CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/406,489, filed October 11, 2016, which is incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to rotary gate valves. More specifically, in certain embodiments, the present disclosure relates to low cost subsea rotary gate valves and associated systems.

[0003] In subsea well systems, production fluids are often produced from multiple well locations located on the sea bed. The produced fluids may be directed into subsea flow lines that ultimately direct the fluid to collection facilities located at the surface. The flow of fluid from each well and along the various subsea production lines and systems may be controlled by various valves that can be located at the wellheads or at various locations along the production flow.

[0004] Currently, ball valves and gate valves are being utilized as valves in subsea pipelines. Examples of conventional ball and gate valves are described in U.S. Patent Nos. 7,523,916, 6,688,324, 6,145,594, 4,436,279, and 4,294,284 and U.S. Patent Application Publication Nos. 2015/0369001, 2011/0308619, 2010/0300696, 2007/0209724, the entireties of which are hereby incorporated by reference.

[0005] However, the use of these conventional valves may be problematic. Conventional valves may not be piggable resulting in the degradation of functional or sealing integrity of the valves and subsea pipelines of gas hydrates, wax, and/or asphaltenes. In addition, conventional subsea valves may also not be capable of bi-directional sealing shortly after being put into service. Furthermore, conventional valves typically are costly due to their size, weight, and envelope dimensions.

[0006] It is desirable to develop a new type of subsea valve that is bi-directionally piggable, allows for bi-directional sealing, and is less costly than conventional subsea valves.

SUMMARY

[0007] The present disclosure relates generally to rotary gate valves. More specifically, in certain embodiments, the present disclosure relates to low cost subsea rotary gate valves and associated systems.

[0008] In one embodiment, the present disclosure provides a rotary gate valve comprising a valve body, wherein the valve body defines a fluid flow pathway, a closure member cavity, and a stem cavity, a closure member disposed in the closure member cavity, and a stem disposed in the stem cavity.

[0009] In another embodiment, the present disclosure provides a subsea system comprising: a subsea flow line and a rotary gate valve connected to the subsea flow line, wherein the rotary gate valve comprises a valve body, wherein the valve body defines a fluid flow pathway, a closure member cavity, and a stem cavity, a closure member disposed in the closure member cavity, and a stem disposed in the stem cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings.

[0011] Figure 1 is an illustration of a rotary gate valve in accordance with certain embodiments of the present disclosure.

[0012] Figure 2 is section view of the rotary gate valve of Figure 1.

[0013] Figure 3 is an illustration of a metal to metal seal for a rotary gate valve in accordance with certain embodiments of the present disclosure.

[0014] Figure 4 is an illustration of a subsea system in accordance with certain embodiments of the present disclosure.

[0015] The features and advantages of the present disclosure will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the disclosure.

DETAILED DESCRIPTION

[0016] The description that follows includes exemplary apparatuses, methods, techniques, and/or instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.

[0017] The present disclosure relates generally to rotary gate valves. More specifically, in certain embodiments, the present disclosure relates to low cost subsea rotary gate valves and associated systems.

[0018] In certain embodiments, the present disclosure provides a rotary gate valve. In certain embodiments, the rotary gate valve may be a subsea rotary gate valve. In certain embodiments, the rotary gate valve may be a rotary slab gate valve, a rotary wedge gate valve, a rotary double expanding gate valve, or a rotary pressure seal gate valve. In certain embodiments, the rotary gate valves described herein may be ¼ turn rotary gate valves.

[0019] Some desirable attributes of the rotary gate valves discussed herein is that they may be less costly than conventional subsea valves. In certain embodiments, the rotary gate valves described herein may weigh significantly less than conventional subsea valves, in particular those that are remotely operated. In certain embodiments, the rotary gate valves discussed herein may have a significantly smaller sail dimension than conventional subsea valves. In certain embodiments, the rotary gate valves discussed herein may have internal (valve side) spring return fail safe functionality. In certain embodiments, the valve may fail safe in the event an ROV or other collision subsea completely detaches the hydraulic or electrically or electro hydraulic operator. In certain embodiments, the rotary gate valves described herein may be capable of bi-directional sealing and/or bi-directional pigging.

[0020] Referring now to Figures 1 and 2, Figures 1 and 2 illustrate rotary gate valve 100. In certain embodiments, rotary gate valve 100 may comprise a subsea rotary gate valve. In certain embodiments, rotary gate valve 100 may comprise valve body 110, closure member 120, and stem 130.

[0021] In certain embodiments, valve body 110 may comprise a 2-piece valve body. In certain embodiments, valve body 110 may comprise first end cover 111 and second end cover 112. In certain embodiments first end cover 111 and second end cover 112 may be bolted together using cover stud 114 and cover nut 115. In certain embodiments, gasket 113 may be used to seal first end cover 111 and second end cover 112. In certain embodiments valve body 110 may be bonnet-less.

[0022] In certain embodiments, valve body 110 may have a circular cross sectional geometry. In certain embodiments, valve body may define a fluid flow pathway 101, closure member cavity 102, and stem cavity 103. In certain embodiments, fluid pathway 101 may have a circular cross sectional geometry. In certain embodiments, stem cavity 103 may have a circular cross sectional geometry with a diameter in the range of from 0.5 inches to 36 inches. In certain embodiments, valve body 110 may be constructed of carbon steel, stainless steel, austenitic steel, an Inconel alloy, Monel, Alloy 20, Hastalloy, or any combination thereof.

[0023] In certain embodiments, closure member 120 may comprise a gate closure member. In certain embodiments, closure member 120 may be a one-piece closure member. In other embodiments, closure member 120 may be a two-piece closure member. In certain embodiments, closure member 120 may be constructed of carbon steel, stainless steel, austenitic steel, an Inconel alloy, Monel, Alloy 20, Hastalloy, or any combination thereof.

[0024] In certain embodiments, closure member 120 may comprise solid body 121 defining opening 122. In certain embodiments, closure member 120 may further comprise cavity relief 123 and stem axis 126. In certain embodiments, closure member 120 may be capable of rotating along stem axis 126. In certain embodiments, cavity relief 123, stem axis 126, and opening 122 may each be disposed on closure member 120 in a manner sufficient to define an angle in the range of from 0 to 90 degrees. In certain embodiments, cavity relief 123, stem axis 126, and opening 122 may each be disposed on closure member 120 in a manner sufficient to define an angle in the range of from 25 to 45 degrees. In certain embodiments, as shown in Figure 2, cavity relief 123, stem axis 126, and opening 122 may each be disposed on closure member 120 in a manner sufficient to define a 31 degree angle. In certain embodiments, cavity relief 123, stem axis 126, and opening 122 may each be disposed on closure member 120 in a manner sufficient to define a suitable stroke.

[0025] In certain embodiments, opening 122 may have a circular cross sectional geometry. In certain embodiments, closure member 120 may further comprise cavity relief 123. In certain embodiments, cavity relief 123 may be located at each side of a seat seal face. In certain embodiments, cavity relief 123 may comprise tapered edges 124 and recessed portion 125. In certain embodiments, (not illustrated in Figures 1 and 2) closure member 120 may comprise an equalizer hole between a closure member port and a valve cavity. In certain embodiments, the equalizer hole does not render the valve unidirectional flow capable. In certain embodiments, cavity relief 123 may ensure correct alignment between the closure member position and a centralizing location with respect to both seats.

[0026] In certain embodiments, (not illustrated in Figures 1 and 2) closure member 120 may comprise a wedge closure member, a single slab or single/double expanding closure member. In certain embodiments, (not illustrated in Figures 1 and 2) closure member 120 may be configured from a male and female section. In certain embodiments, the male section close position may be controlled by an internal stop and the further rotation of the female segment may allow for expansion of the closure member. In certain embodiments, the male and female sections may be held together with a centralizer mechanism that permits expansion and ensures the two sections are returned to their default position during cycling. In certain embodiments, (not illustrated in Figures 1 and 2) closure member 120 may comprise two gate segments, with springs strategically located between each of the gate segments to provide a mechanical preload force to ensure each closure member segment is in continuous contact with the upstream and downstream seats.

[0027] In certain embodiments, closure member 120 may be connected to interior 115 of valve body 110 by one or more springs 140. In certain embodiments, the one or more springs 140 may provide an internal fail safe mechanism. In other embodiments, closure member 120 may not be connected to interior 111 of valve body 110 by one or more springs. In certain embodiments, springs 140 may be connected to valve body 110 and closure member 120 in a manner that allows closure member 120 to return to an open positon as a fail-safe. In certain embodiments, the one or more springs 140 may be connected to valve body 110 and closure member 120 in a manner that allows closure member 120 to return to a closed as a fail-safe.

[0028] In certain embodiments, closure member 120 may be disposed in closure member cavity 102. In certain embodiments, closure member 120 may be attached to stem 130. In certain embodiments, stem 130 may be connected to closure member 120 utilizing key drives 131. In certain embodiments, key drives 131 may comprise double keyed drives or splined drive arrangements.

[0029] In certain embodiments, closure member 120 and/or stem 130 may be capable of rotating within closure member cavity 102. In certain embodiments, closure member 120 and/or stem 130 may be capable of rotating from an open positon to a closed positon. As used herein, the term open positon refers to an arrangement wherein opening 122 and fluid pathway 101 are aligned creating an unblocked pathway through rotary gate valve 100. As used herein, the term closed position refers to an arrangement wherein cavity relief 123 and fluid pathway 101 are aligned thus creating a blocked pathway through rotary gate valve 100. In certain embodiments, closure member 120 and/or stem 130 may be capable of rotating within closure member cavity 102 from an open position to a closed positon, and vice versa. In certain embodiments, closure member 120 and/or stem 130 may be capable of rotating an amount in the range of from 0 degrees to 90 degrees to transition from an open positon to a closed positon or vice versa. In certain embodiments, closure member 120 and/or stem 130 may be capable of rotating an amount in the range of from 25 degrees to 45 degrees to transition from an open positon to a closed positon or vice versa.

[0030] In certain embodiments, stem 130 may rest in stem guide bush 132 resting in an end of stem cavity 103 in first end cover 111. In certain embodiments, stem guide bush 132 may provide a permanently energized metal to metal stem seal. In certain embodiments, antistatic device 133 may provide electrical continuity between closure member 120, stem 130, and stem guide bush 132. In certain embodiments, stem guide bush 132 may be double seal welded to the valve body. In certain embodiments, a second stem guide bush 132 may rest in an end of stem cavity 103 on the body end cover 112. In certain embodiments, the second stem guide bush 132 may provide a means of supporting the stem that reduces input operating torque and ensures closure members position with respect to sealing integrity.

[0031] In certain embodiments, stem spacer ring/rings 134 may be used to align and centralize closure member 120 to ensure optimum positioning of closure member 120.

[0032] In certain embodiments, rotary gate valve 100 may comprise seals 135. In certain embodiments, seals 135 may be used as a back seat bush. In certain embodiments, seals 135 may be permanently energized metal to metal seals. In certain embodiments, seals 135 may be single, double, or multipoint seals. In certain embodiments, seals 135 may be single or double live spring loaded. In certain embodiments, seals 135 may be hard faced or non-hard faced.

[0033] Referring now to Figure 3, Figure 3 illustrates seal 135. In certain embodiments, seal 135 may comprise of single, multipoint media seals. In certain embodiments, seal 135 may comprise metallic, single or double metallic, multipoint metallic seals. In certain embodiments, seal 135 may comprise plastics or elastomer. In certain embodiments, seal 135 may comprise one or more environmental seal rings 11, one or more media stem seal or seat seal rings 12, mechanically energized seal ring 13, and spring 14. In certain embodiments, media stem seal or seat seal rings 12, and mechanically energized seal ring 13 may be arranged such that if mechanically energized seal ring 13 were to fail, the lower media stem seal or seat seal ring 12 may become mechanically energized. In certain embodiments, the upper environmental seal ring 11 may be mechanically energized by tightening a gland bolt nut, for example gland nut 125. In certain embodiments, environmental seal rings 11 may be arranged such that if the upper environmental seal ring 11 was to fail, the lower environmental seal ring 11 would maintain a seal.

[0034] Referring back to Figures 1 and 2, in certain embodiments, gland sleeve 150 may be disposed within stem cavity 103 of second end cover 112. In certain embodiments, seal 136, gland 137, and gland seal 138 may be capable of providing a seal between gland sleeve 150 and stem 130. In certain embodiments, seal 136 and comprise any combination of features discussed above with respect to seal 135. In certain embodiments, gland 137 may be capable of mechanically preloading the pressure energized stem seals and prevent extrusion of seal rings 138 in high pressure environments. In certain embodiments, gland seal 138 may be capable of containing pipe line media egress to the environment and sea water ingress to the valve internals.

[0035] In certain embodiments, gland plate 139 may be connected to gland sleeve 150 utilizing gland stud 151 and gland nut 152.

[0036] In certain embodiments, closure member 120 may contact seats 160 to prevent flow in the closed position and permit flow in the open position. In certain embodiments, seats 160 may prevent pigging debris ingress into closure member cavity 102. In certain embodiments, seals 161 provide a seal between closure member 120 and valve body 110 at seats 160. In certain embodiments, seal 161 may comprise seal welded seats, or SPE/DPE secondary sealing configurations (single piston effect/double piston effect soft seals - secondary seals), or metallic threaded seals.

[0037] In certain embodiments, not illustrated in Figures 1 and 2, stem 130 may be connected to a drive system. In certain embodiments, the drive system may provide a rotary stroke function. In certain embodiments, the drive system may comprise a direct drive rotary system, an indirect drive rotary system, or a direct or indirect drive lever system for valve functionality

[0038] Referring now to Figure 4, Figure 4 illustrates valve system 1000. In certain embodiments, valve system 1000 may comprise subsea flowline 1100 and rotary valve 1200. In certain embodiments, rotary valve 1200 may comprise any combination of features discussed above with respect to rotary gate valve 100.

[0039] In certain embodiments, subsea flowline 1100 may comprise any conventional subsea flowline. In certain embodiments, subsea flowline may be located on a seafloor. In certain embodiments, first portion 1101 of subsea flowline may be connected to a first end of rotary valve 1200. In certain embodiments, second portion 1102 of subsea flowline 1100 may be connected to a second end of rotary valve 1200. In certain embodiments, flanges 1105 may be used to connect flowline 1100 to rotary valve 1200. In certain embodiments, first portion 1101 and or second portion 1102 of subsea flowline 1100 may be connected to rotary valve 1200 utilizing studs 1103 and stud nuts 1104.

[0040] While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible.

[0041] Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.