Linear motion j-slot flow control device

Abstract

The present application relates to a kind of linear motion J-shaped slot flow control device, including cylinder, piston assembly, positioning pin and flow bushing, the cylinder includes sleeve body, upper joint and lower joint, the sleeve body is equipped with oil inlet hole on one end close to the lower joint.The piston assembly includes piston body and sleeve, the sleeve is sleeved on the piston body, the sleeve and the piston body are rotationally fitted, the J-shaped slot is formed on the outside wall of the sleeve, the piston assembly is sleeved in the sleeve body and can move along the cylinder, when the piston assembly moves, the positioning pin moves along the J-shaped slot;The flow bushing is fixedly sleeved in the sleeve body, the flow bushing is aligned with the oil inlet hole, the flow bushing is equipped with several flow holes, the movement of the piston assembly can adjust the number of flow hole communicated with the oil inlet hole.The linear motion J-shaped slot flow control device realizes the flow regulation of multiple opening degrees of producing layer.

Description

Technical Field

[0001] This invention relates to a J-shaped groove flow control device for linear motion, belonging to the field of oil drilling and completion and oil and gas extraction. Background Technology

[0002] Intelligent well completion technology primarily utilizes downhole hydraulic power to remotely control downhole flow control valves, enabling stratified production control of downhole oil and gas formations from the surface, achieving multi-layer combined production and inter-layer optimization. Employing intelligent well completion technology, the opening degree of downhole producing formations can be controlled. If only opening or closing of a producing formation is required, a downhole flow control valve with two opening degrees can be used; for more precise control of the flow rate of a single producing formation, multiple opening degrees are needed.

[0003] Patent CN201020685155.0 uses a J-shaped groove, but the J-shaped groove is exposed outside the well fluid; Patent CN201410618870.5 uses a J-shaped groove structure, and the sliding sleeve rotates and moves axially with the J-shaped groove, resulting in large circumferential and axial friction at the seal; Patents CN202010212062.4, CN202122435413.0, and CN202210188793.9 use a J-shaped groove to achieve circumferential throttling orifice transformation, but circumferential sealing is not easy to guarantee; CN202210611394.9 uses a displacement sensor, but in the high temperature and high pressure environment downhole, the durability of electronic components is not easy to meet. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a linear motion J-groove flow control device, offering a simple J-groove control for multi-opening downhole flow control, enabling flow regulation at multiple openings in the producing formation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a linear motion J-groove flow control device, comprising:

[0007] The cylinder body includes a sleeve, an upper connector, and a lower connector, with a cavity formed between the sleeve, the upper connector, and the lower connector. An oil inlet hole is provided on the sleeve near the lower connector.

[0008] A piston assembly includes a piston body and a sleeve fitted over the piston body. The sleeve is rotatably fitted with the piston body. A J-shaped groove is formed on the outer side wall of the sleeve. The piston assembly is fitted over the sleeve and can move along the cylinder. A partition is formed in the middle of the piston body, which divides the cavity into a left end cavity and a right end cavity. A right cavity oil passage and a left cavity oil passage are provided on the side wall of the sleeve. The left cavity oil passage communicates with the left end cavity, and the right cavity oil passage communicates with the right end cavity.

[0009] A positioning pin is fixed on the sleeve body, and the bottom of the positioning pin is inserted into the J-shaped groove. When the piston assembly moves, the positioning pin moves along the J-shaped groove. When the positioning pin reaches the end of the J-shaped groove, it can push the sleeve to rotate circumferentially.

[0010] A flow bushing is fixedly fitted inside the sleeve body. The flow bushing is aligned with the oil inlet hole. The flow bushing is provided with a plurality of flow holes. The number of flow holes communicating with the oil inlet hole can be adjusted by moving the piston assembly.

[0011] Preferably, the sleeve and the piston body are rotatably connected by a rotating assembly. The rotating assembly includes two J-shaped groove seats, a semi-circular axial positioning sleeve, a steel ball, a retaining spring, and a retaining ring. The two J-shaped groove seats are respectively fixedly installed at both ends of the sleeve. Both the J-shaped groove seats and the sleeve have an arc-shaped surface on their opposite sides. The steel ball is sandwiched in the arc-shaped surface, and the diameter of the arc-shaped surface is slightly smaller than the diameter of the steel ball. The J-shaped groove seat at one end is limited by the step formed by the partition, and the J-shaped groove seat at the other end is limited by the semi-circular axial positioning sleeve. The semi-circular axial positioning sleeve is fixedly sleeved on the piston body, and the retaining ring is fixedly sleeved on the semi-circular axial positioning sleeve. The retaining spring is also sleeved on the outside of the retaining ring. The retaining ring is used for circumferential limitation of the semi-circular axial positioning sleeve, and the retaining spring is used for axial limitation of the retaining ring.

[0012] Preferably, the J-shaped groove flow control device for linear motion further includes a claw mechanism. The claw mechanism includes a retaining ring and a retaining tooth connected to one end of the retaining ring. The claw mechanism is located in the right end cavity and is fixedly sleeved on the piston body. The piston body is provided with a plurality of slots that cooperate with the retaining tooth. When the piston body reaches the open position, the retaining tooth engages in the corresponding slot to achieve positioning.

[0013] Preferably, the J-groove flow control device for linear motion further includes a claw retaining ring and at least two retaining ring sealing rings. One end of the claw retaining ring abuts against the flow bushing, and the other end of the claw retaining ring abuts against the retaining ring. The retaining ring sealing rings are respectively fixedly embedded in the inner and outer side walls of the claw retaining ring to achieve sealing contact with the inner wall of the sleeve and the piston body, respectively.

[0014] Preferably, the J-groove flow control device for linear motion further includes an axial sealing structure, which includes a sealing ring, an outer static seal, and a mechanical seal. One end of the mechanical seal abuts against the lower connector, and the other end abuts against the flow bushing through the sealing ring. The outer static seal is embedded in the inner wall of the sleeve and makes sealing contact with the mechanical seal.

[0015] Preferably, the J-groove flow control device for linear motion further includes a sealing bushing and a piston sealing ring. The sealing bushing is fixedly sleeved in the sleeve body, and one end of the sealing bushing abuts against the upper connector. The piston sealing ring is fixedly embedded in the inner and outer side walls of the sealing bushing and makes sealing contact with the piston body and the interior of the sleeve body, respectively.

[0016] Preferably, a first limiting step is formed on the upper connector, and a second limiting step is formed on the lower connector. The first limiting step and the second limiting step are used to limit the piston body at both ends, respectively.

[0017] Preferably, the J-shaped groove includes a plurality of limiting grooves, one end of which is connected and the connected end is used for the positioning pin to pass through. The turning point between each two adjacent limiting grooves is a first inclined surface. An intermediate groove is formed on the side opposite to each first inclined surface. The turning point between two adjacent intermediate grooves is a second inclined surface, and the second inclined surface is directly opposite the limiting groove.

[0018] Preferably, the J-shaped groove includes a first limiting groove, a second limiting groove, a third limiting groove, and a fourth limiting groove. The length of the first limiting groove is greater than the lengths of the second limiting groove, the third limiting groove, and the fourth limiting groove. The lengths of the second limiting groove, the third limiting groove, and the fourth limiting groove are distributed in a stepped manner from short to long.

[0019] Preferably, the outer wall of the flow bushing is provided with a pin hole, and the flow bushing is fixed in the sleeve body through the pin hole and the pin inserted in the pin hole.

[0020] Preferably, the J-shaped groove includes two sets, and the two sets of J-shaped grooves are symmetrically arranged on the outer side wall of the sleeve. The positioning pin includes two pins, and each set of J-shaped grooves corresponds to one positioning pin.

[0021] The present invention has the following advantages due to the adoption of the above technical solutions:

[0022] 1. Utilize two hydraulic lines to achieve downhole production flow control at multiple opening degrees for a single production layer;

[0023] 2. The rotational motion is accomplished by using an empty sleeve. The sleeve is rotatably connected to the piston body. The piston and the sliding sleeve only move axially to reduce friction and wear.

[0024] 3. By adopting downhole mechanical seal technology, the sliding sleeve does not generate circumferential movement, thus avoiding the rotational friction caused by interference fit of the mechanical seal and improving the reliability of the mechanical seal;

[0025] 4. The hydraulic cylinder body is composed of three parts: upper connector, lower connector, and cylinder liner, which is different from other cylinder bodies composed of four or more sections. It has a reasonable and compact structure, and the motion principle of each component is simple and practical, which reduces the processing cost. It adopts hydraulic remote control, which not only has high safety performance, but also improves work efficiency. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] In the attached diagram:

[0028] Figure 1 This is a cross-sectional schematic diagram of a J-shaped flow control device with linear motion in the closed state.

[0029] Figure 2 This is a cross-sectional view of the piston assembly;

[0030] Figure 3 This is an unfolded view of the J-shaped groove on the sleeve;

[0031] Figure 4 This is a cross-sectional view of the flow bushing;

[0032] Figure 5 This is a cross-sectional view of the J-shaped flow control device with linear motion in its intermediate state;

[0033] Figure 6 This is a cross-sectional view of a J-shaped flow control device with linear motion in its fully open state;

[0034] Figure 7 This is a view of the J-groove flow control device in linear motion with its opening at 2 degrees.

[0035] Figure 8 This is a view of the J-shaped groove flow control device in linear motion at opening degree 3. Detailed Implementation

[0036] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, 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 to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0037] An embodiment of the present invention provides a linear motion J-groove flow control device, including a cylinder, a piston assembly, a locating pin, and a flow bushing. The cylinder includes a sleeve, an upper connector, and a lower connector, with a cavity formed between the sleeve, the upper connector, and the lower connector. An oil inlet hole is provided on the sleeve near the lower connector. The piston assembly includes a piston body and a sleeve fitted over the piston body. The sleeve and the piston body are rotatably fitted together. A J-groove is formed on the outer wall of the sleeve. The piston assembly is fitted over the sleeve and can move and rotate along the cylinder. A partition is formed in the middle of the piston body. The partition divides the cavity into a left end cavity and a right end cavity. A right cavity oil passage and a left cavity oil passage are provided on the side wall of the sleeve. The left cavity oil passage communicates with the left end cavity, and the right cavity oil passage communicates with the right end cavity. A positioning pin is fixed to the sleeve, with its bottom inserted into the J-shaped groove. When the piston assembly moves, the positioning pin moves along the J-shaped groove. A flow-through bushing is fixedly fitted inside the sleeve, aligned with the oil inlet. The flow-through bushing has several flow-through holes, and the movement of the piston assembly can adjust the number of flow-through holes communicating with the oil inlet.

[0038] Two hydraulic control lines connect to the oil ports of the left and right end chambers, respectively. The axial movement of the piston assembly is controlled by a J-groove to regulate the piston body opening. The downhole hydraulically controlled piston body requires sealing and isolating numerous hydraulic oil and production fluid chambers, employing non-metallic or metallic contact seals, resulting in high contact and friction forces. To avoid friction caused by the sleeve rotating the piston body, an empty sleeve performs the rotational motion, while the piston body only moves axially, reducing friction and wear. A simple downhole flow control device with multi-opening control via a J-groove on the sleeve is provided, enabling flow regulation at multiple openings in the producing formation.

[0039] Example 1

[0040] like Figures 1 to 4As shown, Embodiment 1 of the present invention provides a linear motion J-groove flow control device, including a cylinder, a piston assembly 100, a positioning pin 7, and a flow bushing 18. The cylinder includes a sleeve 3, an upper connector 1, and a lower connector 24, with a cavity formed between the sleeve 3, the upper connector 1, and the lower connector 24. An oil inlet hole 19 is provided on the sleeve 3 near the lower connector 24. The piston assembly 100 includes a piston body 101 and a sleeve 200 sleeved outside the piston body 101. The sleeve 200 is rotatably fitted with the piston body 101. A J-groove is formed on the outer side wall of the sleeve 200. The piston assembly 100 is sleeved inside the sleeve 3 and can move and rotate along the cylinder. A partition is formed in the middle of the piston body 101, dividing the cavity into a left end cavity and a right end cavity 9. A right cavity oil passage 8 and a left cavity oil passage 9 are provided on the side wall of the sleeve 3. The left cavity oil passage and the... The left end cavity is connected, and the right cavity oil passage is connected to the right end cavity 9; the positioning pin 7 is fixed on the sleeve 3, and the bottom of the positioning pin 7 is inserted into the J-shaped groove. When the piston assembly 100 moves, the positioning pin 7 moves along the J-shaped groove; the flow bushing 18 is fixedly sleeved in the sleeve 3, and the flow bushing 18 is aligned with the oil inlet hole 19. The flow bushing 18 is provided with a plurality of flow holes. The movement of the piston assembly 100 can adjust the number of flow holes in the flow bushing 18 that are connected to the oil inlet hole 19.

[0041] The sleeve 200 is loosely fitted onto the hollow piston body 101. The sleeve 200 is axially positioned but not circumferentially positioned. When the piston body 101 moves axially, the sleeve 200, loosely fitted onto the piston body 101, moves axially along with it. When the inclined surface of the J-shaped groove encounters the positioning pin 7 on the cylinder, the positioning pin 7 contacts the inclined surface of the J-shaped groove. When the axial force of the piston assembly 100 is large enough, the sleeve 200 will continue to move along the axis with the piston body 101. The inclined surface of the J-shaped groove is subjected to the action of the positioning pin, generating a circumferential force, and the sleeve 200 rotates simultaneously along the axis. In this way, the piston body 101 only performs axial movement, while the sleeve 200 performs both axial and circumferential movements. The stroke of the axial movement of the piston body 101 corresponds to the opening size of the lower flow bushing 18, which is axially limited by the J-shaped groove. Each time the sleeve 200 rotates one groove position, it controls the axial movement distance of the piston body 101, thereby controlling the opening size of the lower sliding sleeve.

[0042] Two hydraulic control lines are connected to the left end cavity port 13 and the right end cavity port 2, respectively. The axial movement of the piston assembly 100 is controlled by a J-shaped groove to control the opening degree of the piston body 101. The downhole hydraulically controlled piston body 101 requires sealing and isolating numerous hydraulic oil and production fluid chambers, employing non-metallic or metallic contact seals, resulting in high contact force and friction. To prevent the sleeve 200 from rotating the piston body 101, the sleeve 200 is used for rotational movement, while the piston body 101 only moves axially, reducing friction and wear. A simple downhole flow control device with multi-opening control via the J-shaped groove on the sleeve 200 is provided to achieve flow regulation at multiple opening degrees in the producing formation.

[0043] The sleeve 200 and the piston body 101 are rotatably connected via a rotating assembly. The rotating assembly includes two J-shaped groove seats 106, a semi-circular axial positioning sleeve 105, a steel ball 107, a retaining ring 103, and a retaining ring 104. The two J-shaped groove seats 106 are respectively fixedly installed at both ends of the sleeve 200. Both the J-shaped groove seats 106 and the sleeve 200 have an arc-shaped surface on their opposite sides. The steel ball 107 is clamped within the arc-shaped surface, and the diameter of the arc-shaped surface is slightly smaller than the diameter of the steel ball 107. The steel ball 107 is located at one end... The J-shaped groove seat 106 is limited by the step formed by the partition, and the other end of the J-shaped groove seat 106 is limited by the semi-circular axial positioning sleeve 105. The semi-circular axial positioning sleeve 105 is fixedly sleeved on the piston body 101. The retaining ring 104 is fixedly sleeved on the semi-circular axial positioning sleeve 105. The retaining ring 104 is also sleeved on the outside of the retaining ring 104. The retaining ring 104 is used for circumferential limitation of the semi-circular axial positioning sleeve 105, and the retaining ring 103 is used for axial limitation of the retaining ring 104.

[0044] The linear motion J-groove flow control device further includes a claw mechanism, which includes a retaining ring 12 and a retaining tooth 10 connected to one end of the retaining ring 12. The claw mechanism is located within the right end cavity 9 and is fixedly sleeved on the piston body 101. The piston body 101 has several slots that cooperate with the retaining tooth 10. When the piston body 101 reaches the open position, the retaining tooth 10 engages in the corresponding slot to achieve positioning. When the piston body 101 is in the open position, the retaining tooth 10 enters the slot to achieve positioning, preventing the piston from moving due to gravity and unbalanced axial loads. The slots include a first slot 109, a second slot 110, a third slot 111, and a fourth slot 112.

[0045] The linear motion J-groove flow control device further includes a claw retaining ring 16 and at least two retaining ring sealing rings 15. One end of the claw retaining ring 16 abuts against the flow bushing 18, and the other end of the claw retaining ring 16 abuts against the retaining ring 12. The retaining ring sealing rings 15 are respectively fixedly embedded in the inner and outer side walls of the claw retaining ring 16 to achieve sealing contact with the inner wall of the sleeve and the piston body 101, respectively.

[0046] The linear motion J-groove flow control device also includes a sealing structure, which includes a sealing ring 20, an outer circular static seal 21, and a mechanical seal ring 22. One end of the mechanical seal ring 22 abuts against the lower connector 24, and the other end abuts against the flow bushing 18 through the sealing ring 20. The outer circular static seal 21 is embedded in the inner wall of the sleeve and has a sealing contact with the mechanical seal ring 22.

[0047] The linear motion J-groove flow control device also includes a sealing bushing 5 and a piston sealing ring 4. The sealing bushing 5 is fixedly sleeved inside the sleeve body 3, and one end of the sealing bushing 5 abuts against the upper connector 1. The piston sealing ring 4 is fixedly embedded in the inner and outer side walls of the sealing bushing 5. The piston sealing ring 4 embedded in the inner side wall of the sealing bushing 5 and the piston sealing ring 4 embedded in the outer side wall of the sealing bushing 5 respectively make sealing contact with the piston body 101 and the interior of the sleeve body 3.

[0048] A first limiting step is formed on the upper connector 1, and a second limiting step 23 is formed on the lower connector 24. The first limiting step and the second limiting step 23 are used to limit the two ends of the piston body 101, respectively.

[0049] The J-shaped groove includes several limiting grooves, one end of which is connected to the other end for the positioning pin 7 to pass through. The turning point between each two adjacent limiting grooves is a first inclined surface. An intermediate groove is formed on the side opposite to each first inclined surface. The turning point between two adjacent intermediate grooves is a second inclined surface 202, which is directly opposite the limiting groove.

[0050] The J-shaped groove includes a first limiting groove 201, a second limiting groove 203, a third limiting groove 204, and a fourth limiting groove 205. The length of the first limiting groove 201 is greater than the lengths of the second limiting groove 203, the third limiting groove 204, and the fourth limiting groove 205. The lengths of the second limiting groove 203, the third limiting groove 204, and the fourth limiting groove 205 are distributed in a stepped manner from short to long.

[0051] The flow bushing 18 has a first flow hole 51, a second flow hole 52 and a third flow hole 53. The connection and disconnection between the first flow hole 51, the second flow hole 52 and the third flow hole 53 and the oil inlet hole 19 and the interior of the bushing can be adjusted by the movement and rotation of the piston body 101 and the sleeve 200.

[0052] The outer wall of the flow bushing 18 is provided with a pin hole, and the flow bushing 18 is fixed in the sleeve body 3 by a pin 17 and the pin hole.

[0053] Figure 1 This diagram illustrates the downhole flow control device in its initial or closed state. The piston body 101 is at the rightmost end of the sleeve 3, and the leftmost end of the sleeve 200 on the piston body 101 is in contact with the positioning pin 7. The number of circumferential grooves in the J-shaped groove determines the opening degree of the downhole flow controller; the diagram shows 8 grooves. Using symmetrically arranged J-shaped groove positioning pins 7, 4 opening degrees can be achieved. Other numbers of circumferential grooves can achieve other opening degrees, but the number of openings in the flow bushing 18 needs to be adjusted accordingly, and the size of the openings in the flow bushing 18 can be adjusted according to production needs. At this time, the J-shaped groove, along with the piston body 101, is at the rightmost end of the sleeve 3, and the positioning pin 7 is at position a, the leftmost end of the J-shaped groove track. The rightmost end of the piston body 101 is in contact with the second limiting step 23, restricting the piston body from moving to the right. The locking tooth 10 is exactly at the position of the first locking groove 109 on the piston body 101, locking the piston body to achieve axial positioning. Simultaneously, the step of the sealing part on the piston body contacts the left end of the locking tooth 10, achieving redundant positioning. At this point, the left side of the piston body 101 is fully inserted into the mechanical seal ring 22, achieving bidirectional isolation between the internal and external well fluids.

[0054] like Figure 5 As shown, the process from the closed state to the fully open state is as follows:

[0055] When hydraulic oil is injected into the right-end cavity 9, that is... Figure 5 When hydraulic oil is pumped through the right end cavity oil port 2, right cavity oil passage 8, and right cavity inlet oil port 11, when the pressure is sufficiently high, the pressure acts on the right end face of the piston body 101, overcoming the friction of the sealing surface and the holding force of the retaining ring 12, pushing the piston assembly 100 to the left. The retaining teeth 10 open radially outward along the inclined surface of the first retaining groove 109, and the piston assembly 100 moves further to the left until the retaining teeth 10 are completely engaged with the outer surface of the piston body 101, and remain in contact with the outer surface of the piston body 101 as the piston body 101 moves. Figure 3On sleeve 200, the J-shaped groove moves to the left along with piston body 101 along with locating pin 7, from position a to b, until locating pin 7 contacts the second inclined surface c of the J-shaped groove. As sleeve 200 continues to move to the left, restricted by inclined surface c, sleeve 200 cannot move axially directly. Instead, under the restriction of locating pin 7, the second inclined surface c is in contact with sleeve 200. While continuing to move to the left, sleeve 200 rotates upward along the axial direction of piston body 101 (as shown in the diagram) and moves along the path from c to d until position d of sleeve 200 reaches the position of locating pin 7. At this point, locating pin 7 restricts sleeve 200 and piston body 101 from moving further to the left via the groove edge at d. Simultaneously, the left end of piston body 101 reaches the first limiting step on upper connector 1, restricting piston body 101 from moving to the left. To achieve circumferential isolation between the sleeve 200 and the piston body 101, the sleeve 200 is loosely fitted onto the piston body 101, and the steel ball 107 reduces circumferential friction. The right end of the J-shaped groove seat 106 and the right end of the sleeve 200 are made into an arc surface, with the diameter of the arc surface slightly smaller than the diameter of the steel ball, achieving a slight interference contact between the steel ball and the arc surface, increasing the resistance to movement and preventing the J-shaped groove from rotating freely on the steel ball, thus preventing over-rotation of the J-shaped groove. Simultaneously, to achieve axial positioning of the J-shaped groove, two semi-circular axial positioning sleeves 105 are used, with their right-end steps contacting the J-shaped groove seat 106 to prevent axial movement. The semi-circular axial positioning sleeves 105 are fitted onto the piston body 101 through an outer circular concave ring on the piston body. A retaining ring 104 is used to circumferentially restrict the radial displacement of the semi-circular axial positioning sleeves 105, and a retaining spring 103 is used to restrict the axial movement of the retaining ring 104. The dimensions ensure a slight axial interference fit between the semi-circular axial positioning sleeve 105, the J-shaped groove seat 106, the steel ball 107, and the sleeve 200.

[0056] When the piston assembly 100 moves to the left end of the cylinder, that is, when the piston assembly 100 is in the middle state, the piston body 101 is fully open, and the first flow hole 51, the second flow hole 52 and the third flow hole 53 on the flow bushing 18 are not blocked by the piston body 101, and the liquid inside and outside the oil sleeve can communicate.

[0057] like Figure 6 As shown, the working process from the intermediate state to the fully open state is as follows:

[0058] Hydraulic oil is injected again into the oil port 13 of the left end cavity of the sleeve. The hydraulic oil enters the left end cavity of the cylinder through the oil injection port 14 of the left end cavity. Figure 6When the pressure in the left end cavity is large enough to overcome the friction of the sealing surface and the holding force of the retaining ring 12, the piston body 101 is pushed to the right. At this time, the positioning pin 7 moves from position d in the J-shaped groove to the inclined surface e. As the piston body moves further to the right, the J-shaped groove rotates upward and moves to the right under the combined action of the positioning pin 7 and the inclined surface e. Until it enters the groove fg, the sleeve 200 stops rotating, but continues to move to the right along gf until f contacts the positioning pin 7. Restricted by f, the sleeve 200 can no longer move to the right, and at the same time, the retaining teeth 10 on the retaining ring 12 fall into the fourth retaining groove 112 on the piston body 101, achieving axial positioning. At this time, the first, second, and third flow holes on the flow bushing 18 are not blocked by the piston body 101, and the internal and external well fluids of the downhole flow control device communicate through the first, second, and third flow holes, that is, the downhole flow control device is fully open, i.e., opening degree 3. The circumferential positioning pin 7 keeps the first flow hole, the second flow hole, and the third flow hole circumferentially aligned with the oil inlet hole 19.

[0059] To achieve opening degree 1 from the closed state, pressure is applied to the right chamber of the hydraulic cylinder, causing the piston to move to the left limit, putting the flow control device in the middle state first. Then, pressure is applied to the left end of the hydraulic cylinder, causing the piston to enter the opening degree 3, i.e., the fully open position.

[0060] like Figure 7 As shown, to change the opening from 3 to 2, the procedure is as follows:

[0061] That is, pressure is applied to the right cavity 9 through the oil port 2 at the right end. When the pressure in the right cavity is sufficient to overcome the frictional resistance of the sealing surface and the force generated by the retaining teeth 10 on the retaining ring 12, the piston moves to the left, reaches the left limit, and enters the intermediate state, i.e., as shown. Figure 5 Under the constraint of the locating pin 7, the sleeve 200 moves axially from position f to g and then to h via the locating pin 7. After contacting the inclined plane h, it simultaneously moves axially to the left and rotates upwards, reaching i along h. At this time, the piston assembly 100 reaches the left limit position of the hydraulic cylinder. When hydraulic oil is injected into the left end cavity oil port 13 again, the hydraulic oil enters the left end of the hydraulic cylinder. When the pressure is large enough, the piston assembly 100 moves to the right until it reaches position opening 2, as shown. Figure 7As shown. At this time, the opening 2 (53) of the flow bushing and the opening 1 (54) of the flow bushing 18 open simultaneously, achieving an opening degree of 2. Under the restriction of the positioning pin 7, the sleeve 200 moves axially from position i to j through the positioning pin 7. After contacting the inclined surface j, it moves axially to the right and rotates upwards, moving along j to l, and then from l to k. After reaching k, it is limited by the left end contour of the k groove, and the J-shaped groove cannot continue to move to the right, that is, it reaches the position of opening degree 2. At the same time, the retaining teeth 10 on the retaining ring 12 fall into the third retaining groove 111 on the piston body 101, achieving axial positioning. At this time, the third flow hole 53 and the second flow hole 52 on the flow bushing 18 are not blocked by the piston body 101, and the internal and external well fluids of the downhole flow control device communicate through the third flow hole 53 and the fourth flow hole 54, that is, the opening degree 2 of the downhole flow control device is achieved.

[0062] like Figure 8 As shown, to change the opening from 2 to 1, the same steps are performed:

[0063] That is, pressure is applied to the right end of the hydraulic cylinder through the oil port 2 of the right end cavity. When the pressure in the right end cavity 9 is sufficient to overcome the frictional resistance of the sealing surface and the force generated by the retaining teeth 10 on the retaining ring 12, the piston assembly 100 moves to the left, reaches the left limit, and enters the intermediate state, i.e., as shown. Figure 5 Under the constraint of the locating pin 7, the sleeve 200 moves axially from position k to l and then to m via the locating pin 7. After contacting the second inclined plane m, it simultaneously moves axially to the left and rotates upwards, reaching n along the second inclined plane m. At this time, the piston assembly 100 reaches the left limit position of the cylinder, i.e., the middle position. When hydraulic oil is injected into the left end cavity oil port 13 again, the hydraulic oil enters the left end cavity. When the pressure is large enough, the piston assembly 100 moves to the right until it reaches position opening 1, as shown. Figure 7 As shown. At this time, the flow bushing opening 1, i.e., 54, opens, achieving an opening degree of 1. Under the constraint of the positioning pin 7, the sleeve 200 moves axially from position n to o through the positioning pin 7. After contacting the inclined plane o, it simultaneously moves axially to the right and rotates upward, moving along o to q, and then from q to p. After reaching p, the sleeve 200 cannot continue to move to the right due to the left end contour limit of the p groove, i.e., it reaches the position of opening degree 1. At the same time, the retaining teeth 10 on the retaining ring 12 fall into the second retaining groove 110 on the piston body, achieving axial positioning. At this time, the third flow hole 53 on the flow bushing 18 is not blocked by the piston body 101, and the internal and external well fluids of the downhole flow control device communicate through the third flow hole 53, i.e., achieving the opening degree 1 of the downhole flow control device.

[0064] To change the opening degree from 1 to fully closed, perform the same steps as above:

[0065] That is, pressure is applied to the right end of the cylinder through the oil port 2 of the right cavity. When the pressure in the right cavity is sufficient to overcome the frictional resistance of the sealing surface and the force generated by the claws on the retaining ring 12, the piston moves to the left, reaches the left limit, and enters the intermediate state, i.e. Figure 5 Under the constraint of the locating pin 7, the sleeve 200 moves axially from position p to q and then to r via the locating pin 7. After contacting the inclined plane r, it simultaneously moves axially to the left and rotates upwards, reaching s along r. At this time, the piston body 101 reaches the left limit position of the cylinder, i.e., the middle position. When hydraulic oil is injected into the left end cavity oil port 13 again, the hydraulic oil enters the left end of the cylinder. When the pressure is large enough, the piston assembly 100 moves to the right until it reaches the position opening degree 0, i.e., the fully closed state. Figure 8 As shown. At this time, the first, second, and third flow holes of the flow bushing are all blocked, and the piston assembly 100 is inserted along the inner hole of the mechanical seal ring 22 to achieve the isolation of the internal and external well fluids. Under the restriction of the positioning pin 7, the sleeve 200 moves axially from position s to t through the positioning pin 7. After contacting the inclined surface t, it moves axially to the right and rotates upwards, reaching b along t, and then moving axially from b to a. After reaching a, the sleeve 200 cannot continue to move to the right due to the left end contour limit of groove a, that is, it reaches the fully closed position. At the same time, the retaining teeth 10 on the retaining ring 12 fall into the first retaining groove 109 on the piston body 101 to achieve axial positioning. At this time, the first flow hole 51, second flow hole 52, and third flow hole 53 on the flow bushing 18 are blocked by the piston body 101, and the internal and external well fluids of the downhole flow control device cannot communicate, that is, the downhole flow control device is completely closed.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A J-shaped groove flow control device for linear motion, characterized in that, include: The cylinder body includes a sleeve, an upper connector, and a lower connector, with a cavity formed between the sleeve, the upper connector, and the lower connector. An oil inlet hole is provided on the sleeve near the lower connector. A piston assembly includes a piston body and a sleeve fitted over the piston body. The sleeve is rotatably fitted with the piston body. A J-shaped groove is formed on the outer side wall of the sleeve. The piston assembly is fitted over the sleeve and can move along the cylinder. A partition is formed in the middle of the piston body, which divides the cavity into a left end cavity and a right end cavity. A right cavity oil passage and a left cavity oil passage are formed on the side wall of the sleeve. The left cavity oil passage communicates with the left end cavity, and the right cavity oil passage communicates with the right end cavity. A positioning pin is fixed on the sleeve body, and the bottom of the positioning pin is inserted into the J-shaped groove. When the piston assembly moves, the positioning pin moves along the J-shaped groove. When the positioning pin reaches the end of the J-shaped groove, it can push the sleeve to rotate circumferentially. A flow bushing is fixedly fitted inside the sleeve body. The flow bushing is aligned with the oil inlet hole. The flow bushing is provided with a plurality of flow holes. The movement of the piston assembly can adjust the number of flow holes communicating with the oil inlet hole. The sleeve and the piston body are rotatably connected by a rotating assembly. The rotating assembly includes two J-shaped groove seats, a semi-circular axial positioning sleeve, a steel ball, a retaining spring, and a retaining ring. The two J-shaped groove seats are respectively fixedly installed at both ends of the sleeve. Both the J-shaped groove seats and the sleeve have arc-shaped surfaces on opposite sides. The steel ball is sandwiched in the arc-shaped surface, and the diameter of the arc-shaped surface is slightly smaller than the diameter of the steel ball. The J-shaped groove seat at one end is limited by the step formed by the partition, and the J-shaped groove seat at the other end is limited by the semi-circular axial positioning sleeve. The semi-circular axial positioning sleeve is fixedly sleeved on the piston body, and the retaining ring is fixedly sleeved on the semi-circular axial positioning sleeve. The retaining spring is also sleeved on the outside of the retaining ring. The retaining ring is used for circumferential limitation of the semi-circular axial positioning sleeve, and the retaining spring is used for axial limitation of the retaining ring.

2. The J-groove flow control device for linear motion according to claim 1, characterized in that, It also includes a claw mechanism, which includes a retaining ring and a retaining tooth connected to one end of the retaining ring. The claw mechanism is located in the right end cavity and is fixedly sleeved on the piston body. The piston body is provided with a number of slots that cooperate with the retaining tooth. When the piston body reaches the open position, the retaining tooth engages in the corresponding slot to achieve positioning.

3. The J-groove flow control device for linear motion according to claim 2, characterized in that, It also includes a retaining ring and at least two retaining ring seals. One end of the retaining ring abuts against the flow bushing, and the other end of the retaining ring abuts against the retaining ring. The retaining ring seals are fixedly embedded in the inner side wall of the retaining ring to achieve a sealing contact with the piston body, and the retaining ring seals are fixedly embedded in the outer side wall of the retaining ring to achieve a sealing contact with the inner wall of the sleeve.

4. The J-groove flow control device for linear motion according to claim 3, characterized in that, It also includes an axial sealing structure, which includes a sealing ring, an outer static seal, and a mechanical seal. One end of the mechanical seal abuts against the lower connector, and the other end abuts against the flow bushing through the sealing ring. The outer static seal is embedded in the inner wall of the sleeve and makes sealing contact with the mechanical seal.

5. The J-groove flow control device for linear motion according to claim 1, characterized in that, It also includes a sealing bushing and a piston sealing ring. The sealing bushing is fixedly sleeved in the sleeve body, and one end of the sealing bushing abuts against the upper connector. The piston sealing ring is fixedly embedded in the inner and outer side walls of the sealing bushing and makes sealing contact with the piston body and the interior of the sleeve body, respectively.

6. The J-groove flow control device for linear motion according to claim 1, characterized in that, A first limiting step is formed on the upper connector, and a second limiting step is formed on the lower connector. The first limiting step and the second limiting step are used to limit the piston body at both ends, respectively.

7. The J-groove flow control device for linear motion according to claim 1, characterized in that, The J-shaped groove includes several limiting grooves, one end of which is connected to the other end for the positioning pin to pass through. The turning point between each two adjacent limiting grooves is a first inclined surface. An intermediate groove is formed on the side opposite to each first inclined surface. The turning point between two adjacent intermediate grooves is a second inclined surface, which is directly opposite the limiting groove.

8. The J-groove flow control device for linear motion according to claim 7, characterized in that, The J-shaped groove includes a first limiting groove, a second limiting groove, a third limiting groove, and a fourth limiting groove. The length of the first limiting groove is greater than the lengths of the second, third, and fourth limiting grooves. The lengths of the second, third, and fourth limiting grooves are distributed in a stepped manner from shortest to longest.

9. The J-groove flow control device for linear motion according to claim 8, characterized in that, The outer wall of the flow bushing is provided with a pin hole, and the flow bushing is fixed in the sleeve body through the pin hole and the pin inserted in the pin hole.

10. The J-groove flow control device for linear motion according to claim 8, characterized in that, The J-shaped groove includes two sets, which are symmetrically arranged on the outer side wall of the sleeve. The positioning pin includes two pins, with each set of J-shaped grooves corresponding to one positioning pin.

Images