Robust Gas Lift Valve Suitable for Use in Harsh Environments

This application claims priority to U.S. patent application Ser. No. 18/352,098 filed on Jul. 13, 2023 and entitled “Robust Gas Lift Value Suitable for Use in Harsh Environment” and U.S. Provisional Patent Application No. 63/483,988 filed on Feb. 9, 2023 and entitled “Robust Gas Lift Value Suitable for Use in Harsh Environments.”

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The present disclosure relates to gas lift valves for use in artificial gas lift applications. In certain such applications, pressurized gas is used to form or supplement gas within production fluids to promote the production of, for example, oil and gas from a well.

In many artificial gas lift applications one or more gas lift valves are used to control the injection of gas into reservoir fluids. In such applications, pressurized gas is applied to the input of the one or more gas lift valves and each gas lift valve can be set to open when the pressure of the applied gas reaches a certain set pressure, sometimes referred to as a charge pressure. This charge pressure also correlates to a relative closing pressure of the valve.

In many of such applications, the pressure setting at which a given gas lift valve will open is set by the injection of a gas (typically nitrogen) through a valve element (typically a dill or Schrader-type valve) into a cavity within the gas lift valve (often referred to as a dome). In operation, the pressurized gas within the cavity or chamber acts against a biasing member within the valve, typically in the form of a bellow, that, in turn, acts against a movable valve element. In such applications, when the pressure within the reservoir meets or exceeds the set point pressure for a given valve, the valve will be forced open and a gas applied at the input of the valve will be injected into the reservoir fluids.

A long standing problem in the field of artificial gas lift is that conventional gas lift valves often do not operate properly (or over a desired length of time) in certain environments and/or that such gas lift valves are subject to damage if uncommon well conditions are encountered.

For example, in applications where a gas lift valve is used in a high temperature environment, it is not uncommon for one or more of the internal gasketing materials maintaining the gas pressure within the dome in the valve to either degrade, expand, or adjust to the point that a seal maintaining the pressure containment within the dome fails in part or in total. When such an event occurs, some or all of the pressurized gas within the dome will exit the gas lift valve, resulting in either complete failure of the gas lift valve or sub-optimum performance of the valve as a result of the undesired change in the internal charge pressure in the valve.

A further long standing problem in the field of artificial gas lift valves is that conventional valves are prone to failure in the event that the reservoir in which the valve is operating is subjected to an unanticipated spike in pressure. Such an unexpected pressure spike can occur, for example, when a well adject to a producing well in which a gas lift valve is positioned, is undergoing a hydraulic fracturing operation. In such applications, very high-pressure fluids are injected into the well undergoing the hydraulic fracturing operation with the goal of creating or expanding fractures within the rock surfaces or other formations adjacent the treated well. In such operations, it is possible that a fracture will be created that can extend from the treated reservoir to the producing reservoirs in which the gas lift valve is positioned which can result in a significant spike in the reservoir pressure of the producing well. It is known that such an undesired pressure spike (or “frac hit”) can damage conventional gas lift valves, either rendering the valve—and typically more than one gas lift valves within the producing well-inoperable, or causing an adjustment in the pressure setting of the valve (or multiple valves) resulting in non-optimal valve operations.

One object of the embodiments discussed herein is to reduce or overcome the above-identified and other problems associated with conventional gas lift valve constructions.

It is to be understood that the discussion above is provided for illustrative purposes only and is not intended to and does not limit the scope or subject matter of the appended or ultimately issued claims or those of any related patent application or patent. Thus, none of the appended claims, ultimately issued claims or claims of any related application or patent are to be limited by the above discussion or construed to address, include, or exclude each or any of the above-cited features or disadvantages merely because such were mentioned herein.

A brief non-limiting summary of one of the many possible embodiments of the inventions disclosed herein is a gas lift valve including a body defining an interior charging chamber, the interior charging chamber defining a volume; a housing defining a bore in fluid communication with the charging chamber where the bore has a maximum internal diameter; a plug positioned within the bore, where the plug has a maximum outer diameter greater than the maximum internal diameter of the bore in the housing; a first O-ring forming a seal between an external surface of the plug and an interior surface of the bore; a crush washer positioned between the plug and a surface of the housing which serves as a sealing component; and a cap defining an interior bore, the cap being positioned with respect to the housing such that the plug is positioned within the cap interior bore; and a second resilient element forming a seal between a first external surface of the housing and a first interior surface of the cap.

Additionally or alternately, the positioning of the plug and the crush washer can form a cavity between the valve assembly and the plug and wherein the volume of the cavity is less than 0.007% of the total volume of the charging chamber.

None of these brief summaries of the inventions is intended to limit or otherwise affect the scope of what has been disclosed and enabled or the appended claims, and nothing stated in this Brief Summary of the Invention is intended as a definition of a claim term or phrase or as a disavowal or disclaimer of claim scope.

While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawings and are described in more detail below. The figures and detailed descriptions of these embodiments are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art and to enable such person to make and use the inventive concepts illustrated and taught by the specific embodiments.

The Figures described above, and the written description of specific structures and functions below, are not presented to limit the scope of the inventions disclosed or the scope of the appended claims. Rather, the Figures and written description are provided to teach a person skilled in this art to make and use the inventions for which patent protection is sought.

A person of skill in this art having benefit of this disclosure will understand that the inventions are disclosed and taught herein by reference to specific embodiments, and that these specific embodiments are susceptible to numerous and various modifications and alternative forms without departing from the inventions we possess. For example, and not limitation, a person of skill in this art having benefit of this disclosure will understand that Figures and/or embodiments that use one or more common structures or elements, such as a structure or an element identified by a common reference number, are linked together for all purposes of supporting and enabling our inventions, and that such individual Figures or embodiments are not disparate disclosures. A person of skill in this art having benefit of this disclosure immediately will recognize and understand the various other embodiments of our inventions having one or more of the structures or elements illustrated and/or described in the various linked embodiments. In other words, not all possible embodiments of our inventions are described or illustrated in this application, and one or more of the claims to our inventions may not be directed to a specific, disclosed example. Nonetheless, a person of skill in this art having benefit of this disclosure will understand that the claims are fully supported by the entirety of this disclosure.

Those persons skilled in this art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related, and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill in this art having benefit of this disclosure.

Further, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the scope of what is claimed.

Reference throughout this disclosure to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one of the many possible embodiments of the present inventions. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

The description of elements in each Figure may refer to elements of proceeding Figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements. In some possible embodiments, the functions/actions/structures noted in the figures may occur out of the order noted in the block diagrams and/or operational illustrations. For example, two operations shown as occurring in succession, in fact, may be executed substantially concurrently or the operations may be executed in the reverse order, depending upon the functionality/acts/structure involved.

Turning now to several descriptions, with reference to figures, or particular embodiments incorporating one or more aspects of the disclosed inventions,illustrates an exemplary embodiment of a robust gas lift valveconstructed in accordance with certain teachings of this disclosure that is suitable for use in harsh environments. Such harsh environments include, but are not limited to, downhole environments where the gas lift valve will be subject to high temperatures; environments (downhole or otherwise) where the gas lift valve may be subject to impacts and/or vibrations after it is set; environments where the gas lift valve may be subjected to potentially harmful chemicals and/or well bore fluids, gases, and foreign wellbore materials from a reservoir, and/or environments where there is a possibility of malicious adjustment of a set gas lift valve before it is positioned downhole.

In the illustrated embodiment of, the main externally visible body of the gas lift valvegas lift valve includes, from right to left in the figure a valve seat housing, a bellow housing, a dome housing, and a valve core housing.

Although not illustrated in, in different implementations additional housings or mechanisms may be coupled to the gas lift valveprior to its installation for use downhole. For example, in some embodiments a check valve assembly and/or a latching assembly may be coupled (via threads or otherwise) to the distal end of the valve seat housing.

The described housing elements may be formed from any material suitable for use in the intended or potential operation environments in which the valvemay be used. Such materials include, but are not limited to 316 stainless steel, other grades of stainless steel, various metal alloys including Monel, heat, or chemical steel such as steel treated with a nitriding process; or any other suitable material. In some embodiments, each of the housings will be formed from the same material. In other embodiments, the housing components may each be formed from different materials and/or only some of the housing elements may be formed from the same material. The various housing elements may be formed through a machining process, a casting process, aD printing process, combinations of the foregoing, or any other suitable construction process or combination of processes.

In the embodiment ofeach of the housing elements is coupled to an adjacent element via a threaded connection, although alternative connection methods could be used without departing from the teachings of this disclosure. Such alternate connection methods include friction welding, press fitting, brazing, soldering, gas-tight quick connect connection and other suitable types of connections.

In the embodiment of. The dome housingis depicted as a component separate from the valve core housingand the dome housingand the valve core housingare shown as being connected via a threaded connection. This is only one example of a valve constructed according to the teachings of this disclosure. Alternative embodiments are envisioned, wherein other coupling methods are used (as discussed above). Still further alternative embodiments are envisioned wherein the valve housingand the dome housingare formed as a single, integral component.

Additional details of the exemplary gas lift valveare reflected in, which depicts the exemplary valvein cross section.

As reflected in, the valve seat housingdefines a plurality of openings(only one of which is through which injection gas may pass).

As also shown, in the figure a valve seatis positioned within a recess formed in the seat housing, and a resilient sealing element in the form of an O-ringis positioned within a grove formed in the seat housing to form seal between valve seat/O-ringassembly and the seat housing. The O-ringmay be formed of any suitable material, including elastomeric materials such as VitonD, a FFKM base material such as Chemraz, a harsh environment material such as Kalrez, or any other suitable O-Ring material. In some embodiments, the elastomeric material may be selected to have a high temperature rating for example, in some embodiments, a temperature rating of 350° Fahrenheit or greater. It will be appreciated that the material used to form the O-Ringmay be used to form any of the O-Rings or other resilient structures disclosed herein.

A retaining clipmay be used to help retain the valve seat/O-ringassembly within the valve seat. The retaining clipmay be constructed of brass, stainless steel, alloy steel, Inconel, or any other suitable material.

As shown in, the valve seatincludes an interior bore that, when not blocked, creates a path for fluid (e.g., injection gas) to flow from the outside of the gas lift valve, through the openingsin the valve seat housing, through the bore in the valve seat, and out of a discharge port of the valve or through the discharge port of the vale into an affixed check valve or other additional affixed feature. Any such additional affixed features may be attached to the valveusing threads, a latching mechanism, O-Ring sealing fixture, or any other suitable method of attachment.

In the exemplary valveof, a movable bellow assembly is positioned in the interior of the bellow housingthat includes a guide rod, a bellowpositioned about the guide rod, and a ball stem assembly. In the example of, the ball stem assemblyincludes a stem and a valve ball positioned within the stem. It will be appreciated that in alternate embodiments, the valve stem assemblycould be formed as an integral component including a stem portion and a valve sealing portion.

In the example of, a bellow adapteris positioned between the bellowand the ball stem assembly. The bellow adaptermay be coupled to the bellowat a first end of the bellow adapter(the left end in) end and to the ball stem assemblya second end of the bellow adapter(the right end in) through any suitable process. Such connecting processes can include brazing, welding, or any other suitable process.

The end of the bellownot coupled to the bellow adaptermay be coupled to a projecting surface of the guide rod, as further shown in.

In the example of, the construction of the dome housingis such that a surface of the dome housinggenerally abuts a surface of the guide rod. A washer element, which may take the form of a crush washer, may be positioned between the guide rodand the generally abutting surface of the dome housing. In embodiments where the washer elementtakes the form of a crush washer, the crush washer may be formed from copper, stainless steel, or any other suitable material. It will be appreciated that such materials can be used to form any or all crush washers disclosed herein.

In the example, of, the bellow adapter includes a recess in which a projecting portion of the guide rodis positioned. It will be appreciated that, because of this arrangement, the bellow adapter(and therefore the ball stem assemblycoupled to one end of the bellow adapter) can move relative to the guide rodas the bellowcompresses and de-compresses. It will be further appreciated that as the bellowcompresses and/or decompresses (and moves relative to the guide rod) the valve ball (or sealing surface) of the valve stem assemblywill move into and out of engagement with the valve seat, thus blocking or permitting the flow of injection gas from outside the gas lift valve, through the openingsin the valve seat housing, and through the opening in the valve seatand out of the discharge port of the valve.

In the example of, the bellow housingis coupled at one end to an end of the dome housingand an and a resilient sealing element in the form of O-ring(positioned within a recess in the dome housing) is used to provide a seal between the two housing elements. The O-ring may be formed from the same material, or a different material, as O-Ring, discussed above.

For the exemplary gas lift valveof, the end of the dome housingnot coupled to the bellow housingis coupled to the valve core housing. It will be appreciated that, in embodiments, where the dome housingand the valve core housingare formed as an integral component, there will be no such coupling.

In the example of, the dome housingdefines a first interior bore that serves to at least partially define an interior charging chamberthat exists at least partially within the dome housing. In the example of, the interior charging chamberis partially (although primarily in the example) defined by the first interior bore, which is bounded by interior surfaces of the dome housingand partially defined by a second interior borebounded by interior surfaces of a recess in the valve core housing(discussed below). Thus, in the illustrated example, the charging chamber exists partially within the dome housing and partially within the valve core housing. It will be appreciated that, in alternate embodiments the interior charging chambermay be defined by interior surfaces of the valve core housingor, in embodiments where the valve core housingis integrally formed with the dome housing, by the interior of the integral component alone.

It will be appreciated that the first interior bore within the dome housing will have a first internal or interior cross sectional diameter and that the second interior borewithin the valve core housing will have a second internal or interior cross sectional diameter.

As reflected in, in the exemplary embodiment, the valve core housingincludes and defines, in addition to the second interior borediscussed above, a third bore of a third internal or interior cross-sectional diameter or dimension, and a fourth boreof a fourth internal or interior cross sectional dimension in fluid communication with each other. In the example of, the fourth interior boreis positioned between the second and the third interior bores.

In the example, ofa portion of the third interior bore is threaded.

The third bore is not separately labeled inbut will be understood to be the bore in valve core housingin which the intermediate sealing element(discussed below) is positioned. As reflected in the figures, the first, second, third and fourth bores are—in the absence of any elements positioned within the bores—in fluid communication with one another.

As reflected in the figures, both the third interior bore and the fourth interior bore have, respectively, third and fourth internal or interior cross sectional diameters.

As may be noted, in, the first bore, second bore, third bore, and fourth bores all pass axially through the valve core housing. As reflected in the figure, the interior cross-sectional diameter dimension of the fourth boreis smaller than the interior cross-sectional diameter dimensions of both the first boreand the second bore, and the interior cross sectional dimension of the first boreis greater than the interior cross-sectional dimension of the second bore. In the example of, the interior cross sectional diameter of the third bore is greater than the interior cross sectional diameter of the fourth bore, but less than the interior cross-sectional diameter of the second bore.

It will be appreciated that, in the example ofand other anticipated embodiments, the interior cross-sections of the bores corresponding to the first, second and third bores may not be exactly constant throughout the corresponding bore structures. For example, inthe interior cross section of the bore corresponding to the third bore varies slightly across its axial length. In such instances, the references herein to the interior cross sectional diameter should be understood to refer to the maximum interior cross sectional diameters of the corresponding bore sections.

In the illustrated example, a valve assemblyis positioned within the bore. The valve assemblymay take the form of a Schrader type valve core and, more particular, a valve core of the type that includes nitrile sealing elements, such as a nitrile valve core available from Dill Air Control Products or a sealing element comprising any other suitable material such as Viton, FFKM, Kalrez, Chemraz, or any other suitable elastomeric or sealing material. In the example of, the valve assemblyis positioned such that it is substantially completely within the fourth bore. Alternate embodiments are envisioned, however, wherein portions of the valve assemblyextend into one or both of the second boreor the third bore. For example, as shown in, in one embodiment, the valve assemblycan comprise a main body and a stem wherein only the main body portion is positioned completely within the fourth bore.

In the example of, the valve core housingincludes a first exterior surface or sectionhaving a first external diameter, a second exterior surface or sectionhaving a second external diameter, and a third exterior surface or sectionhaving a third external diameter. In the example, of, the second external diameter of the second exterior surfaceis less than the first external diameter of the first exterior surface.

In the example of, at least portions of the outer surfaces of the second sectionand the third sectionare threaded, and the outer surface of the first exterior sectionis substantially smooth. As depicted in, the outer diameter of the first sectionis greater than the outer diameters of the second and third sectionsand. In the example of, the outer diameter of the second sectionis less than the outer diameter of third section. This is exemplary as the diameters of the second and third sections,may be the same, or substantially the same, or the outer diameter of the third sectionmay be greater than the outer diameter of the second section.