The present disclosure generally relates to oilfield equipment and, in particular, to materials used in downhole tools and wellbore systems. More particularly still, the present disclosure relates to methods and systems for operating a downhole valve, such as a downhole flapper valve.
Surface controlled, subsurface safety valves are commonly used to shut in oil and gas wells in the event of a failure or hazardous condition at the well surface. Such safety valves are typically fitted into the production tubing and operate to block the flow of formation fluid upwardly therethrough. The subsurface safety valve provides shutoff of production flow in response to a variety of out-of-range safety conditions that can be sensed or indicated at the surface. For example, the out-of-range safety conditions may include a fire on the platform, a high or low flow line temperature or pressure condition, or operator override.
During production, a hydraulically operated subsurface safety valve is typically held open by the application of hydraulic fluid pressure via an auxiliary control conduit that extends along the tubing string within an annulus between the tubing and the well casing. Flapper type subsurface safety valves utilize a closure plate which is actuated by longitudinal movement of a hydraulically actuated operator tube system, which can be a rod-style piston, a concentric tubular piston, or in the case of an electrically operated subsurface safety valve, an electro-mechanical operator. The flapper valve closure plate is maintained in the valve open position by an operator tube which is extended by the application of hydraulic pressure onto the piston. Upon removal of the operator tube from the flapper plate, the flapper plate is then rotated to the valve closed position by a torsion spring or tension member.
Typically, the flapper closure plate is supported for rotational movement by a hinge assembly that includes a hinge pin and a torsion spring or tension member. Generally, the torsion spring is looped around the hinge pin to urge the flapper valve to the valve closed position. These valves generally require clearance near the pivot pin of the flapper to allow for the torsion spring to be positioned about the pivot pin. Providing this clearance near the pivot pin reduces the size of the hinge pin or surrounding elements of the flapper valve.
The present disclosure is directed to subsurface equipment, such as a flapper valve with a beam spring and methods that overcome one or more of the shortcomings in the prior art.
Various embodiments of the present disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure. In the drawings, like reference numbers may indicate identical or functionally similar elements. Embodiments are described in detail hereinafter with reference to the accompanying figures, in which:
Referring initially to
A wellbore 75 extends through the various earth strata including the formation 20 and has a casing string 80 cemented therein. Disposed in a substantially horizontal portion of the wellbore 75 is a lower completion assembly 85 that includes at least one screen assembly, such as screen assembly 90 or screen assembly 95 or screen assembly 100, and may include various other components, such as a latch subassembly 105, a packer 110, a packer 115, a packer 120, and a packer 125.
Disposed in the wellbore 75 is an upper completion assembly 130 that couples to the latch subassembly 105 to place the upper completion assembly 130 and the tubing 70 in communication with the lower completion assembly 85. In some embodiments, the latch subassembly 105 is omitted.
A subsurface safety valve assembly 135, which includes a flapper valve plate and a spring, is located within the production tubing 70 or is in series with the production tubing 70. The safety valve assembly 135 closes to seal the wellhead 40 from the well formation 20 in the event of abnormal conditions. Generally, during production from the well formation 20, the flapper valve plate is maintained in the valve open position by hydraulic control pressure received from a surface control system through a control conduit or a variety of other mechanisms.
Referring now to
In one or more example embodiments, a flapper plate 140 is pivotally mounted onto a hinge sub 145 via a hinge assembly 147, with the hinge sub 145 being fixedly coupled relative to the housing 135a. In one or more example embodiments, a valve seat 150 is confined within a counterbore formed on the hinge sub 145 or at least in part by the hinge sub 145. In one or more example embodiments, the valve seat 150 forms a portion of the passage 135b. Generally, the flapper plate 140 is positioned to move within a flapper chamber 155 between an open position and a closed position. In some embodiments, the flapper chamber 155 is formed within the passage 135b and along a longitudinal axis 135c of the housing 135a between the valve seat 150 and an internal shoulder 160 spaced from the valve seat 150. While the flapper plate 140 is illustrated as pivotally mounted onto the hinge sub 145, there are multiple configurations, as illustrated herein, for pivotally mounting the flapper plate 140 relative to the valve seat 150. For example, and in some embodiments, the hinge sub 145 is integrally formed with the housing 135a and thus the plate 140 is mounted to the housing 135a. In some embodiments, the hinge sub 145 is a valve housing and forms the flapper chamber 155. Regardless, the flapper plate 140 pivots about a pivot axis or pivot point 165 via a pin 170 that extends through the flapper plate 140 and a portion of the hinge sub 145. The flapper plate 140 is biased to the valve closed position as shown in
In some embodiments and as illustrated in
In some embodiments, the bridge portion 175c is accommodated in the spacing 308. In some embodiments, an outwardly-facing groove 330 is formed in the sub 145 and sized to accommodate the bridge portion 175d of the spring 175. When the bridge portion 175d of the spring 175 is accommodated in the groove 330, the bridge portion 175d of the spring 175 is fixed relative to the sub 145 (fixed along the axis 135c of the housing 135a and generally fixed rotationally relative to the groove 330) while the bridge portion 175c is longitudinally movable along the axes 135c and 140a and movable rotationally relative to the plate 140 within the spacing 308.
During operation and as illustrated in
When the plate 140 is in the closed position and as illustrated in
As the flapper plate 140 is opened, forces increase in the spring 175 allowing the spring 175 to stress. As such, the arms 175a and 175b activate, energize, load, or flex and move the bridge portion 175c towards and against the shoulders 306a and 307a, which shifts the bridge portion 175c closer to the pivot point 165 (from TA1 to TA2), allowing for a new loaded configuration. As the bridge portion 175c slides across the upper surface 185 of the flapper plate 140 to reduce TA1 to TA2, the valve assembly 135 is a variable torque valve. That is, the location along the flapper plate (measured along the axis 140a) at which the spring 175 applies load varies between the open and closed position to provide variable torque.
When the plate 140 is in the open position and as illustrated in
To ensure the flapper plate 140 opens completely, the footprint of the spring 175 when viewed in the cross-section view of
Generally, the spring 175 is composed of a material with a selected Young's Modulus and the arms 175a, 175b are sized with a cross-section that provides predetermined strength and elastic properties. In some embodiments, the dual arm and the curved geometry of the spring 175 prevents the spring 175 from overstressing when the plate 140 is in the open position. In some embodiments, shortening of the torque arm from TA1 to TA2 reduces the stresses on the spring 175. In some embodiments, Zopen being spaced from the pivot point 165 in a direction opposite from Zclosed reduces the stresses on the spring 175 and/or the plate 140. In some embodiments, the compressional strength of the spring 175 is dependent, almost entirely, from R1 (illustrated in
Another embodiment of the spring 175 is identified by the numeral 350 in
In some embodiments, the springs 175 and 350 reduce or eliminate interference with the performance of a resilient seal positioned near the pin 170 by reducing turbulent flow created by the springs 175 and 350. That is, the springs 175 and 350 allow for the sub 145 to cover the resilient seal (when the resilient seal is positioned between the sub 145 and the passage 135b) and offer protection from debris as each of the springs 175 and 350 mounts to the sub 145 at a location at or near the internal shoulder 160, or away from the hinge or pivot point 165. In some embodiments, the mounting of the springs 175 and 350 to the sub 145 at a location at or near the shoulder 160 results in the arms 175a and 175b extending away from the plate 140 and towards the internal shoulder 160 when the plate 140 is in the open or closed position. In some embodiments, the springs 175 and 350 do not require significant removal of material from the plate 140, thus allowing for a stronger plate 140, which is desirable in the design of high pressure flappers when compared to very thin flappers. In some embodiments, the valve assembly 135 is considered “sand resistant” or more “sand resistant” compared to conventional valve assemblies. That is, sand build-up does not result in flapper closure failure. In some embodiments, the springs 175 and 350 work well during slam closures. In some embodiments, the springs 175 and 350 are compatible with relatively large spring wire. For example, arms 175a and 175b with a ¼″ diameter compare favorably to the 0.05″−0.09″ wire used with torsion springs. In some embodiments, the springs 175 and 350 do not require removal of hinge material, which allows for a strong hinge. Thus, the hinge material and pin size can be optimized independently of the closure mechanism (e.g., the pin 170 and flapper hinge can be thickened). In some embodiments, the springs 175 and 350 offer reliable torque at different positions of the plate 140. In some embodiments, the springs 175 and 350 have different landing positions on the flapper plate 140 during the pre-set and loaded configurations. In some embodiments, the springs 175 and 350 generate low stresses in both the fully open and the closed position due to the geometry of the arched arms 175a, 175b and the relatively small deflection.
Another embodiment of the spring 175 is identified by the reference numeral 400 illustrated in
When using the spring 400, compressional forces acting on the flapper plate 140 are positioned away from the flapper pin 170. Moreover, the arms 400a and 400b assist in closing the flapper plate 140 via the radially-inward force applied to the left and right sides 205 and 210. In some embodiments, the radially-inward force applied to the left and right sides 205 and 210 are via the groove 440 and the opposing groove on the right side 210. Generally, the spring 400 generates low stresses in both the fully open and the closed position, due to the geometry of the arms 400a and 400b and the relatively short deflection when positioned close to the pivot point 165. Generally, the compressional loads are force driven using the spring 400, therefore the valve seat 150 can be situated anywhere in relation to the pivot point 165. In some embodiments, the use of the plurality of springs 402a, 402b, 402c, etc. allows for the spring 400 to have a higher deflection while maintaining a big cross-sectional area defined by the sheath 403 and high strength. Moreover, in some embodiments, the use of the plurality of springs 402a, 402b, 402c, etc. eliminates or reduces residual stress and deformation.
In some embodiments, and as illustrated in
While in some embodiments the pin 460 is distinct from the housing 465, in other embodiments and as illustrated in
Another embodiment of the spring 400 is identified by the reference numeral 500 illustrated in
Generally, the spring 500 does not extend between the hinge that is created by the pin 170, the sub 145, and the plate 140. That is, the pin 170 is spaced from the spring 500, which improves the performance of the resilient seal.
Another embodiment of the valve assembly 135 is identified by the reference numeral 600 illustrated in
In some embodiments, the spring 606 reinforces the elastic properties of the spring 400 and increases the torque output. Pinning the spring 606 further from the pivot point 165 yields higher deflection when the plate 140 opens. That is, the spring 400 is pinned at the distance Z′ from the pivot point 165 while the spring 606 is pinned at the distance Z from the pivot point 165, with Z′ being larger than Z. In some embodiments, the spring 606 has a smaller cross-section and/or lower “E” to produce higher deflection to result in a less-than-stiff spring to produce a lower load. In an example embodiment, both of the springs 400 and 606 are accommodated (in a stacked formation) in the grooves, such as the groove 440 and a groove 440′, formed on the surface 185 of the plate 140.
In some embodiments and as illustrated in
In some embodiments, the coupler 610 is omitted and the fulcrum assembly 455 pins the springs 400 and 606 to the sub 145. In other embodiments, the coupler 610 includes the pin 460 and it extends across both the springs 400 and 606.
Another embodiment of the valve assembly 135 is identified by the reference numeral 700 illustrated in
The geometry of the arms 400a and 400b and the bridge portions 400c and 400d can vary, as illustrated in
Another embodiment of the valve assembly 135 is identified by the reference numeral 800 illustrated in
In some embodiments, calculation of the deflection of each of the springs 175, 350, 400, 500, 606, and 805 is based on the following equation:
y=3EI/FL3 (1)
F=force
L=length
E=Young's modulus
I=moment of inertia
With I for rectangular cross-section is:
I=1/12bh3 (2)
b=base of cross-section
h=height of cross-section
r=radius of cross-section
With I for round cross-section is:
I=((π/4)*r4) (3)
Generally, at least a portion of each of the springs 175, 350, 400, 500, 606, and 805 extends within the flapper valve chamber 155. Generally, at least a portion of each of the springs 175, 350, 400, 500, 606, and 805 extends away from the flapper plate 140 and towards the internal shoulder 160 when the flapper plate 140 is in the closed position. In some embodiments, each of the springs 175, 350, 400, 500, 606, and 805 extends away from the flapper plate 140 in the direction illustrated in the arrow 312 (
Another embodiment of the valve assembly 135 is identified by the reference numeral 850 illustrated in
In some embodiments and referring back to
In this embodiment, a longitudinal axis of the opening 857 formed by the retainer ring 855a is parallel to, or coaxial with, the longitudinal axis 135c of the housing 135a. Moreover, the retainer ring 855a at least partially surrounds the interior passageway 135b. As illustrated, the retainer ring 855a surrounds at least 270 degrees of the interior passageway 135b, at least 220 degrees of the interior passageway 135b, at least 200 degrees of the interior passageway 135b, and/or at least 180 degrees of the interior passageway 135b.
In some embodiments, the arms 855b and 855c contact the flapper plate 140 generally on the top portion 195 of the upper surface 185 of the flapper plate 140. In some embodiments and as illustrated in
As illustrated, the spring 855 is spaced in its entirety from the hinge assembly 147 when in the valve closed position and the valve open position. Specifically, there is no portion(s) of the spring 855 that is in contact with the pin 170.
Another embodiment of the valve assembly 850 is identified by the reference numeral 880 is illustrated in
In some embodiments, the springs 175, 350, 400, 500, 606, 805, and 855 do not require clearance near the pivot pin 170, and thus allow for increased sizes, as thus strength, of the flapper plate 140 and the pivot pin 170.
In some embodiments, the springs 175, 350, 400, 500, 606, 805, and 855 apply a force to the flapper plate 140 to urge the plate 140 to an open or closed position. That is, each of the springs 175, 350, 400, 500, 606, 805, and 855 provides a holding force to hold the flapper plate 140 in either an open or closed position. In some embodiments, when the flapper plate 140 is moved out of the open or closed position past a fulcrum point, each of the springs 175, 350, 400, 500, 606, 805, and 855 applies a force to the flapper to urge it to the opposite position (i.e. from closed to open, or from open to closed). This occurs when the force applied by the springs 175, 350, 400, 500, 606, 805, and 855 is applied at a point that is past the pivot point of the flapper plate 140. Therefore, the force would be applied to one side of the pivot point in one position (e.g., Zclosed is measured from one side of pivot point 165 and Zopen is measured from another side of pivot point 165 in
In some embodiments, the springs 175, 350, 400, 500, 606, and 805 apply a force to the right and left side portions 205 and 210 of the flapper plate 140 when the flapper plate 140 is in the open position because the springs 175, 350, 400, 500, 606, and 805 engage the right and left side portions 205 and 210 of the flapper plate 140 to urge it away from the open position, in addition to the force applied to the flapper plate 140 via the bridge portions 175c, 350c, 400c, 500c, 606c, and 805c, which increases the surface area through which the force of the spring is applied to the flapper plate 140.
Various attachment points of the springs 175, 350, 400, 500, 606, and 805 to the flapper plate 140 and the housing 135a or the sub 145 provide a wide range of forces to accommodate various flapper valve designs.
In some embodiments, while the springs 175, 350, 400, 500, 606, and 805 are considered to be compression springs, some or all of the springs 175, 350, 400, 500, 606, and 805 are considered torsion springs or beam springs. In some embodiments, the bridge portions 175c, 350c, 400c, 500c, 606c, and 805c are spaced longitudinally between the pivot point 165 and the shoulder 160, which allows for the size of pivot pin 170 and/or surrounding elements to be enlarged. In some embodiments, each of the springs 175, 350, 400, 500, 606, 805, and 855 does not require space at the pivot pin 170.
In some embodiments, the springs 175, 350, 400, 500, 606, 805, and 855 are sized to accommodate a variety of plate sizes and weights.
In some embodiments, and when the distances Z and/or Z′ for the springs 400 and 606, respectively, can be adjusted prior to the valve assembly 135 being run downhole, the valve assembly 135 is a valve with adjustable torque.
In some embodiments, each of the springs 175, 350, 400, 500, 606, and 805 is a beam spring with torsional properties for operating the valve assembly 135.
In some embodiments, the springs 175, 350, 400, 500, 606, and 805 are different from a traditional torsion spring in that spring forces acting on the springs 175, 350, 400, 500, 606, and 805 are bending stresses while the forces acting on a torsion spring are torsional stresses.
In some embodiments and due to the shape of the springs 175, 350, 400, 500, 606, 805, and 855, the forces acting on the plate 140 are positioned away from the hinge assembly 147 (e.g., the pivot point 165 and the flapper pin 170). This allows the forces generated by the springs 175, 350, 400, 500, 606, 805, and 855 to avoid any critical areas of the flapper plate 140 and to be symmetrically centralized to generate extremely high flapper torque outputs.
Generally, the flapper torque is maximized by allowing the springs 175, 350, 400, 500, 606, and 805 to deflect both laterally and axially through compression.
While a concentric piston-type operated tubing-retrievable safety valve is illustrated here, the springs 175, 350, 400, 500, 606, 805, and 855 are capable of being used in a variety of other types of valves, such as a rod piston operated valve, an electric actuator type valve, etc. Moreover, the springs 175, 350, 400, 500, 606, 805, and 855 may be used with a variety of flapper closure plates.
In this disclosure, the description of one axis being perpendicular to another axis is used when the one axis is in a plane that is perpendicular to the plane in with the another axis lies. That is, although the one axis and the another axis do not intersect, they are considered perpendicular to one another.
In an example embodiment and as shown in
In one or more example embodiments, the printer 910 is a three-dimensional printer. In one or more example embodiments, the printer 910 includes a layer deposition mechanism for depositing material in successive adjacent layers; and a bonding mechanism for selectively bonding one or more materials deposited in each layer. In one or more example embodiments, the printer 910 is arranged to form a unitary printed body by depositing and selectively bonding a plurality of layers of material one on top of the other. In one or more example embodiments, the printer 910 is arranged to deposit and selectively bond two or more different materials in each layer, and wherein the bonding mechanism includes a first device for bonding a first material in each layer and a second device, different from the first device, for bonding a second material in each layer. In one or more example embodiments, the first device is an ink jet printer for selectively applying a solvent, activator or adhesive onto a deposited layer of material. In one or more example embodiments, the second device is a laser for selectively sintering material in a deposited layer of material. In one or more example embodiments, the layer deposition means includes a device for selectively depositing at least the first and second materials in each layer. In one or more example embodiments, any one of the two or more different materials may be ABS plastic, PLA, polyamide, glass filled polyamide, stereolithography materials, silver, titanium, steel, wax, photopolymers, polycarbonate, and a variety of other materials. In one or more example embodiments, the printer 910 may involve fused deposition modeling, selective laser sintering, and/or multi jet modeling. In operation, the computer processor 920 executes a plurality of instructions stored on the computer readable medium 925. As a result, the computer 905 communicates with the printer 910, causing the printer 910 to manufacture the springs 175, 350, 400, 500, 606, 805, and 855 or at least a portion thereof. In one or more example embodiments, manufacturing the springs 175, 350, 400, 500, 606, 805, and 855 and/or portions of the valve assembly 135 using the system 900 results in an integrally formed springs 175, 350, 400, 500, 606, 805, and 855 and/or portions of the valve assembly 135.
In one or more exemplary embodiments, as illustrated in
In several exemplary embodiments, the one or more computers 905, the printer 910, and/or one or more components thereof, are, or at least include, the computing device 1000 and/or components thereof, and/or one or more computing devices that are substantially similar to the computing device 1000 and/or components thereof. In several exemplary embodiments, one or more of the above-described components of one or more of the computing device 1000, one or more computers 905, and the printer 910 and/or one or more components thereof, include respective pluralities of same components.
In several exemplary embodiments, a computer system typically includes at least hardware capable of executing machine readable instructions, as well as the software for executing acts (typically machine-readable instructions) that produce a desired result. In several exemplary embodiments, a computer system may include hybrids of hardware and software, as well as computer sub-systems.
In several exemplary embodiments, hardware generally includes at least processor-capable platforms, such as client-machines (also known as personal computers or servers), and hand-held processing devices (such as smart phones, tablet computers, personal digital assistants (PDAs), or personal computing devices (PCDs), for example). In several exemplary embodiments, hardware may include any physical device that is capable of storing machine-readable instructions, such as memory or other data storage devices. In several exemplary embodiments, other forms of hardware include hardware sub-systems, including transfer devices such as modems, modem cards, ports, and port cards, for example.
In several exemplary embodiments, software includes any machine code stored in any memory medium, such as RAM or ROM, and machine code stored on other devices (such as floppy disks, flash memory, or a CD ROM, for example). In several exemplary embodiments, software may include source or object code. In several exemplary embodiments, software encompasses any set of instructions capable of being executed on a computing device such as, for example, on a client machine or server.
In several exemplary embodiments, combinations of software and hardware could also be used for providing enhanced functionality and performance for certain embodiments of the present disclosure. In one or more exemplary embodiments, software functions may be directly manufactured into a silicon chip. Accordingly, it should be understood that combinations of hardware and software are also included within the definition of a computer system and are thus envisioned by the present disclosure as possible equivalent structures and equivalent methods.
In several exemplary embodiments, computer readable mediums include, for example, passive data storage, such as a random-access memory (RAM) as well as semi-permanent data storage such as a compact disk read only memory (CD-ROM). One or more exemplary embodiments of the present disclosure may be embodied in the RAM of a computer to transform a standard computer into a new specific computing machine. In several exemplary embodiments, data structures are defined organizations of data that may enable an embodiment of the present disclosure. In one or more exemplary embodiments, a data structure may provide an organization of data, or an organization of executable code.
In several exemplary embodiments, the network 915, and/or one or more portions thereof, may be designed to work on any specific architecture. In one or more exemplary embodiments, one or more portions of the network 915 may be executed on a single computer, local area networks, client-server networks, wide area networks, internets, hand-held and other portable and wireless devices and networks.
In several exemplary embodiments, a database may be any standard or proprietary database software, such as Oracle, Microsoft Access, Sybase, or DBase II, for example. In several exemplary embodiments, the database may have fields, records, data, and other database elements that may be associated through database specific software. In several exemplary embodiments, data may be mapped. In several exemplary embodiments, mapping is the process of associating one data entry with another data entry. In one or more exemplary embodiments, the data contained in the location of a character file can be mapped to a field in a second table. In several exemplary embodiments, the physical location of the database is not limiting, and the database may be distributed. In one or more exemplary embodiments, the database may exist remotely from the server, and run on a separate platform. In one or more exemplary embodiments, the database may be accessible across the Internet. In several exemplary embodiments, more than one database may be implemented.
In several exemplary embodiments, a computer program, such as a plurality of instructions stored on a computer readable medium, such as the computer readable medium 925, the system memory 1000e, and/or any combination thereof, may be executed by a processor to cause the processor to carry out or implement in whole or in part the operation of the system 900, and/or any combination thereof. In several exemplary embodiments, such a processor may include one or more of the computer processor 920, the processor 1000a, and/or any combination thereof. In several exemplary embodiments, such a processor may execute the plurality of instructions in connection with a virtual computer system.
In several exemplary embodiments, a plurality of instructions stored on a computer readable medium may be executed by one or more processors to cause the one or more processors to carry out or implement in whole or in part the above-described operation of each of the above-described exemplary embodiments of the system, the method, and/or any combination thereof. In several exemplary embodiments, such a processor may include one or more of the microprocessor 1000a, any processor(s) that are part of the components of the system, and/or any combination thereof, and such a computer readable medium may be distributed among one or more components of the system. In several exemplary embodiments, such a processor may execute the plurality of instructions in connection with a virtual computer system. In several exemplary embodiments, such a plurality of instructions may communicate directly with the one or more processors, and/or may interact with one or more operating systems, middleware, firmware, other applications, and/or any combination thereof, to cause the one or more processors to execute the instructions. In one or more exemplary embodiments, the instructions may be generated, using in part, advanced numerical method for topology optimization to determine optimum chamber shape, chamber size and distribution, and chamber density distribution for the plurality of chambers 745, or other topological features. During operation of the system 900, the computer processor 920 executes the plurality of instructions that causes the manufacture of the springs 175, 350, 400, 500, 606, and 805 and/or portions of the valve assembly 135 using additive manufacturing. Thus, the springs 175, 350, 400, 500, 606, and 805 and/or portions of the valve assembly 135 is at least partially manufactured using an additive manufacturing process. In one or more exemplary embodiments, the use of three-dimensional, or additive, manufacturing to manufacture downhole equipment, such as the springs 175, 350, 400, 500, 606, and 805 and/or portions of the valve assembly 135, will allow increased flexibility in the strategic placement of material to retain strength in one direction but reduce strength, or weaken the tool in another direction in which significant strength is not needed.
A flapper valve assembly is disclosed that includes a tubular forming an interior passageway; a valve seat forming a portion of the interior passageway; a flapper plate that is pivotably mounted to the tubular at a pivot point such that the flapper plate is pivotable between a valve closed position in which the flapper plate sealingly engages the valve seat and a valve open position in which the flapper plate does not sealingly engage the valve seat; and a spring engaging the flapper plate such that the flapper plate is biased towards the valve closed position; wherein, when the flapper plate is in the valve open position, the spring engages a top of the flapper plate at a first distance from the pivot point; wherein, when the flapper plate is in the valve closed position, the spring engages the top of the flapper plate at a second distance from the pivot point; and wherein the second distance is greater than the first distance. In one embodiment, wherein, when the flapper plate is in the valve open position, a first lever arm is defined by the first distance and a first angle of the flapper plate relative to a longitudinal axis of the interior passageway; wherein, when the flapper plate is in the valve closed position, a second lever arm is defined by the second distance and a second angle of the flapper plate relative to the longitudinal axis of the interior passageway; and wherein the second lever arm is greater than the first lever arm. In one embodiment, first and second protrusions are formed on a top surface of the flapper plate; wherein the first protrusion is spaced from the second protrusion along a longitudinal axis of the flapper plate; and wherein a portion of the spring is trapped between the first and second protrusions of the flapper plate. In one embodiment, a difference between the second distance and the first distance is based on a distance between the second protrusion and the first protrusion. In one embodiment, when the flapper plate is in the valve closed position, the portion of the first spring is engaged with the first protrusion; and wherein, when the flapper plate is in the valve open position, the portion of the first spring is engaged with the second protrusion. In one embodiment, the spring includes spaced right and left arms; wherein an end portion of the spring extends between the first arm and the second arm; wherein the end portion of the spring engages the flapper plate; wherein a cross-section of the end portion has a first shape; and wherein a cross-section of the second arm has a second shape that is different from the first shape. In one embodiment, the spring includes spaced right and left arms; wherein an end portion of the spring extends between the first arm and the second arm; wherein the end portion of the spring engages the flapper plate; wherein a cross-section of a portion of the first arm has a first shape; and wherein a cross-section of another portion of the first arm has a second shape that is different from the first shape. In one embodiment, wherein the spring includes spaced right and left arms; and wherein, when the flapper plate is in the valve closed position, each of the right and left arms extends away from the flapper plate and towards the internal shoulder. In one embodiment, wherein the spring is pinned to the tubular at a location at or near the internal shoulder.
A method of operating a flapper valve assembly is disclosed that includes a flapper plate that is biased closed relative to a valve seat using a spring, the method including: applying torque, by positioning the spring on a surface of the flapper plate, to bias the flapper plate towards a closed position relative to the valve seat; and changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the closed position to increase the torque applied to the flapper plate. In one embodiment, wherein the flapper plate pivots about a pivot point when moving between the closed position and an open position; and wherein changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the closed position includes increasing a distance between the spring and the pivot point. In one embodiment, wherein first and second protrusions are formed on the surface of the flapper plate; wherein the first protrusion is spaced from the second protrusion along a longitudinal axis of the flapper plate; wherein an end portion of the spring is trapped between the first and second protrusions of the flapper plate; wherein, when in the open position, the end portion of the spring contacts the second protrusion; and wherein, increasing the distance between the spring and the pivot point includes moving the end portion of the spring such that the end portion no longer contacts the second protrusion and contacts the first protrusion. In one embodiment, wherein increasing the distance is a function of the spacing between the second protrusion and the first protrusion. In one embodiment, wherein the spring includes spaced right and left arms; wherein an end portion of the spring extends between the first arm and the second arm; wherein the end portion of the spring engages the flapper plate; wherein a cross-section of the end portion has a first shape; and wherein a cross-section of the second arm has a second shape that is different from the first shape. In one embodiment, wherein the spring includes spaced right and left arms; wherein an end portion of the spring extends between the first arm and the second arm; wherein the end portion of the spring engages the flapper plate; wherein a cross-section of a portion of the first arm has a first shape; and wherein a cross-section of another portion of the first arm has a second shape that is different from the first shape. In one embodiment, wherein the flapper valve assembly further includes a tubular forming an interior passageway and including an internal shoulder; wherein the spring includes spaced right and left arms; wherein the valve seat forms a portion of the interior passageway and is spaced from the internal shoulder to form a flapper chamber; wherein the flapper plate is pivotably mounted to the tubular at a pivot point and positioned within the flapper chamber; and wherein, when the flapper plate is in the closed position, each of the right and left arms extends away from the flapper plate and towards the internal shoulder. In one embodiment, further including changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the open position. In one embodiment, wherein changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the open position includes decreasing the distance between the spring and the pivot point. In one embodiment, wherein first and second protrusions are formed on the surface of the flapper plate; wherein the first protrusion is spaced from the second protrusion along a longitudinal axis of the flapper plate; wherein an end portion of the spring is trapped between the first and second protrusions of the flapper plate; wherein, when in the closed position, the end portion of the spring contacts the first protrusion; and wherein, changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the open position includes moving the end portion of the spring such that the end portion no longer contacts the first protrusion and contacts the second protrusion. In one embodiment, wherein the spring is pinned to the tubular at a location at or near the internal shoulder; and wherein changing the positioning of the spring relative to the surface of the flapper plate when the flapper plate moves into the closed position further includes pivoting the spring about the location.
It is understood that variations may be made in the foregoing without departing from the scope of the disclosure. Furthermore, the elements and teachings of the various illustrative example embodiments may be combined in whole or in part in some or all of the illustrative example embodiments. In addition, one or more of the elements and teachings of the various illustrative example embodiments may be omitted, at least in part, and/or combined, at least in part, with one or more of the other elements and teachings of the various illustrative embodiments.
Any spatial references such as, for example, “upper,” “lower,” “above,” “below,” “between,” “vertical,” “horizontal,” “angular,” “upwards,” “downwards,” “side-to-side,” “left-to-right,” “right-to-left,” “top-to-bottom,” “bottom-to-top,” “top,” “bottom,” “bottom-up,” “top-down,” “front-to-back,” etc., are for the purpose of illustration only and do not limit the specific orientation or location of the structure described above.
In several example embodiments, one or more of the operational steps in each embodiment may be omitted. Moreover, in some instances, some features of the present disclosure may be employed without a corresponding use of the other features. Moreover, one or more of the above-described embodiments and/or variations may be combined in whole or in part with any one or more of the other above-described embodiments and/or variations.
Although several example embodiments have been described in detail above, the embodiments described are examples only and are not limiting, and those skilled in the art will readily appreciate that many other modifications, changes, and/or substitutions are possible in the example embodiments without materially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications, changes, and/or substitutions are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Moreover, it is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the word “means” together with an associated function.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/034364 | 5/29/2019 | WO | 00 |