Gravel packing segmented sand-removing valve

Abstract

The invention relates to the technical field of open hole horizontal well gravel packing, and discloses a gravel packing segmented sand removal valve which particularly comprises a valve element of a cylindrical structure, a second through hole, a third through hole, a third through hole, a third through hole, a third through hole and a third through hole, and the bottom end of the valve element is closed; a flow channel top cover used for blocking the fifth through hole and a top cover spring used for restraining the flow channel top cover from being opened are arranged in the valve element, and when the external pressure of the fifth through hole is larger than the elastic force of the top cover spring, the fifth through hole is communicated. The valve body is of a variable-diameter cylindrical structure, and a first through hole is formed in the side wall of a small-diameter section; according to the gravel packing segmented sand-removing valve, the double-flow-channel design is adopted, when the liquid returning opening is opened, the inner hole of the lower flushing pipe is automatically blocked, the situation that a lower reservoir is polluted due to the fact that sand-carrying liquid flows to the toe end is avoided, when the pressure of the liquid returning opening is reduced, the valve element can be automatically reset, and the inner hole of the lower flushing pipe is opened again.

Description

Technical Field

[0001] This invention relates to the field of gravel packing technology for open-hole horizontal wells, and more specifically, to a gravel packing segmented sand removal valve. Background Technology

[0002] In open-hole horizontal well forward gravel circulation packing operations in the oil extraction field, during the transport of slurry in the annulus outside the screen pipe in the horizontal section, especially in the long horizontal section, it is very easy for sand to be prematurely desorbed due to factors such as wellbore collapse and maximum sand carrying distance, forming sand bridges, blocking the slurry transport channel, resulting in over-packing in the upper section and the formation of a packing deficit area in the lower section.

[0003] To improve filling efficiency, domestic and international experts and scholars have proposed segmented filling technology, using open-hole packers to separate the wellbore and filling it segment by segment, effectively reducing the adverse effects of sand bridges on filling efficiency. However, segmented filling technology has disadvantages, including: complex tool structure, requiring multiple filling valves to be installed on the sand-control outer tubing string, resulting in high tool design difficulty and manufacturing costs; complex operation procedures, requiring operators to have higher technical skills and experience; and high operational risks, as the opening and closing of each valve can become a potential point of failure.

[0004] To address the aforementioned issues, Chinese invention patent application number 201210534470.7 proposes a segmented desanding valve technology. Several desanding valves are installed at specified intervals on the flushing pipe, initially closed upon entry into the well. Their rubber sleeves, in conjunction with the sealing cylinder of the sand-control outer tubing string, divide the flushing annulus into several segments. Upon commencement of operations, the slurry is forced to be transported as far towards the toe as possible within the annulus outside the screen pipe, completing desanding first in the lowest segment. As the sand embankment accumulates towards the heel, the outer side of the lowest desanding valve is covered by gravel, creating a pressure difference across the rubber sleeve. Under this pressure difference, the desanding valve automatically opens, thus opening a new return port on the flushing pipe for the filling operation of the upper segment, significantly shortening the return path, effectively reducing bottomhole flowing pressure, minimizing sand-carrying fluid loss, and preventing reservoir fracturing. During the entire filling operation, the desanding valves of each section are opened sequentially from the toe to the heel, completing the filling of each well section from bottom to top in sequence. Therefore, this technology has both the simplicity of general filling and the high filling efficiency of segmented filling.

[0005] However, existing segmented sand removal valve technology still has shortcomings, including: 1. The inability to seal the lower flushing pipe inner hole while opening the return port causes the sand-carrying liquid to flow towards the toe end after entering the flushing pipe inner hole through the sand removal valve, thus squeezing into the lower reservoir and causing pollution. 2. The valve cannot be closed again after filling, so subsequent processes such as positive circulation to replace the adhesive, extruding biological enzymes, and extruding acid cannot be carried out.

[0006] Therefore, how to solve the problem that the existing segmented desanding valve cannot seal the inner hole of the lower flushing pipe while the return port is open, causing the sand-carrying liquid to flow to the toe end and thus contaminating the lower reservoir, and that the return port cannot be closed again after filling is completed, affecting subsequent operations, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a gravel filling segmented sand removal valve, which adopts a dual-channel design. When the return port is open, it automatically seals the inner hole of the lower flushing pipe to prevent the sand-carrying liquid from flowing to the toe end and causing pollution of the lower reservoir. When the pressure of the return port drops, it automatically closes. When the positive flushing pressure increases, the valve core can automatically reset and open the inner hole of the lower flushing pipe again.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A gravel-filled segmented sand removal valve includes: The valve core has a cylindrical structure and is closed at the bottom. A fifth through hole is provided on the upper side wall and a third through hole is provided on the lower side wall. The valve core is provided with a flow channel top cover for blocking the fifth through hole and a top cover spring for inhibiting the opening of the flow channel top cover. When the external pressure of the fifth through hole is greater than the elastic force of the top cover spring, the fifth through hole is open. The valve body is a cylindrical structure with a variable diameter, including a small-diameter section and a large-diameter section. A first through hole is provided on the side wall of the small-diameter section. The valve core is slidably and sealingly installed in the small-diameter section of the valve body. When the valve core is at the end of the first sliding stroke, the third through hole is located in the large-diameter section and communicates with the inner cavity of the large-diameter section. The first through hole and the fifth through hole do not overlap. When the valve core is at the end of the second sliding stroke, the third through hole is located in the small-diameter section and is blocked by the inner wall of the small-diameter section. The first through hole and the fifth through hole communicate.

[0009] Preferably, the valve core is composed of a dual-channel pipe coaxially fixed and inner sleeved on a switch sleeve; the bottom end of the dual-channel pipe is sealed, and the third through hole is provided on the lower side wall of the dual-channel pipe; the third through hole, the inner cavity of the dual-channel pipe and the inner cavity of the switch sleeve are connected to form an inner flow channel. The upper end of the dual-channel pipe is provided with an outer ring fixing protrusion that is fixed to the switch sleeve. A fourth through hole is provided inside the outer ring fixing protrusion, and the center line of the fourth through hole is parallel to the center line of the dual-channel pipe. A first annular space, closed at both ends, appears between the switch sleeve and the upper half of the pipe wall of the dual-channel pipe. The fifth through hole is provided on the side wall of the switch sleeve. The inner cavity of the switch sleeve, the fourth through hole, the first annular space, and the fifth through hole are connected to form an outer flow channel.

[0010] Preferably, the flow channel top cover is slidably installed inside the switch sleeve, the lower end of the flow channel top cover blocks the fourth through hole, and a top cover spring is provided inside the switch sleeve to inhibit the sliding of the flow channel top cover.

[0011] Preferably, the valve body is composed of a sliding sleeve base coaxially fixed inside the outer cylinder, and the sliding sleeve base is a variable diameter sleeve including a large diameter section and a small diameter section. The lower half of the dual-channel pipe slides and seals against the inner wall of the small-diameter section of the sliding sleeve base. When the valve core is at the end of the first stroke of the slide, the first through hole and the fifth through hole are misaligned and blocked, and the third through hole extends into the inner cavity of the large-diameter section of the sliding sleeve base, that is, the inner flow channel is open and the outer flow channel is closed. The first through hole is provided on the side wall of the outer cylinder. When the valve core is at the second stroke end point of the sliding, the first through hole is connected to the first annulus, and the third through hole is blocked by the inner wall of the small diameter section of the sliding sleeve base, that is, the outer flow channel is connected and the inner flow channel is cut off.

[0012] Preferably, a locking component is provided between the valve core and the valve body to prevent them from sliding relative to each other; A sliding spring is provided between the valve core and the valve body to prevent relative sliding between them; When the valve core is at the end of the first stroke of the slide, the locking assembly is in the locked state and the sliding sleeve spring is in the compressed and stored state. When the valve core is at the end of the second stroke of the sliding motion, the locking assembly is in the unlocked state and the sliding sleeve spring is in the natural state.

[0013] Preferably, a second annular space with its lower end closed is formed between the small-diameter section of the sliding sleeve base and the tube wall of the outer cylinder, and the switch sliding sleeve is inserted into the second annular space from the upper end, and the switch sliding sleeve closes the upper end of the second annular space; The locking assembly includes an unlocking piston that is slidably and sealingly installed in the second annulus, a piston spring that inhibits the sliding of the unlocking piston, a locking through hole that penetrates the side wall of the switch sleeve, a locking ball receiving groove and a locking steel ball that are disposed on the outer wall of the sleeve base. The unlocking piston can push the locking steel ball to be simultaneously accommodated in the locking through hole and the locking ball receiving groove, thereby limiting the relative movement of the sliding sleeve base and the switch sliding sleeve.

[0014] Preferably, the diameter of the locking steel ball is greater than the wall thickness of the switch sleeve, and the locking steel ball is accommodated within the locking through hole; The inner wall of the unlocking piston is provided with an unlocking ring groove; When the unlocking piston moves to the point where the unlocking ring groove overlaps with the locking through hole, the locking steel ball can be simultaneously accommodated in both the unlocking ring groove and the locking through hole.

[0015] Preferably, the outer cylinder has a second through hole on its side wall, and the sliding sleeve base has a sixth through hole on its side wall of the small diameter section. The sixth through hole can simultaneously connect the inner flow channel and the second annulus. The second through hole and the sixth through hole are respectively connected to the second annulus at both ends of the unlocking piston. When the sum of the pressure at the sixth through hole and the elastic force of the piston spring is greater than the pressure at the second through hole, the unlocking piston moves to the end of the first stroke to lock the sliding sleeve base and the switch sliding sleeve. When the sum of the pressure at the sixth through hole and the elastic force of the piston spring is less than the pressure at the second through hole, the unlocking piston moves to the second stroke end point to unlock the sliding sleeve base and the switch sliding sleeve.

[0016] Preferably, when the valve core is at the end of the first stroke, the third through hole communicates only with the inner cavity of the large-diameter section of the sliding sleeve base; when the valve core is at the end of the second stroke, the third through hole communicates only with the sixth through hole.

[0017] Preferably, a spring base is provided inside the second annular cavity, the spring base is fixedly connected to the switch sliding sleeve, and the two ends of the piston spring abut against the unlocking piston and the spring base, respectively.

[0018] Preferably, a rubber sleeve is coaxially fixedly connected to the lower end of the sliding sleeve base, and a number of rubber sleeves are arranged at intervals on the outer wall of the rubber sleeve, with a spacer ring between two adjacent groups of rubber sleeves.

[0019] Preferably, a lower connector is coaxially fixed at the lower end of the rubber sleeve, the lower end of the lower connector is provided with an external thread on its outer wall, and the upper end of the outer cylinder is provided with an internal thread on its inner wall.

[0020] The gravel-filled segmented sand removal valve provided by this invention has at least the following advantages compared with the prior art: 1. The fifth through hole at the upper end of the valve core and the first through hole on the valve body are used to achieve the flow of the return port and allow for the return of liquid. When the fifth through hole and the first through hole are connected, the third through hole on the lower side wall of the valve core is blocked by the inner wall of the valve body, which blocks the inner hole of the lower flushing pipe and prevents the sand-carrying liquid from flowing to the toe end. 2. By setting a flow channel top cover at the fifth through hole, the return port can be automatically closed when the pressure drops due to the action of the top cover spring. Forward flushing can cause the valve core to reset, thereby opening the inner hole of the lower flushing pipe again without affecting subsequent operations. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the specific gravel filling segmented sand removal valve provided by the present invention; Figure 2 Provided by the present invention Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the specific outer cylinder provided by the present invention; Figure 4 This is a schematic diagram of the specific dual-channel pipe structure provided by the present invention; Figure 5 This is a schematic diagram of the structure of the specific switch sleeve provided by the present invention; Figure 6 This is a schematic diagram of the specific unlocking piston provided by the present invention; Figure 7 This is a schematic diagram of the specific sliding sleeve base provided by the present invention; Figure 8 This is a schematic diagram of the specific top ring provided by the present invention.

[0023] Figures 1-8 middle: 1. Outer cylinder; 101. First through hole; 102. Second through hole; 103. Inner ring sealing protrusion; 2. Top ring; 201. Wrench groove; 3. Flow channel top cover; 4. Dual-channel through pipe; 401. Third through hole; 402. Fourth through hole; 403. Outer ring fixing protrusion; 5. Switch sleeve; 501. Fifth through hole; 502. Locking through hole; 503. Outer ring sealing protrusion; 6. Unlock the piston; 601. Unlock the ring groove; 7. Spring base; 8. Sliding sleeve base; 801. Sixth through hole; 802. Locking ball receiving groove; 9. Rubber sleeve; 10. Rubber sleeve; 11. Spacer ring; 12. Lower connector; 13. Sliding sleeve spring; 14. Top cover spring; 15. Locking steel ball; 16. Piston spring; 17. First ring empty; 18. Second annular space; 19. Valve body; 20. Valve core. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The core of this invention is to provide a gravel-filled segmented sand removal valve, which adopts a dual-channel design. When the return port is open, it automatically seals the inner hole of the lower flushing pipe to prevent sand-carrying liquid from flowing to the toe end and to prevent contamination of the lower reservoir. It also automatically closes when the pressure of the return port drops. When the positive flushing pressure increases, the valve core can automatically reset and open the inner hole of the lower flushing pipe again.

[0026] Please refer to Figures 1-8 A gravel-filled segmented sand removal valve, comprising: The valve core 20 has a cylindrical structure and is closed at the bottom. The upper side wall is provided with a fifth through hole 501 and the lower side wall is provided with a third through hole 401. The valve core 20 is provided with a flow channel top cover 3 for blocking the fifth through hole 501 and a top cover spring 14 for inhibiting the opening of the flow channel top cover 3. When the external pressure of the fifth through hole 501 is greater than the elastic force of the top cover spring 14, the fifth through hole 501 is opened. The valve body 19 is a cylindrical structure with a variable diameter, including a small diameter section and a large diameter section. The side wall of the small diameter section is provided with a first through hole 101. The valve core 20 is slidably and sealingly installed in the small diameter section of the valve body 19. When the valve core 20 is at the end of the first sliding stroke, the third through hole 401 is in the large diameter section and communicates with the inner cavity of the large diameter section. The first through hole 101 and the fifth through hole 501 do not overlap. When the valve core 20 is at the end of the second sliding stroke, the third through hole 401 is in the small diameter section and is blocked by the inner wall of the small diameter section. The first through hole 101 and the fifth through hole 501 communicate.

[0027] Before the open-hole horizontal well forward circulation gravel packing operation, the gravel packing segment desanding valve (hereinafter referred to as desanding valve) is alternately connected with the flushing pipe to form the packing service inner string (hereinafter referred to as inner string); the sand filter pipe and the sealing cylinder are alternately connected to form the sand control packing outer string (hereinafter referred to as outer string); the inner string is placed inside the outer string, and then the combination of the inner string and the outer string is run into the well; During the positive circulation tubing replacement process, the washing fluid is injected into the inner tubing from the wellhead. At this time, the internal flow channels of each desanding valve are open, and the washing fluid can directly reach the toe and then flow out from the float at the end of the outer tubing. It then flows back up along the annulus between the outer tubing and the open hole wall to replace the residual drilling fluid in the annulus. During the gravel filling operation, the slurry is transported forward through the top filling tool into the annulus between the outer tubing and the open hole wall. The rubber sleeve 10 of the desanding valve, together with the sealing sleeve of the outer tubing, divides the annulus between the outer tubing and the inner tubing into several sections. After the operation begins, the slurry is forced to be transported as far towards the toe as possible in the annulus to prevent the formation of sand bridges in the middle of the horizontal section.

[0028] Multiple desanding valves installed on the flushing pipe are named sequentially from the toe end to the heel end as first desanding valve, second desanding valve, third desanding valve, etc. From the toe end to the heel end, the pipe is divided into first section, second section, third section, etc., with the desanding valves as the dividing points. When the β wave is laid from the toe end to the heel end and reaches the outside of the first desanding valve, the outer flow channel of the first desanding valve is opened, and the sand-carrying fluid enters the inner cavity of the inner tubing through the outer flow channel and is finally discharged from the wellhead.

[0029] Before the first desanding valve is opened, the gravel filling of the first well section is completed. After the first desanding valve is opened, a new return fluid port is established at the location of the flushing pipe, and the gravel filling of the second well section continues. During this process, the gravel filling process between the first and second well sections is automatically and seamlessly connected. In this way, each desanding valve is opened in sequence, and finally the gravel filling of each well section is completed.

[0030] It is worth noting that at the instant the first desanding valve opens, that is, the pressure difference Δ formed between the sixth through hole 801 and the second through hole 102 of the first desanding valve... P When the force of the piston spring 16 is sufficient to overcome the spring force, a pressure difference Δ is also formed between the sixth through hole 801 and the second through hole 102 of the second sand removal valve. P 2, and Δ P 2 is slightly greater than Δ P 1. Therefore, the spring force of the piston spring 16 of the second desanding valve is greater than that of the piston spring 16 of the first desanding valve to prevent the second desanding valve from opening prematurely.

[0031] Similarly, the spring force of the piston spring 16 of the third sand removal valve is greater than that of the piston spring of the second sand removal valve.

[0032] In the positive circulation replacement of adhesive liquid, the valve core 20 of each desanding valve is required to be reset, that is, to close the return port and open the internal flow channel of the desanding valve, that is, to restore the state of the desanding valve to the state of the positive circulation replacement of the outer slurry.

[0033] At this point, high-pressure de-gumming liquid is injected into the inner cavity of the inner tubing. Each sand removal valve sequentially opens the inner flow channel from the heel end to the toe end until the de-gumming liquid is injected into the toe end through the inner tubing. At this time, the flow path of the desanding valve is as follows: when the high-pressure desanding liquid is injected, the pressure at the fifth through hole 501 drops, the top cover 3 of the flow path resets, and the fifth through hole 501 is blocked. As the pressure in the inner cavity of the inner tube increases, the valve core 20 resets, and the third through hole 401 is opened, that is, the inner cavity of the inner tube is opened again. The desanding liquid reaches the end outlet through the inner cavity of the inner tube. With the operation of slowly lifting the inner tube, the desanding liquid is squeezed into the gravel filling strip laid on the outside of the outer tube, thereby degrading the residual gelling agent in the filling strip and realizing more compact settlement of the gravel.

[0034] During this process, the relative movement of the valve core 20 and the valve body 19 enables the switching between the first through hole 101 and the fifth through hole 501, as well as the switching between the third through hole 401. The switching between the two is opposite and cannot be switched at the same time. That is, when the return port is open, the inner hole of the flushing pipe is automatically closed to prevent the sand-carrying liquid from flowing to the toe end and causing contamination of the toe end.

[0035] In some embodiments, the valve core 20 is composed of a dual-channel pipe 4 coaxially fixed and inner sleeved on the switch sleeve 5; the bottom end of the dual-channel pipe 4 is sealed, and a third through hole 401 is provided on the lower side wall of the dual-channel pipe 4. The third through hole 401, the inner cavity of the dual-channel pipe 4 and the inner cavity of the switch sleeve 5 are connected to form an inner channel. like Figure 4 As shown, the upper end of the dual-channel pipe 4 is provided with an outer ring fixing protrusion 403 that is fixed to the switch sliding sleeve 5. The outer ring fixing protrusion 403 is provided with a through fourth through hole 402. The center line of the fourth through hole 402 is parallel to the center line of the dual-channel pipe 4. A first annular space 17 with both ends closed appears between the switch sleeve 5 and the upper half of the pipe wall of the dual-channel pipe 4. The fifth through hole 501 is set on the side wall of the switch sleeve 5. The inner cavity of the switch sleeve 5, the fourth through hole 402, the first annular space 17, and the fifth through hole 501 are connected to form an outer flow channel. like Figure 1 and Figure 5 As shown, the outer wall of the switch sleeve 5 is provided with an outer ring sealing protrusion 503. The outer ring sealing protrusion 503 slides and seals with the inner wall of the outer cylinder 1 through a rubber ring, so that the first annular cavity 17 has good sealing performance when it is not connected with the first through hole 101. Furthermore, the separation of the inner and outer flow channels is achieved through the fourth through hole 402 at the upper end of the dual-flow pipe 4 and the third through hole 401 on the lower side wall. The switching between the inner flow channel and the outer flow channel is achieved through the relative movement of the dual-flow pipe 4 and the sliding sleeve base 8. The switching between the outer flow channel and the outer flow channel is achieved through the relative movement of the switching sleeve 5 and the outer cylinder 1. When the inner flow channel is open, the first through hole 101 and the fifth through hole 501 are misaligned, that is, the outer flow channel is closed. When the outer flow channel is open, the third through hole 401 is blocked by the inner wall of the sliding sleeve base 8, that is, the inner flow channel is closed. Thus, the mutual switching between the inner and outer flow channels is realized.

[0036] In some embodiments, the flow channel top cover 3 is slidably installed in the switch sleeve 5, the lower end of the flow channel top cover 3 blocks the fourth through hole 402, and the switch sleeve 5 is provided with a top cover spring 14 to suppress the sliding of the flow channel top cover 3. In some embodiments, the centerline of the fourth through hole 402 is the radial direction of the dual-channel pipe 4, that is, the flow channel top cover 3 is set on the inner wall of the dual-channel pipe 4 and supported by a radial spring, or a ring-shaped rubber ring is directly used as the flow channel top cover 3 to block the fourth through hole 402. The external pressure of the fourth through hole 402 causes the rubber ring to change, thereby opening the fourth through hole 402. In this embodiment, the center line of the fourth through hole 402 is parallel to the center line of the dual flow channel pipe 4, that is, the flow channel top cover 3 can be arranged at the end of the dual flow channel pipe 4. Moreover, the center line of the top cover spring 14 is also parallel to the center line of the dual flow channel pipe 4, which facilitates assembly and helps to improve the stability of the equipment.

[0037] In some embodiments, to further improve assembly convenience, the top end of the switch sleeve 5 is fixed with a top ring 2 via a threaded connection, which abuts against the top cover spring 14 and the sleeve spring 13, such as... Figure 8 As shown, a wrench groove 201 is provided on the upper inner wall of the top ring 2 to facilitate tightening of the top ring 2 from the top.

[0038] In some embodiments, the valve body 19 is composed of a sliding sleeve base 8 coaxially fixed inside the outer cylinder 1, and the sliding sleeve base 8 is a variable diameter sleeve including a large diameter section and a small diameter section. The lower half of the dual-channel pipe 4 slides and seals with the inner wall of the small-diameter section of the sliding sleeve base 8. When the valve core 20 is at the end of the first stroke of the sliding, the first through hole 101 and the fifth through hole 501 are misaligned and blocked, and the third through hole 401 extends into the inner cavity of the large-diameter section of the sliding sleeve base 8, that is, the inner flow channel is open and the outer flow channel is closed. The first through hole 101 is provided on the side wall of the outer cylinder 1. When the valve core 20 is at the end of the second stroke of the sliding, the first through hole 101 is connected to the first annulus 17, and the third through hole 401 is blocked by the inner wall of the small diameter section of the sliding sleeve base 8, that is, the outer flow channel is connected and the inner flow channel is cut off.

[0039] like Figure 3 As shown, the inner walls of both the upper and lower ends of the first through hole 101 are provided with inner ring sealing protrusions 103, which slide and seal with the outer wall of the switch sleeve 5 through the rubber ring, thereby improving the sealing performance of the first through hole 101 when the external flow channel is not open; at the same time, the upper and lower ends of the outer cylinder 1 are provided with internal threads, the upper end is used to connect the punch pipe, and the lower end is used to connect with the outer wall of the large diameter section of the sleeve base 8. like Figure 7 As shown, the sliding sleeve base 8 is a variable diameter sleeve. The small diameter section is inserted into the outer cylinder 1, and the outer wall of the lower end of the large diameter section is provided with external threads for connecting the rubber sleeve 9 below. Meanwhile, several sets of rubber rings are provided on the inner wall of the sliding sleeve base 8 to increase the sealing between its inner wall and the outer wall of the dual-channel pipe 4.

[0040] In some embodiments, a locking component is provided between the valve core 20 and the valve body 19 to prevent them from sliding relative to each other; A sliding spring 13 is provided between the valve core 20 and the valve body 19 to prevent them from sliding relative to each other; When the valve core 20 is at the end of the first stroke of the slide, the locking assembly is in the locked state and the sliding sleeve spring 13 is in the compressed and stored state. When the valve core 20 is at the end of the second stroke of the slide, the locking assembly is in the unlocked state and the sliding sleeve spring 13 is in the natural state.

[0041] like Figure 1 and Figure 2 As shown, during the placement of the inner tube column, some vibration is inevitable, which will affect the relative position of the valve core 20 and the valve body 19. When the sand removal valve is placed, the internal flow channel is in the open state by default. If the relative position of the valve core 20 and the valve body 19 changes, it will inevitably affect the conduction state of the sand removal valve. Therefore, adding a locking component between the two helps to ensure the stability of the conduction state of the sand removal valve. In conjunction with the locking assembly, a sliding spring 13 is added as the power source for the relative movement of the valve core 20 and the valve body 19. In the initial state, the sliding spring 13 is in a compressed and energy-storing state. When the locking assembly is unlocked, the sliding spring 13 can drive the valve core 20 to move relative to the valve body 19, thereby realizing the change of the sand removal valve's conduction state.

[0042] In some embodiments, a second annular cavity 18 with its lower end closed is formed between the small diameter section of the sliding sleeve base 8 and the tube wall of the outer cylinder 1. The switch sliding sleeve 5 is inserted into the second annular cavity 18 from the upper end, and the switch sliding sleeve 5 closes the upper end of the second annular cavity 18. The locking assembly includes an unlocking piston 6 that is slidably sealed in the second annulus 18, a piston spring 16 that inhibits the sliding of the unlocking piston 6, a locking through hole 502 that penetrates the side wall of the switch sleeve 5, a locking ball receiving groove 802 and a locking steel ball 15 that are provided on the outer wall of the sleeve base 8. The unlocking piston 6 can push the locking steel ball 15 to be simultaneously accommodated in the locking through hole 502 and the locking ball receiving groove 802, in order to limit the relative movement of the sliding sleeve base 8 and the switch sliding sleeve 5; like Figure 2 As shown, by utilizing the movement of the locking steel ball 15 within the locking through hole 502, when it is simultaneously accommodated within the locking ball receiving groove 802, the locking of the sliding sleeve base 8 and the switch sliding sleeve 5 can be completed, that is, the locking of the valve core 20 and the valve body 19 can be completed. At the same time, the unlocking piston 6 blocks the locking through hole 502 from the other end, thereby preventing the locking steel ball 15 from disengaging and thus stabilizing the locking of the locking assembly.

[0043] In some embodiments, the diameter of the locking steel ball 15 is greater than the wall thickness of the switch sleeve 5, and the locking steel ball 15 is accommodated in the locking through hole 502. like Figure 6 As shown, the inner wall of the unlocking piston 6 is provided with an unlocking ring groove 601; When the unlocking piston 6 moves to the point where the unlocking ring groove 601 overlaps with the locking through hole 502, the locking steel ball 15 can be accommodated in both the unlocking ring groove 601 and the locking through hole 502. When the unlocking piston 6 is activated, the blockage of the locking through hole 502 is removed, the locking steel ball 15 disengages from the locking ball receiving groove 802, thereby unlocking, and the relative movement of the switch sleeve 5 and the sleeve base 8 is no longer restricted.

[0044] In some embodiments, the side wall of the outer cylinder 1 is provided with a second through hole 102, and the side wall of the small diameter section of the sliding sleeve base 8 is provided with a sixth through hole 801. The sixth through hole 801 can simultaneously connect the inner flow channel and the second annulus 18. The second through hole 102 and the sixth through hole 801 are respectively connected to the second annulus 18 at both ends of the unlocking piston 6. When the sum of the pressure at the sixth through hole 801 and the elastic force of the piston spring 16 is greater than the pressure at the second through hole 102, the unlocking piston 6 moves to the end of the first stroke to lock the anti-slip sleeve base 8 and the switch sleeve 5. When the sum of the pressure at the sixth through hole 801 and the elastic force of the piston spring 16 is less than the pressure at the second through hole 102, the unlocking piston 6 moves to the second stroke end point to unlock the sliding sleeve base 8 and the switch sliding sleeve 5.

[0045] When the valve core 20 is at the end of the first stroke, the third through hole 401 communicates only with the inner cavity of the large-diameter section of the sliding sleeve base 8; when the valve core 20 is at the end of the second stroke, the third through hole 401 communicates only with the sixth through hole 801. By setting a second through hole 102 to connect the annulus between the inner and outer tubing, and a sixth through hole 801 to connect the inner cavity of the inner tubing, the movement direction of the unlocking piston 6 is determined by comparing the pressure in the annulus and the inner cavity of the inner tubing. That is, it moves towards the low-pressure end. This allows the sand removal valve to automatically open the outer flow channel and close the inner flow channel when the pressure at the return port increases to a level greater than the pressure in the inner cavity of the inner tubing, so that the sand-carrying fluid can quickly flow back to the wellhead through the inner cavity of the inner tubing.

[0046] In some embodiments, a spring base 7 is provided inside the second annular cavity 18. The spring base 7 is fixedly connected to the switch sliding sleeve 5, and the two ends of the piston spring 16 abut against the unlocking piston 6 and the spring base 7 respectively. By setting the spring base 7, when the switch sleeve 5 slides upward, the spring base 7 slides upward synchronously, and the deformation of the piston spring 16 further increases, so that the unlocking piston 6 has a certain reverse movement tendency. When the pressure of the inner tube increases and the above-mentioned annular pressure decreases, the piston spring 16 can provide a certain driving force for the switch sleeve 5 to slide downward, and can also provide a certain driving force for the unlocking piston 6 to reset.

[0047] In some embodiments, a rubber sleeve 9 is coaxially fixedly connected to the lower end of the sliding base 8, and a number of rubber sleeves 10 are spaced apart on the outer wall of the rubber sleeve 9, with a spacer ring 11 between two adjacent sets of rubber sleeves 10. When implementing gravel filling in open-hole horizontal wells, it is necessary to cut off the annulus between the inner and outer tubing strings. At this time, the rubber sleeve 10 is used in conjunction with the inner wall of the sealing cylinder to achieve a seal. When the β wave is just laid to the outside of the desanding valve at the current position, the pressure outside the return port rises rapidly, which facilitates the rapid opening of the external flow channel of the desanding valve, so that the sand-carrying fluid enters the inner cavity of the inner tubing string through the desanding valve for return. In some embodiments, a lower connector 12 is coaxially fixedly provided at the lower end of the rubber sleeve 9, and the lower outer wall of the lower connector 12 is provided with an external thread, while the upper inner wall of the outer cylinder 1 is provided with an internal thread. Internal or external threads are provided at both ends of the valve body 19 to facilitate connection with the flushing pipe.

[0048] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0049] The gravel-filled segmented sand removal valve provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A gravel pack sand screen valve characterized by, It includes: The valve core (20) is a cylindrical structure, and the bottom end is closed, and the fifth through hole (501) is arranged on the side wall of the upper end, and the third through hole (401) is arranged on the side wall of the lower end; the valve core (20) is provided with a flow channel top cover (3) for blocking the fifth through hole (501), and a top cover spring (14) for inhibiting the opening of the flow channel top cover (3); when the external pressure of the fifth through hole (501) is greater than the elastic force of the top cover spring (14), the fifth through hole (501) is conducted. The valve body (19) is a variable diameter cylindrical structure including a small diameter section and a large diameter section, and the side wall of the small diameter section is provided with a first through hole (101); the valve core (20) is slidably and sealingly installed in the small diameter section of the valve body (19); when the valve core (20) is at the sliding first stroke endpoint, the third through hole (401) is in the large diameter section and is in communication with the inner cavity of the large diameter section, and the first through hole (101) and the fifth through hole (501) are not overlapped; when the valve core (20) is at the sliding second stroke endpoint, the third through hole (401) is in the small diameter section and is blocked by the inner wall of the small diameter section, and the first through hole (101) and the fifth through hole (501) are in communication.

2. The gravel pack sand screen valve of claim 1, wherein, The valve core (20) is coaxially fixed in the switch sleeve (5) by a double-flow passage pipe (4); the bottom end of the double-flow passage pipe (4) is sealed, the third through hole (401) is arranged on the lower end side wall of the double-flow passage pipe (4), and the third through hole (401), the inner cavity of the double-flow passage pipe (4) and the inner cavity of the switch sleeve (5) are communicated to form an inner flow channel; The upper end of the double-flow passage pipe (4) is externally provided with an outer ring fixed protrusion (403) fixed with the switch sleeve (5), the outer ring fixed protrusion (403) is internally provided with a penetrating fourth through hole (402), and the center line of the fourth through hole (402) is parallel to the center line of the double-flow passage pipe (4); The switch sleeve (5) and the pipe wall of the upper half of the double-flow passage pipe (4) form a first annular space (17) with two closed ends, the fifth through hole (501) is arranged on the side wall of the switch sleeve (5), and the inner cavity of the switch sleeve (5), the fourth through hole (402), the first annular space (17) and the fifth through hole (501) are communicated to form an outer flow channel.

3. The gravel pack sand screen valve of claim 2, wherein, The flow channel top cover (3) is slidably installed in the switch sleeve (5), the lower end of the flow channel top cover (3) blocks the fourth through hole (402), and the switch sleeve (5) is provided with a top cover spring (14) for inhibiting the sliding of the flow channel top cover (3).

4. The gravel pack sand screen valve of claim 2, wherein, The valve body (19) is coaxially fixed in the outer cylinder (1) by a sleeve base (8), and the sleeve base (8) is a variable diameter sleeve including a large diameter section and a small diameter section; The lower half of the double-flow passage pipe (4) is in sliding seal with the inner wall of the small-diameter section of the sliding sleeve base (8), when the valve core (20) is at the sliding first stroke endpoint, the first through hole (101) and the fifth through hole (501) are in staggered blockage, the third through hole (401) extends into the large-diameter section inner cavity of the sliding sleeve base (8), that is, the inner flow passage is conducted, and the outer flow passage is cut off; The first through hole (101) is arranged on the side wall of the outer cylinder (1), when the valve core (20) is at the sliding second stroke endpoint, the first through hole (101) is in conduction with the first annular space (17), and the third through hole (401) is blocked by the inner wall of the small-diameter section of the sliding sleeve base (8), that is, the outer flow passage is conducted, and the inner flow passage is cut off.

5. The gravel pack sand screen valve of claim 4, wherein, A locking assembly is arranged between the valve core (20) and the valve body (19) to lock the relative sliding of the two; A sliding sleeve spring (13) is arranged between the valve core (20) and the valve body (19) to inhibit the relative sliding of the two; When the valve core (20) is at the sliding first stroke endpoint, the locking assembly is in a locked state, and the sliding sleeve spring (13) is in a compressed energy storage state; When the valve core (20) is at the sliding second stroke endpoint, the locking assembly is in an unlocked state, and the sliding sleeve spring (13) is in a natural state.

6. The gravel pack sand screen valve of claim 5 wherein, The small-diameter section of the sliding sleeve base (8) and the pipe wall of the outer cylinder (1) form a second annular space (18) with a closed lower end, the switch sliding sleeve (5) is inserted into the second annular space (18) from the upper end, and the switch sliding sleeve (5) closes the upper end of the second annular space (18); The locking assembly includes an unlocking piston (6) slidingly sealed in the second annular space (18), a piston spring (16) inhibiting the sliding of the unlocking piston (6), a locking through hole (502) penetrating through the side wall of the switch sliding sleeve (5), a locking ball accommodating groove (802) and a locking steel ball (15) arranged on the outer wall of the sliding sleeve base (8); The unlocking piston (6) can push the locking steel ball (15) while being accommodated in the locking through hole (502) and the locking ball accommodating groove (802), for limiting the relative movement of the sliding sleeve base (8) and the switch sliding sleeve (5).

7. The gravel pack sand screen valve of claim 6 wherein, The ball diameter of the locking steel ball (15) is greater than the wall thickness of the switch sliding sleeve (5), and the locking steel ball (15) is accommodated in the locking through hole (502); The inner wall of the unlocking piston (6) is provided with an unlocking ring groove (601); When the unlocking piston (6) moves to the position where the unlocking ring groove (601) overlaps with the locking through hole (502), the locking steel ball (15) can be simultaneously accommodated in the unlocking ring groove (601) and the locking through hole (502).

8. The gravel pack sand screen valve of claim 7 wherein, The side wall of the outer cylinder (1) is provided with a second through hole (102), the side wall of the small diameter section of the sliding sleeve base (8) is provided with a sixth through hole (801), the sixth through hole (801) can simultaneously communicate the inner flow channel and the second annular space (18), the second through hole (102) and the sixth through hole (801) respectively communicate the second annular space (18) at both ends of the unlocking piston (6); When the sum of the pressure at the sixth through hole (801) and the elastic force of the piston spring (16) is greater than the pressure at the second through hole (102), the unlocking piston (6) moves to the first stroke end point, for locking the sliding sleeve base (8) and the switch sliding sleeve (5); When the sum of the pressure at the sixth through hole (801) and the elastic force of the piston spring (16) is less than the pressure at the second through hole (102), the unlocking piston (6) moves to the second stroke end point, for unlocking the sliding sleeve base (8) and the switch sliding sleeve (5).

9. The gravel pack sand screen valve of claim 8 wherein, When the valve core (20) is at the first stroke end point, the third through hole (401) only communicates with the large diameter section inner cavity of the sliding sleeve base (8); when the valve core (20) is at the second stroke end point, the third through hole (401) only communicates with the sixth through hole (801).

10. The gravel pack sand screen valve of claim 8, wherein, The second annular space (18) is internally provided with a spring base (7), the spring base (7) is fixedly connected with the switch sliding sleeve (5), and the two ends of the piston spring (16) respectively abut against the unlocking piston (6) and the spring base (7).

11. The gravel pack sand screen valve of any of claims 1-10, wherein, The lower end of the sliding sleeve base (8) is coaxially fixedly connected with a rubber sleeve sleeve pipe (9), and the outer wall of the rubber sleeve sleeve pipe (9) is intermittently provided with a plurality of groups of rubber sleeves (10), and a spacer ring (11) is arranged between adjacent two groups of rubber sleeves (10).

12. The gravel pack sand screen valve of claim 11, wherein, The lower end of the rubber sleeve sleeve pipe (9) is coaxially fixedly provided with a lower connector (12), the lower end outer wall of the lower connector (12) is provided with external threads, and the upper end inner wall of the outer cylinder (1) is provided with internal threads.

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