A circulating valve with self-locking function

Abstract

The application discloses a circulating valve with self-locking function, and belongs to the technical field of oil well circulating valves.The circulating valve comprises an outer sleeve, a first through hole is arranged on the outer sleeve, an inner sleeve is in limiting sliding connection with the outer sleeve, a first elastic member is arranged between the outer sleeve and the inner sleeve, the outer sleeve and the inner sleeve are in common sliding connection with a sliding cylinder, a second through hole is arranged on the sliding cylinder, the sliding cylinder is fixedly connected with a sliding seat, the sliding seat is fixedly connected with an elastic plate, and the elastic plate is fixedly connected with a sealing seat.The sliding seat, the elastic plate and the sealing seat are cooperatively used, so that when a ball is thrown, the ball moves downwardly to the sliding seat, the elastic plate and the sealing seat, the sealing seat is closed and sealed with the ball, the double auxiliary small ball structure is abandoned, the communication and the closure of the device can be realized only by the movement of the sealing seat, the operation success rate is improved, and the space in the ball receiving net is effectively utilized.

Description

Technical Field

[0001] This invention relates to the field of oil well circulation valve technology, and in particular to a circulation valve with a self-locking function. Background Technology

[0002] In oil well operations, it is often necessary to use ball-dropping pressure to drive the opening and closing of circulation valves in downhole tools, in order to establish a fluid circulation channel between the pipe and the annulus, and to complete processes such as reverse circulation sand flushing, displacement well control, and gas lift fluid discharge.

[0003] In the current use of ball-drop type circulation valves, a combination structure of "main large ball + two auxiliary small balls" is generally adopted: first, the large ball is dropped to establish the main seal, realizing the closure of the main channel of the circulation valve, and the bypass channel of the circulation valve is connected to the oil well. Then, two auxiliary small balls are dropped to form a double auxiliary seal. The pressure difference generated by the small balls blocking the bypass channel of the circulation valve and the oil well triggers the sliding sleeve to move. Then, the large ball and the small balls fall into the ball receiving net. However, the small balls are prone to getting stuck in the tubing coupling, inner wall scratches or weld protrusions during the fall. When the small balls are dropped, they are prone to interference, accumulation and blockage of the main channel, resulting in operation failure. At the same time, one large ball and two small balls are required for each circulation, which seriously restricts the load-bearing capacity of the ball receiving net and limits the number of times the circulation valve can be used. Summary of the Invention

[0004] To overcome the shortcomings mentioned in the background above, the present invention provides a circulation valve with a self-locking function.

[0005] The technical solution of the present invention is: a circulation valve with a self-locking function, comprising an outer sleeve, the outer sleeve having symmetrically distributed first through holes, an inner sleeve being slidably connected to the outer sleeve, a first elastic element being disposed between the outer sleeve and the inner sleeve, a sliding cylinder being slidably connected to the outer sleeve and the inner sleeve, the sliding cylinder having symmetrically distributed second through holes, the first through holes being used to communicate with the outside through the corresponding second through holes, a sliding seat being fixedly connected to the sliding cylinder, the inner sleeve being slidably connected to the sliding seat, a circumferentially distributed elastic plate being fixedly connected to the sliding seat, a sealing seat being fixedly connected to the elastic plate, the sealing seat being used to contact the ball being thrown, and a support and locking assembly being disposed inside the sliding cylinder, the support and locking assembly being used to lock the ball being thrown.

[0006] Furthermore, the supporting and locking assembly includes a connector fixedly connected to the sliding cylinder. The connector is hinged to circumferentially distributed baffles, which together buffer the ball. A third elastic element is provided between each of the circumferentially distributed baffles and the connector. The inner sleeve is fixedly connected to circumferentially distributed limiting elements. Each baffle corresponds to one limiting element, and the baffles are slidably connected to their corresponding limiting elements. Each circumferentially distributed limiting element is slidably connected to the connector. A second elastic element is fixedly connected between the limiting elements and the connector. A clamping plate is fixedly connected to each baffle, and the circumferentially distributed clamping plates are used to lock the ball.

[0007] Furthermore, the clamping plate is provided with a rough surface to increase the coefficient of friction with the thrown ball.

[0008] Furthermore, the limiting member has symmetrically distributed first guide straight grooves, symmetrically distributed second guide straight grooves, and symmetrically distributed widening grooves. The first guide straight groove of the limiting member is connected to the adjacent second guide straight groove and the adjacent widening groove. The second guide straight groove of the limiting member is connected to the adjacent widening groove, and the second guide straight groove of the limiting member and the adjacent widening groove are smoothly connected. The first guide straight groove of the limiting member is used for sliding of the connecting member, and the second guide straight groove and the widening groove of the limiting member are used for moving of the barrier plate.

[0009] Furthermore, the elastic coefficient of the first elastic element is greater than that of the second elastic element.

[0010] Furthermore, the circumferentially distributed barrier plates are located on the side of the circumferentially distributed sealing seat away from the sliding seat.

[0011] Furthermore, each of the circumferentially distributed barrier plates has an inclined surface on its upper side, and the inclined surface of the barrier plate is used to guide the ball being thrown.

[0012] Furthermore, the outer sleeve is provided with a compression section, which is used to compress the circumferentially distributed sealing seats.

[0013] Furthermore, the sliding cylinder is provided with a third through hole and a fourth through hole. The first through hole on one side is used to connect the third through hole to the outside, and the first through hole on the other side is used to connect the fourth through hole to the outside.

[0014] Furthermore, the third through hole is located between the second through hole and the fourth through hole, and the second through hole is located on the side of the third through hole away from the sliding seat.

[0015] The present invention has the following advantages: Through the synergistic action of the sliding seat, the elastic plate, and the sealing seat, when the ball is thrown, the ball causes the sliding seat, the elastic plate, and the sealing seat to move downward, thereby closing the sealing seat and sealing it with the ball. When the tubing does not need to be injected with liquid, the sealing seat moves upward under the action of the first elastic element. This design eliminates the need for a double auxiliary ball structure, and the connection and closure of the device can be achieved solely through the movement of the sealing seat, improving the success rate of the operation. At the same time, it makes effective use of the space within the ball receiving net, increasing the number of times the device can be used. Simultaneously, it limits and compresses the ball, achieving self-locking of the ball.

[0016] The baffle plate buffers and guides the ball, while the limiting device ensures the sealing seat closes by first displacing the baffle plate. Then the baffle plate swings to release the ball, which falls onto the closed sealing seat. This process first buffers and guides the ball before unlocking and sealing, reducing the direct impact of the ball on the sealing seat and improving the integrity of the sealing surface. At the same time, the clamping plate compresses the ball, effectively resisting the high-pressure backlash force downhole and reducing the probability of it coming out.

[0017] The third and fourth through holes and two second through holes on the sliding cylinder allow for flexible single-sided or double-sided fluid injection, adapting to various operational needs such as well washing, fracturing, and fluid drainage, thus expanding the applicability of this device. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the inner sleeve and sliding cylinder of the present invention; Figure 3 This is a three-dimensional structural diagram of the connector and barrier plate of the present invention; Figure 4 This is a three-dimensional structural diagram of the sliding seat, elastic plate, and sealing seat of the present invention; Figure 5 This is an exploded three-dimensional structural diagram of the outer sleeve and inner sleeve of the present invention; Figure 6 This is a three-dimensional structural diagram of the barrier plate and limiting member of the present invention; Figure 7 For the present invention Figure 6 An enlarged 3D structural diagram at point A in the middle; Figure 8 This is an exploded three-dimensional structural diagram of the limiting member and clamping plate of the present invention; Figure 9 This is a three-dimensional structural diagram of the elastic plate and sealing seat of the present invention in another state.

[0019] In the attached drawings, the following are the reference numerals: 1. Outer sleeve; 101. First through hole; 2. Inner sleeve; 102. First elastic element; 3. Sliding cylinder; 103. Second through hole; 4. Sliding seat; 5. Elastic plate; 6. Sealing seat; 201. Connector; 202. Barrier plate; 2022. Third elastic element; 203. Limiting element; 204. Second elastic element; 301. Extrusion part; 401. Clamping plate; 501. Third through hole; 502. Fourth through hole. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments. Example 1

[0021] A circulation valve with a self-locking function, such as Figures 1-7 and Figure 9 As shown, the device includes an outer sleeve 1 with symmetrically distributed first through holes 101. An inner sleeve 2 is slidably connected to the outer sleeve 1. A first elastic element 102 is provided between the outer sleeve 1 and the inner sleeve 2. A sliding cylinder 3 is slidably connected to the outer sleeve 1 and the inner sleeve 2. A second through hole 103 is symmetrically distributed on the sliding cylinder 3. The first through hole 101 is used to connect the corresponding second through hole 103 to the outside. A sliding seat 4 is fixedly connected to the sliding cylinder 3. The inner sleeve 2 is slidably connected to the sliding seat 4. A circumferentially distributed elastic plate 5 is fixedly connected to the sliding seat 4. A sealing seat 6 is fixedly connected to the elastic plate 5. The sealing seat 6 is used to contact the ball. A support and locking assembly is provided inside the sliding cylinder 3. The support and locking assembly is used to lock the ball.

[0022] In the above scheme, the outer sleeve 1 has an upper connector and a lower connector. The upper connector of the outer sleeve 1 is threaded to the oil pipe column, and the lower connector of the outer sleeve 1 is threaded to the packer. A ball-blocking net is threaded between the lower connector of the outer sleeve 1 and the packer. The ball-blocking net is used to intercept the ball. There are two first through holes 101 and two second through holes 103. The inner sleeve 2 has four circumferentially distributed limiting through grooves. The sliding seat 4 has four circumferentially distributed protrusions. The limiting through grooves of the inner sleeve 2 correspond one-to-one with the protrusions of the sliding seat 4. The protrusions of the sliding seat 4 slide within the corresponding limiting through grooves of the inner sleeve 2. There are six elastic plates 5. The first elastic element 102 is a spring.

[0023] like Figures 3-9As shown, the supporting and locking assembly includes a connector 201, which is fixedly connected to the sliding cylinder 3. The connector 201 is hinged to circumferentially distributed baffles 202, which together buffer the ball being thrown. A third elastic element 2022 is provided between each of the circumferentially distributed baffles 202 and the connector 201. A circumferentially distributed limiting element 203 is fixedly connected to the inner sleeve 2. The baffles 202 and the limiting elements 203 correspond one-to-one, and the baffles... The partition 202 is slidably connected to the corresponding limiting member 203. The circumferentially distributed limiting members 203 are all slidably connected to the connecting member 201. A second elastic member 204 is fixedly connected between the limiting member 203 and the connecting member 201. A clamping plate 401 is fixedly connected to the partition 202. The circumferentially distributed clamping plates 401 are used to lock the ball together. The clamping plates 401 have a rough surface to increase the coefficient of friction with the ball. The limiting members 203 are symmetrically distributed. The first guide straight groove, the symmetrically distributed second guide straight groove, and the symmetrically distributed widening groove are all present. The first guide straight groove of the limiting member 203 is connected to the adjacent second guide straight groove and the adjacent widening groove. The second guide straight groove of the limiting member 203 is connected to the adjacent widening groove, and the second guide straight groove of the limiting member 203 and the adjacent widening groove are smoothly connected. The first guide straight groove of the limiting member 203 is used for sliding of the connecting member 201. The second guide straight groove and the widening groove of the limiting member 203 are used for moving of the barrier plate 202. The elastic coefficient of the first elastic member 102 is greater than the elastic coefficient of the second elastic member 204. The circumferentially distributed barrier plate 202 is located on the side of the circumferentially distributed sealing seat 6 away from the sliding seat 4. The upper side of the circumferentially distributed barrier plate 202 is provided with an inclined surface. The inclined surface of the barrier plate 202 is used to guide the ball. The outer sleeve 1 is provided with a pressing part 301, which is used to press the circumferentially distributed sealing seat 6.

[0024] In the above scheme, the connector 201 consists of a ring and four U-shaped rods. The ring of the connector 201 is fixedly connected to the sliding cylinder 3. The U-shaped rods of the connector 201 correspond one-to-one with the limiting members 203, and the U-shaped rods of the connector 201 pass through the corresponding limiting members 203. The baffle plate 202 has a sliding block, which is rotatably connected to the corresponding U-shaped rod on the connector 201. The cross-section of the sliding block of the baffle plate 202 is oval. The third elastic element 2022 is a torsion spring. When the baffle plate 202 moves downward, the sliding block of the baffle plate 202 slides along the two second guide straight grooves of the corresponding limiting member 203. When the sliding block of the baffle plate 202 enters the widened groove of the limiting member 203, the limiting member 203 loses its restraint on the corresponding baffle plate 202. The sliding block is limited to swing. At this time, the baffle plate 202 swings adaptively under the action of the ball. The second elastic element 204 is a spring. When the ball is seated on the sealing seat 6, all the clamping plates 401 are in contact with the upper side of the ball. At the same time, the clamping plates 401 squeeze the ball to effectively resist the high pressure back force downhole and reduce the probability of detachment. When all the sealing seats 6 are in contact with the squeezing part 301, the elastic plate 5 is in a stored state. Under the action of the corresponding elastic plate 5, all the sealing seats 6 are in an open state, and there is a gap between two adjacent sealing seats 6. When all the sealing seats 6 lose contact with the squeezing part 301, the elastic plate 5 stores more force, and all the sealing seats 6 are in a closed ring state. At this time, there is no gap between two adjacent sealing seats 6.

[0025] Working Principle: Before using this device, first connect the upper connector of the outer sleeve 1 to the tubing string, and the lower connector of the outer sleeve 1 to the packer. Then, lower the tubing string, packer, and this device into the well. After reaching the preset depth, the operator seals the section with the packer and then fracturing it. After fracturing, the operator places the ball into the tubing string. As the ball moves downward, it contacts the baffles 202. The four baffles 202 work together to buffer the ball, and then simultaneously guide the ball towards the center. The operator injects fracturing fluid into the tubing string. As the fracturing fluid pressure increases... Under the action of the ball, the four barrier plates 202 are squeezed and moved downward. The four barrier plates 202 together drive the connecting piece 201 to move downward. The connecting piece 201 drives the sliding cylinder 3 to move together. The sliding cylinder 3 drives the sliding seat 4, the elastic plate 5 and the sealing seat 6 to move together. During this process, the second elastic element 204 is compressed and stores power. The connecting piece 201 and the four barrier plates 202 slide relative to the limiting element 203. As the barrier plates 202 move downward, all the sealing seats 6 lose contact with the squeezing part 301. The sealing seats 6 drive the corresponding elastic plates 5 to swing adaptively. The elastic plates 5 store power further. Then all the sealing seats 6 close.

[0026] After all the sealing seats 6 are closed, the baffle plate 202 enters the widened groove from the second guide groove of the corresponding limiting member 203. The baffle plate 202 buffers and guides the ball, and in conjunction with the limiting member 203, the baffle plate 202 moves downward to ensure that the sealing seat 6 is closed. Then the baffle plate 202 swings to release the ball and let it fall onto the closed sealing seat 6. This achieves buffering and guiding of the ball before unlocking and sealing, reducing the direct impact of the ball on the sealing seat 6 and improving the integrity of the sealing surface on the sealing seat 6. All four baffle plates 202 swing outward, and the third elastic member 2022 is twisted and stores force. Then the ball loses contact with all the baffle plates 202, and the third elastic member 2022 releases its elastic force. At this time, all the clamping plates 401 are in contact with the ball. This setting effectively resists the high pressure back force downhole and prevents the ball from falling out. At this time, all the baffle plates 202 swing to the position where... Figure 9 As shown in the diagram, the ball is then thrown onto all the sealing seats 6, making contact with all the sealing seats 6. Subsequently, the protrusion of the sliding seat 4 contacts the lower side of the corresponding limiting groove on the inner sleeve 2. At this time, the U-shaped rod of the connecting piece 201 contacts the lower side of the first guide groove of the corresponding limiting piece 203. The sliding seat 4, through the protrusion, presses the inner sleeve 2 downwards together. The first elastic member 102 compresses and stores force, causing the sliding seat 4 to move along with its components. The inner sleeve 2 causes the limiting piece 203 to move downwards. At this time, the elastic plate 5, the sealing seats 6, and the ball are in the following states: Figure 9 As shown, the first through hole 101 is connected to the corresponding second through hole 103 to complete the setting of the ball and the sealing seat 6. When the ball falls, the ball causes the sliding seat 4, the elastic plate 5 and the sealing seat 6 to move downward, thereby closing the sealing seat 6 and sealing it with the ball. At the same time, the clamping plate 401 limits and squeezes the ball.

[0027] After the ball is launched and the sealing seat 6 is set, the fracturing fluid flows out through the second through hole 103 and the corresponding first through hole 101. After a period of time (this period of time depends on the specific situation on site and will not be specified here), the operator stops injecting fracturing fluid into the tubing. When the pressure of the fracturing fluid is less than the compressed elastic force of the first elastic element 102, the first elastic element 102 releases its elastic force and squeezes the inner sleeve 2, causing the inner sleeve 2 to move upward. The inner sleeve 2 drives the sliding seat 4, the elastic plate 5, and the sealing seat 6 to move upward together. The sliding seat 4 drives all its parts to move. As the sealing seat 6 moves upward, all the elastic plates 5 release their elastic force, and all the sealing seats 6 come into contact with the compression part 301. The contact between two adjacent sealing seats 6 is lost, and all the sealing seats 6 open. At this time, all the sealing seats 6 lose contact with the ball, and all the baffle plates 202 return to their original positions. Figure 6As shown, simultaneously, the ball passes through all the sealing seats 6 and enters the ball-blocking net between the lower joint of the outer sleeve 1 and the packer. After the first elastic element 102 resets, all the second elastic elements 204 release their elastic force, and the connecting element 201 moves all its parts upward together. At this time, all the limiting elements 203 slide relative to the connecting element 201, and the blocking plate 202 enters the second guide straight groove of the limiting element 203 from the widened groove of the corresponding limiting element 203. As the elastic force of the second elastic element 204 is fully released, the connecting element 201 and the blocking plate 202 both reach the position shown. Figure 4 As shown, the opening and closing process of this device is completed. This setting abandons the dual auxiliary ball structure. The connection and closure of this device and the bypass channel can be achieved by moving the sealing seat 6 alone, which improves the success rate of the operation. At the same time, the space inside the ball receiving net is effectively utilized, which increases the number of times the device can be used. Then, when fracturing is required at the next position, the above steps can be repeated. Example 2

[0028] Based on Example 1, such as Figures 2-4 and Figure 9 As shown, the sliding cylinder 3 is provided with a third through hole 501 and a fourth through hole 502. The first through hole 101 on one side is used to connect the third through hole 501 to the outside, and the first through hole 101 on the other side is used to connect the fourth through hole 502 to the outside. The third through hole 501 is located between the second through hole 103 and the fourth through hole 502, and the second through hole 103 is located on the side of the third through hole 501 away from the sliding seat 4.

[0029] In the above scheme, the third through hole 501 can communicate with the first through hole 101 on the right, and the fourth through hole 502 can communicate with the first through hole 101 on the left. Figure 3 In the state shown, the distance between the fourth through hole 502 and the first through hole 101 on the left is not less than the distance from the opening to the closing of all the sealing seats 6.

[0030] Working principle: During the downward movement of the sliding cylinder 3, the fourth through hole 502 first connects with the first through hole 101 on the left. As the sliding cylinder 3 continues to move, the fourth through hole 502 gradually loses connection with the first through hole 101. Then, the third through hole 501 connects with the first through hole 101 on the right. As the third through hole 501 gradually loses connection with the first through hole 101 on the right, the two second through holes 103 connect with the corresponding first through holes 101 respectively.

[0031] The sealing seat 6, the barrier plate 202 and the clamping plate 401 achieve Figure 9After reaching the indicated state, the operator can reduce the pressure of the fracturing fluid according to the specific working conditions to achieve the connection between the fourth through hole 502 and the first through hole 101 on the left, or the third through hole 501 and the first through hole 101 on the right. The third through hole 501, the fourth through hole 502 and the two second through holes 103 on the sliding cylinder 3 can flexibly realize single-sided or double-sided fluid injection, adapting to the needs of various operation processes such as well washing, fracturing, and fluid drainage, thereby improving the applicability of this device.

[0032] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A circulation valve with a self-locking function, comprising an outer sleeve (1), wherein the outer sleeve (1) is provided with symmetrically distributed first through holes (101), the outer sleeve (1) is slidably connected to an inner sleeve (2), a first elastic element (102) is provided between the outer sleeve (1) and the inner sleeve (2), the outer sleeve (1) and the inner sleeve (2) are slidably connected to a sliding cylinder (3), wherein the sliding cylinder (3) is provided with symmetrically distributed second through holes (103), the first through holes (101) being used to communicate with the outside through the corresponding second through holes (103), characterized in that: The sliding cylinder (3) is fixedly connected to a sliding seat (4), the inner sleeve (2) is slidably connected to the sliding seat (4), the sliding seat (4) is fixedly connected to a circumferentially distributed elastic plate (5), the elastic plate (5) is fixedly connected to a sealing seat (6), the sealing seat (6) is used to contact the ball, and a support locking assembly is provided inside the sliding cylinder (3), the support locking assembly is used to lock the ball; The supporting and locking assembly includes a connector (201), which is fixedly connected to the sliding cylinder (3). The connector (201) is hinged to a circumferentially distributed baffle plate (202). The circumferentially distributed baffle plate (202) is used to buffer the ball. A third elastic element (2022) is provided between the circumferentially distributed baffle plate (202) and the connector (201). The inner sleeve (2) is fixedly connected to a circumferentially distributed limiting element (203). The partition (202) corresponds one-to-one with the limiting member (203), and the partition (202) is slidably connected to the corresponding limiting member (203). The circumferentially distributed limiting members (203) are all slidably connected to the connecting member (201). A second elastic member (204) is fixed between the limiting member (203) and the connecting member (201). The partition (202) is fixedly connected to a clamping plate (401). The circumferentially distributed clamping plates (401) are used to lock the ball together.

2. A circulation valve with a self-locking function according to claim 1, characterized in that: The clamping plate (401) is provided with a rough surface to increase the coefficient of friction with the ball.

3. A circulation valve with a self-locking function according to claim 2, characterized in that: The limiting member (203) has a symmetrically distributed first guide straight groove, a symmetrically distributed second guide straight groove, and a symmetrically distributed widening groove. The first guide straight groove of the limiting member (203) is connected to the adjacent second guide straight groove and the adjacent widening groove. The second guide straight groove of the limiting member (203) is connected to the adjacent widening groove, and the second guide straight groove of the limiting member (203) and the adjacent widening groove are smoothly connected. The first guide straight groove of the limiting member (203) is used for the sliding of the connecting member (201), and the second guide straight groove and the widening groove of the limiting member (203) are used for the movement of the barrier plate (202).

4. A circulation valve with a self-locking function according to claim 3, characterized in that: The elastic coefficient of the first elastic element (102) is greater than that of the second elastic element (204).

5. A circulation valve with a self-locking function according to claim 4, characterized in that: The circumferentially distributed barrier plate (202) is located on the side of the circumferentially distributed sealing seat (6) away from the sliding seat (4).

6. A circulation valve with a self-locking function according to claim 5, characterized in that: The upper side of each of the circumferentially distributed barrier plates (202) is provided with an inclined surface, which is used to guide the ball.

7. A circulation valve with a self-locking function according to claim 1, characterized in that: The outer sleeve (1) is provided with a compression part (301), which is used to compress the circumferentially distributed sealing seats (6).

8. A circulation valve with a self-locking function according to claim 1, characterized in that: The sliding cylinder (3) is provided with a third through hole (501) and a fourth through hole (502). The first through hole (101) on one side is used to connect the third through hole (501) with the outside, and the first through hole (101) on the other side is used to connect the fourth through hole (502) with the outside.

9. A circulation valve with a self-locking function according to claim 8, characterized in that: The third through hole (501) is located between the second through hole (103) and the fourth through hole (502), and the second through hole (103) is located on the side of the third through hole (501) away from the sliding seat (4).

Images