Drop ball retrievable isolation valve

Abstract

The application discloses a ball-throwing type fishable isolation valve, which comprises a valve body, a lower ball seat, an upper rubber plug seat, a ball and a fish spear type rubber plug.

Description

Technical Field

[0001] This invention belongs to the field of isolation valve technology, and more specifically, relates to a ball-throwing type retrievable isolation valve. Background Technology

[0002] Currently, the existing staged cementing cementing operation technologies in China mainly include two types: staged clamps and packers combined with blind plates, and top cementing with a drill-free plug. The first type requires running a small drill bit to drill the blind plate after staged cementing. The second type, because the isolation device remains in a blind-plugged state throughout the running process, maintains a pressure difference between the fluids inside and outside the completion string. Excessive pressure difference can cause the staged cementing device to fail or the drill-free plug to open prematurely, preventing subsequent operations. Therefore, to reduce the adverse effects of the internal and external pressure difference on the completion string running, timely grouting is necessary to balance the pressure; however, excessive grouting can affect the construction progress and reduce efficiency. Simultaneously, there is a risk of blind plate falling off and casing disengagement during blind plate drilling. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a ball-operated retrievable isolation valve. This valve ensures full patency between the inside and outside of the tubing string before the ball is inserted during the running-in of the well casing, reducing the pressure difference between the inside and outside of the tubing string, decreasing the number of grouting operations, and improving construction efficiency. Simultaneously, if the tubing string is difficult to run, the pump can be easily and promptly activated to reduce running resistance. Upon reaching the predetermined position, the isolation valve can form a blind plug by inserting the ball, facilitating staged cementing operations. After the operation is completed, it can be retrieved using a spear-type rubber plug, avoiding blind plate treatment operations.

[0004] To achieve the above objectives, the present invention provides a ball-throwing type retrievable isolation valve, the isolation valve comprising:

[0005] Valve body, wherein a valve cavity is provided within the valve body;

[0006] The lower ball seat is detachably disposed in the valve cavity. The lower ball seat is hourglass-shaped, and a first opening is formed in the middle of the lower ball seat.

[0007] The upper rubber stopper seat has its lower end detachably connected to the upper end of the lower ball seat. The upper rubber stopper seat has a conical part inside, and the lower end of the conical part has a second opening. The upper end of the upper rubber stopper seat is connected to the valve body by a pin.

[0008] A sphere, wherein the diameter of the sphere is greater than the diameter of the first opening and less than the diameter of the second opening;

[0009] A spear-shaped rubber stopper includes a core rod and a first locking block and a second locking block in the shape of barbs disposed on the outer periphery of the core rod. The first locking block and the second locking block respectively cooperate with the first opening and the second opening. Under the downward pressure of the spear-shaped rubber stopper, the sphere can deform and pass through the second opening.

[0010] Optionally, a protrusion is provided on the inner wall of the valve cavity, and the protrusion is engaged with the lower end of the lower ball seat.

[0011] Optionally, the upper end of the lower ball seat is provided with a straight cylindrical part, and a guide groove and a slot are provided on the outer wall of the straight cylindrical part. The top of the guide groove is open, and the slot penetrates the outer wall of the straight cylindrical part.

[0012] Optionally, the lower end of the upper rubber stopper seat is provided with a guide key and a hook. The guide key can be inserted into the guide groove, and the hook can be engaged with the slot. The length of the guide key is greater than the length of the hook.

[0013] Optionally, the grab hook includes a grab hook rod extending downward along the outer wall of the lower end of the upper rubber stopper seat. The lower end of the grab hook rod is wedge-shaped, and a groove is provided on the outer side of the grab hook rod. The groove forms a hook portion at the lower end of the grab hook rod, which can be engaged in the slot. The groove can accommodate the upper side wall of the slot.

[0014] Optionally, a pin hole is provided on the outer wall of the upper end of the upper rubber stopper seat, and the upper rubber stopper seat can be fixed to the outer wall of the valve body through the pin hole and the pin.

[0015] Optionally, a through groove is provided on the tapered wall of the tapered portion.

[0016] Optionally, it also includes a rubber plug sleeve milling rod, which is detachably connected to the upper end of the core rod.

[0017] Optionally, the first locking block and the second locking block are made of rubber, and the second locking block can block the second opening and deform under the action of downward pressure to pass through the second opening.

[0018] Optionally, the sphere is made of plastic or nylon.

[0019] This invention provides a ball-throwing type retrievable isolation valve, the advantages of which are:

[0020] 1. When the well completion string is being run, the isolation valve ensures that the well completion string is in full-bore condition before the ball is dropped. Theoretically, this reduces the pressure difference between the inside and outside of the string to near zero, avoiding the risk of stage clamp failure due to excessive pressure difference.

[0021] 2. The isolation valve can be used to flush the wellbore at any time during the well completion string running process, which greatly reduces the resistance when the string is run. If the string is difficult to run, the pump can be turned on in time to reduce the running resistance. After reaching the predetermined position, the isolation valve can form a blind plug by dropping a ball, and then carry out staged cementing operations.

[0022] 3. After the cement injection operation is completed, the isolation valve can be retrieved using a spear-type rubber stopper. The lower ball seat and the upper rubber stopper seat can be removed, avoiding blind plate treatment. This greatly reduces engineering risks, improves construction efficiency, and reduces construction costs.

[0023] 4. This device can reduce the internal and external pressure difference when running the completion string without changing the construction procedure, eliminating the engineering risks caused by drilling blind plates, saving construction time, and reducing completion costs.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0026] Figure 1 A schematic diagram of a ball-throwing retrievable isolation valve according to an embodiment of the present invention is shown.

[0027] Figure 2 A schematic diagram of the structure of a retrieval-type rubber plug for a ball-throwing type retrievable isolation valve according to an embodiment of the present invention is shown.

[0028] Figure 3 A schematic diagram of the lower ball seat of a ball-type retrievable isolation valve according to an embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram of the upper rubber plug seat of a ball-throwing retrievable isolation valve according to an embodiment of the present invention is shown.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Valve body; 2. Lower ball seat; 3. First opening; 4. Upper rubber plug seat; 5. Conical part; 6. Second opening; 7. Ball; 8. Spear-type rubber plug; 9. Core rod; 10. First locking block; 11. Second locking block; 12. Straight cylinder part; 13. Guide groove; 14. Slot; 15. Guide key; 16. Hook; 17. Hook rod; 18. Groove; 19. Hook part; 20. Pin hole; 21. Through groove; 22. Rubber plug sleeve milling rod. Detailed Implementation

[0032] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0033] This invention provides a ball-throwing type retrievable isolation valve, the isolation valve comprising:

[0034] The valve body contains a valve cavity.

[0035] The lower ball seat is detachably installed in the valve cavity. The lower ball seat is hourglass-shaped, and the first opening is formed in the middle of the lower ball seat.

[0036] The upper rubber stopper seat has a detachable connection between its lower end and the upper end of the lower ball seat. The upper rubber stopper seat has a conical part inside, and a second opening is provided at the lower end of the conical part. The upper end of the upper rubber stopper seat is connected to the valve body by a pin.

[0037] A sphere, the diameter of which is greater than the diameter of the first opening but less than the diameter of the second opening;

[0038] The spear-type rubber stopper includes a core rod and a first locking block and a second locking block with barbs disposed on the outer periphery of the core rod. The first locking block and the second locking block respectively cooperate with a first opening and a second opening. Under the downward pressure of the spear-type rubber stopper, the ball can deform and pass through the second opening.

[0039] Specifically, the lower ball seat is detachably installed in the valve cavity and is detachably connected to the upper rubber plug seat. At this time, due to the existence of the first and second openings, a passage is formed in the valve body of the isolation valve. When the ball is inserted, the ball can fall through the second opening and block the first opening, thereby achieving blind blocking. After the spear-type rubber plug is inserted, the first locking block first moves down through the second opening, and the second locking block reaches the top of the second opening and blocks it. At this time, under the action of pressure, the shear force cuts the pin, and the spear-type rubber plug and the upper rubber plug seat move downwards at the same time. The upper rubber plug seat is connected to the lower ball seat, and the lower end of the spear-type rubber plug squeezes the ball downwards. The ball deforms and falls through the second opening. The first locking block can pass through the first opening and engage with it, and the second locking block can pass through the second opening and engage with it. At this time, by using a retrieval tool to connect the upper end of the spear-type rubber plug, the spear-type rubber plug can be lifted up, and the spear-type rubber plug can drive the lower ball seat and the upper rubber plug seat to retrieve them.

[0040] Optionally, a protrusion is provided on the inner wall of the valve cavity, and the protrusion is engaged with the lower end of the lower ball seat.

[0041] Specifically, the lower end of the hourglass-shaped structure of the lower ball seat is umbrella-shaped, and the umbrella-shaped lower end of the lower ball seat sits on the protrusion to form a one-way locking structure, so the lower ball seat cannot move downwards.

[0042] Optionally, the upper end of the lower ball seat is provided with a straight cylindrical part, and a guide groove and a slot are provided on the outer wall of the straight cylindrical part. The top of the guide groove is open, and the slot passes through the outer wall of the straight cylindrical part.

[0043] Specifically, multiple guide grooves and slots can be provided, and the guide grooves and slots are staggered. The guide grooves are through-type track grooves from top to bottom, and the slots are rectangular radial openings.

[0044] Optionally, the lower end of the upper rubber stopper seat is provided with a guide key and a hook. The guide key can be inserted into the guide groove, and the hook can be engaged with the slot. The length of the guide key is greater than the length of the hook.

[0045] Specifically, in the initial state, the lower half of the guide key is inserted into the guide groove, and the lower end of the grab hook rests on the upper edge of the lower ball seat without being engaged in the slot. When the upper rubber stopper is subjected to downward pressure, the upper rubber stopper moves downward under the guidance of the guide key and the guide groove, causing the grab hook to also move downward and engage in the slot. This achieves the connection between the upper rubber stopper and the lower ball seat. The connection between the upper rubber stopper and the lower ball seat allows them to form a whole, making it easy to retrieve.

[0046] Optionally, the grab hook includes a grab hook rod extending downward along the outer wall of the lower end of the upper rubber stopper seat. The lower end of the grab hook rod is wedge-shaped, and a groove is provided on the outer side of the grab hook rod. The groove makes the lower end of the grab hook rod form a hook portion, which can be engaged in the slot. The groove can accommodate the upper side wall of the slot.

[0047] Specifically, the wedge shape at the lower end of the grab hook rod gradually tapers from top to bottom. When the upper rubber stopper is subjected to downward pressure, the upper rubber stopper moves downward under the guidance of the guide key and guide groove. Due to the presence of the wedge shape, the grab hook rod deforms inward and moves downward until the hook part moves into the slot and then pops out, engaging the slot. At this time, the upper side wall of the slot just engages with the groove, causing the grab hook rod to return to its original deformation, ensuring a stable engagement between the hook part and the slot, and improving the reliability of the engagement.

[0048] Optionally, a pin hole is provided on the outer wall of the upper end of the upper rubber plug seat, and the upper rubber plug seat can be fixed to the outer wall of the valve body through the pin hole and the pin.

[0049] Specifically, multiple pin holes can be set, and the number of pins used can be determined based on the construction pressure value of the well completion operation according to the on-site construction conditions, to ensure that the pins can be sheared off.

[0050] Optionally, a through groove is provided on the conical wall of the conical part.

[0051] Specifically, the through-slot can be used to reduce the hydraulic pressure difference between the upper and lower parts of the tubing when retrieving the upper rubber stopper seat and the lower ball seat.

[0052] Optionally, it also includes a rubber plug sleeve milling rod, which is detachably connected to the upper end of the core rod.

[0053] Specifically, the plug sleeve milling rod can be detachably connected to the metal extension rod at the upper end of the core rod via threads.

[0054] Optionally, the first and second locking blocks are made of rubber, and the second locking block can block the second opening and deform under the action of downward pressure to pass through the second opening.

[0055] Specifically, the barbed first locking block can move downward under pressure and deform through the first opening until it reaches below the first opening. At this time, the barbed first locking block returns to its shape and locks itself below the first opening. Similarly, the second locking block can also lock itself below the second opening. Both can be subjected to force at the same time to retrieve the lower ball seat and the upper rubber stopper seat.

[0056] In one example, there are two second locking blocks, which are positioned above the first locking block. When the first locking block engages below the first opening, the second locking block positioned below engages below the second opening, while the second locking block positioned above remains above the second opening.

[0057] Alternatively, the sphere may be made of plastic or nylon.

[0058] Example

[0059] like Figures 1 to 4 As shown, the present invention provides a ball-throwing type retrievable isolation valve, the isolation valve comprising:

[0060] Valve body 1, with a valve cavity provided inside the valve body 1;

[0061] The lower ball seat 2 is detachably installed in the valve cavity. The lower ball seat 2 is hourglass-shaped, and the middle of the lower ball seat 2 forms a first opening 3.

[0062] The upper rubber stopper seat 4 is detachably connected to the upper end of the lower ball seat 2. The upper rubber stopper seat 4 has a conical part 5 inside, and a second opening 6 is provided at the lower end of the conical part 5. The upper end of the upper rubber stopper seat 4 is connected to the valve body 1 by a pin.

[0063] Sphere 7, the diameter of sphere 7 is greater than the diameter of the first opening 3 and less than the diameter of the second opening 6;

[0064] The spear-type rubber stopper 8 includes a core rod 9 and a barbed first locking block 10 and a second locking block 11 disposed on the outer periphery of the core rod 9. The first locking block 10 and the second locking block 11 respectively cooperate with the first opening 3 and the second opening 6. Under the downward pressure of the spear-type rubber stopper 8, the ball 7 can deform and pass through the second opening 6.

[0065] In this embodiment, a protrusion is provided on the inner wall of the valve cavity, and the protrusion is engaged with the lower end of the lower ball seat 2.

[0066] In this embodiment, a straight cylindrical part 12 is provided at the upper end of the lower ball seat 2. A guide groove 13 and a slot 14 are provided on the outer wall of the straight cylindrical part 12. The top of the guide groove 13 is open, and the slot 14 penetrates the outer wall of the straight cylindrical part 12.

[0067] In this embodiment, the lower end of the upper rubber stopper seat 4 is provided with a guide key 15 and a hook 16. The guide key 15 can be inserted into the guide groove 13, and the hook 16 can be engaged with the slot 14. The length of the guide key 15 is greater than the length of the hook 16.

[0068] In this embodiment, the grab hook 16 includes a grab hook rod 17 extending downward along the outer wall of the lower end of the upper rubber stopper seat 4. The lower end of the grab hook rod 17 is wedge-shaped, and a groove 18 is provided on the outer side of the grab hook rod 17. The groove 18 forms a hook portion 19 at the lower end of the grab hook rod 17. The hook portion 19 can be engaged in the slot 14, and the groove 18 can accommodate the upper side wall of the slot 14.

[0069] In this embodiment, a pin hole 20 is provided on the outer wall of the upper end of the upper rubber stopper seat 4. The upper rubber stopper seat 4 can be fixed to the outer wall of the valve body 1 through the pin hole 20 and the pin.

[0070] In this embodiment, a through groove 21 is provided on the conical wall of the conical part 5.

[0071] In this embodiment, a rubber plug sleeve milling rod 22 is also included, which is detachably connected to the upper end of the core rod 9.

[0072] In this embodiment, the first locking block 10 and the second locking block 11 are made of rubber. The second locking block 11 can block the second opening 6 and deform under the action of the downward force to pass through the second opening 6.

[0073] In this embodiment, the material of the sphere 7 is plastic or nylon.

[0074] In summary, when using the ball-throwing retrievable isolation valve provided by this invention, taking the use of the isolation valve in conjunction with a classifying clamp and a packer as an example:

[0075] First, the construction pressure value for well completion operations is determined based on the on-site construction conditions. Based on this pressure value, the number of pins used to fix the upper rubber plug seat 4 to the isolation valve body is determined. The isolation valve is connected sequentially to the stage clamp and packer, with the connection sequence from bottom to top as follows: isolation valve + 1 casing + packer + 1 casing + packer + 1 casing + stage clamp + casing connected to the wellhead. If the completion string encounters problems such as increased resistance during the running-in process, the pump can be started at any time to circulate and flush the wellbore in a timely manner to reduce running-in resistance. Initially, the isolation valve has the lower ball seat 2 installed on a protrusion inside the valve body 1, and the upper rubber plug seat 4 inserted into the guide groove 13 via the guide key 15. The hook portion 19 at the bottom of the grab hook 16 rests against the upper edge of the lower ball seat 2. After the isolation valve reaches the predetermined position, a hard nylon ball 7 is inserted into the string, and the ball 7 is pumped to the first opening 3 of the lower ball seat 2, forming a blind plug for the entire string.

[0076] Then, the pressure is increased to expand and seal the packer, and the staged clamp is opened to establish circulation. Subsequently, staged cement injection is performed, and the spear-type rubber stopper 8 is inserted. The first locking block 10 passes through the first opening 3, and a second locking block 11 below it is engaged above the second opening 6. Under pumping pressure, the second locking block 11 presses down on the conical part 5, and then down on the upper rubber stopper seat 4. The upper rubber stopper seat 4 shears the pin, causing it to descend along the guide groove 13, causing the hook 16 on the upper rubber stopper seat 4 to deform and move downwards until it engages in the slot 14 on the lower ball seat 2. Simultaneously, the lower end of the spear-type rubber stopper 8 deforms the ball 7 and falls through the first opening 3 of the lower ball seat 2. As the spear-type rubber stopper 8 continues to move downwards, the first locking block 10 deforms and engages with the first opening 3 of the lower ball seat 2. The second locking block 11 deforms and engages with the second opening 6 of the upper rubber stopper seat 4.

[0077] Finally, the retrieval string with the rubber plug sleeve milling rod 22 is lowered to the position of the spear-type rubber plug 8, so that the rubber plug sleeve milling rod 22 is connected to the spear-type rubber plug 8. After the pump is turned on, the spear-type rubber plug 8 is lifted up, bringing out the upper rubber plug seat 4 and the lower ball seat 2.

[0078] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A ball-throwing type retrievable isolation valve, characterized in that, The isolation valve includes: Valve body, wherein a valve cavity is provided within the valve body; The lower ball seat is detachably disposed in the valve cavity. The lower ball seat is hourglass-shaped, and a first opening is formed in the middle of the lower ball seat. The upper rubber stopper seat has its lower end detachably connected to the upper end of the lower ball seat. The upper rubber stopper seat has a conical part inside, and a second opening is provided at the lower end of the conical part. A through groove is provided on the conical wall of the conical part. The upper end of the upper rubber stopper seat is connected to the valve body by a pin. A sphere, wherein the diameter of the sphere is greater than the diameter of the first opening and less than the diameter of the second opening; A spear-type rubber stopper includes a core rod and a first locking block and a second locking block with barbs disposed on the outer periphery of the core rod. The first locking block and the second locking block respectively cooperate with the first opening and the second opening. Under the downward pressure of the spear-type rubber stopper, the ball can deform and pass through the first opening. The first locking block deforms and passes through the first opening to complete the engagement of the first locking block with the first opening of the lower ball seat. The second locking block deforms and passes through the second opening to complete the engagement of the second locking block with the second opening of the upper rubber stopper seat.

2. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, The inner wall of the valve cavity is provided with a protrusion, which is engaged with the lower end of the lower ball seat.

3. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, The upper end of the lower ball seat is provided with a straight cylindrical part, and a guide groove and a slot are provided on the outer wall of the straight cylindrical part. The top of the guide groove is open, and the slot passes through the outer wall of the straight cylindrical part.

4. The ball-throwing type retrievable isolation valve according to claim 3, characterized in that, The lower end of the upper rubber stopper seat is provided with a guide key and a hook. The guide key can be inserted into the guide groove, and the hook can be engaged with the slot. The length of the guide key is greater than the length of the hook.

5. The ball-throwing type retrievable isolation valve according to claim 4, characterized in that, The grab hook includes a grab hook rod extending downward along the outer wall of the lower end of the upper rubber stopper seat. The lower end of the grab hook rod is wedge-shaped, and a groove is provided on the outer side of the grab hook rod. The groove forms a hook portion at the lower end of the grab hook rod, which can be engaged in the slot. The groove can accommodate the upper side wall of the slot.

6. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, A pin hole is provided on the outer wall of the upper end of the upper rubber stopper seat, and the upper rubber stopper seat can be fixed to the outer wall of the valve body through the pin hole and the pin.

7. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, It also includes a rubber plug sleeve milling rod, which is detachably connected to the upper end of the core rod.

8. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, The first locking block and the second locking block are made of rubber. The second locking block can block the second opening and deform under the action of downward pressure to pass through the second opening.

9. The ball-throwing type retrievable isolation valve according to claim 1, characterized in that, The sphere is made of plastic or nylon.

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