A hydraulic staged cementer for cementing

Abstract

The application provides a hydraulic staged cementing device for well cementation and relates to the field of oil well cementation. The staged cementing device comprises a cementing device body, a working ring groove is arranged in the middle part of the inner cavity of the cementing device body, a matched opening sleeve is arranged in the inner part of the working ring groove, an extension pipe is arranged on the inner side of the bottom of the opening sleeve, the outer diameter of the extension pipe is consistent with the inner diameter of the pipe segment below the working ring groove of the cementing device body, second through holes are arranged on the upper sides of the two sides of the extension pipe, and unequal pitch compression springs are arranged on the outer part of the extension pipe below the inner part of the working ring groove. High pressure cement is extruded into the inner part of the containing groove, the closing sleeve is extruded upwards, the cementing hole is resealed, the situation that the opening and closing sleeves are not released smoothly due to the fact that the shearing pin cannot be completely and perfectly broken off at one time during pressure holding in the prior art is avoided, and the use performance is more stable.

Description

Technical Field

[0001] This invention relates to the field of oil well cementing technology, specifically to a hydraulic staged cementing device for well cementing. Background Technology

[0002] A staged cement injector, also known as a staged clamp, is used for secondary cementing during the cementing process of oil and gas wells. During cementing operations, cement is injected into the wellbore, and then a cement plug is inserted into the well to force the cement into the annulus between the open hole wall and the tubing via a hydraulic staged cement injector. In existing technology, the opening and closing sleeves within the hydraulic staged cement injector are typically installed inside using shear pins. However, during subsequent pressurization, the applied pressure cannot ensure that the shear pins around the opening and closing sleeves completely and perfectly disconnect in one go, leading to misalignment of the opening and closing sleeves, unsuccessful release, and unstable performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a hydraulic staged cementing device for well cementing, which solves the problem in existing technologies where, during pressurization, it is impossible to ensure that the shear pins are completely and perfectly disconnected in one go, resulting in unsmooth release of the opening and closing sleeves.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a hydraulic staged cementing injector for well cementing, comprising an injector body, wherein a working annular groove is formed in the middle of the inner cavity of the injector body, and a suitable opening sleeve is provided inside the working annular groove. An extension tube is installed around the bottom inner side of the opening sleeve, the outer diameter of the extension tube being consistent with the inner diameter of the section of the injector body located below the working annular groove. Second through holes are formed on both sides of the extension tube, and a sleeve is provided on the outside of the extension tube below the inner cavity of the working annular groove. The unequal pitch compression spring has an inner upper receiving groove in the opening sleeve, and a matching closing sleeve is provided inside the receiving groove. A protruding tenon is provided around the top port of the closing sleeve. A groove matching the protruding tenon is provided on the top inner wall of the working ring cavity. A sealing plate is installed on both sides of the bottom of the closing sleeve. The bottom of the sealing plate passes through both sides of the bottom of the receiving groove and extends to the bottom of the second through hole on both sides. The bottom of the sealing plate extends downward on both sides. Multiple first through holes are provided on both sides of the bottom of the receiving groove located on the sealing plate.

[0005] Preferably, a lower connecting pipe is installed at the lower end of the body of the hydraulic graded cementing machine for cementing, and the inner diameter of the lower connecting pipe is the same as the inner diameter of the section of the hydraulic graded cementing machine body located below the working annular groove.

[0006] Preferably, an upper connecting pipe is installed at the upper internal end of the body of the hydraulic staged cementing device for well cementing.

[0007] Preferably, the hydraulic graded cement injector for cementing further includes an opening plug and a closing plug. The outer diameter of the widest part of the opening plug is consistent with the inner diameter of the upper connecting pipe. The outer diameter of the widest part of the opening plug is consistent with the inner diameter of the pipe section above the working ring groove of the hydraulic graded cement injector body. The outer diameter of the widest part of the opening plug is consistent with the inner diameter of the opening sleeve. The outer diameter of the widest part of the opening plug is consistent with the inner diameter of the extension pipe. A plug support ring is provided around the inner side of the bottom port of the extension pipe. A cross-section adapted to the plug support ring is provided on the lower outer side of the opening plug.

[0008] Preferably, the outer diameter of the thickest part of the closing plug is the same as the outer diameter of the thickest part of the opening plug.

[0009] Preferably, cement injection holes are provided on both sides of the body of the hydraulic graded cementing device for cementing.

[0010] Working principle: This hydraulic staged cementing injector is connected in series with other required casings via the lower and upper connecting pipes. Then, with the assistance of a centralizer, it is lowered into the well. When cementing is required using this hydraulic staged cementing injector, firstly, the opening plug is inserted into the pipe. The opening plug descends until it is tightly fitted with the plug ring. Then, pre-fluid is injected into the pipe. Figure 4-5 As shown, once the pre-flush fluid touches the top of the opening plug, it will be cut off. Then, with appropriate pressurization, the extension tube will be pushed downwards, causing the opening sleeve to move down and expose the cement injection hole. Due to the graded elastic force of the unequal pitch compression spring, the opening sleeve will only move down a partial distance. Since the extension sections on both sides of the bottom of the sealing plate just touch the bottom inner wall of the working annular groove, the second through hole is still completely blocked by the sealing plate. At this point, the high-pressure pre-flush fluid will break through the hole cover, causing the self-cementing hole to surge into the external annulus. After continuous injection, it will displace the drilling fluid in the annulus and then inject cement slurry into the well. The cement slurry will follow the path of the pre-flush fluid into the external annulus, forming an isolation protective layer between the casing and the wellbore. Then, the closing plug is inserted into the tube, and pressure is applied to the closing plug, which will push the cement slurry in the tube, causing most of it to enter the annulus. Figure 6-7As shown, when the closing plug moves down to the cement injection hole, the pipe is pressurized again. At this time, the cement slurry between the opening plug and the closing plug can no longer be discharged into the annulus. Therefore, when the pipe is pressurized again, the opening plug will push the extension pipe down again until the unequal pitch compression spring can no longer be compressed. At this time, due to the obstruction of the extension sections on both sides of the bottom of the sealing plate, the closing sleeve and the sealing plate are stuck at the original height. Then, the cement slurry between the opening plug and the closing plug will flow into the receiving groove through the second through hole and the first through hole, thereby continuously pushing the closing sleeve upward until the protruding tenon at the top end of the closing sleeve is embedded in the slot. At this time, the cement injection hole is re-sealed and the cement slurry is injected. After the cement slurry solidifies, the opening plug and the closing plug can be drilled out to achieve the penetration of the sleeve.

[0011] This invention provides a hydraulic staged cementing device for well cementing. It has the following beneficial effects:

[0012] This invention injects high-pressure cement into the receiving groove through the second and first through holes, thereby extruding the closing sleeve upwards. When the closing sleeve and the slot are interlocked, the cement injection hole can be resealed. This avoids the method in the prior art where the opening and closing sleeves of the hydraulic graded cement injector for cementing need to be installed inside the hydraulic graded cement injector using shear pins. This also avoids the situation where the shear pins cannot be completely and perfectly disconnected at once during pressurization, which would lead to unsmooth release of the opening and closing sleeves. The performance is more stable. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention;

[0014] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0015] Figure 3 This is a schematic diagram of the opening and closing sleeve structures of the present invention;

[0016] Figure 4 This is a schematic diagram showing the state of the plug being engaged in an embodiment of the present invention;

[0017] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0018] Figure 6 This is a schematic diagram showing the state of the closing plug in an embodiment of the present invention;

[0019] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0020] Figure 8 This is a schematic diagram showing the state of the closing sleeve re-sealing the cement injection hole in an embodiment of the present invention;

[0021] Figure 9 for Figure 8 Enlarged view of point D in the middle.

[0022] The components include: 1. Cement injector body; 2. Lower connecting pipe; 3. Upper connecting pipe; 4. Opening plug; 5. Closing plug; 6. Cement injection hole; 7. Working ring groove; 8. Opening sleeve; 9. First through hole; 10. Extension pipe; 11. Second through hole; 12. Closing sleeve; 13. Sealing plate; 14. Slot; 15. Unequal pitch compression spring; and 16. Plug ring. Detailed Implementation

[0023] 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.

[0024] Example:

[0025] like Figure 1-3 As shown, this embodiment of the invention provides a hydraulic staged cementing injector for well cementing, including a cementing injector body 1. A working annular groove 7 is formed in the middle of the inner cavity of the cementing injector body 1. Cement injection holes 6 are formed on both sides of the cementing injector body 1. The cement injection holes 6 are connected to the working annular groove 7. When cementing, cement is injected from the inside of the working annular groove 7 into the external annular space through the cement injection holes 6, thereby realizing the cementing work. Furthermore, when running the casing, the cement injection holes 6 also need to be plugged with a cap from the external opening. At the same time, the cap can only be forced open by high pressure from the inside of the working annular groove 7 to the outside, so as to prevent impurities in the well from entering the hydraulic staged cementing injector for well cementing during casing running.

[0026] Furthermore, a suitable opening sleeve 8 is provided inside the working ring groove 7. An extension tube 10 is installed around the bottom inner side of the opening sleeve 8. The outer diameter of the extension tube 10 is consistent with the inner diameter of the section of the cement injector body 1 located below the working ring groove 7 to ensure sealing. A second through hole 11 is provided on both sides of the extension tube 10. An unequal pitch compression spring 15 is sleeved on the outside of the extension tube 10 located below the inside of the working ring groove 7.

[0027] When no further cementing is performed, the top end of the sleeve 8 will be tightly pressed against the inner wall of the top of the working ring groove 7 under the action of the unequal pitch compression spring 15, while the outside of the extension tube 10 will be tightly pressed against the lower inside of the cement injector body 1, thereby achieving a sealing effect on the cement injection hole 6.

[0028] In this embodiment, the unequal pitch compression spring 15 is a mature existing technology, and its technical principle will not be described in detail here. The purpose of using the unequal pitch compression spring 15 is to provide two states of compression. When it is initially compressed, it can compress the spring segments with a sparser pitch with a lower pressure. When the spring segments with a sparser pitch are fully compressed, the spring segments with a denser pitch require a higher pressure to compress. Therefore, the unequal pitch compression spring 15 can provide two elastic force effects.

[0029] Furthermore, an accommodating groove is provided on the upper part of the opening sleeve 8, and a matching closing sleeve 12 is provided inside the accommodating groove. A protruding tenon is provided around the top end of the closing sleeve 12. A slot 14 that matches the protruding tenon is provided on the top inner wall of the working ring groove cavity 7. A sealing plate 13 is installed on both sides of the bottom of the closing sleeve 12. The bottom of the sealing plate 13 passes through both sides of the bottom of the accommodating groove and extends to the bottom of the second through hole 11 on both sides. The bottom of the sealing plate 13 extends downward on both sides. Multiple first through holes 9 are provided on both sides of the bottom of the accommodating groove located on the sealing plate 13.

[0030] In this embodiment, when the opening sleeve 8 moves downward, the cement injection hole 6 is exposed. After the hole cover is opened by high pressure, cement can be injected into the annulus through the cement injection hole 6 from inside the working annular groove 7 to achieve the purpose of cement injection. After the cement injection is completed, this embodiment envisions squeezing high-pressure cement into the receiving groove through the second through hole 11 and the first through hole 9, thereby squeezing the closing sleeve 12 upward. When the closing sleeve 12 and the slot 14 are interlocked, the cement injection hole 6 can be resealed. This avoids the method in the prior art where the opening and closing sleeves of the hydraulic graded cement injector for cementing need to be installed inside the hydraulic graded cement injector for cementing by means of shearing pins. This avoids the situation where the shearing pins cannot be completely and perfectly disconnected at one time during pressure buildup, resulting in unsmooth release of the opening and closing sleeves. The performance is more stable.

[0031] Furthermore, a lower connecting pipe 2 is installed at the lower end of the body 1 of the hydraulic staged cementing machine for cementing. The inner diameter of the lower connecting pipe 2 is the same as the inner diameter of the pipe section of the cementing machine body 1 located below the working annular groove 7.

[0032] An upper connecting pipe 3 is installed at the upper part of the interior of the cement injection device body 1.

[0033] The upper connecting pipe 3 and the lower connecting pipe 2 are used for connecting with other sleeves.

[0034] Furthermore, the hydraulic staged cementing tool for cementing also includes an opening plug 4 and a closing plug 5. The outer diameter of the thickest part of the opening plug 4 is consistent with the inner diameter of the upper connecting pipe 3. The outer diameter of the thickest part of the opening plug 4 is consistent with the inner diameter of the pipe section above the working ring groove 7 of the cementing tool body 1. The outer diameter of the thickest part of the opening plug 4 is consistent with the inner diameter of the opening sleeve 8. The outer diameter of the thickest part of the opening plug 4 is consistent with the inner diameter of the extension pipe 10. A plug support ring 16 is provided around the inner side of the bottom end of the extension pipe 10. A cross surface adapted to the plug support ring 16 is provided on the lower outer side of the opening plug 4. The outer diameter of the thickest part of the closing plug 5 is consistent with the outer diameter of the thickest part of the opening plug 4.

[0035] The opening plug 4 and the closing plug 5 are used to drive the opening sleeve 8 and the closing sleeve 12 to move, respectively.

[0036] Furthermore, such as Figure 4-9 As shown in the figure, this embodiment also provides a method for using a hydraulic staged cementing device for well cementing, including the following steps:

[0037] 1. Connect the hydraulic staged cementing machine for cementing to other required casings in series through the lower connecting pipe 2 and the upper connecting pipe 3, and then complete the well run-in with the assistance of the centralizer.

[0038] 2. When it is necessary to use this hydraulic graded cementing machine to perform cementing, first, insert the opening plug 4 into the pipe. The opening plug 4 will fall down until it is tightly fitted with the plug ring 16.

[0039] Third, inject the pre-fluid into the tube, such as... Figure 4-5 As shown, once the pre-filled fluid touches the top of the opening plug 4, it will be cut off. Then, after appropriate pressurization, the extension tube 10 can be pushed downward, causing the opening sleeve 8 to move down to expose the cement injection hole 6. Due to the graded elastic force of the unequal pitch compression spring 15, the opening sleeve 8 will only move down a certain distance. Since the extension sections on both sides of the bottom of the sealing plate 13 just touch the bottom inner wall of the working annular groove 7, the second through hole 11 is still completely blocked by the sealing plate 13. At this time, the high-pressure pre-filled fluid will break through the hole cover and then pour the self-injecting cement hole 6 into the annulus. After continuous injection, it will displace the drilling fluid in the annulus and exit the well.

[0040] Fourth, cement slurry is then injected into the well. At this time, the cement slurry will follow the pre-flush fluid into the annulus, thereby forming an isolation and protective layer between the casing and the well wall. Then, the shut-off plug 5 is put into the pipe, and pressure is applied to the shut-off plug 5, which will push the cement slurry in the pipe so that most of it enters the annulus.

[0041] V. For example Figure 6-7As shown, when the closing plug 5 moves down to the cement injection hole 6, the pipe is pressurized again. At this time, the cement slurry between the opening plug 4 and the closing plug 5 can no longer be discharged into the annular space. Therefore, when the pipe is pressurized again, the opening plug 4 will push the extension pipe 10 down again until the unequal pitch compression spring 15 can no longer be compressed. At this time, due to the obstruction of the extension sections on both sides of the bottom of the sealing plate 13, the closing sleeve 12 and the sealing plate 13 are retained at their original height. Then, the cement slurry between the opening plug 4 and the closing plug 5 will flow into the receiving groove through the second through hole 11 and the first through hole 9, thereby continuously pushing the closing sleeve 12 upward. Figure 8-9 As shown, the cement injection hole 6 is sealed again until the protruding tenon at the top port of the closed sleeve 12 is inserted into the slot 14.

[0042] 6. After the cement grout has solidified, the opening plug 4 and closing plug 5 can be drilled out to achieve casing connection.

[0043] 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, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydraulic staged cementing device for well cementing, comprising a cementing device body (1), characterized in that: The cement injector body (1) has a working ring groove (7) in the middle of its inner cavity. A suitable opening sleeve (8) is installed inside the working ring groove (7). An extension tube (10) is installed around the bottom inner side of the opening sleeve (8). The outer diameter of the extension tube (10) is the same as the inner diameter of the section of the cement injector body (1) below the working ring groove (7). Second through holes (11) are opened on both sides of the extension tube (10). A non-standard... An equal-pitch compression spring (15) has an inner upper cavity for the opening sleeve (8), and a matching closing sleeve (12) is provided inside the cavity. A protruding latch is provided around the top end of the closing sleeve (12). A groove (14) matching the protruding latch is provided on the inner top wall of the working ring cavity (7). A sealing plate (13) is installed on both sides of the bottom of the closing sleeve (12). The bottom of the sealing plate (13) passes through both sides of the bottom of the cavity and extends to the bottom of the second through hole (11) on both sides. The bottom sides of the sealing plate (13) extend downwards. The bottom of the receiving groove is provided with multiple first through holes (9) on both sides of the sealing plate (13). A lower connecting pipe (2) is installed at the lower end of the cement injector body (1). The inner diameter of the lower connecting pipe (2) is the same as the inner diameter of the section of the cement injector body (1) below the working ring groove (7). An upper connecting pipe (3) is installed at the upper end of the cement injector body (1). It also includes an opening plug (4) and a closing plug (5). The thickest part of the opening plug (4) The outer diameter is consistent with the inner diameter of the upper connecting pipe (3). The outer diameter of the thickest part of the opening plug (4) is consistent with the inner diameter of the section of the cement injector body (1) above the working ring groove (7). The outer diameter of the thickest part of the opening plug (4) is consistent with the inner diameter of the opening sleeve (8). The outer diameter of the thickest part of the opening plug (4) is consistent with the inner diameter of the extension pipe (10). A plug support ring (16) is provided around the inner side of the bottom port of the extension pipe (10). A cut surface that matches the plug support ring (16) is provided on the lower outer side of the opening plug (4).

2. The hydraulic staged cementing device for well cementing according to claim 1, characterized in that: The outer diameter of the thickest part of the closing plug (5) is the same as the outer diameter of the thickest part of the opening plug (4).

3. A hydraulic staged cementing device for well cementing according to claim 2, characterized in that: The cement injector body (1) has cement injection holes (6) on both sides.

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