A cyclic segmented completion tool for reservoirs

Abstract

This invention discloses a reservoir-based circulating staged completion tool, relating to the technical field of oil and gas extraction equipment. It includes an upper connector, to which an outer cylinder is fixedly connected; a lower connector is fixedly connected to the outer cylinder; an inner sliding sleeve is slidably connected within the outer cylinder; the inner sliding sleeve has a sealing surface that supports and seals against the ball; a protective membrane disposed on the inner sliding sleeve; a connecting ring fixedly connected to the protective membrane; and support plates, circumferentially distributed and all fixedly connected to the connecting ring. All support plates are jointly fixedly connected to a support ring, which supports the ball. This invention, by stacking the upper part of the protective membrane on the sealing surface of the inner sliding sleeve, isolates the sealing surface from the fracturing fluid, reducing erosion of the upper inner sliding sleeve by the fracturing fluid during fracturing, improving the sealing performance between the ball and the sealing surface during this stage of fracturing, and providing a guarantee for subsequent fracturing.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction equipment technology, and in particular to a circulating segmented well completion tool for oil reservoirs. Background Technology

[0002] With the large-scale development of unconventional oil and gas resources such as shale oil and tight gas, horizontal well staged fracturing technology has become a core means to improve single-well production. Among the many staged fracturing processes, ball-drop sliding sleeve multi-stage staged fracturing technology has been widely used in oil reservoirs both domestically and internationally due to its advantages such as mature technology, high operational efficiency, and relatively controllable cost.

[0003] In the ball-drop sleeve staged fracturing process, the completion string is equipped with multiple stages of ball-drop sleeves. Each ball-drop sleeve contains a ball seat, and the inner diameter of the ball seat increases progressively from the bottom of the well to the wellhead. During construction, fracturing is performed stage by stage from the bottom of the well to the wellhead. When the ball is first dropped into the ball-drop sleeve, it matches the ball seat of the first-stage sleeve at the deepest point in the well. After the ball is seated, pressure is applied to open the first-stage sleeve, completing the first stage of fracturing. Subsequently, a fracturing ball with a larger diameter is dropped and seated in the second-stage ball seat, opening the second-stage sleeve and completing the second stage of fracturing. This process continues until all stages of fracturing are completed. After fracturing, circulation is performed to remove residual fracturing fluid.

[0004] In the above process, because the fracturing fluid contains some quartz sand, ceramsite and other substances, when fracturing the lower section, the fracturing fluid will flow through the upper unused ball seat. Since the sealing surface of the upper ball seat is completely exposed in the flow channel, the sand-containing fracturing fluid will have a continuous abrasive erosion effect on the sealing surface, affecting the sealing performance between the ball seat sealing surface and the matching ball, resulting in the inability to reach the specific pressure value during fracturing and the inability to complete effective fracturing. Summary of the Invention

[0005] To overcome the shortcomings mentioned in the background above, the present invention provides a circulating segmented completion tool for oil reservoirs.

[0006] Technical Solution: A reservoir-use circulating segmented completion tool includes an upper connector, an outer cylinder fixedly connected to the upper connector, a lower connector fixedly connected to the outer cylinder, an inner sliding sleeve slidably connected inside the outer cylinder, and a sealing surface provided on the inner sliding sleeve for supporting the ball and forming a seal with the ball; a protective membrane disposed on the inner sliding sleeve; a connecting ring fixedly connected to the protective membrane; support plates distributed circumferentially and all fixedly connected to the connecting ring, all of which are jointly fixedly connected to the support ring, the support ring for supporting the ball; and a release component disposed on the connecting ring for releasing the restriction on the protective membrane; the release component includes: a sliding... The sliding columns are arranged in a circular pattern and slidably connected to the connecting ring. A first elastic element is installed between the connecting ring and all the sliding columns. Several pairs of support frames are arranged in a circular pattern and fixedly connected to the inner sliding sleeve. Each pair of support frames is rotatably connected to a swing plate. The swing plate corresponds to one of the sliding columns, and the sliding column is used to press the corresponding swing plate. The extrusion columns are arranged in a circular pattern and slidably connected to the inner sliding sleeve. The swing plate corresponds to one of the extrusion columns, and the swing plate is used to press the corresponding extrusion column. A fixing ring is fixedly connected to all the extrusion columns and is used to limit the stacking portion of the protective film.

[0007] Preferably, the protective film is cylindrical with its upper part stacked and placed on the sealing surface of the inner sliding sleeve. The end of the protective film away from the connecting ring is fixed to the inner sliding sleeve, and the stacked part of the protective film is used to protect the sealing surface of the inner sliding sleeve.

[0008] Preferably, the sealing surface of the inner sliding sleeve is coaxial with the support ring.

[0009] Preferably, the support ring is fixedly connected to evenly distributed connecting strips, and all the connecting strips are jointly fixedly connected to a fixing strip.

[0010] Preferably, the fixing strip and the evenly distributed connecting strips are both located above the protective film.

[0011] Preferably, both the fixing strip and the evenly distributed connecting strips are made of deformable elastic material to cushion the impact of other balls passing by.

[0012] Preferably, the system further includes circumferentially distributed shearing plates, which are fixedly connected to the inner sliding sleeve and are all located above the support ring. Each shearing plate is hinged to a baffle for blocking the ball throw. A triggering component is disposed within the inner sliding sleeve for releasing the restriction on all the baffles. The triggering component includes: a sliding rod, which is circumferentially distributed and slidably connected to the inner sliding sleeve. Each baffle corresponds to one sliding rod. A first pull rope and a second pull rope are fixedly connected to both ends of each sliding rod. The first pull rope is fixedly connected to the corresponding baffle, and the second pull rope is fixedly connected to the connecting ring.

[0013] Preferably, each of the circumferentially distributed baffles is fixed with a limiting block, and the limiting block is made of rubber and is used to compress the ball during the throw.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: By stacking the upper part of the protective film on the sealing surface of the inner sliding sleeve, the present invention isolates the sealing surface from the fracturing fluid, reduces the erosion of the upper inner sliding sleeve by the fracturing fluid during the fracturing process, improves the sealing performance between the ball and the sealing surface during this stage of fracturing, and provides a guarantee for subsequent fracturing.

[0015] This invention uses connecting strips and fixing strips to form a guide net to guide the ball as it passes through the support ring. At the same time, when the small ball comes into contact with the connecting strips and fixing strips, the connecting strips and fixing strips will undergo elastic deformation to intercept and buffer the small ball, reducing the damage caused by the large impact force when the small ball comes into contact with the sealing surface.

[0016] This invention uses a baffle to block the fracturing fluid and a limiting block to limit the ball drop, reducing direct contact between the ball drop and the fracturing fluid, ensuring the stability of the seal during fracturing, and improving the reliability of downhole operations. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the outer cylinder and inner sliding sleeve of the present invention; Figure 3 This is a three-dimensional structural diagram of the inner sliding sleeve and protective film of the present invention; Figure 4 This is a three-dimensional structural diagram of the protective film, support ring, and sliding column of the present invention; Figure 5 For the present invention Figure 4 Enlarged 3D structural diagram at point A; Figure 6 This is a three-dimensional structural diagram of the baffle sliding rod and the limiting block of the present invention; Figure 7 For the present invention Figure 6 Enlarged 3D structural diagram at point B; Figure 8 This is a schematic diagram of the three-dimensional structure of the protective film of the present invention after it has been unfolded.

[0018] In the attached diagram, the following are the reference numerals: 1. Upper connector, 2. Outer cylinder, 3. Lower connector, 4. Inner sliding sleeve, 5. Protective film, 6. Connecting ring, 7. Support plate, 8. Support ring, 201. Sliding column, 202. Support frame, 203. Swing plate, 204. Extrusion column, 205. Fixing ring, 301. Connecting strip, 302. Fixing strip, 401. Shearing plate, 402. Baffle, 501. Sliding rod, 502. First pull rope, 503. Second pull rope, 601. Limiting block. Detailed Implementation

[0019] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0020] Example 1; A type of reservoir-based circulating staged completion tool, such as Figures 1-6 and Figure 8 As shown, it includes an upper connector 1, an outer cylinder 2 fixedly connected to the upper connector 1, a lower connector 3 fixedly connected to the outer cylinder 2, an inner sliding sleeve 4 slidably connected inside the outer cylinder 2, and a sealing surface provided on the inner sliding sleeve 4. The sealing surface of the inner sliding sleeve 4 is used to support the ball and form a seal with the ball; a protective film 5 is provided on the inner sliding sleeve 4; a connecting ring 6 is fixedly connected to the protective film 5; support plates 7 are distributed circumferentially and are all fixedly connected to the connecting ring 6. All support plates 7 are jointly fixedly connected to a support ring 8, which is used to support the ball; and a release component is provided on the connecting ring 6 to release the restriction on the protective film 5. The protective film 5 is cylindrical, with its upper part stacked and placed at the sealing surface of the inner sliding sleeve 4. The end of the protective film 5 away from the connecting ring 6 is fixedly connected to the inner sliding sleeve 4. The stacked part of the protective film 5 is used to protect the sealing surface of the inner sliding sleeve 4. The sealing surface of the inner sliding sleeve 4 is coaxial with the support ring 8.

[0021] In the above scheme, both the outer cylinder 2 and the inner sliding sleeve 4 are provided with fracturing holes for discharging fracturing fluid for fracturing. The outer cylinder 2 has a limiting pin, which is used to limit the corresponding inner sliding sleeve 4. The limiting pin breaks when the fracturing fluid pressurizes the corresponding ball, thus losing its limiting effect on the corresponding inner sliding sleeve 4. The inner sliding sleeve 4 has a clamping groove. The upper end of the protective film 5 is fixed to the inner sliding sleeve 4, and the lower end of the protective film 5 is fixed to the connecting ring 6. The protective film 5 is made of high-temperature resistant and wear-resistant material, such as polytetrafluoroethylene. In the initial state, part of the protective film 5 is stacked on the sealing surface of the inner sliding sleeve 4 to reduce the erosion of the sealing surface by the fracturing fluid and ensure subsequent... The sealing surface and the ball are sealed together. After the protective film 5 is released from the limit, the overlapping part is completely out of contact with the inner sliding sleeve 4. The setting of the protective film 5 isolates the sealing surface from the fracturing fluid, reduces the erosion of the upper inner sliding sleeve 4 by the fracturing fluid during the fracturing process, improves the sealing performance between the ball and the sealing surface during this stage of fracturing, and provides a guarantee for subsequent fracturing. The connecting ring 6 has three guide parts and three support plates 7. The upper ends of the three support plates 7 are fixedly connected to the support ring 8. The support ring 8 is located above the sealing surface on the inner sliding sleeve 4. It buffers the ball that matches the ball seat on the inner sliding sleeve 4 and reduces the impact force when the ball seals with the sealing surface.

[0022] like Figure 4 , Figure 5 and Figure 8 As shown, the release assembly includes: sliding posts 201, circumferentially distributed, all slidably connected to the connecting ring 6, with a first elastic element installed between the connecting ring 6 and all sliding posts 201; several pairs of support frames 202, circumferentially distributed, all fixedly connected to the inner sliding sleeve 4, each pair of support frames 202 being rotatably connected to a swing plate 203, the swing plate 203 corresponding one-to-one with the sliding post 201, the sliding post 201 being used to press the corresponding swing plate 203; pressing posts 204, circumferentially distributed, all slidably connected to the inner sliding sleeve 4, the swing plate 203 corresponding one-to-one with the pressing post 204, the swing plate 203 being used to press the corresponding pressing post 204; and a fixing ring 205, fixedly connected to all pressing posts 204, the fixing ring 205 being used to limit the stacking portion of the protective film 5.

[0023] In the above scheme, the number of sliding columns 201 corresponds one-to-one with the number of fixed cylinders on the connecting ring 6. The sliding columns 201 slide within the corresponding fixed cylinders on the connecting ring 6. The projection of the three sliding columns 201 onto the horizontal plane is within the range of the projection of the corresponding support ring 8 onto the horizontal plane. There are three pairs of support frames 202. There are three swing plates 203 and three pressing columns 204. The swing plate 203 is located on the moving path of the corresponding sliding column 201. Its elastic element is a spring plate, which is used to reset the sliding column 201, so that the sliding column 201 and the fixed cylinder 6 slide within the fixed cylinder 6. When the sealing surfaces of the inner sliding sleeve 4 do not match, the ball is buffered and guided to pass over the sliding post 201. The three sliding posts 201 and the corresponding support ring 8 can simultaneously contact the ball that matches the sealing surface of the corresponding inner sliding sleeve 4. In the initial state, the fixed ring 205 clamps the stacked protective film 5 into the pressing groove of the ball seat on the inner sliding sleeve 4. After the protective film 5 is released from its limit, all the sliding posts 201 lose contact with the corresponding swing plate 203, and all the swing plates 203 lose contact with the corresponding pressing post 204.

[0024] like Figure 4 and Figure 8 As shown, the support ring 8 is fixed with evenly distributed connecting strips 301, and all the connecting strips 301 are fixed with a fixing strip 302. The fixing strip 302 and the evenly distributed connecting strips 301 are both located above the protective film 5. The fixing strip 302 and the evenly distributed connecting strips 301 are both made of deformable elastic material, which is used to buffer other balls when they pass by.

[0025] In the above scheme, the connecting strip 301 can be set according to the site requirements, and the fixing strip 302 is composed of circumferentially evenly distributed wavy elastic strips connected end to end. The connecting strip 301 and the fixing strip 302 are used to intercept, buffer and guide the ball that passes through the corresponding support ring 8, reducing the damage caused by the large impact force when the ball passes through the corresponding support ring 8 and contacts the sealing surface.

[0026] When using this device for reservoir fracturing, firstly, the multi-stage (number of stages depends on the specific site conditions) device is fixed inside the completion string (the outer cylinder 2 is fixed inside the completion string via the upper connector 1 and the lower connector 3). Then, the operator drops a ball that matches the inner sliding sleeve 4 inside the bottom outer cylinder 2 into the completion string. Under gravity, the ball moves downwards along the inner wall of the completion string until it reaches above the uppermost inner sliding sleeve 4 (the subsequent actions in this section are described using the relevant parts of the inner sliding sleeve 4 as an example). As the ball continues to move downwards, it first contacts part of the connecting strip 301. The connecting strip 301 in contact with the ball... The ball deforms under the influence of gravity. The connecting strip 301, which is in contact with the ball, causes the fixing strip 302 to deform as well. The ball rolls towards the center under the action of the connecting strip 301 and the fixing strip 302. Then the fixing strip 302 expands outwards. When the ball passes through the fixing strip 302 and the small ball comes into contact with the connecting strip 301 and the fixing strip 302, the connecting strip 301 and the fixing strip 302 will undergo elastic deformation, which intercepts and buffers the small ball, reducing the damage caused by the large impact force when the small ball comes into contact with the sealing surface. The ball gradually passes through the multi-stage inner sliding sleeve 4 until the ball reaches the top of the matching inner sliding sleeve 4.

[0027] After the ball reaches above the matching inner sliding sleeve 4, the ball contacts all three sliding posts 201 inside the matching inner sliding sleeve 4. Under the weight of the ball, the sliding posts 201 move downwards, pressing the corresponding swing plates 203. The swing plates 203 swing relative to each pair of support frames 202, and the swing plates 203 press the corresponding pressing posts 204. All the pressing posts 204 move upwards, and all the pressing posts 204 drive the fixing ring 205 to move upwards together. During this process, all the pressing posts 204 slide relative to the inner sliding sleeve 4 until the fixing ring 205 is completely removed. After the ball seat on the inner sliding sleeve 4 is pressed into the groove, the fixing ring 205 loses its pressure on the protective film 5. Simultaneously with the ball contacting the corresponding sliding post 201, it contacts the corresponding support ring 8. Under the weight of the ball, the protective film 5 gradually moves. The portion of the protective film 5 stacked on the inner sliding sleeve 4 loses contact with the inner sliding sleeve until the ball contacts the sealing surface of the inner sliding sleeve 4. At this point, the support ring 8 and all its components stop moving. As the protective film 5 moves downwards, all the swing plates 203 lose contact with their corresponding pressing posts 204. At this point, the protective film 5, support ring 8, and swing plates 203 reach... Figure 8 The state shown.

[0028] When support ring 8 reaches Figure 8After reaching the indicated state, as the fracturing fluid continues to be pressurized, the inner sliding sleeve 4 moves downward until the fracturing hole of the inner sliding sleeve 4 matches the fracturing hole of the outer cylinder 2. At this point, the lower part of the inner sliding sleeve 4 contacts the lower part of the outer cylinder 2, completing the setting of the bottom inner sliding sleeve 4 by the ball drop. Afterward, the fracturing fluid passes through the fracturing holes of the inner sliding sleeve 4 and the fracturing holes of the outer cylinder 2, allowing the fracturing fluid to be introduced into the well wall and creating fractures in the well wall to facilitate the subsequent flow of oil and gas.

[0029] After fracturing the bottom layer of the wellbore, the workers stop injecting fracturing fluid and then continue to drop balls one size larger than the matching inner sliding sleeve 4 into the completion string. This process is repeated until the sealing surface of the inner sliding sleeve 4, matching the ball, is set. Fracturing fluid is then injected again for multi-stage fracturing. A protective film 5 is initially placed on the sealing surface of the inner sliding sleeve 4 and then fixed in place by a retaining ring 205. This isolates the sealing surface from the fracturing fluid, reducing erosion of the upper inner sliding sleeve 4 sealing surface during fracturing and improving the sealing performance between the ball and the sealing surface during this stage of fracturing. This provides a guarantee for subsequent fracturing until multi-stage fracturing is completed, at which point the workers can proceed with their subsequent work.

[0030] Example 2; Based on Example 1, such as Figure 3 and Figures 6-8 As shown, it also includes circumferentially distributed shear plates 401, which are fixedly connected to the inner sliding sleeve 4 and are all located above the support ring 8. The shear plates 401 are hinged to baffles 402, which are used to block the ball from being thrown. A triggering component is provided in the inner sliding sleeve 4 to release the limit on all baffles 402.

[0031] In the above scheme, the baffle 402 has a shear block that restricts the baffle 402 near the adjacent shear plate 401. When the baffle 402 is not swinging, the baffle 402 contacts the inner wall of the inner sliding sleeve 4, and the shear block contacts the shear plate 401 and is used to support the baffle 402. When the baffle 402 swings, the baffle 402 squeezes the shear block to contact the shear plate 401 first. The shear plate 401 cuts the shear block on the baffle 402. After the ball contacts the sealing surface, the baffle 402 forms a circular plate by swinging, which can cover the ball and reduce the direct contact between the ball and the fracturing fluid.

[0032] like Figures 6-8As shown, the triggering component includes: a sliding rod 501, which is circumferentially distributed and slidably connected to the inner sliding sleeve 4. The baffle 402 corresponds one-to-one with the sliding rod 501. The two ends of the sliding rod 501 are respectively fixedly connected to a first pull rope 502 and a second pull rope 503. The first pull rope 502 is fixedly connected to the corresponding baffle 402, and the second pull rope 503 is fixedly connected to the connecting ring 6. Limiting blocks 601 are fixedly connected to the circumferentially distributed baffles 402. The limiting blocks 601 are made of rubber and are used to squeeze the ball.

[0033] In the above scheme, there are eight sliding rods 501, eight first pull ropes 502 and eight second pull ropes 503. The swing of the baffle 402 is triggered by the downward movement of the connecting ring 6 through a purely mechanical structure, which improves the reliability of downhole operation. The ball is limited by the limiting block 601, which ensures the stability of the seal during fracturing.

[0034] When the support ring 8 moves downward, all the support plates 7 move downward through the connecting ring 6, causing all the second pull ropes 503 to move downward. The second pull ropes 503 cause the corresponding sliding rods 501 to move together. All the sliding rods 501 slide relative to the inner sliding sleeve 4. The sliding rods 501 cause the corresponding first pull ropes 502 to move. The first pull ropes 502 cause the corresponding baffles 402 to move. The shearing blocks on the baffles 402 are sheared off by the adjacent shearing plates 401. The shearing blocks lose their restraint on the adjacent baffles 402. 01 rotates relative to the adjacent baffle 402, causing baffle 402 to swing under the action of the adjacent first pull rope 502 and its own weight. Baffle 402 drives the corresponding limiting block 601 to move together, so that after the ball contacts the sealing surface, baffle 402 forms a ring plate through swinging. At the same time, the limiting block 601 limits the ball, reducing the direct contact between the ball and the fracturing fluid, ensuring the stability of the seal during fracturing, and improving the reliability of downhole operation. Finally, baffle 402 and sliding rod 501 reach... Figure 8 The state shown.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A reservoir-use circulating segmented completion tool, comprising an upper connector (1), an outer cylinder (2) fixedly connected to the upper connector (1), a lower connector (3) fixedly connected to the outer cylinder (2), an inner sliding sleeve (4) slidably connected inside the outer cylinder (2), a sealing surface provided on the inner sliding sleeve (4), the sealing surface of the inner sliding sleeve (4) being used to support the ball and form a seal with the ball, characterized in that, Also includes: A protective film (5) is disposed on the inner sliding sleeve (4); The connecting ring (6) is fixed to the protective film (5); The support plates (7) are distributed in a circle and are all fixed to the connecting ring (6). All the support plates (7) are fixed to the support ring (8), which is used to support the ball. A release component, disposed on the connecting ring (6), is used to release the restriction on the protective film (5); The release component includes: The sliding columns (201) are distributed in a circle and are all slidably connected to the connecting ring (6). A first elastic element is installed between the connecting ring (6) and all the sliding columns (201). The support frame (202) is arranged in several pairs in a circle and is fixed in the inner sliding sleeve (4). Each pair of support frames (202) is rotatably connected to a swing plate (203). The swing plate (203) corresponds one-to-one with the sliding column (201). The sliding column (201) is used to press the corresponding swing plate (203). The extrusion columns (204) are distributed in a circle and are all slidably connected in the inner sleeve (4). The swing plate (203) corresponds to the extrusion column (204) one by one. The swing plate (203) is used to extrude the corresponding extrusion column (204). A retaining ring (205) is fixed to all of the extrusion posts (204) and the retaining ring (205) is used to limit the stacking portion of the protective film (5).

2. The reservoir-use circulating segmented completion tool according to claim 1, characterized in that, The protective film (5) is cylindrical with its upper part stacked and placed on the sealing surface of the inner sliding sleeve (4). The end of the protective film (5) away from the connecting ring (6) is fixed to the inner sliding sleeve (4). The stacked part of the protective film (5) is used to protect the sealing surface of the inner sliding sleeve (4).

3. The reservoir-use circulating segmented completion tool according to claim 2, characterized in that, The sealing surface of the inner sleeve (4) is coaxial with the support ring (8).

4. The reservoir-use circulating segmented completion tool according to claim 1, characterized in that, The support ring (8) is fixed with evenly distributed connecting strips (301), and all the connecting strips (301) are fixed with a fixing strip (302).

5. A reservoir-use circulating segmented completion tool according to claim 4, characterized in that, The fixing strip (302) and the evenly distributed connecting strips (301) are both located above the protective film (5).

6. A reservoir-use circulating segmented completion tool according to claim 5, characterized in that, The fixing strip (302) and the evenly distributed connecting strips (301) are both made of deformable elastic material, used to buffer other balls as they pass by.

7. A reservoir-use circulating segmented completion tool according to claim 4, characterized in that, It also includes circumferentially distributed shear plates (401), which are fixed inside the inner sliding sleeve (4) and are all located above the support ring (8). Each shear plate (401) is hinged to a baffle (402), which is used to block the ball from being thrown. A trigger component, located within the inner sleeve (4), is used to release the limiting effect on all the baffles (402); The triggering component includes: The sliding rods (501) are distributed in a circle and are slidably connected in the inner sliding sleeve (4). The baffle (402) corresponds to the sliding rod (501) one by one. The two ends of the sliding rod (501) are respectively fixed with a first pull rope (502) and a second pull rope (503). The first pull rope (502) is fixed to the corresponding baffle (402), and the second pull rope (503) is fixed to the connecting ring (6).

8. A reservoir-use circulating segmented completion tool according to claim 7, characterized in that, Each of the circumferentially distributed baffles (402) is fixed with a limiting block (601), and the limiting block (601) is made of rubber and is used to squeeze the ball.

Images