Ultrahigh-pressure sand-prevention fracturing valve

Abstract

The ultrahigh-pressure sand-prevention fracturing valve comprises a valve body, an upper valve cover, a lower valve cover, a valve rod, a valve plate and a valve seat, the upper valve cover is installed at the top of the valve body, the lower valve cover is installed at the bottom of the valve body, a valve cavity is formed in the valve body, the valve seat is connected into the valve cavity, the valve plate is movably connected with the valve seat, and a flow guide hole is formed in the valve plate. The size of the flow guide hole is matched with the inner diameter of the valve seat, the valve plate is fixedly connected with the valve rod, a sand scraping groove is formed in the edge of the valve plate, the top end of the valve rod penetrates through the upper valve cover and then is connected with a lifting driving assembly, and the lifting driving assembly drives the valve plate to linearly move in the valve cavity through the valve rod so as to achieve switching of the opening state and the closing state of the flow channel. Hard alloy is arranged in the backing ring groove of the flange face of the valve body and the contact face of the valve seat and the valve plate in a surfacing mode, and the valve seat and the valve body are sealed through a circumferential sealing structure. The machining difficulty of the valve can be reduced, the success rate is increased, meanwhile, the corrosion resistance of the sealing part of the valve can be enhanced, and the service life of the valve is prolonged.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development equipment technology, and in particular to an ultra-high pressure anti-sand fracturing valve. Background Technology

[0002] In the development of oil and gas fields, fracturing is an important production enhancement measure, and fracturing wellhead valves are key components to ensure the smooth progress of fracturing operations. They operate under harsh conditions and need to have characteristics such as corrosion resistance, high pressure resistance, and high wear resistance.

[0003] Currently, commonly used fracturing valves adopt a single valve seat end face double sealing ring structure. Its characteristic is that the medium enters the valve body cavity to form a post-valve seal. However, this structure has very high requirements for the flatness, symmetry, and perpendicularity of the valve seat cavity E surface. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-high pressure anti-sand fracturing valve to solve the above-mentioned problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses an ultra-high pressure sand fracturing valve, comprising a valve body, an upper valve cover, a lower valve cover, a valve stem, a valve plate, and a valve seat. The upper valve cover is installed on the top of the valve body, and the lower valve cover is installed on the bottom. The valve body has a valve cavity, and the valve seat is connected to the valve cavity. The valve plate is movably connected to the valve seat, and a flow guide hole is provided on the valve plate. The size of the flow guide hole is adapted to the inner diameter of the valve seat. The valve plate is fixedly connected to the valve stem, and a sand scraping groove is provided on the edge of the valve plate. The top end of the valve stem passes through the upper valve cover and is connected to a lifting drive assembly. The lifting drive assembly drives the valve plate to move linearly within the valve cavity through the valve stem to switch the flow channel between open and closed states. The bottom end of the valve stem passes through the lower valve cover and extends outward. Hard alloy is welded into the gasket groove of the valve body flange and the contact surface between the valve seat and the valve plate. A circumferential sealing structure is used to achieve sealing between the valve seat and the valve body.

[0007] Furthermore, the circumferential sealing structure includes a sand-blocking ring, a rectangular ring, and a circumferential sealing ring. The sealing end of the valve seat is provided with the sand-blocking ring, the rectangular ring, and the circumferential sealing ring in sequence from the inside to the outside, and the opening of the circumferential sealing ring faces the valve plate.

[0008] Furthermore, the lifting drive assembly includes a valve cap, a nut sleeve, a valve stem sleeve, a ball screw, and a handwheel. The valve cap is installed on the top of the upper valve cover. The nut sleeve is rotatably connected inside the valve cap. The ball screw is fixed to the top of the valve stem. The nut sleeve is sleeved on the ball screw and threadedly connected to the ball screw. The top of the nut sleeve is fixedly connected to the valve stem sleeve. The handwheel is connected to the top of the valve stem sleeve via a thread or keyway.

[0009] Furthermore, an annular receiving cavity is provided on the inner wall of the connection between the upper valve cover and the lower valve cover and the valve stem. A rod assembly seal is provided in the annular receiving cavity. A packing gland is provided on the valve stem. The packing gland is fitted and installed in the annular receiving cavity and abuts against the rod assembly seal.

[0010] Furthermore, a T-groove is provided at the position opposite to the valve plate, and the top of the valve plate is embedded in the T-groove.

[0011] Furthermore, a spring is provided on the back of the valve seat to provide elastic support, which can automatically compensate for deformation when the valve plate is closed.

[0012] Furthermore, both the upper valve cover and the lower valve cover are provided with grease injection ports, and a sealing grease injection valve is provided at the grease injection port.

[0013] Furthermore, a balance bar is fixedly connected to the lower part of the valve stem, and a guide cone surface is provided at the bottom of the balance bar. The guide cone surface can automatically correct the positional deviation of the valve stem.

[0014] Furthermore, a guide plate is also provided inside the valve cavity. The guide plate is symmetrically arranged on both sides of the valve stem, and the top of the guide plate is embedded in the bottom of the valve seat. The valve stem and the guide plate are slidably connected.

[0015] Furthermore, the mating surfaces of the upper valve cover and the lower valve cover with the valve body are sealed with stainless steel metal gaskets.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0017] The ultra-high pressure sand-resistant fracturing valve of the present invention effectively avoids the shortcomings of existing fracturing valves that use a single valve seat end face double sealing ring structure, which has high requirements for the flatness, symmetry, and perpendicularity of the valve seat cavity E-face. This reduces the difficulty of valve processing and improves the success rate. At the same time, the welding of the flange gasket groove on the valve body, as well as the welding of the valve cover, valve body, and valve seat cavity end face, can enhance the corrosion resistance of the valve sealing parts. Furthermore, the use of a circumferential main seal in the valve seat sealing part avoids the problems of sand entering the valve cavity and sealing failure that often occur with the original end face seal during use. By using a circumferential seal, a sand-resistant effect can be achieved, thus improving the service life of the valve. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the ultra-high pressure anti-sand fracturing valve of the present invention;

[0020] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0021] Explanation of reference numerals in the attached drawings: 1. Protective cover; 2. Connecting ring; 3. Indicator rod; 4. Rotating lifting ring; 5. Seal grease injection valve; 6. Lower valve cover; 7. Valve body; 8. Balance bar; 9. Valve seat; 10. Valve plate; 11. Drain plug; 12. Upper valve cover; 13. Valve stem; 14. Thrust ball bearing; 15. Nut sleeve; 16. Valve cap; 17. Ball screw; 18. Valve stem connector; 19. Handwheel; 20. O-ring; 21. Support ring; 22. Stop bolt; 23. Packing gland; 24. Stem assembly seal; 25. Guide plate; 26. Sand baffle ring; 27. Rectangular ring; 28. Circumferential sealing ring. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the terms "length," "width," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 , Figure 2 As shown, the ultra-high pressure sand-resistant fracturing valve of this embodiment includes a valve body 7, an upper valve cover 12, a lower valve cover 6, a valve stem 13, a valve plate 10, and a valve seat 9. The upper valve cover 12 is installed on the top of the valve body 7, and the lower valve cover 6 is installed on the bottom. A valve cavity is provided inside the valve body 7, and the valve seat 9 is connected inside the valve cavity. The valve plate 10 is movably connected to the valve seat 9, and a guide hole is provided on the valve plate 10. The size of the guide hole is adapted to the inner diameter of the valve seat 9. The valve plate 10 is fixedly connected to the valve stem 13, and a sand scraping groove is provided on the edge of the valve plate 10 to prevent sand particles from accumulating. To prevent the valve from being sealed, the top of the valve stem 13 passes through the upper valve cover 12 and is connected to a lifting drive assembly. The lifting drive assembly drives the valve plate 10 to move linearly within the valve cavity via the valve stem 13 to switch the flow channel between open and closed states. The bottom of the valve stem 13 passes through the lower valve cover 6 and extends outward. At this time, the bottom of the valve stem 13 passes through the lower valve cover 6 and is connected to an indicator rod 3 via a connecting ring 2. A protective cover 1 is connected to the bottom of the lower valve cover 6. Rotating lifting rings 4 are symmetrically arranged on both sides of the upper valve cover 12 and the lower valve cover 6 to facilitate the installation and operation of the valve.

[0027] Hard alloy is welded into the gasket groove of the flange face of valve body 7 and the contact surface between valve seat 9 and valve plate 10 to form a metal-to-metal seal, which can enhance the corrosion resistance of the valve sealing parts. At the same time, the valve seat 9 and valve body 7 adopt a circumferential sealing structure to achieve a seal, which can avoid the problems of sand entering the valve cavity and sealing failure that often occur when the original end face seal is used. By adopting a circumferential seal, a sand prevention effect can be achieved, the service life of the valve can be improved, and the reliable operation of the valve under ultra-high pressure conditions can be guaranteed.

[0028] Specifically, the circumferential sealing structure includes a sand-blocking ring 26, a rectangular ring 27, and a circumferential sealing ring 28. The sealing end of the valve seat 9 is provided with the sand-blocking ring 26, the rectangular ring 27, and the circumferential sealing ring 28 sequentially from the inside to the outside, and the opening of the circumferential sealing ring 28 faces the valve plate 10. At this time, the pressure flows through the gap between the valve seat 9 and the sand-blocking ring 26, through the rectangular ring 27 and the circumferential sealing ring 28, and enters the valve cavity. After the valve cavity is pressurized, it flows to the opposite valve seat 9. Because the opening of the circumferential sealing ring 28 on the valve seat 9 faces the valve plate 10, the pressure enters the circumferential sealing ring 28, causing its interior to expand and deform. The lip on the outer circle of the circumferential sealing ring 28 achieves a sealing effect with the valve body and valve cavity. The faster and higher the pressure enters the circumferential sealing ring 28, the faster the lip deforms, and the easier it is to achieve a sealing effect.

[0029] Furthermore, the lifting drive assembly includes a valve cap 16, a nut sleeve 15, a valve stem connector 18, a ball screw 17, and a handwheel 19. The valve cap 16 is mounted on the top of the upper valve cover 12. The nut sleeve 15 is rotatably connected inside the valve cap 16. The ball screw 17 is fixed to the top of the valve stem 13. The nut sleeve 15 is fitted onto the ball screw 17 and is threadedly connected to the ball screw 17. The top of the nut sleeve 15 is fixedly connected to the valve stem connector 18. The handwheel 19 is connected to the top of the valve stem connector 18 via threads or a keyway. The handwheel 19 drives the nut sleeve 15 to rotate. Since the nut sleeve 15 is threadedly connected to the ball screw 17, the rotational motion can be converted into valve rotation. The linear motion of rod 13, at this time, the ball screw 17 has higher transmission efficiency and lower friction than ordinary screws, which is suitable for high-load drive under ultra-high pressure conditions. The bottom of the nut sleeve 15 is rotatably connected to the inner wall of the valve cap 16 through a thrust ball bearing 14, which bears axial load and reduces rotational friction. An O-ring 20 and a support ring 21 are provided at the connection between the middle of the nut sleeve 15 and the valve cap 16. The O-ring 20 and the support ring 21 achieve radial sealing and support, preventing medium leakage and nut sleeve sway. A stop bolt 22 is connected to the side wall of the valve cap 16. The stop bolt 22 can limit the axial movement of the nut sleeve 15 and ensure structural stability.

[0030] Meanwhile, an annular receiving cavity is provided on the inner wall of the connection between the upper valve cover 12 and the lower valve cover 6 and the valve stem 13. A rod combination seal 24 is installed within the annular receiving cavity. The main material of the stuffing box is high-performance filled PTFE, which can withstand high-pressure impacts. Combined with a corrosion-resistant alloy spring, it is suitable for dynamic sealing requirements in various harsh environments. Furthermore, the valve has a low opening and closing torque. A packing gland 23 is fitted over the valve stem 13, which is installed within the annular receiving cavity and abuts against the rod combination seal 24, further enhancing the sealing effect. Both the upper valve cover 12 and the lower valve cover 6 are provided with grease injection ports, each equipped with a grease injection valve 5, which allows for the injection of grease to enhance high-pressure sealing.

[0031] Preferably, a T-groove is provided at the position opposite to the valve plate 10, and the top of the valve plate 10 is embedded in the T-groove.

[0032] In this embodiment, a spring is provided on the back of the valve seat 9 to provide elastic support. This spring can automatically compensate for minor deformations when the valve plate 10 is closed, maintain uniform contact of the sealing surface, and improve sealing reliability. It is especially suitable for material deformation caused by high temperature or high pressure.

[0033] Among them, the lower part of the valve stem 13 is fixedly connected to the balance bar 8, and the bottom of the balance bar 8 is provided with a guide cone surface. The guide cone surface can automatically correct the positional deviation of the valve stem 13 and reduce the risk of uneven wear and leakage.

[0034] Furthermore, a guide plate 25 is provided inside the valve cavity. The guide plate 25 is symmetrically arranged on both sides of the valve stem 13, and the top of the guide plate 25 is embedded in the bottom of the valve seat 9. The valve stem 13 and the guide plate 25 are slidably connected to each other, which further guides the linear movement of the valve stem, prevents deflection, and improves operational stability.

[0035] Preferably, the upper valve cover 12 and the lower valve cover 6 are fixedly connected to the valve body 7 by symmetrically arranged high-strength alloy steel bolts, and the mating surfaces of the upper valve cover 12 and the lower valve cover 6 with the valve body 7 are sealed with stainless steel metal gaskets to ensure no leakage under high pressure.

[0036] In addition, the valve body 7 and the connecting pipe flange can be made of the same material to avoid electrochemical corrosion and extend the overall service life of the valve and pipeline.

[0037] When using the ultra-high pressure sand-resistant fracturing valve in this embodiment, considering its requirements for high pressure, corrosion resistance, and rapid response, the following instructions are provided in stages according to the operation procedure:

[0038] 1. Initial state (normally closed design): The valve plate 10 is fully pressed against the valve seat 9 under the drive of the valve stem 13, and the sealing surfaces are tightly fitted (using metal-to-metal or composite sealing). At this time, the flow channel of the valve body is completely blocked, and the medium pressure acts on the back of the valve plate 10 to form a self-reinforcing sealing force; the stuffing box of the valve stem 13 is in a pre-tightened state to ensure static sealing, the grease injection channel is not activated, and the spare sealing grease is stored in the cavity.

[0039] 2. Opening process: The ball screw 17 is driven upward by the handwheel 19, which drives the valve stem 13 to rise vertically at a speed of 0.5-2 m / s. The valve stem 13 pulls the valve plate 10 to move upward synchronously along the guide groove and separates it from the sealing surface of the valve seat 9. The valve plate 10 is raised to the fully open position, forming a straight flow channel with a pressure drop of <0.1 bar. The guide plate can prevent the valve plate 10 from rotating and ensure accurate alignment when the sealing surface is closed for the second time. When the valve stem 13 moves, the lip of the stem combination seal 24 adaptively adjusts the clamping force according to the pressure change. Since sand-containing media may scour the edge of the valve plate 10, the sand scraping groove can guide the particles to be discharged from the sealing area.

[0040] 3. Working medium passage stage: The fracturing fluid (including proppant) passes through the valve at a flow rate of 10-15 m / s. Turbulent loss is minimized when the valve plate 10 is fully open. At this time, instantaneous pressure shock (such as water hammer effect) can be absorbed by the spring buffer structure on the back of the valve seat 9, avoiding instantaneous detachment of the sealing surface.

[0041] 4. Closing process: Handwheel 19 drives ball screw 17 downward, valve plate 10 descends at a constant speed, and the speed drops to 0.1m / s when it is close to closing to reduce impact; before valve plate 10 contacts valve seat 9, the guide cone surface of balance bar 8 automatically corrects the position deviation (tolerance <0.05mm), and the final clamping force of valve plate 10 reaches 1.5 times the system pressure. The metal sealing surface fills the micro-unevenness through plastic deformation to achieve the VI-level zero leakage required by AP I 6A.

[0042] 5. Special working conditions: When the valve plate 10 is closed, the scraping groove on the edge of the valve plate 10 removes the attached sand particles to prevent particles from embedding into the sealing surface; the drain plug 11 at the bottom of the valve cavity is opened periodically (once every 8 hours) to discharge the deposited sand; a pressure gauge interface is reserved on the side wall of the valve body 7 for monitoring the cavity pressure.

[0043] The ultra-high pressure sand-resistant fracturing valve of this embodiment can ensure that the valve can withstand high pressure and high abrasion media during fracturing operations, while facilitating on-site maintenance, achieving rapid response, high pressure sealing and long service life. With regular maintenance (packing replacement cycle of 500 actions), its performance can be effectively maintained.

[0044] The ultra-high pressure sand-resistant fracturing valve of the present invention effectively avoids the shortcomings of existing fracturing valves that use a single valve seat end face double sealing ring structure, which has high requirements for the flatness, symmetry, and perpendicularity of the valve seat cavity E-face. This reduces the difficulty of valve processing and improves the success rate. At the same time, the welding of the flange gasket groove on the valve body, as well as the welding of the valve cover, valve body, and valve seat cavity end face, can enhance the corrosion resistance of the valve sealing parts. Furthermore, the use of a circumferential main seal in the valve seat sealing part avoids the problems of sand entering the valve cavity and sealing failure that often occur with the original end face seal during use. By using a circumferential seal, a sand-resistant effect can be achieved, thus improving the service life of the valve.

[0045] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An ultra-high pressure anti-sand fracturing valve, characterized in that, The valve includes a valve body, an upper valve cover, a lower valve cover, a valve stem, a valve plate, and a valve seat. The upper valve cover is installed on the top of the valve body, and the lower valve cover is installed on the bottom. The valve body has a valve cavity, and the valve seat is connected to the valve cavity. The valve plate is movably connected to the valve seat, and the valve plate has a flow guide hole. The size of the flow guide hole is adapted to the inner diameter of the valve seat. The valve plate is fixedly connected to the valve stem, and the edge of the valve plate is provided with a scraping groove. The top end of the valve stem passes through the upper valve cover and is connected to the lifting drive assembly. The lifting drive assembly drives the valve plate to move linearly within the valve cavity through the valve stem to switch the flow channel open and closed states. The bottom end of the valve stem passes through the lower valve cover and extends outward. Hard alloy is welded into the gasket groove of the valve body flange and the contact surface between the valve seat and the valve plate. A circumferential sealing structure is used between the valve seat and the valve body to achieve sealing.

2. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, The circumferential sealing structure includes a sand-blocking ring, a rectangular ring, and a circumferential sealing ring. The sealing end of the valve seat is provided with the sand-blocking ring, the rectangular ring, and the circumferential sealing ring in sequence from the inside to the outside, and the opening of the circumferential sealing ring faces the valve plate.

3. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, The lifting drive assembly includes a valve cap, a nut sleeve, a valve stem connector, a ball screw, and a handwheel. The valve cap is installed on the top of the upper valve cover. The nut sleeve is rotatably connected inside the valve cap. The ball screw is fixed to the top of the valve stem. The nut sleeve is sleeved on the ball screw and threadedly connected to the ball screw. The top of the nut sleeve is fixedly connected to the valve stem connector. The handwheel is connected to the top of the valve stem connector via a thread or keyway.

4. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, The upper valve cover and the lower valve cover are provided with an annular receiving cavity on the inner wall at the connection with the valve stem. A rod assembly seal is provided in the annular receiving cavity. A packing gland is provided on the valve stem. The packing gland is installed in the annular receiving cavity and abuts against the rod assembly seal.

5. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, A T-slot is provided at the position opposite to the valve plate, and the top of the valve plate is embedded in the T-slot.

6. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, The valve seat is provided with a spring on its back, which provides elastic support and can automatically compensate for deformation when the valve plate is closed.

7. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, Both the upper valve cover and the lower valve cover are provided with grease inlets, and a sealing grease injection valve is provided at the grease inlet.

8. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, A balance bar is fixedly connected to the lower part of the valve stem, and a guide cone surface is provided at the bottom of the balance bar. The guide cone surface can automatically correct the positional deviation of the valve stem.

9. The ultra-high pressure anti-sand fracturing valve according to claim 1, characterized in that, The valve cavity is also provided with a guide plate, which is symmetrically arranged on both sides of the valve stem, and the top of the guide plate is embedded in the bottom of the valve seat. The valve stem and the guide plate are slidably connected.

10. An ultra-high pressure anti-sand fracturing valve according to any one of claims 1-9, characterized in that, The mating surfaces of the upper valve cover and the lower valve cover with the valve body are sealed with stainless steel metal gaskets.

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