1. Field of the Invention
Embodiments of the invention generally relate to a pressure relief valve assembly for a casing.
2. Description of the Related Art
Traditional well construction, such as the drilling of an oil or gas well, includes a wellbore or borehole being drilled through a series of formations. Each formation, through which the well passes, must be sealed so as to avoid an undesirable passage of formation fluids, gases or materials out of the formation and into the borehole. Conventional well architecture includes cementing casings in the borehole to isolate or seal each formation. The casings prevent the collapse of the borehole wall and prevent the undesired inflow of fluids from the formation into the borehole.
In standard practice, each succeeding casing placed in the wellbore has an outside diameter significantly reduced in size when compared to the casing previously installed. The borehole is drilled in intervals whereby a casing, which is to be installed in a lower borehole interval, is lowered through a previously installed casing of an upper borehole interval and then cemented in the borehole. The purpose of the cement around the casing is to fix the casing in the well and to seal the borehole around the casing in order to prevent vertical flow of fluid alongside the casing towards other formation layers or even to the earth's surface.
If the cement seal is breached, due to high pressure in the formations and/or poor bonding in the cement for example, fluids (liquid or gas) may begin to migrate up the borehole. The fluids may flow into the annuli between previously installed casings and cause undesirable pressure differentials across the casings. The fluid gas may also flow into the annuli between the casings and other drilling or production tubular members that are disposed in the borehole. Some of the casings and other tubulars, such as the larger diameter casings, may not be rated to handle the unexpected pressure increases, which can result in the collapse or burst of a casing or tubular.
Therefore, there is a need for apparatus and methods to prevent wellbore casing or tubular failure due to unexpected downhole pressure changes.
In one embodiment, a valve assembly includes a tubular body having a port for fluid communication; a collar disposed around the tubular body; and a closure member disposed inside the collar and configured to control fluid communication through the port in response to a pressure differential. In another embodiment, the collar is eccentrically disposed relative to the body. In yet another embodiment, the closure member may be a sleeve or a piston.
In another embodiment, a valve assembly includes a tubular body having a port for fluid communication between an exterior of the valve assembly and an interior of the valve assembly; a chamber formed in a wall of the tubular body, the chamber in fluid communication with the port; and a closure member disposed in the chamber and configured to control fluid communication through the port in response to a pressure differential. In yet another embodiment, the valve assembly includes a biasing member for biasing the closure member in a closed position. The valve assembly may include a plug disposed on an end opposite the closure member. In one aspect, the activation force of the closure member is adjustable. The activation force may be adjusted by changing a location of the plug.
In another embodiment, the chamber is formed at an angle relative to a longitudinal axis of the tubular body. The angle may be an acute angle, or the angle may be about 5 degrees to 75 degrees. In yet another embodiment, the chamber is substantially formed in a raised portion of the wall having an increased wall thickness. In yet another embodiment, a fluid path formed on the raised portion in communication with the exterior port.
So that the manner in which the above recited features of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In one embodiment, a pressure relief valve assembly may be coupled to one or more casings and/or tubular members to control fluid communication therebetween. The valve assembly is a one-way valve assembly that relieves pressure within an annulus formed between adjacent casings and/or tubular members to prevent burst or collapse of the casings and/or tubular members. The valve assembly may be resettable downhole.
The wellbore 5 may intersect a high pressure zone 50 within the formation 80. Fluids within the high pressure zone 50 are sealed from the annulus A and B by the sealing material 25 that is disposed between the casing 20 and the wellbore wall. In the event that the sealing material 25 is breached or otherwise compromised, pressurized fluids may migrate upward into the annulus A and cause an unexpected pressure increase. The pressure rise may form a pressure differential across the casings 10, 20 that, if unchecked, may result in leakage through or burst of casing 10, and/or leakage through or collapse of casing 20. One or more valve assemblies 100, 200, 600 are provided to relieve the pressure in the annulus A prior to failure of one or both of the casings 10, 20.
A tubular collar 110 is disposed around the outside of the body 105, as shown in
The valve assembly 100 includes a closure member for operating the relief ports 115. An exemplary closure member is an annular closure sleeve 120. The closure sleeve 120 is movably disposed in the chamber 113. As shown, the closure sleeve 120 is biased in the closed position using a biasing member 135. Exemplary biasing members include a coil spring or a wave spring. The biasing member 135 may be configured to retract in response to a force near or below the collapse rating of the casing 20 or burst rating of casing 10. In the closed position, the closure sleeve 120 blocks fluid communication through the relief ports 115. However, the portion of the chamber 113 above the closure sleeve 120 may fluidly communicate with the bore 101 through a vent port 119. Seals 131 such o-rings may be positioned on the body 105 or the closure sleeve 120 for sealing contact with the closure sleeve 120 or the body 105, respectively. Additionally, a seal 132 may be positioned on the closure sleeve 120 or the collar 110 for sealing contact with the collar 110 or the closure sleeve 120, respectively. If a second collar port 122 is used, the seal 132 is preferably disposed above the second collar port 122.
Referring back to
During operation, pressure in the annulus A may act on the closure sleeve 120 via the first collar port 121 to move the closure sleeve 120 against the force of the biasing member 135. When the pressure in annulus A overcomes the biasing force plus force generated from pressure within casing communicated via port 119, the closure sleeve 120 is retracted to expose the relief ports 115.
When the pressure in the annulus A decreases below the biasing force of the biasing member 135 plus the pressure in annulus B, the biasing member 135 returns the closure sleeve 120 to the closed position, thereby closing off fluid communication through the relief ports 115. In this manner, the valve assembly 100 is operable as a one-way valve in that it will permit fluid flow into the bore 101 of the valve assembly 100 but will prevent fluid flow out of the bore 101 via the relief port 115. The valve assembly 100 is automatically resettable downhole and may be operated multiple times in response to any pressure fluctuations within the wellbore 5.
In another embodiment, the closure sleeve 120 may be held in the open position using a releasable holder. Exemplary releasable holders include a detent, a catch, a collect, or other suitable releasable holding mechanism having a threshold force for releasing an object being held. The releasable holder can releasably hold the closure sleeve 120 in the open position until a predetermined closing pressure differential is reached. In that respect, the predetermined closing pressure differential is lower than the opening pressure differential required to move the closure sleeve 120. In one example, a detent mechanism may include a c-ring coupled to the closure sleeve 120 that engages a shoulder of the collar 110. When moved to the open position, the closure sleeve 120 may move the c-ring across the shoulder with minimal resistance, but when moved to the closed position, the closure sleeve 120 may encounter a greater resistance to move the c-ring across the shoulder. Other detent arrangements may be use with the embodiments described herein.
In operation, the closure sleeve is retracted to expose the relief port when the opening pressure differential is reached; that is, when the pressure in annulus A overcomes the biasing force plus force generated from pressure within casing communicated via port 119. The closure sleeve 120 is held in the open position by the releasable holder until a predetermined closing pressure differential is reached; that is, when the pressure in annulus A is less than the combined force of the biasing force, force from pressure in annulus B, and the force required to release the releasable holder. In this respect, the releasable holder may prevent the closure member 120, 220, 620 from oscillating between the open and closed positions due to minor pressure differential fluctuations.
In another embodiment, the valve assembly uses a piston rod to control the relief port instead of the closure sleeve. In this respect, the annular chamber 113 shown in
A tubular collar 210 is disposed around the outside of the body 205, as shown in
The closure member 220 is used to operate the relief ports 215. An exemplary closure member is a piston 220. The piston 220 includes a piston head 232 and a guide rod 233. The piston head 232 has a larger diameter distal end and smaller diameter proximal end. Seals 231, 234 such as o-rings are provided at each end for sealing engagement with the chamber 213 when in the closed position. The piston 220 is movably disposed in the chamber 213. As shown, the piston 220 is biased in the closed position using a biasing member 235. Exemplary biasing members 235 include a coil spring or a wave spring. The biasing member 235 may be configured to retract in response to a force near or below the burst or collapse rating of the casing 20.
In the closed position, the piston 220 blocks fluid communication through the relief ports 215. However, the relief ports 215 can fluidly communication with a portion of the chamber 213 via a first internal port 236. The first internal port 236 is straddled by the seals 231, 234 at the two ends. Additionally, the relief ports 215 can fluidly communicate with the portion of the chamber 213 above the seal 234 at the proximal end via a second internal port 237. In this respect, fluid pressure in the bore 201 of the body 205 may provide an additional closing force on the piston 220. The second internal port 237 also allows the fluid above the seal 234 to vent when the piston 220 retracts during opening.
Referring back to
During operation, pressure in the annulus A may act on the piston 220 via the first collar port 221 to move the piston 220 against the force of the biasing member 235 and the pressure in annulus B acting on the piston 220 via the first and second internal ports 236, 237. When the pressure in annulus A overcomes the biasing force and the annulus B pressure, the piston 220 is retracted to expose the relief ports 215.
When the force on piston 220 due to pressure in the annulus A decreases below the sum of the force on piston 220 due to pressure in annulus B plus the biasing force of the biasing member 235, the biasing member 235 returns the piston 220 to the closed position, thereby closing off fluid communication through the relief port 215. In this manner, the valve assembly 200 is operable as a one-way valve in that it will permit fluid flow into the bore 201 of the valve assembly 200 but will prevent fluid flow out of the bore 201 via the relief port 215. The valve assembly 200 is automatically resettable downhole and may be operated multiple times in response to any pressure fluctuations within the wellbore 5. As stated above, any of the casings 10, 20, 30 and/or the tubular members 40, 45 may each be provided with one or more valve assemblies 200 to allow fluid flow from a surrounding casing or tubular member to an inner casing or tubular member, while preventing fluid flow in the opposite direction.
A tubular collar 610 is disposed around the outside of the body 605, as shown in
The closure member 620 is used to operate the relief ports 615. An exemplary closure member is a piston 620. The piston 620 includes a piston head 632 and a guide rod 633. The piston head 632 has a smaller diameter middle section. Seals 631, 634, 638 such as o-rings are provided at each end for sealing engagement with the chamber 613 when in the closed position. As shown, seals 634 and 638 are positioned to close off the inflow port 618. The piston 620 is movably disposed in the chamber 613. As shown, the piston 620 is biased in the closed position using a biasing member 635. Exemplary biasing members 635 include a coil spring or a wave spring. The biasing member 635 may be configured to retract in response to a force near or below the burst or collapse rating of the casing 20.
In the closed position, the piston 620 blocks fluid communication through the relief ports 615. However, the relief ports 615 can fluidly communication with a portion of the chamber 613 via a first internal port 636. The first internal port 636 is straddled by the seals 631, 634 at the two ends. Additionally, the bore 601 can fluidly communicate with the portion of the chamber 613 above seal 638 at the proximal end via a second internal port 637 and vent port 639. In this respect, fluid pressure in the bore 601 of the body 605 may provide an additional closing force on the piston 620. The second internal port 637 also allows the fluid above the seal 638 to vent when the piston 620 retracts during opening.
Referring back to
During operation, pressure in the annulus A may act on the piston 620 via the first collar port 621 to move the piston 620 against the force of the biasing member 635 and the pressure in annulus B acting on the piston 620 via the first and second internal ports 636, 637. When the pressure in annulus A overcomes the biasing force and the annulus B pressure, the piston 620 is retracted to open the inflow port 618 and place the inflow port 618 in fluid communication with the relief ports 615.
When the force on piston 620 due to pressure in the annulus A decreases below the sum of the force on piston 620 due to pressure in annulus B plus the biasing force of the biasing member 635, the biasing member 635 returns the piston 620 to the closed position, thereby closing off fluid communication through the relief port 615. In this manner, the valve assembly 600 is operable as a one-way valve in that it will permit fluid flow into the bore 601 of the valve assembly 600 but will prevent fluid flow out of the bore 601 via the relief port 615. The valve assembly 600 is automatically resettable downhole and may be operated multiple times in response to any pressure fluctuations within the wellbore 5. As stated above, any of the casings 10, 20, 30 and/or the tubular members 40, 45 may each be provided with one or more valve assemblies 600 to allow fluid flow from a surrounding casing or tubular member to an inner casing or tubular member, while preventing fluid flow in the opposite direction.
In any of the embodiments described herein, the closure member 120, 220, 620 may be held in the open position using a releasable holder as described above. The releasable holder can releasably hold the closure member 120, 220, 620 in the open position until a predetermined closing pressure differential is reached. In that respect, the predetermined closing pressure differential is lower than the opening pressure differential required to move the closure member 120, 220, 620. In one example, a detent mechanism may include a c-ring coupled to the piston 620 that engages a shoulder of the collar 610. When moved to the open position, the piston 620 may move the c-ring across the shoulder with minimal resistance, but when moved to the closed position, the piston 620 may encounter a greater resistance to move the c-ring across the shoulder. Other detent arrangements may be use with the embodiments described herein.
In operation, the closure member 120, 220, 620 is retracted to expose the relief port when the opening pressure differential is reached; that is, when the pressure in annulus A overcomes the biasing force plus force generated from pressure with casing communicated via port. The closure member 120, 220, 620 is held in the open position by the releasable holder until a predetermined closing pressure differential is reached. In this respect, the releasable holder may prevent the closure member 120, 220, 620 from oscillating between the open and closed positions due to minor pressure differential fluctuations.
In yet another embodiment, a pressure relief valve may be sized for positioning in a hole formed through a wall of the casing or an enlarged section of the casing. In the embodiment shown in
In
The tubular body 705 includes a chamber 713 for housing a closure member 720. The closure member 720 is used to operate the relief port 715. An exemplary closure member is a piston 720. In one embodiment, the piston 720 includes a first portion 721 having a smaller diameter than a second portion 722. A seal 731, 732 is disposed around each of the first and second portions 721, 722 of the piston 720 for sealing engagement with the chamber 713. An exemplary seal is an o-ring. The piston 720 is movably disposed in the chamber 713 to operate the valve. As shown, the piston 720 is biased in the closed position using a biasing member 735. Exemplary biasing members 735 include a coil spring or a wave spring. The biasing member 735 may be configured to retract in response to a force near or below the burst or collapse rating of the casing 20. One or more plugs may optionally be used to enclose the chamber 713. In the embodiment as shown, three plugs 727, 728 are used to close off openings in the tubular body 705 formed during manufacture of the valve assembly 700. The plugs 727, 728 may optionally include a seal 726, a retaining ring 729, or both.
In one embodiment, the chamber 713 can fluidly communicate with the relief port 715 and a chamber port 719 of the body 705. The relief port 715 allows fluid communication between the bore 701 and the portion 741 of the chamber 713 defined by the first seal 731. The chamber port 719 allows fluid communication between the bore 701 and the portion 742 of the chamber 713 defined by the second seal 732. An inflow port 718 and an actuation port 745 allow fluid communication between the exterior of the tubular body 705 and the portion 743 of the chamber 713 between the first seal 731 and the second seal 732. In this respect, these ports 718, 745 are blocked from fluid communication with the bore by the closure member 720 when the valve assembly 700 is in the closed position. The inflow port 718 and the actuation port 745 are positioned such that in the open position, the inflow port 718 is allowed to communicate with the relief port 715, and the actuation port 745 remains blocked from communication with the bore 701.
Referring back to
When the pressure in annulus A is sufficient to overcome the biasing force and the force from the annulus B pressure, the piston 720 is retracted to open the inflow port 718 and place the inflow port 718 in fluid communication with the relief port 715.
When the force on piston 720 due to pressure in the annulus A decreases below the sum of the force on piston 720 due to pressure in annulus B plus the biasing force of the biasing member 735, the biasing member 735 returns the piston 720 to the closed position, thereby closing off fluid communication through the relief port 715. In this manner, the valve assembly 700 is operable as a one-way valve in that it will permit fluid flow into the bore 701 of the valve assembly 700 but will prevent fluid flow out of the bore 701 via the relief port 715. The valve assembly 700 is automatically resettable downhole and may be operated multiple times in response to any pressure fluctuations within the wellbore 5. As stated above, any of the casings 10, 20, 30 and/or the tubular members 40, 45 may each be provided with one or more valve assemblies 700 to allow fluid flow from a surrounding casing or tubular member to an inner casing or tubular member, while preventing fluid flow in the opposite direction.
Referring to
The tubular body 805 includes a chamber 813 for housing a closure member 820. The closure member 820 is used to operate the relief port 815. An exemplary closure member is a piston 820, as illustrated in
In another embodiment, optional cap seals 871, 872 may be disposed around the seals 831, 832. The cap seals 871, 872 may be manufactured from a material having a lower frictional property than the material of the seals 831, 832. Exemplary cap seal materials include polytetrafluorethylene such as Teflon® and thermoplastics such as PEEK. The cap seals 871, 872 may have an annular shape and configured to receive an o-ring seal at its inner surface. The cap seals 871, 872 may prevent extrusion of the o-ring seals during use. The seals 831, 832 may be made from a polymer and may energize the cap seals 871, 872. In another embodiment, the cap seal 871 may include shoulders adapted to engage protrusions that extend into the recess 851. As such, the shoulders and protrusions may prevent extrusion of the cap seal 871. It must be noted that although two different embodiments of the cap seals are shown, the two cap seals 871, 872 on the piston 820 may be the same or different embodiments. Additionally, one or both of the seals 831, 832 may be provided with an optional cap seal; for example, seal 832 is not provided with a cap seal 872, and seal 831 is provided with a cap seal 871.
Referring back to
A plug 828 is provided to engage the other end of the biasing member 835 and to enclose the chamber 813.
In one embodiment, the valve assembly 800 includes an adjustable activation pressure feature. Referring again to
Referring to
Referring back to
When the pressure in annulus A is sufficient to overcome the biasing force of the biasing member 835 and the force from the annulus B pressure, the piston 820 is retracted to open the inflow port 818 and place the inflow port 818 in fluid communication with the relief port 815.
When the force on piston 820 due to pressure in the annulus A falls below the sum of the force on piston 820 due to pressure in annulus B plus the biasing force of the biasing member 835, the biasing member 835 returns the piston 820 to the closed position, thereby closing off fluid communication through the relief port 815. In this manner, the valve assembly 800 is operable as a one-way valve in that it will permit fluid flow into the bore 801 of the valve assembly 800 but will prevent fluid flow out of the bore 801 via the relief port 815. The valve assembly 800 is automatically resettable downhole and may be operated multiple times in response to any pressure fluctuations within the wellbore 5. As stated above, any of the casings 10, 20, 30 and/or the tubular members 40, 45 may each be provided with one or more valve assemblies 800 to allow fluid flow from a surrounding casing or tubular member to an inner casing or tubular member, while preventing fluid flow in the opposite direction.
The tubular body 905 has an axial bore 901 formed therethrough and may include threads at its ends for connection to a tubular such as casing 20. In another embodiment, the tubular body 905 may be integral with the casing 20. The body profile of the tubular body 905 may generally be concentric. In another embodiment, the tubular body 905 may be eccentric.
In one embodiment, a pad 908 is provided on the outer surface of the tubular body 905. As shown in
The chamber 913 for housing the valve components is substantially formed through the pad 908 of the tubular body 905. An opening 975 is provided for access to the chamber 913 and installed of the valve components. In one embodiment, the chamber 913 is formed at an angle relative to the longitudinal axis of the tubular body 905, as shown in
In one embodiment, the chamber 913 is formed by drilling through at least a portion of the pad 908. In this respect, the chamber 913 is in the form of a bore, wherein an axis of the bore is angled relative to the longitudinal axis of the tubular body 905. In another embodiment, the bore may be angled relative to at least two planes.
In another embodiment, the chamber 913 may be positioned substantially parallel with the longitudinal axis. For example, in a casing having a larger annular clearance, the chamber 913 may be formed through the pad at an angle from about 0 degrees to 45 degrees relative to the longitudinal axis.
Similar to the chamber 913 of
Referring to
It is contemplated the fluid path 933 may have any suitable arrangement. For example, the flow path 933 may be one or more channels formed in the pad 908 that intersect with one or both of the ports 918, 945. Also, the fluid path 933 may be a counter-sink recess formed around the one or both of the ports 918, 945. In yet another example, the ports 918, 945 may have separate fluid paths 933.
In any of the embodiments described herein, any of the casings 10, 20, 30 and/or the tubular members 40, 45 may each be provided with one or more valve assemblies 100, 200, 300, 400, 500, 600, 700, 800 to allow fluid flow from a surrounding casing or tubular member to an inner casing or tubular member, while preventing fluid flow in the opposite direction. In one embodiment, a casing or tubular member may be provided with multiple valve assemblies that are spaced apart along the length of the casing or tubular member. The valve assemblies 100, 200, 300, 400, 500, 600, 700, 800 may be operable to open and/or close at different pre-determined pressure setting.
Embodiments of the valve assemblies 100, 200, 300, 400, 500, 600, 700, 800 may be used to prevent collapse of a casing. For example, during an uncontrolled flow situation such as a catastrophic blowout, the hot hydrocarbon fluids from lower portions of the well may heat the fluid which is trapped in the annular space between an outer casing and an inner casing. The annular space may extend from top of the cement level to liner hanger. If the inner casing extends to the surface, then the annul area may extend from the top of the cement level and up to the surface. When the trapped fluid in the annular space is heated by the hot hydrocarbon fluids, the trapped fluid will expand. In some instances, this expansion can collapse the inner casing, thereby making future mitigation of the well more problematic. In this situation, presence of the valve assemblies 100, 200, 300, 400, 500, 600, 700, 800 allow the inner casing to bleed the pressure caused by the heat expansion. As a result, easier methods such as a capping stack can be used to get the well under control again.
In one embodiment, a valve assembly includes a tubular body having a port for fluid communication; a collar disposed around the tubular body; and a closure member disposed inside the collar and configured to control fluid communication through the port in response to a pressure differential. In another embodiment, the collar is eccentrically disposed relative to the body. In yet another embodiment, the closure member may be a sleeve or a piston.
In one embodiment, a valve assembly includes a tubular body having a port for fluid communication; a collar disposed around the tubular body; and a closure member disposed inside the collar and configured to control fluid communication through the port in response to a pressure differential.
In one or more of the embodiments described herein, the collar is eccentrically disposed relative to the body.
In one or more of the embodiments described herein, the closure member comprises a sleeve.
In one or more of the embodiments described herein, a seal is disposed on the closure member.
In one or more of the embodiments described herein, the collar and the body are integrally formed. In one or more of the embodiments described herein, the collar is formed as an enlarged section of the body.
In another embodiment, a method of controlling fluid communication between an exterior of a wellbore tubular and an interior of the wellbore tubular includes installing a valve assembly on the wellbore tubular, wherein the valve assembly includes a collar for housing a closure member and the closure member is configured to operate a port in the valve assembly; and moving the closure member away from the port to open the port in response to a predetermined pressure differential. In one or more of the embodiments described herein, the valve assembly further includes a body and the collar is eccentrically disposed around the body.
In one embodiment, a valve assembly includes a tubular body having a port for fluid communication between an exterior of the valve assembly and an interior of the valve assembly; a chamber formed in a wall of the tubular body, the chamber in fluid communication with the port; and a closure member disposed in the chamber and configured to control fluid communication through the port in response to a pressure differential.
In one or more of the embodiments described herein, the closure member includes a first portion having a smaller diameter than a second portion.
In one or more of the embodiments described herein, the valve assembly includes a seal disposed on each of the first portion and the second portion of the closure member.
In one or more of the embodiments described herein, a cap seal is disposed around the seal, wherein the cap seal has an outer surface that has less friction than the seal.
In one or more of the embodiments described herein, a biasing member is provided to bias the closure member in a closed position. In one or more of the embodiments described herein, a plug disposed on an end opposite the closure member.
In one or more of the embodiments described herein, an activation force of the closure member is adjustable.
In one or more of the embodiments described herein, the activation force is adjusted by changing a location of the plug.
In one or more of the embodiments described herein, the closure member is disposed in an enlarged cross-section of the tubular body.
In one or more of the embodiments described herein, the tubular body has an eccentric outer shape.
In one or more of the embodiments described herein, the closure member comprises a piston.
In another embodiment, a valve assembly includes a tubular body having an exterior port for fluid communication with an exterior of the valve assembly; and an interior port for fluid communication with an interior of the valve assembly; a chamber formed in a wall of the tubular body, the chamber in selective fluid communication with the interior port; a closure member disposed in the chamber and configured to control fluid communication through the interior port in response to a pressure differential between the exterior and the interior of the valve assembly; and a biasing member for biasing the closure member in a closed position.
In one or more of the embodiments described herein, the pressure differential required to open the valve assembly is adjustable.
In one or more of the embodiments described herein, the closure member includes a first portion having a smaller diameter than a second portion. In one or more of the embodiments described herein, a first seal disposed on the first portion and a second seal disposed on the second portion. In one or more of the embodiments described herein, the exterior port is located between the first seal and the second seal. In one or more of the embodiments described herein, the interior port is located ahead of the first seal.
In one or more of the embodiments described herein, a cap seal is disposed around at least one of the first seal and the second seal. In one or more of the embodiments described herein, the cap seal is configured to prevent extrusion from the closure member.
In one or more of the embodiments described herein, a plug is disposed on an end opposite the closure member. In one or more of the embodiments described herein, a distance between the plug and the closure member in the closed position is adjustable.
In one or more of the embodiments described herein, the chamber is formed at an angle relative to a longitudinal axis of the tubular body. In one or more of the embodiments described herein, the angle is about 15 degrees to 75 degrees.
In one or more of the embodiments described herein, the chamber is substantially formed in a raised portion of the wall having an increased wall thickness.
In one or more of the embodiments described herein, a fluid path formed on the raised portion in communication with the exterior port.
In another embodiment, a method of operating a valve assembly includes coupling a valve assembly to a casing, the valve assembly having a tubular body having a port for fluid communication between an exterior of the valve assembly and an interior of the valve assembly; a chamber formed in a wall of the tubular body, the chamber in fluid communication with the port; and a closure member disposed in the chamber and configured to control fluid communication through the port. The method further comprising opening the valve assembly in response to a predetermined pressure differential between the exterior and the interior of the valve assembly.
In one or more embodiments described herein, the valve assembly is configured to open at a predetermined pressure differential, thereby to preventing burst or collapse of the casings and/or tubular members.
While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims benefit of U.S. Provisional Patent Application Ser. No. 61/605,568, filed Mar. 1, 2012; and benefit of U.S. Provisional Patent Application Ser. No. 61/583,085, filed Jan. 4, 2012; and benefit of U.S. Provisional Patent Application Ser. No. 61/535,840, filed Sep. 16, 2011; and benefit of U.S. Provisional Patent Application Ser. No. 61/481,135, filed Apr. 29, 2011, which applications are incorporated herein by reference in their entirety.
Number | Date | Country | |
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61605568 | Mar 2012 | US | |
61583085 | Jan 2012 | US | |
61535840 | Sep 2011 | US | |
61481135 | Apr 2011 | US |