A high-pressure wellhead valve for oil fields

Abstract

This invention relates to the field of wellhead valve technology and discloses a high-pressure wellhead valve for oilfields, comprising a valve assembly, a valve body with a valve cavity inside, a front shaft rotatably connected to the valve body with its top end penetrating the valve body and extending to the outside, and a valve core assembly including a valve core located within the space enclosed by the valve cavity. A sealing element for sealing the front shaft is provided on the outside of the valve core. A valve seat, which fits tightly against the outer surface of the valve core, is detachably installed inside the valve cavity. This high-pressure wellhead valve for oilfields effectively solves the problems of corrosion and wear easily occurring in existing valves under high pressure, high temperature, and highly corrosive working environments, performance degradation of common high-pressure wellhead valves in oilfields under high temperature and high pressure environments, and frequent leakage of the front shaft connected to the actuator.

Description

Technical Field

[0001] The invention relates to the technical field of wellhead valves, and in particular to a high-pressure wellhead valve for oil fields. Background Art

[0002] Leakage of high-pressure wellhead valves is one of the most common problems, which is mainly manifested by fluid passing through the valve when it is normally closed. Leakage may be caused by wear, corrosion or improper assembly between the valve seat and the valve disc. Dealing with leakage problems usually requires replacing the seal or the entire valve, and ensuring correct assembly and commissioning during installation.

[0003] The valve is prone to corrosion and wear in a high-pressure, high-temperature, and highly corrosive working environment. Corrosion and wear not only affect the function and life of the valve, but may also cause safety problems. The performance of common oilfield high-pressure wellhead valves deteriorates in high-temperature and high-pressure environments, and the front shaft connected to the actuator often leaks. In response to this, the present invention designs a high-pressure wellhead valve that can automatically seal the front shaft. Summary of the invention

[0004] Technical issues solved

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a high-pressure wellhead valve for oil fields, which can effectively solve the problems in the prior art that the valve is easily corroded and worn in a high-pressure, high-temperature and highly corrosive working environment, the performance of common oilfield high-pressure wellhead valves decreases in a high-temperature and high-pressure environment, and the front shaft connected to the actuator often leaks.

[0006] Technical Solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] The present invention provides a high-pressure wellhead valve for oil fields, comprising:

[0009] A valve assembly, the valve assembly comprising a valve body, a valve cavity is formed inside the valve body, a front shaft is rotatably connected inside the valve body in a sealed manner, and a top end of the front shaft passes through the valve body and extends to the outside;

[0010] A valve core assembly, the valve core assembly comprising a valve core, the valve core being located in a space surrounded by a valve cavity, and a sealing member that can be used to seal with a front axle is disposed on the outer side of the valve core;

[0011] Wherein, a valve seat which is tightly fitted with the outer surface of the valve core is detachably installed inside the valve cavity.

[0012] Furthermore, an actuator which is in transmission with the top end of the front axle is arranged at the top of the valve body, and a valve seat gland which is in contact with the outer surface of the valve seat is detachably mounted on the port of the valve body through a bolt group.

[0013] Furthermore, the valve core includes two groups of hemispherical plates, the valve core adopts an integrated molding design, the valve seat is provided with two groups and is symmetrically distributed with the valve core as the center, and the upper surface of the valve core is fixedly connected to the bottom end of the front axle.

[0014] Furthermore, a sealing rod is detachably installed at the bottom of the inner wall of the valve cavity, and a sealing gasket is arranged between the sealing rod and the valve cavity, a rear shaft rotating with the top end of the sealing rod is arranged on the lower surface of the valve core, and a threaded seat threadedly connected to the bottom end of the sealing rod is tightly installed at the bottom of the valve body.

[0015] Furthermore, the sealing part includes a horizontal tube and a vertical tube, and the horizontal tube and the vertical tube are vertically distributed. One end of the horizontal tube is fixedly connected to the interior of the vertical tube, and one end of the horizontal tube away from the vertical tube is fixedly connected to the interior of the valve core. A through hole connected to the interior of the horizontal tube is opened in the valve core, the bottom end of the vertical tube is fixedly connected to the interior of the valve core, and the top end of the vertical tube passes through the valve core and extends to the outside.

[0016] Furthermore, a sealing disk that fits with the top of the inner wall of the valve cavity is fixedly connected to the outer circumferential surface of the front shaft, an upper sealing ring is installed on the sealing disk through a groove opened on its upper surface, and a fitting groove is opened on the lower surface of the sealing disk.

[0017] Furthermore, the inner wall of the vertical tube is sealingly and slidingly connected to a lifting rod, the top of the lifting rod is fixedly connected to a sealed plate that fits with the inner wall of the fitting groove, the sealed plate is installed with a lower sealing ring through a built-in groove opened on its circumferential outer surface, and a first lower pressure plate that fits with the outer surface of the lower sealing ring is arranged inside the built-in groove, and the outer surface of the first lower pressure plate is fixedly connected to a second lower pressure plate that fits with the top of the inner wall of the fitting groove through a smooth rod.

[0018] Furthermore, a limiting ring is fixedly connected to the inner wall of the through hole, a piston rod fitting with the limiting ring is slidably connected to the inner wall of the horizontal tube, a strong spring connected to the inner wall of the horizontal tube is arranged at one end of the piston rod away from the limiting ring, and the horizontal tube and the vertical tube are filled with hydraulic oil.

[0019] Beneficial Effects

[0020] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0021] The present invention is provided with a valve core assembly. When the valve core is in an open state, the valve cavity is filled with crude oil. The high-pressure crude oil in the valve cavity flows into the through hole, generating a thrust on the piston rod, driving the piston rod to slide along the inner wall of the horizontal tube. The strong spring is compressed and elastically deformed, and the piston rod squeezes the hydraulic oil in the horizontal tube and the vertical tube, driving the lifting rod to slide upward a short distance along the inner wall of the vertical tube. The lifting rod generates an upward thrust on the sealing plate, driving the upper surface of the sealing plate to approach one side of the second lower pressure plate until the upper surface of the sealing plate fits with the lower surface of the second lower pressure plate. At the same time, the second lower pressure plate slides downward a short distance relative to the sealing plate, driving the first lower pressure plate to squeeze the lower sealing ring. The lower sealing ring is compressed and elastically deformed to fit closely on the top of the inner wall of the valve cavity, sealing the circumferential outer surface of the sealing plate and cooperating with the upper sealing ring to realize "synchronous sealing of the upper and lower parts of the sealing disk". The greater the pressure inside the valve cavity, the better the sealing performance of the lower sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a three-dimensional structural schematic diagram of an embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a partial cross section of an embodiment of the present invention;

[0025] Figure 3 For the embodiment of the present invention Figure 2 A schematic diagram of the structure with a partial enlargement at the center;

[0026] Figure 4 This is a schematic structural diagram of the three-dimensional separation of the valve body, valve seat and valve seat gland in an embodiment of the present invention;

[0027] Figure 5 It is a schematic structural diagram of the three-dimensional separation of the rear axle, the sealing rod and the threaded seat according to an embodiment of the present invention;

[0028] Figure 6 It is a three-dimensional structural schematic diagram of a valve core assembly according to an embodiment of the present invention;

[0029] Figure 7 It is a schematic structural diagram of the three-dimensional separation of the sealing plate, the lower sealing ring and the first lower pressing plate in an embodiment of the present invention.

[0030] The numbers in the figure represent respectively: 1. valve assembly; 11. valve body; 111. valve chamber; 112. valve seat; 113. valve seat cover; 114. sealing rod; 115. threaded seat; 12. front shaft; 121. sealing disk; 122. groove; 123. upper sealing ring; 124. fitting groove; 13. actuator; 2. valve core assembly; 21. valve core; 211. rear shaft; 212. through hole; 213. limit ring; 22. sealing part; 220. strong spring; 221. horizontal tube; 222. vertical tube; 223. lifting rod; 224. sealing plate; 225. built-in groove; 226. lower sealing ring; 227. first lower pressure plate; 228. second lower pressure plate; 229. piston rod. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention will be further described below in conjunction with the embodiments.

[0033] Example:

[0034] See also Figure 1-Figure 7 The present invention provides a technical solution: a high-pressure wellhead valve for oil fields, comprising:

[0035] The valve assembly 1 comprises a valve body 11, wherein a valve cavity 111 is formed inside the valve body 11, a front shaft 12 is rotatably connected inside the valve body 11, and a top end of the front shaft 12 penetrates the valve body 11 and extends to the outside;

[0036] The valve core assembly 2 includes a valve core 21, the valve core 21 is located in the space surrounded by the valve cavity 111, and a sealing member 22 is provided on the outside of the valve core 21 for sealing with the front axle 12;

[0037] A valve seat 112 that fits tightly against the outer surface of the valve core 21 is detachably installed inside the valve cavity 111 .

[0038] An actuator 13 that drives the top of the front shaft 12 is arranged on the top of the valve body 11 , and a valve seat gland 113 that fits the outer surface of the valve seat 112 is detachably mounted on the port of the valve body 11 through a bolt group.

[0039] The valve core 21 includes two groups of hemispherical plates. The valve core 21 adopts an integrated molding design. The valve seat 112 is provided with two groups and is symmetrically distributed with the valve core 21 as the center. The upper surface of the valve core 21 is fixedly connected to the bottom end of the front shaft 12.

[0040] A sealing rod 114 is detachably mounted on the bottom of the inner wall of the valve cavity 111, and a sealing gasket is arranged between the sealing rod 114 and the valve cavity 111. A rear shaft 211 that rotates with the top of the sealing rod 114 is arranged on the lower surface of the valve core 21, and a threaded seat 115 that is threadedly connected to the bottom of the sealing rod 114 is tightly mounted on the bottom of the valve body 11. Since the sealing rod 114 does not rotate, unlike the front shaft 12, the rotation of the valve core 21 requires the drive of the front shaft 12. Therefore, the sealing performance of the front shaft 12 is easily reduced under high temperature and high pressure environments. On the other hand, the sealing rod 114 is driven to fit tightly on the bottom of the inner wall of the valve cavity 111 by rotating the threaded seat 115, and a sealing gasket is arranged on the joint surface of the two until "the sealing rod 114 and the valve body 11 are combined into a whole" (the sealing rod 114 does not need to rotate).

[0041] The sealing member 22 includes a horizontal tube 221 and a vertical tube 222, which are vertically distributed. One end of the horizontal tube 221 is fixedly connected to the interior of the vertical tube 222, and one end of the horizontal tube 221 away from the vertical tube 222 is fixedly connected to the interior of the valve core 21. A through hole 212 connected to the interior of the horizontal tube 221 is provided in the valve core 21. The bottom end of the vertical tube 222 is fixedly connected to the interior of the valve core 21, and the top end of the vertical tube 222 penetrates the valve core 21 and extends to the outside.

[0042] A sealing disk 121 that fits against the top of the inner wall of the valve cavity 111 is fixedly connected to the circumferential outer surface of the front shaft 12. The sealing disk 121 is provided with an upper sealing ring 123 via a groove 122 on its upper surface. A fitting groove 124 is provided on the lower surface of the sealing disk 121.

[0043] The inner wall of the vertical tube 222 is sealingly and slidingly connected to a lifting rod 223, and the top of the lifting rod 223 is fixedly connected to a sealed plate 224 that fits with the inner wall of the fitting groove 124, and the sealed plate 224 is installed with a lower sealing ring 226 through a built-in groove 225 opened on its circumferential outer surface, and the built-in groove 225 is provided with a first lower pressure plate 227 that fits with the outer surface of the lower sealing ring 226, and the outer surface of the first lower pressure plate 227 is fixedly connected to a second lower pressure plate 228 that fits with the top of the inner wall of the fitting groove 124 through a smooth rod.

[0044] A limit ring 213 is fixedly connected to the inner wall of the through hole 212, and a piston rod 229 that fits the limit ring 213 is slidably connected to the inner wall of the cross tube 221. A strong spring 220 connected to the inner wall of the cross tube 221 is arranged at one end of the piston rod 229 away from the limit ring 213, and the cross tube 221 and the vertical tube 222 are filled with hydraulic oil.

[0045] refer to Figure 1-7 The valve is prone to corrosion and wear in a high-pressure, high-temperature, and highly corrosive working environment. Corrosion and wear not only affect the function and life of the valve, but may also cause safety problems. The performance of common oilfield high-pressure wellhead valves deteriorates in high-temperature and high-pressure environments, and the front shaft connected to the actuator often leaks. In response to this, the present invention designs a high-pressure wellhead valve that can automatically seal the front shaft.

[0046] In actual applications, the working principle of the valve core 21 on the valve core assembly 2 is to control the start and stop of the actuator 13 through the PLC. The actuator 13 drives the front shaft 12 to rotate around the inside of the valve body 11 for sealing, drives the valve core 21 and the sealing member 22 to rotate synchronously, and drives the lower surface of the valve core 21 to rotate around the top of the sealing rod 114 through the rear shaft 211 (the sealing rod 114 does not rotate, which is different from the front shaft 12. The rotation of the valve core 21 requires the drive of the front shaft 12. Therefore, the sealing performance of the front shaft 12 is easily reduced under high temperature and high pressure environments). When the outer surface of the valve core 21 rotates to fit with the end face of the valve seat 112, the valve cavity 111 inside the valve body 11 is closed. At this time, the valve is in a closed state. Conversely, when the outer surface of the valve core 21 rotates to separate from the end face of the valve seat 112, the valve cavity 111 inside the valve body 11 is connected. At this time, the valve is in an open state.

[0047] The present invention needs to emphasize that the valve core 21 design of the present invention has the following advantages:

[0048] Advantage 1: the valve core 21 includes two groups of hemispherical plates (the hemispherical valve core is the core component of the eccentric hemispherical valve, and its shape is similar to a hemispherical bowl, with one side of the hemispherical valve core being convex and the other side being concave). The valve core 21 adopts an integrated molding design. The present invention is different from the conventional hemispherical valve core. The present invention is composed of two groups of hemispherical plates and adopts a symmetrical design, so that the force on both sides of the valve core 21 is uniform during operation, thereby reducing the vibration of the valve core 21 and increasing its service life.

[0049] Advantage 2: The two groups of hemispherical plates are sealed with the corresponding valve seats 112 respectively, and the double sealing is better.

[0050] Advantage three, the two hemispherical plates form a whole, and cooperate with the fixation of the vertical pipe 222 (playing the role of reinforcing ribs), so that the strength is significantly improved compared with the original, and the phenomenon of defective products such as deformation or breakage caused during casting can be avoided.

[0051] The existing front axle needs to drive the valve core for rotation adjustment. The front axle and the valve body are generally connected by a seal. Under high temperature and high pressure, the performance of a single seal decreases, which can easily cause leakage in the front axle. In contrast, in the present invention, first, the circumferential outer surface of the front axle 12 is fixedly connected with a sealing disk 121 that fits the top of the inner wall of the valve cavity 111. The sealing disk 121 is installed with an upper sealing ring 123 (basically the same as a conventional seal) through a groove 122 provided on its upper surface. The position of the upper sealing ring 123 is basically constant, and it mainly plays a sealing role for the front axle 12. Secondly, the present invention is provided with a lifting rod 223, a sealing plate 224, a built-in groove 225, a lower sealing ring 226, a first lower pressure plate 227, a second lower pressure plate 228, and a piston rod 229. When the valve core 21 is in a closed state, there is no crude oil in the valve cavity 111, so the sealing of the front axle 12 will not be affected; when the valve core 21 is in an open state, the valve cavity 111 is filled with crude oil, and the high-pressure crude oil in the valve cavity 111 flows into the through hole 212, generating a thrust on the piston rod 229, driving the piston rod 229 to slide along the inner wall of the cross tube 221, and the strong spring 220 is elastically deformed under pressure, and the piston rod 229 squeezes the hydraulic oil in the cross tube 221 and the vertical tube 222, driving the lifting rod 223 to slide upward along the inner wall of the vertical tube 222 for a short distance (symmetrical design on both sides, synchronous upward movement), and the lifting rod 223 generates an upward thrust on the sealing plate 224, driving the upper surface of the sealing plate 224 to move closer to the side of the second lower pressure plate 228 ( The upper surface of the second lower pressure plate 228 is tightly fitted on the top of the inner wall of the fitting groove 124) until the upper surface of the sealing plate 224 is fitted with the lower surface of the second lower pressure plate 228. At the same time, the second lower pressure plate 228 slides downward a short distance relative to the sealing plate 224, driving the first lower pressure plate 227 to squeeze the lower sealing ring 226. The lower sealing ring 226 is elastically deformed under pressure and fits tightly on the top of the inner wall of the valve cavity 111, thereby sealing the circumferential outer surface of the sealing plate 224 and cooperating with the upper sealing ring 123 to achieve "synchronous sealing of the upper and lower parts" of the sealing disk 121 (front axle 12). The greater the pressure inside the valve cavity 111, the better the sealing performance of the lower sealing ring 226 (the lower sealing ring 226 is an automatic seal), which greatly improves the service life of the upper sealing ring 123.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-pressure wellhead valve for oil fields, characterized in that: include: A valve assembly (1), the valve assembly (1) comprising a valve body (11), wherein a valve cavity (111) is provided inside the valve body (11), a front shaft (12) is sealingly rotatably connected inside the valve body (11), and a top end of the front shaft (12) passes through the valve body (11) and extends to the outside; A valve core assembly (2), the valve core assembly (2) comprising a valve core (21), the valve core (21) being located in a space enclosed by the valve cavity (111), and a sealing member (22) which can be used to seal the front axle (12) being provided outside the valve core (21); A valve seat (112) that is tightly fitted to the outer surface of the valve core (21) is detachably mounted inside the valve cavity (111); The sealing member (22) comprises a transverse tube (221) and a vertical tube (222), wherein the transverse tube (221) and the vertical tube (222) are arranged vertically, one end of the transverse tube (221) is fixedly connected to the interior of the vertical tube (222), one end of the transverse tube (221) away from the vertical tube (222) is fixedly connected to the interior of the valve core (21), a through hole (212) connected to the interior of the transverse tube (221) is provided inside the valve core (21), the bottom end of the vertical tube (222) is fixedly connected to the interior of the valve core (21), and the top end of the vertical tube (222) penetrates the valve core (21) and extends to the outside; The inner wall of the through hole (212) is fixedly connected to a limit ring (213); the inner wall of the transverse tube (221) is slidably connected to a piston rod (229) that fits the limit ring (213); a strong spring (220) connected to the inner wall of the transverse tube (221) is provided at one end of the piston rod (229) away from the limit ring (213); and the transverse tube (221) and the vertical tube (222) are filled with hydraulic oil.

2. The high-pressure wellhead valve for oil fields according to claim 1, characterized in that: An actuator (13) is arranged at the top of the valve body (11) and is driven by the top of the front shaft (12). A valve seat gland (113) that fits the outer surface of the valve seat (112) is detachably mounted on the port of the valve body (11) via a bolt assembly.

3. The high-pressure wellhead valve for oil fields according to claim 2, characterized in that: The valve core (21) comprises two groups of hemispherical plates. The valve core (21) is designed as an integrated molding. The valve seat (112) is provided with two groups and is symmetrically distributed with the valve core (21) as the center. The upper surface of the valve core (21) is fixedly connected to the bottom end of the front shaft (12).

4. The high-pressure wellhead valve for oil fields according to claim 1, characterized in that: A sealing rod (114) is detachably mounted on the bottom of the inner wall of the valve cavity (111), and a sealing gasket is provided between the sealing rod (114) and the valve cavity (111). A rear shaft (211) that rotates with the top end of the sealing rod (114) is provided on the lower surface of the valve core (21). A threaded seat (115) that is threadedly connected to the bottom end of the sealing rod (114) is tightly mounted on the bottom of the valve body (11).

5. The high-pressure wellhead valve for oil fields according to claim 1, characterized in that: A sealing disk (121) is fixedly connected to the outer circumferential surface of the front shaft (12) and is fitted to the top of the inner wall of the valve cavity (111). The sealing disk (121) is provided with an upper sealing ring (123) via a groove (122) provided on its upper surface. A fitting groove (124) is provided on the lower surface of the sealing disk (121).

6. The high-pressure wellhead valve for oil fields according to claim 5, characterized in that: The inner wall of the vertical tube (222) is sealingly and slidably connected to a lifting rod (223), and the top of the lifting rod (223) is fixedly connected to a sealing plate (224) that fits with the inner wall of the fitting groove (124), and the sealing plate (224) is installed with a lower sealing ring (226) through a built-in groove (225) opened on its circumferential outer surface, and a first lower pressure plate (227) that fits with the outer surface of the lower sealing ring (226) is arranged inside the built-in groove (225), and the outer surface of the first lower pressure plate (227) is fixedly connected to a second lower pressure plate (228) that fits with the top of the inner wall of the fitting groove (124) through a smooth rod.

Images