Patent Application
20250075590
The technology relates to valves that may be employed in a well system, particularly valves that employ sealing elements which provide a seal between the valve and a tubing hanger, for example.
There is a need in the oilfield to be able to remove equipment such as a valve or a series of valves, collectively and/or more commonly known as a Wellhead Christmas Tree, from a wellhead for servicing purposes. A component known as a Back Pressure Valve (BPV) may be employed for such equipment removal while still maintaining pressure control of the production tubing. An example of a Back Pressure Valve (BPV) is shown in
Another reason for using a Back Pressure Valve may be to facilitate installation of a Blow-Out Preventer to the wellhead in preparation of working over a well. A feature of the Back Pressure Valve is that the Back Pressure Valve has flow through capability in the event that there is a need to kill the well. The design of the Back Pressure Valve with a spring-energized poppet enables the well kill.
There is a step in the process during the removal of the old Wellhead Christmas Tree and replacement with a new one that requires a different component to be utilized. When new/different equipment has been installed onto the wellhead there is a need to confirm the integrity of the new connection to hold pressure. To confirm the integrity of the new connection it is common in the industry to utilize what is known as a Two-Way Check Valve (TWCV). An example prior art Two-Way Check Valve (TWCV) is shown in
The structure of the example prior art Back Pressure Valve (BPV) 120 shown in
The example prior art Back Pressure Valve (BPV) 120 of
A seal 130 is provided in the region of the greatest diameter of valve body 122 but vertically above the external circumferential threads 124 when employed in a wellhead. The seal 130 is accommodated in a seal seating groove 132 which extends around a circumference of the valve body 122. The seal 130 is intended to form a seal between the valve body 122 of Back Pressure Valve (BPV) 120 and the tubing hanger into which the Back Pressure Valve (BPV) 120 is threadingly engaged.
The example prior art Two-Way Check Valve 220 of
A problem with both the prior art Back Pressure Valve (BPV) and the prior art Two-Way Check Valve is that the external threads are designed and configured to break into the seal carrier grooves. The seal seating groove 132 is shown in
The deformation of sealing material into an adjacent threaded region in wellhead valves such as a Back Pressure Valve (BPV) and a Two-Way Check Valve reduces the area of lower pressure surface supporting the seal and prevents the seal from fully radially extruding, which may lead to failure of the seal. The lower or reduced lower pressure surface area is where the seal can extrude into trough 138 as there is nothing to prevent it doing so.
Another disadvantage of the prior art is that, if excessive torque is applied through the valves, the thread can start to cut into the seal rendering it useless. Since torque application is largely a matter of operator feel/sensitivity, application of excessive torque is not uncommon.
The technology disclosed herein seeks to mitigate or eliminate various disadvantages involved in the construction and use of prior art valves that employ seals, such as Back Pressure Valves and Two-Way Check Valves.
In one of its example embodiments and modes, the technology disclosed herein concerns a valve for use in a hanger body of a well system comprises a valve body. The valve body comprises an exterior surface comprising three segments. A first segment of the exterior surface is configured with a helical thread to engage a counter-threaded portion of the tubing hanger body. A second segment of the exterior surface is configured as an essentially circumferential groove to accommodate an essentially toroidal sealing member. The groove comprises essentially right angle shoulders at both intersections of the groove with the exterior surface. A third segment of the exterior surface is configured to be devoid of the helical thread, the third segment being intermediate the first segment and the second segment.
In another of its example aspects the technology disclosed herein concerns a valve for use in a hanger body of a well system. The valve comprises a valve body comprising an exterior surface comprising at least two segments. A first segment of the exterior surface is configured with a helical thread to engage a counter-threaded portion of the tubing hanger body. A second segment of the exterior surface is configured as a groove to accommodate an essentially toroidal sealing member. The valve is configured for insertion into the hanger body in an axial direction. In a radial plane which is perpendicular to the axial direction the groove extends about 0.118 inch.
In yet another of its example aspects the technology disclosed herein concerns a valve for use in a hanger body of a well system. The valve is configured for insertion into the hanger body in an axial direction. In an example embodiment and mode the valve comprises a valve body comprising an exterior surface. A first segment of the exterior surface is configured with a helical thread to engage a counter-threaded portion of the tubing hanger body. A second segment of the exterior surface is configured as an essentially circumferential groove to accommodate an essentially toroidal sealing member. A third segment of the exterior surface configured to be essentially smooth and parallel to the axial direction. The third segment is intermediate the first segment and the second segment, and in the axial direction the third segment of the exterior surface extends for about 0.10 inches.
In still another of its example aspects the technology disclosed herein concerns a method of inserting a valve into a hanger body of a well system. In a basic example embodiment and mode, the method comprises axially inserting a valve into a hanger body of a well system and then rotating the valve to cause axial travel of the valve within the hanger body by engagement of the helical thread with a counter-threaded portion of the tubing hanger body until further axial travel is stopped by a helically threadless segment of an exterior surface of the valve body.
The foregoing and other objects, features, and advantages of the technology disclosed herein will be apparent from the following more particular description of preferred embodiments as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the various views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the technology disclosed herein.
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the technology disclosed herein. However, it will be apparent to those skilled in the art that the technology disclosed herein may be practiced in other embodiments that depart from these specific details. That is, those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the technology disclosed herein and are included within its spirit and scope. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the technology disclosed herein with unnecessary detail. All statements herein reciting principles, aspects, and embodiments of the technology disclosed herein, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
Thus, for example, it will be appreciated by those skilled in the art that block diagrams herein can represent conceptual views of illustrative circuitry or other functional units embodying the principles of the technology. Similarly, it will be appreciated that any flow charts, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.
The technology disclosed herein generally relates to valves for use in a well system. As used herein, “well system” encompasses any application where it is required to isolate the upper portions of a system from pressure generated below the system. Thus “well system” encompasses various applications and installations, such as wellheads, water loop applications, and geothermal applications, for example. Unless otherwise clear from the context, reference herein to “wellhead” may encompass well system. In some of its example aspects the technology disclosed herein may relate to back pressure valves and two-way check valves for well systems, for example, that may be employed for sealing off a well such as those in the oil and gas field to provide well control during secondary maintenance of equipment, such as Wellhead Trees or Blowout Preventers, for example. Further, in one of its example aspects the technology disclosed herein relates to providing a feature that ensures a positive indication that valves for use in a well system, such as back pressure valves and/or two-way check valve, are landed in a correct position within the tubing hanger during the installation process.
The valve body exterior surface 23 is shown in
The exterior surface first segment 41 is configured with an external helical thread 24 to engage a counter-threaded portion of the tubing hanger body, as shown with reference to
The exterior surface second segment 42 is configured as a circumferential groove to accommodate an essentially toroidal-shaped sealing member. For example, exterior surface second segment 42 is configured as seal seating groove 32 which extends around the circumference of valve body 22. The seal seating groove 32 is configured to accommodate seal 30. The seal 30 may be fabricated from any suitable sealing material, such as an elastomeric material, for example. Other materials may also be utilized, such as Teflon® and Hytrel®, taking into consideration that relative compliant nature of material may affect how the material expands to make up the groove and that for some materials, modifications may be necessary such as an open gland, for example, that would accept the different seal material and usage of another component to close the seal groove up.
As shown in more detail in
As also shown in
In an example embodiment and mode, the helical thread has a thread pitch of 0.25 inch, in the axial direction the third segment 43 of the exterior surface extends for about 0.10 inch. In a non-limiting, example embodiment and mode, the third segment 43 of the exterior surface extends in the axial direction 21 for a first axial distance and the groove 32 extends for a second axial distance, and ratio of the first axial distance to the second axial distance is about 3.2 to 1, e.g., 3.2:1.0. In a non-limiting, example embodiment and mode, the ratio of the groove radial distance of groove 32 to the groove axial distance is about 2.7 to 1.0. The example embodiments and modes just mentioned are particularly suitable for use with tubing hangers in which a seal land or surface area may be as small as 0.380 inches. The axial first distance, e.g., axial distance of the third segment 43 of the exterior surface extends, may be greater.
Other constituent elements of valve 20, in an example embodiment and mode in which the valve takes the form of a Back Pressure Valve (BPV), are shown in
The valve 20 of
Normally in a production set up such as shown in
By contrast, the Frac type situation, shown by example in
The valve 20 of
Comparing
As shown in
Thus, the technology disclosed herein encompasses an improved well system valve, such as a back pressure valve and/or a two-way check valve, comprising a bore, a valve seat, a poppet biased onto said seat, a seal land, and an external shoulder. The external shoulder comprises a ring machined 3600 into the outer surface of the body. The machined ring is not threaded and therefore not threadably engageable with the thread machined into the mating component to which the back pressure valve and two-way check valve are designed to be threaded. The ring structure thus ensures a positive stop and clearly identified stopping position within the well system component for the sealing element.
Act 9-2 comprises rotating the valve 20 to cause axial travel of the valve within the hanger body by engagement of a helical thread of the valve with the counter-threaded portion of the tubing hanger body until further axial travel is stopped by a helically threadless segment of the exterior surface of the valve body, e.g., structurally stopped by the third segment, e.g., by exterior surface third segment 43, also known herein as the positive stop ring 43. As example context and optional detail for act 9-2, when the valve 20 is at the correct depth the Parmalee Wrench is pulled downward and rotated counterclockwise at the same time. Depending on geometry, the valve 20 should come to a stop at approximately 5½ to 6 turns. Unlike the prior art, there is no need or structural opportunity to attempt to apply further torque, since the hard stop afforded by the positive stop ring 43 provides the assurance that the seal is correctly seated in the seal diameter of the hanger. No torque is required to effect a seal, with the advantage that the seal may not be prematurely cut during installation as in the case of the prior art.
Thus, in a radial plane which is perpendicular to the axial direction 21 and which forms the intersection of the exterior surface second segment 42 and the exterior surface third segment 43, the exterior surface third segment 43 is threadless. For example, in such radial plane the thread pattern of the exterior surface first segment 41 does not even partially extend into the bottom shoulder 46 of the seal seating groove 32, which occurs at the intersection of exterior surface second segment 42 and the exterior surface third segment 43. That is, no circumferential surface of the exterior surface third segment 43 in such radial plane includes even a portion of the thread pattern of the exterior surface first segment 41. Preferably the entire circumferential surface of the exterior surface third segment 43 is essentially smooth.
In the prior art method it was necessary for an operator to mark the rod that is used to deliver the valve to its destination, then count the number of turns applied to the valve, and then, when there is resistance, to apply a torque. The applied torque was not measured or applied using a torque tool, but rather the operator relied on operator experience to know when the valve is set in the correct place. By contrast, in accordance with one aspect of the technology disclosed herein as exemplified by the method of
Thus, the technology disclosed herein has many beneficial aspects and advantages.
In one of its example aspects the technology disclosed herein relates to a device for plugging off and controlling an oil and gas type well as one example.
In another of its example aspects the technology disclosed herein relates to a device for plugging off and enabling pressure testing of the connection when new equipment has been installed above the tubing hanger.
In yet another of its example aspects the technology disclosed herein relates to a device that, when run, positively stops in the optimum position in the tubing hanger to ensure effective sealing every time.
In still another of its example aspects the technology disclosed herein relates to the upgrading of the sealing system by providing a proprietary seal design and groove.
In at least some of its example aspects, the technology disclosed herein eliminates the disadvantages by taking the guesswork out of running the valves and the seal seating process making it easier, for those new to running this type of equipment, to install it correctly first time every time. In at least some example embodiments and modes this is achieved by including a 360° ring with a chamfer angle machined into it matching the flank angle of the thread and having a seal and gland that is suitably spaced out from the positive stop ring.
In another of its example aspects the seal groove of example embodiments and modes provides a ring feature that is strategically spaced out from the end of the seal groove and positively stops a valve, such as a Back Pressure Valve (BPV) or a Two-Way Check Valve, from being over threaded into the tubing hanger.
The scope of the technology disclosed herein should be determined by the appended claims and their legal equivalents. Therefore, it will be appreciated that the scope of the technology disclosed herein fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the technology disclosed herein is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” The above-described embodiments could be combined with one another. All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the technology disclosed herein, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims.
