Safety valve

Abstract

The invention relates to the field of petroleum field development, in particular to a safety valve which comprises a valve plate, a valve seat, a sealing assembly, an upper connector assembly, a spring compression connector, a spring sleeve, a valve sleeve and a lower connector, and the upper connector assembly, the spring compression connector, the spring sleeve, the valve sleeve and the lower connector are sequentially connected. The sealing assembly comprises a first elastic piece, a stop sleeve and a throttling nozzle, the two ends of the first elastic piece are connected with the spring compression connector and the stop sleeve respectively, the elastic force direction of the first elastic piece is in the axial direction, the throttling nozzle is fixed in the stop sleeve, and the inner diameter of the throttling nozzle is smaller than that of the stop sleeve. The stop sleeve is in sliding connection with the valve seat, and the sliding direction is in the axial direction. The safety valve is provided with the sealing assembly used for controlling the valve plate to be opened or closed, a traditional safety valve needing to be provided with a hydraulic system is replaced, valve emergency closing and gas well production stopping caused by out-of-control and failure of the hydraulic system are avoided, and production stability is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of oil field development, and more particularly to a safety valve. Background Art

[0002] Downhole safety valve is a key safety device installed in the wellbore, which is used to automatically or manually close the oil well in an emergency to prevent accidents such as blowouts, fires, environmental pollution, etc. It is the last line of defense for safe production of oil wells.

[0003] The existing downhole safety valve usually adopts ground-controlled downhole safety valve, the core of which is to provide power through the hydraulic pump on the ground, provide control pipeline and connect with the hydraulic cylinder of the downhole safety valve, the downhole hydraulic cylinder receives hydraulic pressure and pushes the valve core to open or close. However, after long-term use, the hydraulic system of the existing safety valve is prone to problems such as loss of control and failure. For example, the control pipeline may rupture, causing hydraulic oil leakage, so that the hydraulic pressure will drop rapidly. In addition, the hydraulic pump may also fail to work during use. Such conditions will trigger the emergency closure of the safety valve, causing the gas well to stop production, which is not conducive to continuous and stable production. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem of out-of-control failure of the hydraulic system of the prior art downhole safety valve after long-term use, and to provide a safety valve to replace the traditional safety valve that requires the arrangement of a hydraulic system, thereby avoiding out-of-control failure of the hydraulic system and improving production stability.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A safety valve is provided, comprising a valve plate, a valve seat, a sealing assembly, and an upper joint assembly, a spring compression joint, a spring sleeve, a valve sleeve and a lower joint which are connected in sequence, wherein the interiors of the upper joint assembly, the spring compression joint, the spring sleeve, the valve sleeve and the lower joint are all hollow and interconnected to form a flow channel, the valve plate is rotatably connected to the valve sleeve, the valve seat is arranged on the inner wall of the spring sleeve, the sealing assembly is located in the spring sleeve, the sealing assembly comprises a first elastic member, a stop sleeve and a throttle nozzle, the two ends of the first elastic member are respectively connected to the spring compression joint and the stop sleeve, the elastic force direction of the first elastic member is along the axial direction, the throttle nozzle is fixed in the stop sleeve, the inner diameter of the throttle nozzle is smaller than the inner diameter of the stop sleeve, the stop sleeve is slidably connected to the valve seat and the sliding direction is along the axial direction.

[0007] The safety valve of the present invention has an inner diameter of the throttle nozzle that is smaller than that of the stop sleeve. Therefore, the flow rate of the fluid will become faster after passing through the throttle nozzle, and the side of the throttle nozzle with a faster flow rate will be subjected to a smaller pressure. Therefore, a pressure difference will be generated on both sides of the throttle nozzle. Under normal conditions, the flow rate in the well is at a normal value, and the stop sleeve supports one side of the valve plate. When the gas production is at a normal value and the pressure difference on both sides of the throttle nozzle is small, due to the setting of the first elastic member, the first elastic member only produces a small deformation at this time, which is not enough to drive the stop sleeve to produce excessive displacement. The stop sleeve supports one side of the valve plate to limit its closing of the flow channel. When the gas production is too high, the pressure on both sides of the throttle nozzle is too high. When the difference is large, the stop sleeve slides and compresses the first elastic member, and the stop sleeve no longer provides support for the valve plate. The valve plate will rotate and block the flow channel to close the oil well and prevent the occurrence of blowouts. When the gas production value in the oil well returns to normal, the first elastic member will push the stop sleeve to open the valve plate, so that the valve plate is in an open state again, or pressurize the wellhead so that the pressure at the upper end of the valve plate is greater than the pressure at the lower end, so that the valve plate is reopened. The sealing assembly is used to control the opening or closing of the valve plate. There is no need to arrange a hydraulic system, which avoids emergency closure of the valve due to loss of control or failure of the hydraulic system, and stops production of the gas well, thereby ensuring the stability of production.

[0008] Furthermore, the sealing assembly further comprises a supporting sleeve, the supporting sleeve is slidably connected to the inner wall of the spring compression joint, and one end of the supporting sleeve is connected to the stop sleeve. The supporting sleeve is fixedly connected to the stop sleeve and slidably connected to the spring compression joint, thereby improving the sliding stability of the stop sleeve.

[0009] Furthermore, the first elastic member is sleeved on the outside of the support sleeve. The support sleeve can also provide support for the first elastic member to ensure that the deformation direction of the first elastic member is along the axial direction, thereby ensuring that the elastic force direction of the first elastic member is along the axial direction.

[0010] Furthermore, a groove is provided on the inner wall of the spring compression joint, a first mud guard ring is provided in the groove, and the first mud guard ring is interference fit with the support sleeve. When the support sleeve is slidably connected with the spring compression joint, some mud and sand are easily stuck in the connection, increasing wear, and the first mud guard ring can block and scrape away the mud and sand.

[0011] Furthermore, the inner wall of the support sleeve is provided with a first step portion, the inner wall of the stop sleeve is provided with a second step portion, a mounting groove is formed between the first step portion and the second step portion, and the throttle nozzle is fixed in the mounting groove. The throttle nozzle is clamped by the first step portion and the second step portion, and the stability is better.

[0012] Furthermore, the outer wall of the stop sleeve is provided with a third step portion, and the third step portion is used to abut against the valve seat to limit the sliding stroke of the stop sleeve. The third step portion limits the sliding of the stop sleeve to prevent the stop sleeve from separating from the spring sleeve.

[0013] Furthermore, the valve plate and the valve sleeve are connected by a pin shaft, and a second elastic member is mounted on the pin shaft, and the second elastic member is used to close the valve plate or have a closing tendency. The second elastic member can drive the valve plate to rotate to close the flow channel and accelerate the closing of the valve plate.

[0014] Furthermore, a groove is formed on the inner wall of the valve seat, a second mud retaining ring is arranged in the groove, and the second mud retaining ring is interference fit with the stop sleeve. The second mud retaining ring can block and scrape away mud and sand, and prevent mud and sand from entering the connection between the valve seat and the stop sleeve.

[0015] Furthermore, the upper joint assembly further includes a conversion joint, a connecting sleeve and a balancing joint connected in sequence, the balancing joint is connected to the spring compression joint, the balancing joint is provided with a balancing hole, a pressure balancing valve is installed in the balancing hole, a fixing ring is sleeved on the outside of the pressure balancing valve, and a vent hole is provided in the fixing ring. When the valve plate is in a closed state and the operator wants to open the valve plate, the pressure balancing valve can be opened with the help of a probe rod, at which time the flow channel is connected inside and outside, the pressure on both sides of the valve plate is balanced, and the valve plate is opened.

[0016] Furthermore, sealing rings are provided at the connections between the conversion joint, the connection sleeve, the balancing joint, the spring compression joint, the spring sleeve, the valve sleeve and the lower joint, thereby improving the air tightness of the valve.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The sealing assembly is used to control the opening or closing of the valve plate, replacing the traditional safety valve that requires the layout of the hydraulic system. This avoids the emergency closure of the valve and the cessation of gas well production due to the loss of control or failure of the hydraulic system, thus ensuring the stability of production.

[0019] 2. The support sleeve is fixedly connected to the stop sleeve and slidably connected to the spring compression joint, which improves the sliding stability of the stop sleeve. On the other hand, it can also provide support for the first elastic member to ensure that the deformation direction of the first elastic member is along the axial direction, thereby ensuring that the elastic force direction of the first elastic member is along the axial direction;

[0020] 3. The first mud guard ring and the second mud guard ring can block and scrape away mud and sand to reduce wear;

[0021] 4. The setting of the pressure balancing valve provides another way to open the valve plate. When the valve plate is in a closed state, the pressure balancing valve can be opened with the help of a probe rod. At this time, the flow channel is connected inside and outside, and the pressure on both sides of the valve plate is balanced, so that the valve plate is opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a safety valve;

[0023] Figure 2 for Figure 1 A partial enlarged view of position A;

[0024] Figure 3 for Figure 1 A local enlarged view of position B;

[0025] Figure 4 for Figure 1 A local enlarged view of the C position;

[0026] Figure 5 It is a structural schematic diagram when the valve plate is in an open state;

[0027] Figure 6 It is a structural schematic diagram from another perspective when the valve plate is in an open state.

[0028] In the accompanying drawings: 100, upper joint assembly; 110, conversion joint; 120, connecting sleeve; 130, balancing joint; 131, pressure balancing valve; 132, fixing ring; 133, vent; 200, spring compression joint; 210, first mud guard ring; 300, spring sleeve; 400, valve sleeve; 500, valve plate; 510, second elastic member; 600, valve seat; 610, second mud guard ring; 700, lower joint; 800, sealing assembly; 810, first elastic member; 820, stop sleeve; 821, second step portion; 822, third step portion; 830, throttle nozzle; 840, support sleeve; 841, first step portion. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0030] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Embodiment 1

[0032] A safety valve, such as Figure 1-3 and Figure 5 As shown, it includes a valve plate 500, a valve seat 600, a sealing assembly 800, and an upper joint assembly 100, a spring compression joint 200, a spring sleeve 300, a valve sleeve 400 and a lower joint 700 which are threadedly connected in sequence. The interiors of the upper joint assembly 100, the spring compression joint 200, the spring sleeve 300, the valve sleeve 400 and the lower joint 700 are all hollow and interconnected to form a flow channel. The exterior of the valve sleeve 400 is provided with a square groove, and the valve plate 500 is installed in the square groove. The valve plate 500 is rotatably connected to the valve sleeve 400, the valve seat 600 is arranged on the inner wall of the spring sleeve 300, the sealing assembly 800 is located in the spring sleeve 300, and the sealing assembly 800 includes a first elastic member 810, a stop sleeve 820, a throttle nozzle 830 and a support sleeve 840, the inner wall of the support sleeve 840 is provided with a first step portion 841, the inner wall of the stop sleeve 820 is provided with a second step portion 821, and the first step portion 841 and the second step portion 821 are provided between the first step portion 841 and the second step portion 821. The throttle nozzle 830 is fixed in the mounting groove. The outer wall of the stop sleeve 820 is provided with a third step portion 822, which is used to abut against the valve seat 600 to limit the sliding of the stop sleeve 820. The inner diameter of the throttle nozzle 830 is smaller than the inner diameter of the stop sleeve 820. The stop sleeve 820 is slidably connected to the valve seat 600 and the sliding direction is along the axial direction. The support sleeve 840 is slidably connected to the inner wall of the spring compression joint 200, and one end of the support sleeve 840 is in contact with the stop sleeve 820. The first elastic member 810 is sleeved on the outside of the supporting sleeve 840, and the two ends of the first elastic member 810 are respectively connected to the spring compression joint 200 and the stop sleeve 820. The elastic force direction of the first elastic member 810 is along the axial direction. In this embodiment, the first elastic member 810 is a spring, and an annular groove is provided on the inner wall of the spring compression joint 200. A first mud stop ring 210 is arranged in the annular groove. The first mud stop ring 210 is interference fit with the supporting sleeve 840.

[0033] The working principle of this embodiment is as follows:

[0034] In a safety valve of the present invention, since the inner diameter of the throttle nozzle 830 is smaller than the inner diameter of the stop sleeve 820, the flow rate of the fluid will become faster after passing through the throttle nozzle 830, and the side of the throttle nozzle 830 with a faster flow rate is subjected to a smaller pressure, so a pressure difference will be generated on both sides of the throttle nozzle 830. Under normal conditions, the flow rate in the well is at a normal value, and the stop sleeve 820 supports one side of the valve plate 500. When the gas production is at a normal value and the pressure difference on both sides of the throttle nozzle 830 is small, due to the setting of the first elastic member 810, the first elastic member 810 only produces a small deformation at this time, which is not enough to drive the stop sleeve 820 to produce excessive displacement, such as Figure 5 As shown, the stop sleeve 820 supports one side of the valve plate 500 to limit its closing of the flow channel. When the gas production is too high, the pressure difference on both sides of the throttle nozzle 830 is large, and the stop sleeve 820 slides and compresses the first elastic member 810, as shown in FIG. Figure 2 As shown, the stop sleeve 820 no longer provides support for the valve plate 500, and the valve plate 500 will rotate and block the flow channel to close the oil well and prevent the occurrence of blowouts. When the gas production value in the oil well returns to normal, the first elastic member 810 will push the stop sleeve 820 to open the valve plate 500, so that the valve plate 500 is in an open state again, or pressurization can be applied at the wellhead so that the pressure at the upper end of the valve plate 500 is greater than the pressure at the lower end, so that the valve plate 500 is reopened. The sealing assembly 800 is used to control the opening or closing of the valve plate 500. There is no need to arrange a hydraulic system, which avoids emergency closure of the valve due to loss of control or failure of the hydraulic system, and stops production of the gas well, thereby ensuring the stability of production.

[0035] The beneficial effects of this embodiment are as follows:

[0036] The sealing assembly 800 is used to control the opening or closing of the valve plate 500, and there is no need to arrange a hydraulic system, which avoids emergency closure of the valve due to loss of control or failure of the hydraulic system, and stops the production of the gas well, thereby ensuring the stability of production. On the one hand, the support sleeve 840 is fixedly connected to the stop sleeve 820 and slidably connected to the spring compression joint 200, thereby improving the sliding stability of the stop sleeve 820. On the other hand, it can also provide support for the first elastic member 810 to ensure that the deformation direction of the first elastic member 810 is along the axial direction, thereby ensuring that the elastic force direction of the first elastic member 810 is along the axial direction. The first mud retaining ring 210 can block and scrape away mud and sand to reduce wear. The first step portion 841 and the second step portion 821 clamp the throttle nozzle 830 for better stability. The third step portion 822 provides a limit for the stop sleeve 820 to prevent the stop sleeve 820 from separating from the spring sleeve 300.

[0037] In actual application, the elastic coefficient of the first elastic member 810 needs to match the size of the throttle nozzle 830 to ensure that when the pressure difference is higher than the specified value, the valve plate 500 can be closed, and when the pressure difference is lower than the specified value, the valve plate 500 will open. This specified value can be 50psi, 40psi or other values.

[0038] Embodiment 2

[0039] This embodiment is a second embodiment of a safety valve. This embodiment is similar to the first embodiment, except that: Figure 6 As shown, the valve plate 500 and the valve sleeve 400 are connected by a pin shaft, and a second elastic member 510 is mounted on the pin shaft. The second elastic member 510 is used to close the valve plate 500 or have a closing tendency. In this embodiment, the second elastic member 510 is a torsion spring. The second elastic member 510 can drive the valve plate 500 to rotate to close the flow channel and accelerate the closing of the valve plate 500. Figure 2 As shown, an annular groove is provided on the inner wall of the valve seat 600, and a second mud retaining ring 610 is arranged in the groove. The second mud retaining ring 610 is interference fit with the stop sleeve 820. The second mud retaining ring 610 can block and scrape away mud and sand to prevent mud and sand from entering the connection between the valve seat 600 and the stop sleeve 820.

[0040] The rest of the working principles of this embodiment are consistent with those of the first embodiment.

[0041] Embodiment 3

[0042] This embodiment is a third embodiment of a safety valve. This embodiment is similar to the second embodiment, except that: Figure 1 and Figure 4 As shown, the upper joint assembly 100 also includes a conversion joint 110, a connecting sleeve 120 and a balancing joint 130 which are threadedly connected in sequence. The balancing joint 130 is connected to the spring compression joint 200. The two ends of the connecting sleeve 120 are also fixed to the conversion joint 110 and the balancing joint 130 with screws respectively. The balancing joint 130 is provided with a balancing hole, and a pressure balancing valve 131 is installed in the balancing hole. The outer part of the pressure balancing valve 131 is sleeved with a fixing ring 132, and the fixing ring 132 is provided with a vent hole 133. When the valve plate 500 is in a closed state, when the operator wants to open the valve plate 500, the pressure balancing valve 131 can be opened with the help of a probe rod. At this time, the flow channel is connected inside and outside, and the pressure on both sides of the valve plate 500 is balanced, so that the valve plate 500 is opened. A step structure is provided on the outer surface of the connecting sleeve 120, and a V-shaped sealing ring is provided at the step. The sealing ring is located at the connection between the connecting sleeve 120 and the conversion joint 110. O-rings are provided at the connections between the connecting sleeve 120, the balancing joint 130, the spring compression joint 200, the spring sleeve 300, the valve sleeve 400 and the lower joint 700. The setting of the sealing ring improves the air tightness of the valve.

[0043] The rest of the working principles of this embodiment are consistent with those of the second embodiment.

[0044] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A safety valve, comprising a valve plate (500), a valve seat (600), and an upper joint assembly (100), a spring compression joint (200), a spring sleeve (300), a valve sleeve (400), and a lower joint (700) connected in sequence, wherein the interiors of the upper joint assembly (100), the spring compression joint (200), the spring sleeve (300), the valve sleeve (400), and the lower joint (700) are all hollow and interconnected to form a flow channel, the valve plate (500) is rotatably connected to the valve sleeve (400), and the valve seat (600) is arranged on the inner wall of the valve sleeve (400), characterized in that: It also includes a sealing assembly (800) located in the spring sleeve (300), the sealing assembly (800) includes a first elastic member (810), a stop sleeve (820) and a throttle nozzle (830), the two ends of the first elastic member (810) are respectively connected to the spring compression joint (200) and the stop sleeve (820), the elastic force direction of the first elastic member (810) is along the axial direction, the throttle nozzle (830) is fixed in the stop sleeve (820), the inner diameter of the throttle nozzle (830) is smaller than the inner diameter of the stop sleeve (820), and the stop sleeve (820) is slidably connected to the valve seat (600) and the sliding direction is along the axial direction.

2. A safety valve according to claim 1, characterized in that: The sealing assembly (800) further comprises a supporting sleeve (840), wherein the supporting sleeve (840) is slidably connected to the inner wall of the spring compression joint (200), and one end of the supporting sleeve (840) is connected to the stop sleeve (820).

3. A safety valve according to claim 2, characterized in that: The first elastic member (810) is sleeved on the outside of the supporting sleeve (840).

4. A safety valve according to claim 2, characterized in that: The inner wall of the spring compression joint (200) is provided with a groove, a first mud stop ring (210) is arranged in the groove, and the first mud stop ring (210) is interference fit with the support sleeve (840).

5. A safety valve according to claim 2, characterized in that: The inner wall of the support sleeve (840) is provided with a first step portion (841), and the inner wall of the stop sleeve (820) is provided with a second step portion (821). An installation groove is formed between the first step portion (841) and the second step portion (821), and the throttle nozzle (830) is fixed in the installation groove.

6. A safety valve according to any one of claims 1 to 5, characterized in that: The outer wall of the stop sleeve (820) is provided with a third step portion (822), and the third step portion (822) is used to abut against the valve seat (600) to limit the sliding stroke of the stop sleeve (820).

7. A safety valve according to any one of claims 1 to 5, characterized in that: The valve plate (500) and the valve sleeve (400) are connected via a pin shaft, and a second elastic member (510) is sleeved on the pin shaft. The second elastic member (510) is used to close the valve plate (500) or to make it tend to close.

8. A safety valve according to any one of claims 1 to 5, characterized in that: The inner wall of the valve seat (600) is provided with a groove, a second mud stop ring (610) is arranged in the groove, and the second mud stop ring (610) is interference fit with the stop sleeve (820).

9. A safety valve according to any one of claims 1 to 5, characterized in that: The upper joint assembly (100) further comprises a conversion joint (110), a connecting sleeve (120) and a balancing joint (130) which are connected in sequence, the balancing joint (130) being connected to the spring compression joint (200), the balancing joint (130) being provided with a balancing hole, a pressure balancing valve (131) being installed in the balancing hole, a fixing ring (132) being sleeved on the outside of the pressure balancing valve (131), and the fixing ring (132) being provided with a vent hole (133).

10. A safety valve according to claim 9, characterized in that: Sealing rings are provided at the connections between the conversion joint (110), the connecting sleeve (120), the balancing joint (130), the spring compression joint (200), the spring sleeve (300), the valve sleeve (400) and the lower joint (700).

Images