Abstract: A tubing plug is adapted for insertion into a tubing string for sealing the tubing string. The tubing plug is comprised of a housing having an outer surface, wherein the housing is adapted for insertion in the tubing string such that an annulus is defined between the tubing string and the outer surface of the housing and wherein the housing defines a fluid passage therethrough, the fluid passage having an upper end and a lower end. A sealing mechanism is associated with the housing for sealing the annulus and a two-way fluid bypass is provided for selectively permitting a flow of a fluid across the sealing mechanism. Finally, a one-way valve is located at the lower end of the fluid passage for selectively permitting a flow of a fluid in a first direction from the upper end to the lower end of the fluid passage and for preventing a flow of a fluid in a second direction from the lower end to the upper end of the fluid passage.

Abstract: An equalizer valve for a flapper in a subsurface safety valve is described. A tapered plunger is biased by compact spring disposed in the plunger bore. The spring is supported by a C-shaped ring extending into a peripheral groove around the plunger bore.

Abstract: A subsurface safety valve has a tubular valve housing, a valve closure member movable between an open and a closed position, an axially movable opening flow tube for opening the valve closure member. Hydraulic pressure from a control line is used to move a first piston, which in turn moves the axially movable opening prong through the closure member. A balance line can be used to provide a hydrostatic pressure against a second piston. The first and second pistons are coupled to a sliding member within the valve housing. Thus, the opposed piston arrangement substantially offsets any downward force on the first piston.

Abstract: In a drilling apparatus of the type comprising a housing, a proximal seal, a distal seal, a fluid chamber defined by an interior of the housing between the proximal seal and the distal seal, the fluid chamber containing a lubricating fluid having a fluid chamber pressure, a pressure compensation system for compensating for the effects of an ambient pressure exerted on an exterior of the apparatus. The pressure compensation system includes a pressure port in the housing so that the ambient pressure can be communicated to the fluid chamber and a supplementary pressure source for exerting a supplementary pressure on the lubricating fluid contained in the fluid chamber so that the fluid chamber pressure is maintained higher than the ambient pressure.

Abstract: The invention provides an apparatus for actuating a downhole tool by utilizing a pressure differential created by fluid flowing through a conduit. The conduit is in communication with a pressure sensing line that is selectively exposable to areas of the conduit having different pressures. By exposing the pressure sensing line to a portion of the conduit having a predetermined pressure therein, the pressure sensing line causes actuation of a hydraulic tool therebelow.

Abstract: A system and method for controlling production fluid flow from a chamber extending between a casing disposed in a downhole bore and tubing disposed in the casing. A plurality of valves are disposed in respective openings formed in the tubing, and a passage is formed in each valve for connecting the chamber and the tubing interior. The valves are selectively closed to prevent any fluid flow through the passage, and selectively opened to permit fluid flow from the chamber, through the passage, and into the interior of the tubing. Thus, the volume of fluid passing from the chamber, through the valve members, and to the interior of the tubing is controlled.

Abstract: A subsurface safety valve has a tubular valve housing, a valve closure member movable between an open and a closed position, an axially shiftable flow tube for opening the valve closure member. Hydraulic pressure from the control line is used to move a piston, which in turn moves an axially shiftable opening prong through the closure member. A balance line, or second hydraulic line is also used to make the valve well insensitive. An isolation valve is placed in the flow path of the second hydraulic line. The isolation valve prevents gas migration into the balance line. It also provides volume control for the fluid displaced when the piston is moved by pressure from the control line. Further, the valve can be closed by the application of sufficient pressure through the second hydraulic line.

Abstract: A subsurface valve with a pressure-equalizing mechanism is provided to permit pressure above and below a valve closure member to equalize prior to the opening of the valve closure member. The pressure-equalizing mechanism may be installed, for example, in the valve closure member or in an annular housing in the subsurface valve. The mechanism includes a pilot activator disposed for reciprocal movement within a pilot bore. A flow tube that is disposed for longitudinal movement with a longitudinal bore of the subsurface valve is used to shift the pilot activator within the pilot bore from a closed or sealed position to an open or equalizing position. In the open position, fluid pressure below the valve closure member is allowed to flow through a pilot passageway that establishes fluid communication between the pilot bore and a cylinder within which a pilot piston is moveably disposed.

Abstract: A pressure relief system includes a closed space having fluid trapped therein, a chamber defined in the closed space, and a pressure responsive member for controlling fluid flow from the closed space to the chamber. Fluid flows from the closed space to the chamber when the pressure in the closed space exceeds a predetermined pressure.

Abstract: A subsurface valve with a pressure equalizing mechanism is provided to permit pressure above and below a valve closure member to equalize prior to the opening of the valve closure member. An actuating key is releasably engageable with a recess in a flow tube that is moveably disposed within a longitudinal bore of the safety valve. An equalizing plug is disposed for reciprocal movement within a plug bore, and is moveable in response to movement of the actuating key. To open the valve closure member, the flow tube moves downwardly into engagement with the actuating key, thereby carrying the actuating key into engagement with the equalizing plug to shift the equalizing plug to an open or equalizing position. Pressure above and below the valve closure member is equalized through the equalizing plug prior to the opening of the valve closure member by further downward movement of the flow tube.

Abstract: A subsurface well safety valve having a flow tube telescopically movable in a housing for controlling the movement of a valve closure member. A piston and cylinder assembly actuates the flow tube and is in communication with hydraulic control fluid from the well surface on one side and a gas biasing chamber on the second side and includes a spring acting on the flow tube to close the valve. An equalizing system equalizes fluid pressure on opposite sides of the piston and cylinder assembly in the event of a failure in the seal between the piston and cylinder thereby allowing the spring to close the valve. The equalizing system uses fewer components than previous designs and utilizes a new reference chamber design that allows the reference chamber and the piston to be positioned within the same axial length reducing the overall length of the safety valve over previous designs.

Abstract: A downhole safety valve and method of operating a safety valve are provided. In general, the safety valve includes a housing having an interior fluid flow passage therethrough and at least one circulating port in the housing for providing fluid communication between the interior fluid flow passage and the exterior of the housing. A piston is operatively positioned within the housing for movement between a first position and a second position in response to a fluid pressure differential between the interior fluid flow passage and the exterior of the housing. A slip is operatively connected to the piston, whereby over a first range of the movement of the piston the slip moves with the piston, and over a second range of the movement of the piston the slip does not move with the piston. A first valve is positioned within the housing for opening and closing the interior fluid flow passage of the housing, and a second valve is positioned within the housing for opening and closing the circulating port.

Abstract: A release mechanism for use with setting wellbore isolation tools, such as packers or bridge plugs. The release mechanism typically includes a release piston which selectively isolates equalization ports extending from the interior to the exterior of a setting tool body. The release piston may be activated to allow equalization of pressure across the sealing elements of a set isolation tool, typically by applying pressure to the annular space above the isolation tool. The release mechanism may be used to allow a tool body (such as a setting or retrieving tool) to be removed from a set isolation tool under conditions in which high pressure differential exists across the isolation tool.

Abstract: A pressure equalizing subsurface safety valve with a fluid injection system is provided. A fluid injection conduit is connected from a source of injection fluid, such as at the earth's surface, to the subsurface safety valve. A fluid flowpath is provided in the safety valve to transmit injection fluid from the fluid injection conduit to a longitudinal bore of the safety valve. The injection fluids are introduced into the longitudinal bore to resist corrosion of or other damage to the safety valve. The fluid may be injected into the longitudinal bore through a single port, or through a plurality of ports. The fluid injection conduit may also be used to equalize pressure above and below a closure member disposed within the safety valve prior to the opening of the closure member.

Abstract: A downhole check valve includes a body (32) defining a flow passage and a valve assembly (34, 42, 44) mounted in the body, the valve assembly including a valve member (34) movable from a first configuration to a second configuration. In the first configuration the valve member prevents flow in one direction through the passage, and in the second configuration the valve member is retained in an open position. A valve member retaining sleeve (48) is normally restrained in a first configuration and biassed for movement to a second configuration. The retainer is held in the first configuration while the valve member (34) is in the first configuration and is releasable from the first configuration to move the valve member to the open position and retain the valve member in the open position.

Abstract: A sliding sleeve is provided to control the flow of fluids through a tubular conduit. The sliding sleeve may include a housing having a longitudinal bore, at least one annulus pressure port, and at least one fluid flow port. An inner sleeve is disposed for axial movement within the longitudinal bore of the housing, and includes at least one fluid flow port for sealably cooperating with the fluid flow port in the housing to control the flow of fluids through the tubing string. A piston is associated with the inner sleeve and the housing. The piston is initially releasably secured to the housing. The sliding sleeve is initially provided with the fluid flow ports in a closed position, and is actuated by applying annulus pressure to the piston through the at least one annulus pressure port in the housing. The annulus pressure releases the piston from the housing and forces the piston and inner sleeve upwardly to establish fluid communication through the fluid flow ports.

Abstract: A well tool is disclosed, which includes features that enhance the reliability and safety of wellsite operations. In one disclosed embodiment, a pressure relief device is incorporated in a well completion tool. The pressure relief device is in fluid communication with fluid delivery and return flowpaths of the tool. When a predetermined differential fluid pressure is experienced, the pressure relief device opens and permits fluid flow between the fluid delivery and return flowpaths. Associated methods of protecting well tools are disclosed as well.

Abstract: An improved control system, particularly useful for SSVs, is disclosed. The control system has an operating piston which acts on a flow tube to move a flapper to an open position. The flapper is spring-loaded to close when the flow tube moves up. A return spring acts on the piston to lift the flow tube to allow the flapper to close. The operating piston is exposed to a control line from the surface as well as to a bypass piston. Opposing the hydrostatic forces of the control line is a pressurized chamber with a pressure in excess of the hydrostatic pressure. A secondary chamber acts on one side of the equalizing piston and is pressurized to a pressure less than the anticipated hydrostatic pressure in the control line. The system, including the operating piston, is configured so that when leakage occurs into or out of the control system in many places, the SSV will fail toward its failsafe closed position.

Abstract: The invention relates to bypass valves for use in wellbores, particularly but not exclusively to bypass valves used during the setting of hydraulic anchor packers. The invention provides a bypass valve for selectively isolating the interior of a down-hole assembly from the exterior thereof, the bypass valve comprising guide pin in received slot being adapted to permit movement of a piston (30) from a first position to a second position in response to a predetermined pressure differential between a bore (58) of the piston (30) and the exterior of a body (4) but normally preventing movement of the piston (30) to a third position in which the bore (58) of the piston (30) is substantially isolated from the exterior of the body (4), and an extension of the guide slot for overriding the guide pins in the slot, so as to permit movement of the piston (30) to the third position.

Abstract: A subsurface safety valve having a valve member with a pressure equalizing mechanism is provided. The valve member includes a bore therethrough for receiving an equalizing plug. A beam is attached to the upper surface of the valve member for transferring downward motion of a flow tube to unseat the equalizing plug, and thereby establish fluid communication through the valve member prior to the opening of the valve member. A retention member is attached to the lower surface of the valve member to upwardly bias the equalizing plug within the plug bore of the valve member.

Abstract: Several motor driven embodiments are discussed which provide linear motion to a downhole flow control device. The embodiments employ ball screw assemblies or lead screw assemblies. A device for rotational actuation of a downhole flow control device is also disclosed.

Abstract: A tubing retrievable surface controlled subsurface safety valve 106 is adapted to be positioned in a well tubing string 102 to control the flow through the tubing string. The safety valve includes an annular housing or body 200 defining a fluid passageway through which fluids and/or gasses may flow to the surface. The safety valve is equipped with a valve closure member such as flapper 252, positioned in the fluid passageway which is moveable between an open and closed position. The valve closure member is engaged and actuated by a longitudinally extending operator 242 that engages the valve closure member 252. In one embodiment, the longitudinally extending operator 242 may be a tubular member longitudinally moveable within the valve body. The longitudinally extending member 242 is operatively coupled to a spring guide 226. A biasing spring 222 is positioned in a spring chamber 120 defined by a spring housing 228 and the spring guide 226. A spring 256 biases the closure member 252 in the closed position.

Abstract: A variable flow control device having a substantially cylindrical housing with a valve element connected to an inner surface thereof. The valve is movable between an open position and a closed position in the bore. One or more flow control orifices are located in the valve element for controlling the flow of fluids through the housing when the valve element is in the closed position. A drive mechanism is also connected to the valve element for controlling the size of the one or more flow control orifices. As such, a full bore variable flow control device is provided that controls the flow of wellbore fluids without permanent reduction of the internal bore of the production tubing. By closing the flapper valve and selecting the size of the variable orifices, total control of the production flow of the wellbore can be achieved. By opening the flapper valve, full bore wireline operations to the bottom of the well can be performed.

Abstract: A pressure responsive well tool is provided of the general type including a housing having a flow conducting passage therethrough, a pressure conducting channel formed in the housing, and a spring assembly in the housing for storing potential energy in response to an increase in fluid pressure within the pressure conducting channel and releasing the stored potential energy into the pressure conducting channel in response to a decrease in fluid pressure within the pressure conducting channel. A staged latching assembly is operatively connected to the spring assembly for providing at least one intermediate stage pressure position for the spring assembly. The staged latching assembly preferably includes interfering structures on a mandrel and a collet for providing the intermediate stage pressure position. The intermediate stage pressure position of the spring assembly can be used as a stage for selectively directing the spring assembly in either direction, thereby providing better control over the tool.

Abstract: A casing fill and circulator assembly is disclosed. The fill valve is constructed so that the valve member moves out of the main flowpath when the valve is in the open position. The valve is constructed so that flow opens it and the majority of the pressure drop is taken in an area other than the interface between the valve member and the seat. For circulation, the apparatus is advanced further into the casing until a cup seal closes off the top of the casing. Once flow is initiated in that condition, internal pressure in the casing, at very low applied pressures, opens a circulation valve and closes the fill valve so that circulation through the casing is accomplished through the circulation valve while bypassing the fill valve. Erosive effects from flow on the fill valve are thus eliminated during circulation. An alternative dual-function valve in a circulator/filling apparatus is also disclosed where a control system senses applied pressure in the apparatus and opens the valve.

Abstract: A device and method for selectively controlling the flow of production fluid through a tubing string in an oil and gas well according to which a housing is connected to a tubing string for insertion into the well, and well fluid is passed from the ground surface into the housing. The housing is provided with a plug to establish well fluid pressure in the housing to actuate a packer and/or other ancillary devices. The plug can be removed from the hosing by increasing the pressure of the well fluid in the housing above a predetermined value, thus permitting the flow of production fluid from the formation zone, through the housing and the tubing string, and to the ground surface.

Abstract: An annulus vent valve is provided to vent gas or other production fluids from below a packer set within a well in deep-set applications. The valve may broadly include: a body member having a first end, a second end, an outer surface, a longitudinal bore adjacent the second end, and at least one flow port extending from the longitudinal bore to the outer surface; a closure member mounted within the longitudinal bore to control fluid flow therethrough; a mechanism for biasing the closure member to a normally closed position to prevent fluid flow through the longitudinal bore; a closure member actuator disposed for movement within the longitudinal bore to open and close the closure member; a mechanism for biasing the closure member actuator away from the closure member; a piston connected to the closure member actuator and having a first end and a second end; and a gas chamber disposed within the body member and in communication with the second end of the piston.

Abstract: A down hole tool, constructed to be suspended in a well by pipe, includes a housing, a circulation piston, a biasing member and a pressure-compensation system. The housing defines a flow chamber in open fluid communication with the pipe interior, a bypass port for fluid flow between the flow chamber and the well, a mud chamber in open communication with the well, and a sealed chamber separated from the flow chamber by a sealed interface. The circulation piston separates the flow and mud chambers and is arranged for movement between a first, bypass port-blocking position and a second, bypass port-exposing position in response to pressure in the flow chamber. The biasing member biases the circulation piston to its first position, and the pressure-compensation system limits the pressure difference between the flow and sealed chambers, thereby limiting the pressure difference across the sealed interface. The tool has particular application to tools, e.g.

Abstract: A control system for the operation of the subsurface safety valve is disclosed. The control system uses a pressurized gas chamber, as well as a shuttle valve which connects to the main fluid pressure supply from the surface. The shuttle valve is connected to the gaseous chamber as well as to a barrier piston. As a result of the arrangement, leakages between the downstream side of the operating piston and the shuttle valve result in a reestablishment of the pressure balance on the operating system which allows the subsurface safety valve to close. Additionally, in the event of loss of gaseous pressure, the same pressure-balancing effect occurs on the operating piston, which allows the subsurface safety valve to go to a closed position. The configuration of the control system, which includes a gaseous chamber, allows for disconnection of the hydraulic fluid supply before the predetermined depth is reached to facilitate the connection of a tubing hanger.

Abstract: A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.

Abstract: A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.

Abstract: A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.

Abstract: An equalizing subsurface safety valve for controlling fluid flow in a well conduit has a tubular body member with a longitudinal bore extending therethrough, and a flapper hingably connected within the tubular body member to alternately permit and prevent fluid flow through the longitudinal bore. The flapper is biased to a normally closed position to prevent fluid flow through the longitudinal bore. A fluid passage is provided for fluid communication between the longitudinal bore adjacent a first side of the flapper when the flapper is in a closed position and a second side of the closed flapper. A valve closure member is mounted across the fluid passage adjacent the first side of the flapper and is movable along an axis generally transverse to the longitudinal bore, and abuts a valve seat assembly.

Abstract: A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.

Abstract: A new valve has been invented, in some aspects useful in wellbore operations and/or as a mud saver valve which valve has a body through which fluid is flowable, a valve seat connected in and to the body and through which fluid is flowable, a valve member positioned adjacent the valve seat and selectively movable to seat against the valve to close the valve to fluid flow and selectively movable away from the seat to open the valve to fluid flow, and at least one recess on the valve member for holding debris and thereby preventing the debris from inhibiting valve closure.

Abstract: A downhole tool apparatus (34) including a housing (42) adapted to be connected in a pipe string (30), the housing (42) having a generally cylindrical bore (44) defined therein, an operating assembly (112) disposed within the cylindrical bore (44) of the housing (42) having open and closed positions and a mandrel (142) slidably received in the cylindrical bore (44) of the housing (42) and adapted to be selectively telescoped between first and second axial positions relative to the housing (42) to manipulate the operating assembly (112) and selectively rotated between first and second circumferential positions relative to the housing (42) to selectively lock the mandrel (142) in an axial position relative to the housing (42).

Abstract: A retainer valve provides increased safety in wellsite operations. In a preferred embodiment, operation of the retainer valve may be responsive to control line pressure or to tubing pressure. The retainer valve response is controlled by several factors, among which are relative tubing and balance line pressures, and axial positions of a number of pistons relative to a tubular J-slot member. If the control and balance lines are disconnected, or otherwise unavailable for operation of the valve, it may still be operated by manipulation of the tubing pressure at the earth's surface. Thus, the valve may be opened in emergency situations in which the control and balance lines are unavailable, but operation of the valve is still needed in order to safely relieve trapped pressure in the tubing string and/or to kill the well, unlatch a subsea test tree, etc. The retainer valve is also useful as a lubricator valve.

Abstract: An equalizing subsurface safety valve for controlling fluid flow in a well conduit comprises a tubular body member having a longitudinal bore extending therethrough, a flapper hingably connected within the tubular body member to alternately permit and prevent fluid flow through the longitudinal bore, means for biasing the flapper to a normally closed position to prevent fluid flow through the longitudinal bore, a flow tube longitudinally movable within the longitudinal bore for controllably opening the flapper, fluid passage formed within the tubular body for providing fluid communication between the longitudinal bore adjacent a first side of the flapper and a second side of the flapper, and a closure member mounted across the fluid passage adjacent the first side of the flapper and movable along an axis generally transverse to the longitudinal bore.

Abstract: The invention relates to a control system for a subsurface safety valve (SSV). A pressure-balance feature is introduced such that the control system components are unaffected by the depth of placement of the SSV. Through the use of this feature, the standard hydraulic control system used for surface components can also be used for an SSV regardless of its depth of installation. In another feature of the invention, a shuttle valve is provided so that each time the SSV is stroked, a volume of control fluid is purged into the annulus. One embodiment of the shuttle valve may or may not be sensitive to annulus pressure and employs annulus pressure as an aid to stroking the shuttle valve upon application of surface control pressure to assist in actuation of the SSV, while at the same time providing for a purge of a controlled volume of fluid.

Abstract: A ball valve having the capability of cutting coiled tubing extending therethrough. The valve includes a ball rotatably disposed within a housing and adjacent to a seat. Control arms prevent relative longitudinal movement between the ball and seat. The ball defines a pair of slots therein, each slot having a bearing surface. A pair of control pins are disposed on opposite sides of the ball and rotatably disposed in corresponding control frames disposed on opposite sides of the ball. Each control pin has an end with a bearing surface thereon extending into a corresponding slot in the ball so that flat contact is provided between the control pin and the ball. This greater area of contact between the pins and the slots allows a greater load to be transmitted to the ball to provide the shearing load necessary to shear relatively large diameters of coiled tubing which extend through the open valve. The valve is opened and closed by pressure actuation of a piston.

Abstract: An equalizing subsurface safety valve for controlling fluid flow in a well conduit has a tubular body member with a longitudinal bore extending therethrough, and a flapper hingably connected within the tubular body member to alternately permit and prevent fluid flow through the longitudinal bore. The flapper is biased by a spring to a normally closed position to prevent fluid flow through the longitudinal bore. Surface controlled mechanisms are provided to control the opening of the flapper. A fluid passage is provided for fluid communication between the longitudinal bore adjacent a first side of the flapper when the flapper is in a closed position and a second side of the closed flapper. A valve closure member is mounted across the fluid passage adjacent the first side of the flapper and is movable along an axis generally transverse to the longitudinal bore. The valve closure member is contained so that it is prevented from possibly falling into the well.

Abstract: The present invention provides improved casing filling and circulating apparatus for running a casing string into a well bore using a drilling rig casing elevator and related equipment. The casing filling and circulating apparatus includes a flow passage therethrough and a check valve disposed within the flow passage for preventing spillage and for preventing fluid back-flow through the apparatus when the casing string is being lowered into a well bore. Additionally, the filling and circulating apparatus includes a pressure relief seal means which relieves pressure from the casing prior to when the filling and circulating apparatus is disconnected therefrom by back-flow through the apparatus thereby preventing spillage of fluid. Methods of using the casing filling and circulating apparatus are also provided.

Abstract: A tubing test valve (34, 34a) is described for use with a drill string (20) for pressure testing tubulars and downhole equipment, particularly in a cased hole (12) which has a permanent packer (16) fitted. The valve (34) permits self-filling during running-in, but allows pressure testing when stationary in the well (1). The valve (34) also permits multiple entry of the string to, and retrieval from, permanent packers without committing the tool to the locked open position. This is achieved by providing an apertured ball valve (50, 50a) in the tool housing (42, 42a) which can be moved axially and rotated with the bore (70A, 71A) of the housing (42, 42a). The ball valve has side orifices (54, 54a) and a top orifice (52a) which controls flow through the valve (34, 34a). In one embodiment the ball element (50) is suspended by coil spring (64) above the lower valve seat (56) during running-in and is closed for pressure testing by pressuring with fluid from above.

Abstract: The invention relates to a control system for a subsurface safety valve (SSV). A pressure-balance feature is introduced such that the control system components are unaffected by the depth of placement of the SSV. Through the use of this feature, the standard hydraulic control system used for surface components can also be used for an SSV regardless of its depth of installation. In another feature of the invention, a shuttle valve is provided so that each time the SSV is stroked, a volume of control fluid is purged into the annulus. One embodiment of the shuttle valve may or may not be sensitive to annulus pressure and employs annulus pressure as an aid to stroking the shuttle valve upon application of surface control pressure to assist in actuation of the SSV, while at the same time providing for a purge of a controlled volume of fluid.

Abstract: A well testing tool for use in high pressure wells where it is desired to pressure test the equipment includes a mandrel that is ported to the interior of the test string. The ported mandrel allows pressure to equalize between the interior of the string and an annular chamber formed between the mandrel and the tool housing, and thereby eliminates the tendency of the mandrel to deform into the chamber.

Abstract: A pressure test and bypass valve for use in well testing. The apparatus comprises a housing defining a central opening therein and a mandrel slidably disposed in the central opening. A ball valve allows fluid flow through the central opening when in an open position and prevents fluid flow therethrough when in a closed position. A sleeve valve allows communication between the central opening and a well annulus when in an open position and prevents communication between the central opening and the well annulus when in a closed position. The ball valve and sleeve valve are actuated substantially simultaneously in response to well annulus pressure. A rupture disc is ruptured due to differential pressure thereacross. This allows well annulus pressure to act across a differential area on the mandrel such that the mandrel is moved relative to the housing, thereby actuating the valves.

Abstract: An improved method is provided for producing natural gas from wells where gas production has been hampered by the infiltration of water which had heretofore been deemed too expensive to remove when compared to the amount of gas produced from the well. The method includes lowering a conduit from the surface into the well to a depth the water level is to be lowered. Water in the well is allowed to flow into the conduit in a single direction only. A volume of refined natural gas is injected into the conduit below the water contained therein. The injected gas expands within the conduit lifting the volume of water to the surface. Water removed from the well is transported with the injected gas to a storage and processing facility. Lowering of the water level in the well reduces the hydrostatic pressure exerted upon the gas producing horizon to allow gas to flow into the well. Produced gas is transported along with the water and injected gas.

Abstract: A well test string includes an annulus pressure responsive tester valve and a tubing conveyed perforating gun including a tubing pressure actuated time delay firing mechanism. A compression set packer is disposed in the test string between the tester valve and the perforating gun. The packer includes a bypass valve for communicating the well below the packer with the tubing bore. The bypass valve is operably associated with the packer so that the bypass valve is open prior to setting the packer and so that the bypass valve is closed as the packer is set. The compression set packer also includes a one-way equalizer valve for allowing one-way fluid flow from the well below the packer to the tubing bore. The equalizer valve is operably associated with a bypass valve so that the equalizer valve is inoperable when the bypass valve is open, and so that the equalizer valve is operable when the bypass valve is closed.

Abstract: A well pressure monitoring system in which a hydrocarbon fluid is being produced through a Christmas tree or similar flow controller apparatus. Well pressure is transmitted through a tap-off communicated to a pressure sensor. The pressure is thereafter transmitted to a base or control station. To avoid a major uncontrolled flow of the hydrocarbon from the well in the event of inadvertent breakage or accident to the monitoring system, an excess flow control valve is positioned between the well flow and the pressure sensor. The excess flow valve functions to cut off fluid flow, but is provided with a vent passage in the valve actuator through which a minimal amount of the hydrocarbon can escape. When the damage to the monitoring system has been overcome, the vent passage will allow a downstream pressure build-up in the closed system, thus permitting a biasing spring to automatically reset the valve to open and operable position, thereby stabilizing the pressure acting on the actuator.

Abstract: A metal to metal seal (10) is provided that comprises an annular seat (66), a seal member (90) having annular metal skirt (91) adapted to engage the annular seat (66), an undercut section behind the skirt (91), and an annular retainer member (78) disposed in the undercut section behind the skirt (91), the skirt (91) being adapted to deflect toward the retainer member (78) when pressured against the annular seat (66), the amount of deflection being limited by the angular distance between the skirt (91) and the retainer member (78). An annular stop member is provided (144) for optionally transferring excess bearing load around the skirt (91) and an adjustment member is provided (176) for selectively controlling the portion of the bearing load carried by the skirt (91) and to limit deflection of the skirt. Use of the subject metal to metal seal is (10) as a piston seal in surface controlled subsurface safety valves (38) employed in the oil and gas industry.