which the port (4) is obstructed. A plurality of fingers are connected to the sleeve member (2). Each finger defines one segment of a closure member that is closed when the fingers are pivoted inwardly and open when the fingers are pivoted outwardly. An operating surface is positioned within the tubular member, and the fingers are axially slidable thereover as the sleeve member is moved between the first and second positions to close and open the segmented closure.

Abstract: The invention provides a downhole shut-in tool for obtaining formation pressure data. The tool includes a fast-closing main valve and a pressure-relief valve operable between open and closed positions to effect periodic sealing and release of formation pressure with respect to the surface.

Abstract: The present invention provides an improved system and method for performing a desired operation at a remote location in a wellbore. The system is composed of a downhole docking station assembly and a detachable downhole tool assembly. The downhole tool assembly includes electrically operated means to move in the wellbore and an end work device to perform the desired work. The downhole tool can also include an imaging device to provide pictures of the downhole environment and various sensors. Data from the downhole tool is communicated to a surface computer, which controls the operation of the tool and displays pictures of the tool environment. The downhole tool detaches itself from the docking station, travels to the desired location in the wellbore and performs a predefined operation according to programmed instruction. The downhole tool returns and connects to the docking station, where it transfers data relating to the operation and can be recharged for further operation.

Abstract: Methods, apparatus, and systems for low-flow sampling of a fluid source. One illustrative embodiment of the invention is directed to a method for manually sampling a fluid source in a well, including exerting a downward pressure on a sample tube, disposed within a well insert, to allow fluid to pass from the well through a portion of the well insert and into the sample tube to fill at least a portion of the sample tube with the fluid. Another illustrative embodiment of the invention is directed to a method for securing a well insert to an inner wall of a well, including arranging stabilizers on the well insert in a non-extended position, introducing the well insert into the well, arranging the stabilizers on the well insert in an extended position, and expanding a portion of a gasket on the well insert such that the portion of the gasket conforms to a circumference of the inner wall of the well.

Abstract: A tubing conveyed disconnect check valve mechanism having releasable connection with a payload tool and being selectively actuated downhole for disconnecting from the payload tool for retrieval by the tubing string, with the check valve enabled for direct circulating flow and preventing the inflow of wellbore fluids, while permitting the payload tool to remain in the well. A housing is connected to a tubing string, such as coiled tubing, and incorporates at least one check valve and defines a first disconnect connector which is releasably connected with a second disconnect connector of the payload tool housing. A check valve positioning mandrel is releasably retained at a check valve disabling position within the housing for establishing a reverse circulating flow path through the check valve and is released from the housing and moved to a check valve enabling position, closing the reverse circulating flow path and permitting direct circulating flow only.

Abstract: A downhole tool hydraulic firing head includes an automatic drain that is opened when the piston is driven to fire. The automatic drain includes a vent opening from the bore and a sleeve disposed within the bore to move axially with the piston. The sleeve is moveable from a position covering the vent opening to a position clear of the vent opening. A locking collet is disposed between the sleeve and the housing, which locks the sleeve into the position, clear of the vent opening, when the sleeve is moved into that position. This locks the sleeve against returning to the position covering the vent opening when it is urged to move in that direction such as, for example, by venturi forces of the evacuating fluid or by pressure generated from the explosive charges. The firing head is useful to detonate downhole explosive charges, such as those in a perforating gun.

Abstract: A system is provided for unloading accumulated liquids and enhancing the recovery of gas from a reservoir having diminished pressure. An annulus between a tubing string and casing is isolated by a packer and continually pressurized with a slipstream of compressed gas while the well continues to produce. A unique valve positioned in the tubing string is shuttled between a production position in which production fluids are permitted to bypass the valve to the surface and a lift position in which the bypass is blocked and an unloading port is opened to vent high pressure annulus gas to the tubing string above the valve, lifting accumulated liquids with it. Preferably, the valve is actuated to the lift position by the impact of a plunger dropped from a lubricator at the wellhead, when the pressure in the annulus has reached a predetermined threshold.

Abstract: A method and apparatus for obstructing the passage of fluid within a fluid flow conduit and subsequently reconfiguring the tool to allow substantially full-bore passage therethrough. Pressure developed upstream of the obstruction can be utilized to operate pressure actuated tools such as liner hangers. Equipment used in subsequent wellbore operations such as drill pipe darts can pass undamaged through the opened port. In an embodiment, the flow through a tubular is obstructed by placing a ball on an expandable ball seat, developing a pressure differential across the ball seat, equalizing the pressure after the hydraulically actuated tool completes its function, and mechanically manipulating the drill string to open the expandable ball seat and allow the ball to pass through.

Abstract: A device for providing surge pressure reduction with volume compensation and methods of use are presented. Surge pressure reduction and volume compensation are accomplished by pressure-actuated release of the compensation device.

Abstract: A by-pass tool to be incorporated in a drill string, in combination with an activating ball assembly operative to adjust the tool between an activated mode and a de-activated mode. The tool has a valve seat engageable by the activating ball assembly to move its sleeve to a by-pass mode which diverts drilling mud from flowing through the housing to a by-pass flow through the by-pass port. The activating ball assembly has a deformable ball of a size sufficient to engage and to be held captive by the salve seat and a weight attached to the ball and operative to assist in movement of the assembly under the action of gravity to engage the ball with the valve seat. The weight has smaller transverse dimensions that the ball so that it moves downwardly through the valve seat and pulls the ball into engagement with the valve seat.

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 removable ball seat assembly is disclosed. It features a solid ball seat backed up by segmented dogs pinned to each other and mounted under the ball seat. Upon actuating a downhole tool with fluid pressure applied to a ball on the seat, the pressure is increased and the ball and seat move at a regulated rate. The dogs reach a recess and the ball moves through the seat. Subsequent, larger balls can pass through the seat, with the dogs in the recess, at much smaller pressure drops than the original ball.

Abstract: A crossover tool is disclosed that permits access through to the wash pipe below after the conclusion of a known gravel packing operation. A ball is trapped to a sleeve after shifting it so as to allow flow through the crossover for acid treatment in the screen area and a reversing out procedure to remove excess acid. Alternatively, pressure delivered through the wash pipe can operate packers, as part of a gravel packing procedure as outlined in two steps in U.S. Pat. No. 6,311,772 is a single trip. The acid treating or other downhole operation through the wash pipe can also be accomplished in a single trip with the gravel packing assembly.

Abstract: Embodiments of the present invention disclose apparatus and methods that can be used to mechanically actuate a downhole tool with an expandable shifting tool. One embodiment of the invention is an expandable shifting tool comprising a housing having an outer diameter and a plurality of radially extendable elements. The radially extendable elements are longitudinally separated from each other and each extendable element is at least partially contained within the housing. The extendable elements are capable of moving between an extended position and a retracted position and are biased towards the extended position.

Abstract: A downhole flow control device is provided for remotely controlling fluid flow of production or injection fluids, and may offer the capacity to pass wireline tools therethrough. In a broad aspect, the device may include: a body member having a first bore extending from a first end of the body member and through an extension member disposed within the body member, a second bore extending from a second end of the body member and into an annular space disposed about the extension member, a first valve seat disposed within the first bore, and at least one flow port in the extension member establishing fluid communication between the annular space and the first bore; and a first sleeve member remotely shiftable within the first bore, and having a second valve seat adapted for cooperable sealing engagement with the first valve seat to regulate fluid flow through the at least one flow port.

Abstract: A circulation tool includes a housing having a longitudinal bore therethrough, a wall, and at least one lateral port through the housing wall and at least two sliding sleeves. At least one circulation flow passage is disposed within the housing wall. A plurality of circulation paths are created by the selective positioning of the at least two sliding sleeves.

Abstract: A downhole apparatus is described as having an upper mandrel shearably connected to a lower mandrel by a first set of shear pins. Each of the mandrels has an elastomeric cement plug formed around the mandrels. A sleeve is shearably connected within the lower mandrel. The operation of the apparatus, which includes a method for controlling the flow of fluid out of the end of a tubular string, involves dropping a first small diameter ball from the earth3 s surface. The ball is sized such that it travels through the upper mandrel and settles into the sleeve which is connected within the lower mandrel. By increasing pump pressure at the earth's surface, the lower mandrel is separated from the upper mandrel by shearing the first set of shear pins.

Abstract: A technique for deploying a liner within a wellbore. The technique utilizes a flush bore running tool that may be coupled to the interior of the liner during deployment of the liner. The mechanism for coupling the running tool and the liner permits the use of the full diameter of the liner after the running tool is released and removed from the liner.

Abstract: A sliding sleeve valve and method for assembly is disclosed. The valve comprises a segmented main body that is assembled from a top, middle and bottom segments. The middle segment has flow apertures. A closing sleeve is co-axially mounted in the assembled main body. The closing sleeve has flow apertures that are intended to communicate with the flow apertures of the middle section when the valve is open. The closing sleeve is sealed by seal means within the main body to prevent undesired fluid flow across the valve. The seal means comprise primary, secondary and tertiary seals acting in cooperative combinations. The seals comprise O-Ring and Vee-stack seals located within the body of the valve. The sliding sleeve valve has a fluid pressure equalization means to permit equalization of fluid pressure across the valve before it is fully opened or fully closed in order to reduce wear on the seals.

Abstract: A protective member that is disposed within the longitudinal bore of a well tool, the well tool including an actuating mechanism adapted to be mechanically activated from the longitudinal bore. The actuating mechanism includes an engagement section, preferably a profile. The protective member, preferably a sleeve, substantially covers the actuating mechanism while leaving the engagement section exposed to the longitudinal bore. In a preferred embodiment, the sleeve is slidably disposed within the longitudinal bore between a first position and a second position. A biasing mechanism biases the sleeve into the first position, in which a sleeve first end is proximate the profile. Operation of the apparatus enables a method for preventing the inadvertent mechanical activation of the actuating mechanism of a well tool as peripheral equipment is passed through the longitudinal bore of the well tool.

Abstract: A formation isolation valve assembly for use in a well includes first and second fluid paths that are coupled to at least first and second completion zones. A first valve controls fluid flow from the first zone to the first fluid path, and a second valve controls fluid flow from a second zone to the second fluid path. The valves may include ball valves and sleeve valves.

Abstract: The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. In the open position, the port collar permits communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking mechanism for the opened and closed positions comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. The mating ratchet teeth are designed to secure the sleeve in a first position within the housing. A second set of mating ratchet teeth secures the sleeve in a second position.

Abstract: The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. In the open position, the port collar permits communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking mechanism for the opened and closed positions comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. The mating ratchet teeth are designed to secure the sleeve in a first position within the housing. A second set of mating ratchet teeth secures the sleeve in a second position.

Abstract: Several downhole flow control devices are disclosed which are meterable and are also capable of shutting of a particular zone in a well. The several embodiments include a multiple valve body, a toroidal inflatable valve, and a series of related choke systems. The downhole flow control choke mechanisms each include a downhole electronics package to provide programming or decision making capacity as well as motor actuation systems. Each choke mechanism also includes a system whereby the device can be converted to manual operation and actuated by a conventional shifting tool.

Abstract: A differential float and cementing valve assembly used to position and cement casing in a wellbore. A poppet valve mounted in the flapper gate of a check valve provides a regulated back-flow of drilling fluid through the check valve. A leaf spring biases the poppet valve to its closed position. Drilling fluid pressure in the wellbore overcomes the spring force to open the poppet valve and permit drilling fluid to back-flow into the casing. The regulated admission of drilling fluid into the casing permits the casing to sink into the well at a controlled rate while automatically maintaining a desired level of drilling fluid in the casing. With the casing at the bottom of the well, a cement slurry is pumped through the casing. A setting ball moving in advance of the cement slurry deactivates the poppet valve and its flapper gate and activates a second check valve in the assembly to prevent cement back-flow.

Abstract: An apparatus (30) and method for regulating fluid flow through a downhole tubing string (28) is disclosed. The apparatus (30) comprises a generally tubular outer housing (32) having a housing port (38) formed through a sidewall portion thereof. First and second seats (78, 68) are disposed within the housing (32), each having sealing surface (82, 76) that are sealingly engageable to one another to substantially prevent fluid flow therebetween. A sleeve (44) is slidably disposed within the first and second seats (68, 78). The sleeve (44) has a flow passage extending generally axially therethrough and is variably positionable relative to the first seat (78) to regulate fluid flow through a sleeve port (46). The sleeve (44) has first and second positions relative to the second seat (68). In the first position, a seal (66) is disposed between the sleeve (44) and the first seat (78), thereby preventing fluid flow through the sleeve port (46).

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: A relievable check valve assembly having various trigger forms for oil wells and water wells adapted to control the liquid flow when inserted tubing is being removed from a well.