A single reverse circulation shut-in test valve

Abstract

The present invention proposes a single reverse circulation shut-in test valve, comprising an outer cylinder, on which a reverse circulation hole is provided; a core shaft provided in the outer cylinder, which is in a first position in an initial state and blocks the reverse circulation hole, and moves to a second position under the action of pressure to open the reverse circulation hole; a ball valve assembly provided in the outer cylinder, the upper end of which is connected to the core shaft; wherein the core shaft drives the ball valve assembly to close during the process of moving from the first position to the second position. The present invention can improve the upper and lower pressure bearing capacity of the ball valve, and has the function of reverse circulation well killing.

Description

Technical Field

[0001] The invention relates to a primary reverse circulation well shut-in test valve, belonging to the field of petroleum engineering testing. Background Art

[0002] Conventional testing generally uses a test valve that can open and close the well multiple times, such as an LPR-N valve or an OMNI valve. Before entering the well, this type of test valve needs to be calculated based on the pressure of the formation being tested, and a certain pressure of nitrogen needs to be injected into the nitrogen chamber of the tool on the ground. However, for ultra-deep, high-temperature, and high-pressure wells, the pressure of the injected nitrogen is greater than the tool's specification. And the ball valve that shuts in the tool does not meet the requirements. Therefore, for ultra-deep, high-temperature, and high-pressure wells, conventional multiple well-opening and well-closing testing technology does not meet the requirements of the site. A single well-closing valve, namely the RDS valve, is usually used. The upper and lower pressures of the ball valve of this valve also do not meet the requirements. The upper and lower pressures of the ball valve of foreign tools can reach up to 70MPa. When testing the well, the liquid column on the upper part of the ball valve will balance some pressures. However, in extreme cases, such as high-yield gas wells, the moment the ball valve is closed, the lower and upper pressure difference will appear to be higher than the tool specification, resulting in test failure and tool damage. Summary of the invention

[0003] In view of the above technical problems existing in the prior art, the present invention proposes a single reverse circulation shut-in test valve, which can improve the bottom and top pressure bearing capacity of the ball valve and has the function of reverse circulation well killing.

[0004] The present invention provides a single reverse circulation shut-in test valve, comprising:

[0005] An outer cylinder, wherein a reverse circulation hole is provided on the outer cylinder;

[0006] a core shaft disposed in the outer cylinder, wherein the core shaft is in a first position in an initial state and blocks the reverse circulation hole, and moves to a second position under the action of pressure to open the reverse circulation hole;

[0007] A ball valve assembly is disposed in the outer cylinder, and the upper end of the ball valve assembly is connected to the core shaft;

[0008] Wherein, the core shaft drives the ball valve assembly to close during the process of moving from the first position to the second position.

[0009] A further improvement of the present invention is that the outer cylinder comprises an upper outer cylinder provided with the reverse circulation hole, a connecting outer cylinder is provided at the bottom of the upper outer cylinder, a ball valve outer cylinder is connected to the bottom of the connecting outer cylinder; the ball valve assembly is provided in the ball valve outer cylinder.

[0010] A further improvement of the present invention is that the core shaft is connected to the upper outer cylinder via a shear pin when in the first position; an outer step structure is provided on the outer wall of the core shaft, and an inner step structure matching the outer step structure is provided on the inner wall of the upper outer cylinder.

[0011] A further improvement of the present invention is that a rupture disk hole is provided on the upper outer cylinder, and a rupture disk is installed in the rupture disk hole;

[0012] When the pressure in the annulus between the upper outer tube and the casing is pressurized, the rupture disk breaks when the pressure in the annulus increases to a certain value, and the pressure in the annulus enters between the upper outer tube and the core shaft through the rupture disk hole and applies pressure to the inner step structure, so that the core shaft moves from the first position to the second position.

[0013] A further improvement of the present invention is that the ball seat assembly comprises a ball valve body, an upper ball seat is arranged above the ball valve body, and a lower ball seat is arranged below the ball valve body;

[0014] Wherein, the upper ball seat is connected to the upper seat ring, and the lower ball seat is connected to the lower seat ring.

[0015] A further improvement of the present invention is that a switch groove is provided on the outer side wall of the ball valve body;

[0016] An operating arm is arranged between the upper seat ring and the outer tube of the ball valve. The operating arm moves axially along with the movement of the core shaft. A switch protrusion matching with the switch groove is arranged at the lower end of the operating arm.

[0017] A further improvement of the present invention is that a seat spring is arranged on the lower ball seat, and the seat spring provides an elastic force tending to open the ball valve body.

[0018] A further improvement of the present invention is that a balancing sleeve is provided at the upper end of the operating arm, and the balancing sleeve seals the space between the lower seat ring and the outer cylinder of the ball valve.

[0019] A further improvement of the present invention is that a locking claw is provided below the core shaft, a connecting joint is provided at the lower end of the locking claw, and the lower end of the connecting joint is connected to the balancing sleeve.

[0020] A further improvement of the present invention is that the connecting joint comprises a first connecting joint and a second connecting joint, and the first connecting joint and the second connecting joint are connected to the locking claw via a clamp;

[0021] Furthermore, an anti-retraction locking mechanism is provided between the second connecting joint and the lower seat ring.

[0022] A further improvement of the present invention is that the anti-backward locking mechanism includes inner anti-backward teeth arranged on the inner side of the second connecting joint, and the outer side of the lower seat ring is provided with outer anti-backward teeth matching with the inner anti-backward teeth.

[0023] A further improvement of the present invention is that a lower joint for connecting a lower tool or an oil pipe is provided at the lower end of the ball valve outer tube.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] The one-time reverse circulation shut-in test valve of the present invention can improve the pressure bearing capacity of the ball valve and has the function of reverse circulation well killing. The ball seat assembly can shut down the well, and the reverse circulation hole is used for reverse circulation well killing.

[0026] The shear pin in the present invention can connect the core shaft and the outer cylinder to prevent the core shaft from moving in advance and causing the ball valve assembly to close in advance. The balancing sleeve can seal the space between the lower seat ring and the ball valve outer cylinder to prevent the pressure from directly transmitting to the position of the ball valve body through the gap between the lower ball seat and the ball seat body, causing the ball valve to lose its seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0028] Figure 1 The figure shows a structural schematic diagram of a primary reverse circulation shut-in test valve according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 A partial schematic diagram of the upper part of the core shaft and the upper outer cylinder is shown;

[0030] Figure 3 for Figure 1 A partial schematic diagram of the middle portion of the ball valve assembly is shown;

[0031] Figure 4 for Figure 1 A partial schematic diagram of the lower part of the embodiment of the present invention shows the structure of the lower joint.

[0032] In the drawings, the same reference numerals are used for the same components, but the drawings are not drawn to scale.

[0033] The meanings of the various reference numerals in the accompanying drawings are as follows: 1. outer cylinder, 2. core shaft, 3. ball valve assembly, 11. upper outer cylinder, 12. connecting outer cylinder, 13. ball valve outer cylinder, 14. reverse circulation hole, 15. rupture disk hole, 16. rupture disk, 17. shear pin, 18. lower joint, 21. outer step structure, 22. locking claw, 23. first connecting joint, 24. second connecting joint, 25. clamp, 26. anti-retraction locking mechanism, 27. balancing sleeve, 30. ball valve body, 31. operating arm, 32. switch protrusion, 33. upper ball seat, 34. lower ball seat, 35. upper seat ring, 36. lower seat ring, 37. seat spring. DETAILED DESCRIPTION

[0034] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0035] Figure 1 A reverse circulation shut-in test valve according to an embodiment of the present invention is schematically shown, comprising an outer cylinder 1, on which a reverse circulation hole 14 is arranged. The reverse circulation hole 14 is arranged at the upper part of the outer cylinder 1 and radially arranged on the outer cylinder 1, and a plurality of reverse circulation holes 14 are arranged in a circle. A core shaft 2 is arranged inside the outer cylinder 1, and the core shaft 2 is connected to the outer cylinder 1 in the initial state, and can move in the outer cylinder 1 under the action of a certain pressure. In the initial state, the core shaft 2 is in the first position of the outer cylinder 1, and the upper end of the core shaft 2 blocks the reverse circulation hole 14; when subjected to a certain pressure, the core shaft 2 moves downward along the axial direction of the outer cylinder 1, and when it moves to the second position, the upper end of the core shaft 2 is located below the reverse circulation hole 14, so that the reverse circulation hole 14 is opened.

[0036] In this embodiment, a ball valve assembly 3 is also provided in the outer tube 1, and the ball valve assembly 3 can be opened or closed. In the initial state, the ball valve assembly 3 is in an open state, and the internal space of the outer tube 1 is in a conducting state. When the well is shut in, the ball valve assembly 3 is closed, and the internal space of the outer tube 1 is blocked by the ball valve assembly 3.

[0037] The closing of the ball valve assembly 3 is controlled by the core shaft 2. The upper end of the ball valve assembly 3 is directly or indirectly connected to the core shaft 2. When the core shaft 2 moves axially, it drives the ball valve assembly 3 to open or close. In the initial state, the core shaft 2 is in the first position, and the ball valve assembly 3 is in an open state. When the core shaft 2 is subjected to pressure, it moves downward, driving the ball valve assembly 3 to close. When the pressure is continued, the core shaft 2 moves to the second position, and the reverse circulation hole 14 on the upper part of the outer tube 1 is opened, so that the reverse circulation between the annulus and the oil pipe can be realized. In this embodiment, the upper side is the direction toward the wellhead, and the lower side is the direction away from the wellhead.

[0038] In one embodiment, the outer cylinder 1 includes an upper outer cylinder 11, a connecting outer cylinder 12 and a ball valve outer cylinder 13. The upper outer cylinder 11 is provided with the reverse circulation hole 14. The upper end of the connecting outer cylinder 12 is connected to the upper outer cylinder 11, and the lower end is connected to the ball valve outer cylinder 13, and the length thereof is selected as required. The ball valve assembly 3 is provided in the ball valve outer cylinder 13.

[0039] In one embodiment, the mandrel 2 is connected to the upper outer cylinder 11 through a shear pin 17 when in the first position, so that the mandrel 2 can always be connected to the outer cylinder 1 during the process of being lowered into the well, so as to prevent it from moving to the second position in advance to close the ball valve assembly 3. The shear pin 17 is sheared off under the action of pressure, so that the mandrel 2 is separated from the outer cylinder 1, so that the mandrel 2 can move along the axial direction of the outer cylinder 1. In this embodiment, an outer step structure 21 is provided on the outer wall of the mandrel 2, and the diameter of the part above the outer step structure 21 on the outer wall of the mandrel 2 is smaller, and the diameter of the part below the step structure is larger. In this way, the outer step structure 21 is facing upward, and when the pressure from above increases, a certain pressure can be applied to the outer step structure 21, so that the mandrel 2 is subjected to a downward force, so that the mandrel 2 moves from the first position to the second position. An inner step structure matching the outer step structure 21 is provided on the inner wall of the upper outer cylinder 11.

[0040] In one embodiment, Figure 2 As shown, the upper outer cylinder 11 is also provided with a rupture disk hole 15, and a rupture disk 16 is installed on the rupture disk hole 15. The rupture disk hole 15 is arranged below the reverse circulation hole 14 and radially arranged on the outer cylinder 1, and the inside and the outside of the upper outer cylinder 11 are connected after the rupture disk 16 is broken. In this embodiment, there is a small gap between the upper outer cylinder 11 and the core shaft 2, which can be used to transmit pressure.

[0041] The rupture pressure of the rupture disk 16 is designed and selected according to the specific site conditions.

[0042] When the reverse circulation shut-in test valve described in this embodiment is working, during the process of pressurizing the annulus between the upper outer tube 11 and the casing, the rupture disk 16 breaks when the pressure in the annulus increases to a certain value, and the pressure in the annulus enters between the upper outer tube 11 and the core shaft 2 through the rupture disk hole 15 and applies pressure to the inner step structure. When the pressure increases to a certain value, the shear pin 17 is sheared off, and the core shaft 2 is separated from the upper outer tube 11. In this way, the core shaft 2 moves from the first position to the second position under the action of pressure.

[0043] In one embodiment, Figure 3As shown, the ball seat assembly includes a ball valve body 30, an upper ball seat 33 is arranged above the ball valve body 30, and a lower ball seat 34 is arranged below the ball valve body 30. The ball valve body 30 is rotatably connected to the upper ball seat 33, and the ball valve body 30 can rotate on the upper ball seat 33 to open or close. In this embodiment, the upper ball seat 33 is connected to the upper seat ring 35, and the lower ball seat 34 is connected to the lower seat ring 36. Preferably, the upper seat ring 35 and the lower seat ring 36 are fixedly connected to the ball valve outer cylinder 13.

[0044] In one embodiment, a switch groove is provided on the upper part of the outer wall of the ball valve body 30, and the switch groove is a spherical groove. A certain space is provided between the upper seat ring 35 and the ball valve outer tube 13, which can be an annular space or a strip space provided along the axial direction. An operating arm 31 is installed in the space, and the upper end of the operating arm 31 is indirectly connected to the core shaft 2, and can move axially with the movement of the core shaft 2. The lower end of the operating arm 31 is provided with a switch protrusion 32 that cooperates with the switch groove, and the switch protrusion 32 is a circular switch.

[0045] When the single reverse circulation shut-in test valve according to this embodiment is used, when the core shaft 2 moves downward, the operating arm 31 is driven to move downward, and the operating arm 31 provides an upward thrust to the ball valve body 30. The thrust of the operating arm 31 on the ball valve body 30 is converted into a force that pushes the ball valve body 30 to rotate along the lower ball seat 34 after the switch protrusion 32 and the switch groove rotate and cooperate, so that the ball valve body 30 rotates to the closed position.

[0046] In one embodiment, a seat spring 37 is provided on the lower ball seat 34, and the seat spring 37 provides an elastic force to open the ball valve body 30. The seat spring 37 is preferably a disc spring, which is used to keep the ball valve body 30 in an open state at the initial state, and can buffer the pressure at the bottom of the ball valve after the ball valve body 30 is closed.

[0047] In one embodiment, a balancing sleeve 27 is provided at the upper end of the operating arm 31, and sealing rings are provided on the inner and outer sides of the balancing sleeve 27 for sealing between the lower seat ring 36 and the ball valve outer tube 13. The balancing sleeve 27 can seal the space between the lower seat ring 36 and the ball valve outer tube 13, thereby preventing the pressure from being directly transmitted to the position of the ball valve body 30 through the gap between the lower ball seat 34 and the ball seat body, causing the ball valve to lose its seal.

[0048] In one embodiment, Figure 3As shown, a locking claw 22 is provided below the core shaft 2, and a connecting joint is provided at the lower end of the locking claw 22, and the lower end of the connecting joint is connected to the balancing sleeve 27. The locking claw 22 is used to determine the travel distance of the ball valve closing and the stopping function. Its claw has a certain elasticity. When the core shaft 2 is pushed downward, when it reaches the diameter change, its claw elastically opens and gets stuck at the diameter change. At this time, the core shaft 2 continues to move downward. The locking claw 22 does not move upward at any time. And the pressure at the lower end acts on the ball valve, which is linked and finally acts on the locking claw 22.

[0049] In one embodiment, the connecting joint includes a first connecting joint 23 and a second connecting joint 24, and the first connecting joint 23 and the second connecting joint 24 are connected to the locking claw 22 through a clamp 25; and an anti-retraction locking mechanism 26 is arranged between the second connecting joint 24 and the lower seat ring 36.

[0050] In a preferred embodiment, the anti-backward locking mechanism 26 includes an inner anti-backward tooth disposed on the inner side of the second connecting joint 24, and an outer anti-backward tooth matched with the inner anti-backward tooth is disposed on the outer side of the lower seat ring 36. When the core shaft 2 drives the connecting joint to move downward, the second connecting joint 24 moves downward so that the outer anti-backward tooth meshes with the inner anti-backward tooth and moves inward.

[0051] In one embodiment, Figure 4 As shown, the lower end of the ball valve outer tube 13 is provided with a lower joint 18 connected to a lower tool or oil pipe.

[0052] The process of using the single reverse circulation shut-in test valve according to the present embodiment is as follows: first, the test valve according to the present embodiment is connected to the bottom of the well by using an oil pipe, and the packer is connected below and set. When it is necessary to conduct a downhole shut-in test, the annulus of the oil casing is pressurized, and when the pressure in the annulus rises to a certain value, the pressure breaks the rupture disk 16 and enters between the outer cylinder 1 and the core shaft 2 through the rupture disk hole 15. The pressure is applied to the core shaft 2, and the shear pin 17 is sheared under the action of the pressure, so that the core shaft 2 is separated from the upper outer cylinder 11.

[0053] The mandrel 2 moves downward under the action of pressure and moves from the first position to the second position. In the process of the mandrel 2 moving downward, the locking claw 22, the connecting joint and the balancing sleeve 27 are pushed downward at the same time, thereby pushing the operating arm 31 downward. The downward thrust of the operating arm 31 is converted into an inward thrust under the action of the switch protrusion 32 and the switch groove, so that the ball valve body 30 rotates and closes, and the ball valve body 30 cuts off the oil pipe to achieve downhole well shut-in.

[0054] When the locking claw 22 moves downward to the cavity, the locking claw 22 is elastically opened, and the mandrel cannot act on the locking claw 22 downward. This structural design limits the moving distance of the operating arm 31 and determines the distance of the ball valve opening. The mandrel continues to move downward, so that the reverse circulation hole 14 is connected with the inner cavity of the tool. At this time, the well-killing fluid is injected into the annulus, and the well-killing fluid enters the oil pipe through the reverse circulation hole 14. The well-killing fluid enters from the annulus fluid and flows out from the oil pipe, realizing the reverse circulation well-killing function.

[0055] When the downward pressure of the ball valve increases, the downward pressure pushes the ball valve body 30 and compresses the seat spring 37. The downward pressure of the ball valve body 30 directly acts on the second connecting joint 23. Because an anti-retraction locking mechanism 26 is provided between the second connecting joint 23 and the upper seat ring 35, the downward pressure force directly acts on the locking claw 22. The design is a rigid design, and its force can meet the design of pressure resistance of 103.5MPa, thereby increasing the pressure difference between the bottom and the top of the ball valve.

[0056] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made according to the embodiments of the present invention should be included within the scope of protection of the present invention.

Claims

1. A single reverse circulation shut-in test valve, characterized in that: include: An outer cylinder (1), wherein a reverse circulation hole (14) is provided on the outer cylinder (1); a core shaft (2) disposed in the outer cylinder (1), the core shaft (2) being in a first position in an initial state and blocking the reverse circulation hole (14), and moving to a second position under the action of pressure to open the reverse circulation hole (14); A ball valve assembly (3) is arranged in the outer cylinder (1), and the upper end of the ball valve assembly (3) is connected to the core shaft (2); Wherein, in the process of the core shaft (2) moving from the first position to the second position, the core shaft (2) drives the ball valve assembly (3) to close; The outer cylinder (1) comprises an upper outer cylinder (11) provided with the reverse circulation hole (14); a connecting outer cylinder (12) is provided at the bottom of the upper outer cylinder (11); a ball valve outer cylinder (13) is connected to the bottom of the connecting outer cylinder (12); the ball valve assembly (3) is provided in the ball valve outer cylinder (13); The ball valve assembly comprises a ball valve body (30), an upper ball seat (33) is arranged above the ball valve body (30), and a lower ball seat (34) is arranged below the ball valve body (30); The upper ball seat (33) is connected to the upper seat ring (35), and the lower ball seat (34) is connected to the lower seat ring (36); A switch groove is provided on the outer side wall of the ball valve body (30); An operating arm (31) is provided between the upper seat ring (35) and the ball valve outer cylinder (13), the operating arm (31) moves axially along with the movement of the core shaft (2), and a switch protrusion (32) cooperating with the switch groove is provided at the lower end of the operating arm (31); A seat spring (37) is provided on the lower ball seat (34), and the seat spring (37) provides an elastic force to the ball valve body (30) tending to open; A balancing sleeve (27) is provided at the upper end of the operating arm (31), and the balancing sleeve (27) seals the space between the lower seat ring (36) and the ball valve outer cylinder (13).

2. The primary reverse circulation shut-in test valve according to claim 1, characterized in that: When the core shaft (2) is in the first position, it is connected to the upper outer cylinder (11) via a shear pin (17); an outer step structure (21) is provided on the outer wall of the core shaft (2), and an inner step structure matching the outer step structure (21) is provided on the inner wall of the upper outer cylinder (11).

3. The primary reverse circulation shut-in test valve according to claim 2, characterized in that: The upper outer cylinder (11) is provided with a rupture disk hole (15), and a rupture disk (16) is installed in the rupture disk hole (15); When the pressure in the annulus increases to a certain value during the process of pressurizing the upper outer tube (11) and the casing annulus, the rupture disk (16) breaks, and the pressure in the annulus enters between the upper outer tube (11) and the core shaft (2) through the rupture disk hole (15) and applies pressure to the inner step structure, so that the core shaft (2) moves from the first position to the second position.

4. The primary reverse circulation shut-in test valve according to claim 3, characterized in that: A locking claw (22) is provided below the core shaft (2), a connecting joint is provided at the lower end of the locking claw (22), and the lower end of the connecting joint is connected to the balancing sleeve (27).

5. The primary reverse circulation shut-in test valve according to claim 4, characterized in that: The connecting joint comprises a first connecting joint (23) and a second connecting joint (24), wherein the first connecting joint (23) and the second connecting joint (24) are connected to the locking claw (22) via a clamp (25); Furthermore, an anti-retraction locking mechanism (26) is provided between the second connecting joint (23) and the lower seat ring (36).

6. The primary reverse circulation shut-in test valve according to claim 5, characterized in that: The anti-retraction locking mechanism (26) comprises an inner anti-retraction tooth arranged on the inner side of the second connecting joint (23), and the outer side of the lower seat ring (36) is provided with an outer anti-retraction tooth matched with the inner anti-retraction tooth.

7. The primary reverse circulation shut-in test valve according to any one of claims 1 to 6, characterized in that: The lower end of the ball valve outer tube (13) is provided with a lower joint (18) for connecting a lower tool or an oil pipe.

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