High-temperature-resistant and high-pressure-resistant composite one-way valve

Abstract

A high-temperature-resistant and high-pressure-resistant composite one-way valve, comprising an upper valve body (1) and a lower valve body (2) which are connected into a whole by means of a temperature-resistant structural adhesive. A central hole (21) is axially formed in the center of the lower valve body (2); a valve core (3) is provided in the central hole (21); the valve core (3) is integrally cast with a guide rod (7) and a special concrete layer (6) by means of a mold; a rubber layer (5) is provided on the outer surface of the special concrete layer (6); the special concrete layer (6) and the rubber layer (5) are molded into a whole by using a vulcanization molding process; the rubber layer (5) is tightly attached to the upper valve body (1) by means of a conical surface; a spring (4) is sleeved on the guide rod (7); and the lower end of the spring (4) and the lower end of the guide rod (7) are both located in the central hole (21). The valve can withstand a high temperature of 205°C and a high pressure of 10,000 psi.

Description

High temperature and high pressure resistant composite one-way valve

[0001] This application claims priority to the patent application filed with the State Intellectual Property Office of China on March 26, 2024, with application number 202410352186.0 and application name “High temperature and high pressure resistant composite one-way valve”. Technical Field

[0002] The present application belongs to the technical field of oil drilling and cementing equipment, and specifically relates to a composite one-way valve resistant to high temperature and high pressure. Background Art

[0003] Floating equipment is a key component for running casing and performing cementing operations. Floating equipment generally contains one or more one-way valves and forms part of the lower section of the casing, preventing backflow of cement slurry that enters the annular gap of the wellbore wall. The floating equipment must withstand pressure and higher pressure from below the one-way valve and function normally in the temperature environment to which it is exposed. As a component of the floating equipment, the one-way valve is crucial for preventing backflow and is the basis for the success of cementing operations. When the composite one-way valves currently used in the market are used in high-temperature (205°C) and high-pressure (10,000 psi) environments, the valve core material of the one-way valve is easily softened, which can lead to valve core damage, loss of the one-way valve sealing function, and backflow of cement slurry, resulting in cementing failure and significant economic losses. Summary of the Invention

[0004] The purpose of this application is to provide a high temperature and high pressure resistant composite one-way valve, which has the characteristics of high temperature and high pressure resistance.

[0005] The technical solution adopted in the present application is a high-temperature and high-pressure resistant composite one-way valve, comprising an upper valve body and a lower valve body connected into one by a temperature-resistant structural adhesive, a center hole being opened axially in the center of the lower valve body, a valve core being arranged in the center hole, the valve core being cast into one by a guide rod and a special concrete layer through a mold, a rubber layer being provided on the outer surface of the special concrete layer, the special concrete layer and the rubber layer being molded into one by a vulcanization molding process, and the rubber layer being tightly fitted to the upper valve body through a conical surface; a spring being sleeved on the guide rod, and the lower end of the spring and the lower end of the guide rod being both located in the center hole.

[0006] Furthermore, an undercut structure is provided at one end of the guide rod, and the guide rod is reliably connected to the special concrete layer through the undercut structure.

[0007] Furthermore, the rubber layer is designed to have a thickness of 1 mm to 3 mm.

[0008] Furthermore, the designed thickness of the rubber layer is 1.5 mm.

[0009] Furthermore, the upper valve body is injection-molded with a high-strength and temperature-resistant PPS composite material, and the wall thickness of the upper shell of the upper valve body is 1 mm to 5 mm.

[0010] Furthermore, the wall thickness of the upper shell of the upper valve body is 2 mm.

[0011] Furthermore, a plurality of anti-rotation protrusions are evenly arranged on the outer surface of the upper valve body.

[0012] Furthermore, a carbon molecular structure skeleton is provided inside the special concrete layer, and the carbon molecular structure skeleton and the special concrete layer are cast and formed at one time.

[0013] Furthermore, the compressive strength of the carbon molecular structure skeleton and the special concrete layer after casting is greater than or equal to 10,000 psi.

[0014] Furthermore, the carbon molecular structure skeleton and the special concrete layer can withstand a temperature greater than or equal to 205° C. after being cast.

[0015] Furthermore, the carbon molecular structure skeleton is printed and formed using any one of carbon fiber, titanium alloy, high-strength resin and aluminum alloy through 3D printing technology.

[0016] Furthermore, the rubber layer is a fluororubber layer that is oil-resistant, temperature-resistant, and wear-resistant.

[0017] Furthermore, the upper valve body includes an upper shell, on which a first hole body and a second hole body connected to each other are provided. The first hole body is located at one end of the second hole body away from the lower valve body, and the aperture of the second hole body gradually decreases in the direction approaching the first hole body so as to fit with the rubber layer.

[0018] Furthermore, the outer peripheral surface of the special concrete layer includes a tapered matching surface arranged corresponding to the hole wall surface of the second hole body, and at least a portion of the rubber layer covers the tapered matching surface.

[0019] Furthermore, the upper valve body includes an upper shell and a first plug-in portion arranged at the lower end of the upper shell, and the lower valve body includes a lower shell and a second plug-in portion arranged at the upper end of the lower shell, and the first plug-in portion and the second plug-in portion are plug-fitted.

[0020] Furthermore, the first plug-in portion is an annular plug-in groove, the second plug-in portion is an annular plug-in protrusion, the temperature-resistant structural adhesive is coated in the annular plug-in groove, and a guide slope is provided on the side of the annular plug-in protrusion close to the upper valve body.

[0021] Furthermore, the lower valve body includes a lower shell and a central protrusion arranged in the lower shell and located at the bottom of the lower shell, and the central hole is arranged on the central protrusion.

[0022] Furthermore, the center hole includes a first hole section and a second hole section connected to each other, the first hole section is located at the end of the second hole section away from the upper valve body, and the aperture of the first hole section is smaller than the aperture of the second hole section; wherein, the lower end of the guide rod passes through the second hole section and is inserted into the first hole section, and the lower end of the spring is located in the second hole section and contacts the bottom surface of the second hole section.

[0023] Furthermore, the guide rod includes a main rod body and a support seat arranged at the upper end of the main rod body, the support seat is used to support the special concrete layer, the spring is sleeved on the main rod body and the upper end of the spring is in contact with the support seat.

[0024] Furthermore, the main rod body includes a first rod segment and a second rod segment sequentially connected in a direction away from the support seat, and the outer diameter of the first rod segment is greater than the outer diameter of the second rod segment.

[0025] The beneficial effects of this application are:

[0026] The high-temperature and high-pressure resistant composite one-way valve of the present application addresses the problem that the composite one-way valve in the current prior art is not resistant to high temperature and high pressure. The one-way valve core is manufactured by combining special concrete with composite materials, and a special rubber vulcanization process is applied to vulcanize a wear-resistant, heat-resistant and oil-resistant fluororubber surface on the surface of the special concrete. The upper valve body is formed of high-strength and temperature-resistant composite materials, and anti-rotation protrusions are evenly distributed on the circumference of the outer surface of the upper valve body. The spring return principle is used to tightly fit the valve core to the conical surface of the upper valve body, so that it can work normally in an exposed high temperature of 205°C and a high pressure of 10,000 psi, effectively preventing the backflow of cement slurry entering the annular space of the well wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic structural diagram of a high-temperature and high-pressure resistant composite one-way valve of the present application;

[0028] FIG2 is a schematic structural diagram of a valve core of a high-temperature and high-pressure resistant composite one-way valve of the present application;

[0029] FIG3 is a schematic structural diagram of a high-temperature and high-pressure resistant composite one-way valve with a carbon molecular structure skeleton according to the present invention;

[0030] FIG4 is a schematic structural diagram of a valve core of a high-temperature and high-pressure resistant composite one-way valve with a carbon molecular structure skeleton according to the present invention;

[0031] FIG5 is a schematic structural diagram of the carbon molecular structure skeleton of the high-temperature and high-pressure resistant composite one-way valve with a carbon molecular structure skeleton of the present application;

[0032] FIG6 is a schematic diagram of the overall structure of the high-temperature and high-pressure resistant composite one-way valve of the present application;

[0033] FIG7 is a high temperature and high pressure test curve of composite valves currently used in the market;

[0034] FIG8 is a high temperature and high pressure test curve of the high temperature and high pressure resistant composite one-way valve of Example 2 of the present application;

[0035] FIG9 is a high temperature and high pressure test curve of the high temperature and high pressure resistant composite one-way valve with a carbon molecular structure skeleton according to Example 3 of the present application.

[0036] In the figure, 1. upper valve body; 10. upper shell; 11. first hole body; 12. second hole body; 13. first plug-in part; 14. anti-rotation protrusion; 2. lower valve body; 21. center hole; 211. first hole section; 212. second hole section; 22. center protrusion; 23. second plug-in part; 3. valve core; 4. spring; 5. rubber layer; 6. special concrete layer; 7. guide rod; 71. main rod body; 711. first rod section; 712. second rod section; 72. support seat; 8. carbon molecular structure skeleton. DETAILED DESCRIPTION

[0037] The present application is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] Example 1

[0039] The high-temperature, high-pressure composite one-way valve disclosed herein, as shown in Figures 1 and 2, comprises an upper valve body 1, a lower valve body 2, a valve core 3, and a spring 4. The valve core 3, as shown in Figure 2, comprises a rubber layer 5, a special concrete layer 6, and a guide rod 7. The valve core 3 is integrally molded from the guide rod 7 and the special concrete layer 6 using a mold. An undercut is provided at one end of the guide rod 7 to ensure a secure connection to the special concrete layer 6. The special concrete layer 6 and the rubber layer 5 are molded together using a special vulcanization molding process. The rubber layer 5 is designed to have a thickness of 1 mm to 3 mm. The upper valve body 1 is injection molded from a high-strength, high-temperature-resistant PPS composite material. The upper valve body 1 has a shell wall thickness of 1 mm to 5 mm. Several anti-rotation protrusions 14 are evenly distributed on the outer surface of the upper valve body 1. The structure is shown in Figure 6. The lower valve body 2 has a central hole axially defined. The spring 4 is mounted on the guide rod 7 of the valve core 3, with the lower ends of the spring 4 and the lower ends of the guide rod 7 seated together in the central hole of the lower valve body 2. The upper valve body 1 is tightly fitted with the rubber layer 5 of the valve core 3 to achieve sealing through the conical surface, and is connected to the lower valve body 2 as a whole through temperature-resistant structural adhesive.

[0040] As shown in FIG4 and FIG5 , a carbon molecular structure skeleton 8 is provided inside the special concrete layer 6 . The carbon molecular structure skeleton 8 and the special concrete layer 6 are cast and formed at one time, and the compressive strength thereof can reach above 10,000 psi.

[0041] The carbon molecular structure skeleton 8 and the special concrete layer 6 of the present application can withstand a temperature greater than or equal to 205° C. after being cast.

[0042] The high-temperature and high-pressure resistant composite one-way valve of the present application addresses the problem that the composite one-way valve in the current prior art is not resistant to high temperature and high pressure. The one-way valve core is manufactured by combining special concrete with composite materials, and a special rubber vulcanization process is applied to vulcanize a wear-resistant, heat-resistant and oil-resistant fluororubber surface on the surface of the special concrete. The spring 4 reset principle is utilized to tightly fit the valve core 3 on the conical surface of the upper valve body, so that it can work normally in an exposed high temperature of 205°C and a high pressure of 10,000 psi, effectively preventing the backflow of cement slurry entering the annular space of the well wall.

[0043] Example 2

[0044] The high-temperature, high-pressure resistant composite one-way valve of the present application has a structure as shown in Figure 1 and includes an upper valve body 1, a lower valve body 2, a valve core 3, and a spring 4. The valve core 3 structure is shown in Figure 2 and includes a rubber layer 5, a special concrete layer 6, and a guide rod 7. The valve core 3 is cast into one piece by the guide rod 7 and the special concrete layer 6 through a mold. An undercut structure is provided at one end of the guide rod 7 to ensure a reliable connection with the special concrete layer 6. The special concrete layer 6 and the rubber layer 5 are molded into one piece using a special vulcanization molding process. The rubber layer 5 is an oil-resistant, heat-resistant, and wear-resistant fluororubber layer with a designed thickness of 1.5mm. The upper valve body 1 is injection molded using a high-strength, heat-resistant PPS composite material. The upper valve body shell has a wall thickness of 2mm and 24 anti-rotation protrusions 14 are evenly arranged on the outer surface. The lower valve body 2 has an axial center hole. The spring 4 is mounted on the guide rod 7 of the valve core 3, and the lower ends of the spring 4 and the lower ends of the guide rod 7 are seated together in the center hole of the lower valve body 2. The upper valve body 1 and the rubber layer of the valve core 3 are tightly matched through the conical surface, and are connected to the lower valve body 2 into one body through the temperature-resistant structural adhesive.

[0045] Example 3

[0046] As shown in Figure 3, based on Example 2, a carbon molecular structure skeleton 8 is added to the valve core 3. The carbon molecular structure skeleton 8 can be made from materials such as carbon fiber, titanium alloy, high-strength resin, and aluminum alloy, and is formed using 3D printing technology. The carbon molecular structure skeleton 8, guide rod 7, and special concrete layer 6 are finally cast into a single piece in a mold.

[0047] The high temperature and high pressure resistant composite one-way valves of Examples 2 and 3 of the present application were compared with the popular composite valves on the market in the API 10F test. The specific comparison data are shown in Table 1 below:

[0048] Table 1 API 10F test comparison

[0049] The test curve of the composite valve currently on the market is shown in Figure 7, the test curve of the high-temperature and high-pressure resistant composite one-way valve of Example 2 of the present application is shown in Figure 8, and the test curve of the high-temperature and high-pressure resistant composite one-way valve of Example 3 of the present application is shown in Figure 9. Combining Figures 7 to 9 and the test data in Table 1, it can be found that the high-temperature and high-pressure resistant composite one-way valve of the present application has a high-pressure resistance capability of more than twice that of the composite valves currently on the market under a high-temperature environment of 205°C.

[0050] Example 4

[0051] Based on any one of Examples 1 to 3, the specific structure of the high-temperature and high-pressure resistant composite one-way valve of the present application is as follows:

[0052] As shown in Figures 1 and 3, the upper valve body 1 includes an upper shell 10, on which a first hole body 11 and a second hole body 12 are connected. The first hole body 11 is located at the end of the second hole body 12 away from the lower valve body 2, and the aperture of the second hole body 12 gradually decreases in the direction approaching the first hole body 11 so as to fit with the rubber layer 5.

[0053] Specifically, the outer peripheral surface of the special concrete layer 6 includes a tapered matching surface corresponding to the hole wall surface of the second hole body 12 , and at least a portion of the rubber layer 5 covers the tapered matching surface.

[0054] As shown in Figures 1 and 3, the upper valve body 1 includes an upper shell 10 and a first plug-in portion 13 arranged at the lower end of the upper shell 10, and the lower valve body 2 includes a lower shell 20 and a second plug-in portion 23 arranged at the upper end of the lower shell 20. The first plug-in portion 13 and the second plug-in portion 23 are plug-fitted.

[0055] Specifically, the first plug-in portion 13 is an annular plug-in groove, the second plug-in portion 23 is an annular plug-in protrusion, the heat-resistant structural adhesive is coated in the annular plug-in groove, and a guide slope is provided on the side of the annular plug-in protrusion close to the upper valve body 1.

[0056] As shown in FIG. 1 and FIG. 3 , the lower valve body 2 includes a lower shell 20 and a central protrusion 22 disposed in the lower shell 20 and located at the bottom of the lower shell 20 . The central hole 21 is disposed on the central protrusion 22 .

[0057] As shown in Figures 1 and 3, the center hole 21 includes a first hole section 211 and a second hole section 212 connected to each other. The first hole section 211 is located at the end of the second hole section 212 away from the upper valve body 1, and the aperture of the first hole section 211 is smaller than the aperture of the second hole section 212; wherein, the lower end of the guide rod 7 passes through the second hole section 212 and is inserted into the first hole section 211, and the lower end of the spring 4 is located in the second hole section 212 and contacts the bottom surface of the second hole section 212.

[0058] As shown in Figure 2, the guide rod 7 includes a main rod body 71 and a support seat 72 arranged at the upper end of the main rod body 71. The support seat 72 is used to support the special concrete layer 6. The spring 4 is mounted on the main rod body 71 and the upper end of the spring 4 is in contact with the support seat 72; wherein, the main rod body 71 and the support seat 72 are integrally formed or detachably connected.

[0059] As shown in FIG. 2 , the main rod body 71 includes a first rod segment 711 and a second rod segment 712 sequentially connected in a direction away from the support seat 72 . The outer diameter of the first rod segment 711 is greater than the outer diameter of the second rod segment 712 .

Claims

1. High temperature and high pressure resistant composite one-way valve, characterized in that: The invention comprises an upper valve body (1) and a lower valve body (2) connected as one body by heat-resistant structural adhesive, a center hole (21) is opened in the center axis of the lower valve body (2), a valve core (3) is arranged in the center hole, the valve core (3) is cast into one body by a guide rod (7) and a special concrete layer (6) through a mold, a rubber layer (5) is arranged on the outer surface of the special concrete layer (6), the special concrete layer (6) and the rubber layer (5) are molded into one body by a vulcanization molding process, and the rubber layer (5) and the upper valve body (1) are tightly fitted through a conical surface; a spring (4) is sleeved on the guide rod (7), and the lower end of the spring (4) and the lower end of the guide rod (7) are both located in the center hole (21).

2. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: One end of the guide rod (7) is provided with an undercut structure, and the guide rod (7) is reliably connected to the special concrete layer (6) via the undercut structure.

3. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The designed thickness of the rubber layer (5) is 1 mm to 3 mm.

4. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The designed thickness of the rubber layer (5) is 1.5 mm.

5. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The upper valve body (1) is injection-molded using a high-strength and temperature-resistant PPS composite material, and the wall thickness of the upper shell (10) of the upper valve body (1) is 1 mm to 5 mm.

6. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The wall thickness of the upper shell (10) of the upper valve body (1) is 2 mm.

7. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: A plurality of anti-rotation protrusions (14) are evenly arranged on the outer surface of the upper valve body (1).

8. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: A carbon molecular structure skeleton (8) is provided inside the special concrete layer (6), and the carbon molecular structure skeleton (8) and the special concrete layer (6) are cast and formed at one time.

9. The high temperature and high pressure resistant composite one-way valve according to claim 8, characterized in that: The compressive strength of the carbon molecular structure skeleton (8) and the special concrete layer (6) after casting is greater than or equal to 10,000 psi.

10. The high temperature and high pressure resistant composite one-way valve according to claim 10, characterized in that: The carbon molecular structure skeleton (8) and the special concrete layer (6) can withstand a temperature greater than or equal to 205° C. after being cast.

11. The high temperature and high pressure resistant composite one-way valve according to claim 8, characterized in that: The carbon molecular structure skeleton (8) is formed by printing using any one of carbon fibers, titanium alloys, high-strength resins and aluminum alloys through 3D printing technology.

12. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The rubber layer (5) is a fluororubber layer that is oil-resistant, temperature-resistant, and wear-resistant.

13. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The upper valve body (1) includes an upper shell (10), and a first hole body (11) and a second hole body (12) are provided on the upper shell (10), wherein the first hole body (11) is located at an end of the second hole body (12) away from the lower valve body (2), and the aperture of the second hole body (12) gradually decreases in a direction approaching the first hole body (11) so as to fit with the rubber layer (5).

14. The high temperature and high pressure resistant composite one-way valve according to claim 13, characterized in that: The outer peripheral surface of the special concrete layer (6) includes a conical matching surface arranged corresponding to the hole wall surface of the second hole body (12), and at least a portion of the rubber layer (5) covers the conical matching surface.

15. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The upper valve body (1) includes an upper shell (10) and a first plug-in portion (13) arranged at the lower end of the upper shell (10); the lower valve body (2) includes a lower shell (20) and a second plug-in portion (23) arranged at the upper end of the lower shell (20); the first plug-in portion (13) and the second plug-in portion (23) are plug-fitted.

16. The high temperature and high pressure resistant composite one-way valve according to claim 15, characterized in that: The first plug-in portion (13) is an annular plug-in groove, the second plug-in portion (23) is an annular plug-in protrusion, the heat-resistant structural adhesive is coated in the annular plug-in groove, and a guide slope is provided on one side of the annular plug-in protrusion close to the upper valve body (1).

17. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The lower valve body (2) comprises a lower shell (20) and a central protrusion (22) arranged in the lower shell (20) and located at the bottom of the lower shell (20), and the central hole (21) is arranged on the central protrusion (22).

18. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The center hole (21) includes a first hole section (211) and a second hole section (212) connected to each other, the first hole section (211) is located at the end of the second hole section (212) away from the upper valve body (1), and the aperture of the first hole section (211) is smaller than the aperture of the second hole section (212); wherein, the lower end of the guide rod (7) passes through the second hole section (212) and is inserted into the first hole section (211), and the lower end of the spring (4) is located in the second hole section (212) and contacts the bottom surface of the second hole section (212).

19. The high temperature and high pressure resistant composite one-way valve according to claim 18, characterized in that: The guide rod (7) comprises a main rod body (71) and a support seat (72) arranged at the upper end of the main rod body (71); the support seat (72) is used to support the special concrete layer (6); the spring (4) is sleeved on the main rod body (71) and the upper end of the spring (4) is in contact with the support seat (72).

20. The high temperature and high pressure resistant composite one-way valve according to claim 1, characterized in that: The main rod body (71) comprises a first rod segment (711) and a second rod segment (712) connected in sequence in a direction away from the support seat (72); the outer diameter of the first rod segment (711) is greater than the outer diameter of the second rod segment (712).

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