Buoyancy plug for drilling pipe construction

Abstract

The present invention discloses a buoyancy plug for drilling pipe construction, which relates to the field of buoyancy plug devices, including a casing, an annular plate, a closing plate, a top plate and a bottom plate, wherein the annular plate is fixedly connected in the inner cavity of the casing, the closing plate is detachably connected to the top of the annular plate, and the peripheral side of the closing plate is tightly fitted with the inner wall of the casing, the bottom of the closing plate is tightly fitted with the top of the annular plate, a center groove is provided at the center of the closing plate, the top plate and the bottom plate are clamped together after passing through the center groove, and the opposite surfaces of the top plate and the bottom plate are respectively fitted with the top and bottom of the closing plate, and are used to block the center groove. The present invention has a simple structure and is easy to use, which not only avoids unloading residues, but also realizes the secondary use of the closing plate, and can effectively reduce construction costs.

Description

Technical Field

[0001] The invention relates to the field of buoyancy plug devices, in particular to a buoyancy plug used for drilling pipe construction. Background Art

[0002] Large-diameter engineering wells are widely used in large-flow extraction operations of gas, accumulated water and other media in coal mines. In order to meet the functional requirements, the casing is generally thicker in wall, larger in diameter and mass, far exceeding the lifting capacity of the drilling equipment. In order to reduce the lifting burden of the drilling equipment, a buoyancy device is generally installed in the middle or bottom of the casing, and the floating lowering technology is used to complete the lowering of the casing.

[0003] At present, the commonly used buoyancy devices are cement buoyancy plugs or steel plate buoyancy plugs, but it is found in the actual application process that both of these buoyancy plugs have certain defects: when the cement buoyancy plug is drilled through, the broken cement blocks will be mixed into the drilling mud, which will not only destroy the mud performance and affect the cementing quality, but also accumulate in the casing, hindering the normal fluid displacement. At the same time, the cement buoyancy plug has a long production period and complicated procedures; and the existing steel plate buoyancy plug, on the one hand, has poor sealing performance and is prone to slurry leakage; on the other hand, there will be steel plates left in the casing, which will have an adverse effect on the cementing quality and fluid displacement.

[0004] Therefore, how to develop a buoyancy plug for drilling pipe construction with simple structure and easy use, which can avoid unloading residue and realize the secondary utilization of the closing plate and effectively reduce construction costs, has become a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a buoyancy plug for drilling pipe construction, which has a simple structure and is easy to use, avoids unloading residues, and realizes the secondary use of the closing plate, which can effectively reduce the construction cost.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention discloses a buoyancy plug for use in drilling pipe construction, comprising a casing, an annular plate, a closing plate, a top plate and a bottom plate, wherein the annular plate is fixedly connected in the inner cavity of the casing, the closing plate is detachably connected to the top of the annular plate, and the peripheral side of the closing plate is tightly fitted with the inner wall of the casing, the bottom of the closing plate is tightly fitted with the top of the annular plate, a center groove is provided at the center position of the closing plate, the top plate and the bottom plate are clamped together after passing through the center groove, and the opposite surfaces of the top plate and the bottom plate are respectively fitted with the top and bottom of the closing plate, and are used to block the center groove.

[0008] Preferably, a plurality of reinforcing ribs are evenly distributed on the bottom edge of the annular plate, and the annular plate is welded to the pipe wall of the sleeve via the reinforcing ribs.

[0009] Preferably, a side groove is provided on the peripheral side of the closing plate, and a side sealing ring is sleeved and connected in the side groove, and the side sealing ring is used to fit tightly with the tube wall of the sleeve;

[0010] The bottom of the closing plate is provided with a bottom groove, a bottom sealing ring is installed in the bottom groove, and the top of the annular plate is provided with an annular groove matching the bottom sealing ring.

[0011] Preferably, the bottom of the closing plate is annularly and evenly provided with a plurality of plug posts, the top ends of the plug posts are threadedly connected to the closing plate, and the bottom ends of the plug posts are fixedly mounted with anti-slip heads, and the diameter of the anti-slip heads is greater than the diameter of the plug posts;

[0012] The annular plate is provided with slots and arc grooves matching the number of the plug posts, the slots and arc grooves are interconnected, the slots match the size of the anti-slip head, and the arc grooves match the size of the plug posts.

[0013] Preferably, a rubber pad is adhered to the inner wall of the arc-shaped groove.

[0014] Preferably, the central groove is in the shape of a quadrangular pyramid, and the bottom of the top plate is fixedly connected with a quadrangular pyramid block matching the central groove, and the quadrangular pyramid block penetrates the central groove and is connected with the bottom plate by clamping.

[0015] Preferably, a limiting groove is provided inside the central groove, and two wing plates are symmetrically fixedly connected to the circumference of the quadrangular pyramid block, and the wing plates are slidably connected to the limiting groove.

[0016] Preferably, a plug board is provided on the top of the bottom plate, a vertical groove is provided on the top of the plug board, and convex strips are provided on both sides of the plug board;

[0017] A plate groove matching the shape of the plug plate is provided at the bottom of the quadrangular pyramid block, and a side groove matching the convex strip is provided on the side wall of the plate groove.

[0018] Preferably, the bottom of the closing plate is annularly and evenly provided with a plurality of guide rods, the top ends of the guide rods are threadedly connected to the closing plate, the bottom ends of the guide rods are fixedly connected with baffles, and the guide rods are arranged around the circumference of the central groove;

[0019] The bottom plate is provided with a rod groove matching the guide rod, and the bottom plate is connected to the guide rod by slidingly sleeved on the rod groove.

[0020] Preferably, the opposite surfaces of the top plate and the bottom plate are respectively sealed and connected to the top and bottom of the closing plate through rubber sealing rings.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are:

[0022] 1) The present invention can seal the middle section of the casing through the annular plate and the sealing plate, so that a hollow section appears on the upper part of the casing, generating buoyancy to reduce the lifting burden of the drilling equipment. Under the action of the side sealing ring and the bottom sealing ring, the sealing can be effectively ensured to avoid slurry leakage;

[0023] 2) After the pipe is lowered, the top plate is first rotated by a lifting device, and then the top plate is lifted up, so that the closing plate and the annular plate can be separated, and then the closing plate can be completely pulled out of the casing, which not only avoids unloading residues, but also allows the closing plate to be reused, saving construction costs;

[0024] 3) In the process of lowering the pipe, the central groove of the present invention is closed by the top plate and the bottom plate, which can effectively ensure the sealing performance; in the process of lifting the top plate, the central groove will automatically open to allow the slurry to pass through, thereby facilitating the removal of the closing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 This is a cross-sectional view of the overall structure of a buoyancy plug used for drilling pipe construction according to the present invention;

[0027] Figure 2 It is a schematic diagram of the connection structure between the annular plate and the sleeve of the present invention;

[0028] Figure 3 Schematic diagram of the connection structure of the closing plate, top plate and bottom plate of the present invention Figure 1 ;

[0029] Figure 4 Schematic diagram of the connection structure of the closing plate, top plate and bottom plate of the present invention Figure 2 ;

[0030] Figure 5 The cross-sectional view of the connection structure of the closing plate, the top plate and the bottom plate of the present invention Figure 1 ;

[0031] Figure 6 The cross-sectional view of the connection structure of the closing plate, the top plate and the bottom plate of the present invention Figure 2 ;

[0032] Figure 7 It is a structural schematic diagram of the top plate of the present invention;

[0033] Figure 8 It is a structural schematic diagram of the bottom plate of the present invention.

[0034] Explanation of the reference numerals in the accompanying drawings: 1. sleeve; 2. annular plate; 3. reinforcing rib; 4. closing plate; 5. side groove; 6. side sealing ring; 7. bottom groove; 8. bottom sealing ring; 9. annular groove; 10. plug-in column; 11. anti-slip head; 12. slot; 13. arc groove; 14. top plate; 15. bottom plate; 16. tetrahedral block; 17. center groove; 18. wing plate; 19. limiting groove; 20. plug-in plate; 21. convex strip; 22. vertical groove; 23. plate groove; 24. side groove; 25. rod groove; 26. guide rod; 27. baffle. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Embodiment 1:

[0037] like Figure 1-4 As shown, a buoyancy plug for drilling pipe construction includes a casing 1, an annular plate 2 and a closing plate 4, wherein the annular plate 2 is fixedly connected to the inner cavity of the casing 1, the closing plate 4 is detachably connected to the top of the annular plate 2, and the surrounding side of the closing plate 4 is tightly fitted with the inner wall of the casing 1, and the bottom of the closing plate 4 is tightly fitted with the top of the annular plate 2.

[0038] Specifically, a plurality of reinforcing ribs 3 are evenly distributed on the bottom edge of the annular plate 2 , and the annular plate 2 is welded to the pipe wall of the sleeve 1 via the reinforcing ribs 3 .

[0039] Specifically, the welding position of the annular plate 2 can be at the bottom end of the casing 1 or at the middle section of the casing 1, and those skilled in the art can set it according to the actual need of lowering the casing.

[0040] Specifically, a side groove 5 is formed on the circumference of the closing plate 4, and a side sealing ring 6 is sleeved and connected in the side groove 5. The side sealing ring 6 is used to fit tightly with the wall of the sleeve 1;

[0041] A bottom groove 7 is formed at the bottom of the closing plate 4 , a bottom sealing ring 8 is installed in the bottom groove 7 , and an annular groove 9 matching the bottom sealing ring 8 is formed at the top of the annular plate 2 .

[0042] Specifically, the provision of the side sealing ring 6 and the bottom sealing ring 8 can respectively improve the connection sealing performance between the closing plate 4 and the sleeve 1 and the annular plate 2, thereby preventing slurry leakage.

[0043] Specifically, the arrangement of the closing plate 4 and the annular plate 2 can close the middle section of the casing 1, so that a hollow section appears at the upper part of the casing 1, thereby generating buoyancy to reduce the lifting burden of the drilling equipment.

[0044] Specifically, the bottom of the closing plate 4 is evenly distributed in a ring shape with a plurality of plug posts 10, the top of each plug post 10 is threadedly connected to the closing plate 4, and an anti-slip head 11 is fixedly installed at the bottom of each plug post 10, and the diameter of the anti-slip head 11 is larger than the diameter of the plug post 10;

[0045] The annular plate 2 is provided with slots 12 and arc grooves 13 whose number matches the number of the plug posts 10 . The slots 12 and arc grooves 13 are interconnected, and the slots 12 match the size of the anti-slip head 11 , and the arc grooves 13 match the size of the plug posts 10 .

[0046] Specifically, a rubber pad is pasted on the inner wall of the arc-shaped groove 13 .

[0047] Specifically, align the anti-slip head 11 with the slot 12 and insert it downward, so that the opposite surfaces of the closing plate 4 and the annular plate 2 can fit each other. Then, rotate the closing plate 4 to make the plug post 10 enter the arc groove 13. Rotate the closing plate 4 to make the plug post 10 rotate into the arc groove 13. The closing plate 4 and the annular plate 2 can be stably connected through the obstruction of the anti-slip head 11, so that the two are connected as a whole. The friction of the plug post 10 moving in the arc groove 13 can be increased by the rubber pad to prevent the closing plate 4 from rotating at will.

[0048] Specifically, when the closing plate 4 needs to be unloaded, the closing plate 4 is first rotated in the opposite direction to make the position of the anti-dropping head 11 correspond to the position of the slot 12, and then the closing plate 4 is lifted up.

[0049] Specifically, in the present embodiment, the plug post 10, the anti-slip head 11 and the closing plate 4 are integrally formed, which can effectively ensure the overall strength of the device and can withstand a greater load.

[0050] Specifically, the design of the detachable connection between the closing plate 4 and the annular plate 2 in the present invention can not only effectively ensure the sealing, but also allow the closing plate 4 to be removed after use for reuse, thereby effectively reducing the construction cost.

[0051] Embodiment 2:

[0052] like Figure 5-8 As shown, on the basis of Example 1, in this embodiment, a center groove 17 is opened at the center position of the closing plate 4, and the top plate 14 and the bottom plate 15 pass through the center groove 17 and are snapped together, and the opposite surfaces of the top plate 14 and the bottom plate 15 are respectively fitted with the top and bottom of the closing plate 4, and are used to seal the center groove 17.

[0053] Specifically, when the closing plate 4 needs to be removed, the top plate 14 moves upward and the bottom plate 15 moves downward, thereby opening the passage of the central groove 17 and allowing the slurry to pass through, thereby facilitating the upward removal of the closing plate 4 without being blocked by the slurry.

[0054] Specifically, the central groove 17 is in a quadrangular pyramid shape, and a quadrangular pyramid block 16 matching the central groove 17 is fixedly connected to the bottom of the top plate 14 . The quadrangular pyramid block 16 penetrates the central groove 17 and is snap-connected with the bottom plate 15 .

[0055] Specifically, a limiting groove 19 is provided inside the central groove 17 , and two wing plates 18 are symmetrically fixedly connected to the circumference of the quadrangular pyramid block 16 , and the wing plates 18 are slidably connected to the limiting groove 19 .

[0056] Specifically, in actual applications, the wing plate 18 can be made of elastic material. Based on the guiding effect of the slope and the deformation characteristics of the material itself, the tetrahedral block 16 with the wing plate 18 is inserted into the top opening of the center groove 17 for installation; the tetrahedral block 16 can also be designed as a split structure, and each split component is installed in place, and then assembled to realize the assembly of the wing plate 18 and the limit groove 19. In addition, users can also choose other assembly and installation methods according to actual conditions.

[0057] Specifically, a plug board 20 is disposed on the top of the bottom plate 15, a vertical groove 22 is formed on the top of the plug board 20, and convex strips 21 are disposed on both sides of the plug board 20;

[0058] A plate groove 23 matching the shape of the insert plate 20 is formed at the bottom of the quadrangular pyramid block 16 , and a side groove 24 matching the convex strip 21 is formed on the side wall of the plate groove 23 .

[0059] Specifically, in the initial state, the plug plate 20 is inserted into the plate groove 23, and the convex strip 21 is inserted into the side groove 24. This structure effectively connects the tetrahedral block 16 with the bottom plate 15. When the top plate 14 is lifted upward, the bottom plate 15 is blocked by the closing plate 4 and cannot move upward synchronously. At this time, the plug plate 20 will be squeezed and closed, and then disengaged from the plate groove 23. After the plug plate 20 is disengaged, the top plate 14 continues to move upward, thereby opening the passage of the center groove 17.

[0060] Specifically, the setting of the wing plate 18 serves to limit the position of the top plate 14, preventing the top plate 14 from being completely separated from the closing plate 4 during the upward movement. While realizing the opening of the central groove 17, the top plate 14 can also rely on the limiting connection structure between the wing plate 18 and the closing plate 4 to provide a pulling force for the closing plate 4 to move upward, thereby facilitating the upward and withdrawal operation of the closing plate 4.

[0061] Specifically, in order to limit the position of the bottom plate 15 and prevent the bottom plate 15 from completely separating from the closing plate 4, a plurality of guide rods 26 are evenly distributed in an annular shape at the bottom of the closing plate 4, the top ends of the guide rods 26 are threadedly connected to the closing plate 4, the bottom ends of the guide rods 26 are fixedly connected to baffles 27, and the guide rods 26 are arranged around the circumference of the central groove 17;

[0062] The bottom plate 15 is provided with a rod groove 25 matching the guide rod 26 , and the bottom plate 15 is slidably sleeved on the guide rod 26 through the rod groove 25 .

[0063] Specifically, when the tetrahedral block 16 and the bottom plate 15 are separated from each other, the bottom plate 15 will naturally fall along the axial direction of the guide rod 26 due to the effect of gravity. During the falling process, the baffle 27 effectively blocks the bottom plate 15 to prevent it from falling off directly. In this way, the bottom plate 15 can always maintain an integrated connection with the closing plate 4.

[0064] In actual application, after the pipe lowering operation is completed, the top plate 14 is first rotated using a lifting device, and then the top plate 14 is pulled upward, so that the closing plate 4 can be separated from the annular plate 2, and then the closing plate 4 is completely pulled out of the casing 1, which not only avoids unloading residues, but also allows the closing plate 4 to be put into use again, saving construction costs.

[0065] Specifically, the quadrangular pyramid blocking block 16 is in the shape of a quadrangular pyramid. When rotating, it can drive the entire closing plate 4 connected thereto to rotate together, thereby facilitating the separation of the closing plate 4 and the annular plate 2.

[0066] Specifically, during the lowering process, the top plate 14 and the bottom plate 15 close the central groove 17, thereby effectively ensuring the sealing of the system. During the lifting of the top plate 14, the central groove 17 will automatically open to allow slurry to pass through, thereby facilitating the removal of the closing plate 4.

[0067] Specifically, if the device needs to be used again, it is only necessary to insert the plug plate 20 into the plate slot 23 again. The plug plate 20 is made of a steel plate, which not only ensures the stability of the connection, but also has a certain degree of elasticity.

[0068] Specifically, the opposite surfaces of the top plate 14 and the bottom plate 15 are respectively sealed and connected to the top and bottom of the closing plate 4 through rubber sealing rings, which can further improve the sealing effect of the device.

[0069] Specifically, according to actual needs, a connecting structure such as a lifting ring, a connecting tube, etc. can be set on the top of the top plate 14 to help realize the rotation and lifting operation of the top plate 14.

[0070] The assembly steps of the present invention are as follows:

[0071] First, the annular plate 2 is welded inside the casing 1, and then the closing plate 4 is connected to the annular plate 2, thereby forming a buoyancy plug (at this time, the bottom plate 15 and the tetrahedral block 16 are in a snap-connected state).

[0072] The pipe laying process of the present invention is:

[0073] When the pipe is lowered, a hollow section will appear above the buoyancy plug, thereby generating buoyancy and effectively reducing the lifting load of the drilling equipment. When the casing 1 is lowered to the predetermined position, the casing 1 needs to be filled with mud, and then the drill is lowered. The top plate 14 is rotated by the drilling tool, and then the top plate 14 is pulled upward, so that the entire closing plate 4 is pulled out of the casing 1. Finally, slurry is injected between the casing 1 and the well wall to complete the cementing work.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0075] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A buoyancy plug for use in drilling pipe construction, characterized in that: The invention comprises a sleeve (1), an annular plate (2), a closing plate (4), a top plate (14) and a bottom plate (15), wherein the annular plate (2) is fixedly connected in the inner cavity of the sleeve (1), the closing plate (4) is detachably connected to the top of the annular plate (2), and the peripheral side of the closing plate (4) is tightly fitted with the inner wall of the sleeve (1), and the bottom of the closing plate (4) is tightly fitted with the top of the annular plate (2), and a central groove (17) is provided at the central position of the closing plate (4), and the top plate (14) and the bottom plate (15) are inserted through the central groove (17) and then snapped together, and the opposite surfaces of the top plate (14) and the bottom plate (15) are respectively fitted with the top and bottom of the closing plate (4) and are used to block the central groove (17).

2. A buoyancy plug for drilling pipe construction according to claim 1, characterized in that: The bottom edge of the annular plate (2) is evenly provided with a plurality of reinforcing ribs (3), and the annular plate (2) is welded to the wall of the sleeve (1) via the reinforcing ribs (3).

3. A buoyancy plug for drilling pipe construction according to claim 2, characterized in that: A side groove (5) is provided on the circumference of the closing plate (4), and a side sealing ring (6) is sleeved and connected inside the side groove (5), and the side sealing ring (6) is used to fit tightly with the wall of the sleeve (1); The bottom of the closing plate (4) is provided with a bottom groove (7), a bottom sealing ring (8) is installed in the bottom groove (7), and the top of the annular plate (2) is provided with an annular groove (9) matching the bottom sealing ring (8).

4. A buoyancy plug for drilling pipe construction according to claim 3, characterized in that: The bottom of the closing plate (4) is annularly and evenly provided with a plurality of plug posts (10), the top ends of the plug posts (10) are threadedly connected to the closing plate (4), and the bottom ends of the plug posts (10) are fixedly mounted with anti-slip heads (11), and the diameter of the anti-slip heads (11) is greater than the diameter of the plug posts (10); The annular plate (2) is provided with slots (12) and arc-shaped grooves (13) whose number matches the number of the plug posts (10); the slots (12) and arc-shaped grooves (13) are interconnected, and the slots (12) match the size of the anti-slipping head (11), and the arc-shaped grooves (13) match the size of the plug posts (10).

5. A buoyancy plug for drilling pipe construction according to claim 4, characterized in that: A rubber pad is pasted on the inner wall of the arc-shaped groove (13).

6. The buoyancy plug for drilling pipe construction according to claim 1, characterized in that: The central groove (17) is in the shape of a quadrangular pyramid, and a quadrangular pyramid blocking block (16) matching the central groove (17) is fixedly connected to the bottom of the top plate (14). The quadrangular pyramid blocking block (16) penetrates the central groove (17) and is then snap-connected to the bottom plate (15).

7. A buoyancy plug for drilling pipe construction according to claim 6, characterized in that: A limiting groove (19) is provided inside the central groove (17), and two wing plates (18) are symmetrically fixedly connected to the circumference of the quadrangular pyramid block (16), and the wing plates (18) are slidably connected to the limiting groove (19).

8. The buoyancy plug for drilling pipe construction according to claim 6, characterized in that: A plug board (20) is arranged on the top of the bottom plate (15), a vertical groove (22) is opened on the top of the plug board (20), and convex strips (21) are arranged on both sides of the plug board (20); A plate groove (23) matching the shape of the plug plate (20) is provided at the bottom of the quadrangular pyramid block (16), and a side groove (24) matching the convex strip (21) is provided on the side wall of the plate groove (23).

9. The buoyancy plug for drilling pipe construction according to claim 4, characterized in that: The bottom of the closing plate (4) is evenly distributed in a ring shape with a plurality of guide rods (26), the top ends of the guide rods (26) are threadedly connected to the closing plate (4), the bottom ends of the guide rods (26) are fixedly connected to baffles (27), and the guide rods (26) are arranged around the circumference of the central groove (17); The bottom plate (15) is provided with a rod groove (25) matching the guide rod (26), and the bottom plate (15) is slidably sleeved and connected to the guide rod (26) through the rod groove (25).

10. A buoyancy plug for drilling pipe construction according to claim 9, characterized in that: The opposite surfaces of the top plate (14) and the bottom plate (15) are respectively sealed and connected to the top and bottom of the closing plate (4) through rubber sealing rings.

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