Float collar float shoe for cementing large-diameter well

Abstract

The utility model provides a float collar float shoe for well cementation of a large-diameter well, which comprises an outer cylinder, a float collar and a float shoe, the sealing ring is mounted on the inner side of the upper end of the outer cylinder, and a conical hole is formed in the lower end of the inner side of the sealing ring; the upper end of the valve element is of a conical structure; the bottom ring is installed on the inner side of the lower end of the outer cylinder, an inner pipe is fixedly arranged on the bottom ring, and a first through hole is formed in the side wall of the inner pipe; the inner diameter of the outer sleeve is matched with the outer diameter of the inner pipe, a second through hole is formed in the side wall of the outer sleeve, and the first compression spring is installed between the baffle and the bottom ring. The utility model has the beneficial effects that when grouting is stopped, the pressure in a well is greater than the pressure at the upper end of the valve core, the outer sleeve moves upwards, the through hole II and the through hole I do not coincide at the moment, the first sealing is completed, the valve core moves upwards to abut against the conical hole to complete the second sealing and multiple sealing forms, and the sealing effect is ensured; and the other seal can still play a sealing role.

Description

Technical Field

[0001] The utility model belongs to the technical field of floating collars and floating shoes for cementing, in particular to a floating collar and floating shoe for cementing a large-diameter well. Background Art

[0002] In oil production projects, cementing operations are required after completing each stage of large-diameter well drilling operations. During cementing, casing is lowered into the drilled open hole and cement slurry is filled in the gap outside the casing. After the cement slurry solidifies, the casing can be fixed to the well wall and effectively protected.

[0003] A float hoop and a float shoe are installed at the lower end of the casing string. The float hoop and a float shoe are a type of casing coupling or guide shoe that can generate buoyancy. A one-way valve is arranged inside the float hoop and a float shoe prevents cementing slurry from flowing back into the casing. Due to the large grouting volume of large-diameter wells, the current use of float hoop and a float shoe has the following problems: first, the sealing valve core is easily stuck by stones and cannot be sealed; second, the sealing effect of a single valve core cannot be guaranteed; third, after a period of use, the valve core and the seal age and the sealing effect deteriorates, and the process of disassembly and replacement is complicated, resulting in low maintenance efficiency. Utility Model Content

[0004] In view of this, the utility model aims to provide a floating collar and a floating shoe for cementing a large-diameter well, in order to solve at least one of the above-mentioned technical problems.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A floating collar and a floating shoe for cementing a large diameter well, comprising:

[0007] An outer cylinder, wherein a discharge pipe is provided at the lower end of the outer cylinder;

[0008] A sealing ring is installed on the inner side of the upper end of the outer cylinder, and the lower end of the inner side of the sealing ring is a tapered hole;

[0009] A valve core, wherein the upper end of the valve core is a conical structure, the conical structure of the valve core matches the conical hole, and the conical structure of the valve core fits the inner side of the conical hole;

[0010] A bottom ring, the bottom ring is installed on the inner side of the lower end of the outer tube, an inner tube is fixed on the bottom ring, and a through hole 1 is opened on the side wall of the inner tube;

[0011] An outer sleeve, the inner diameter of the outer sleeve matches the outer diameter of the inner tube, a through hole 2 is opened on the side wall of the outer sleeve, the inner tube is installed on the inner side of the outer sleeve, a baffle is provided at the upper end of the outer sleeve, the baffle closes the upper end opening of the outer sleeve, and the valve core is connected to the baffle;

[0012] A first compression spring is installed between the baffle and the bottom ring.

[0013] Furthermore, the lower end of the valve core is fixedly connected to the baffle.

[0014] Furthermore, a guide rod is fixedly provided at the lower end of the valve core, a guide tube matching the guide rod is fixedly provided at the upper end of the baffle plate, and the guide rod is installed on the inner side of the guide tube;

[0015] A second compression spring is arranged between the valve core and the baffle.

[0016] Furthermore, the lower end of the valve core is connected to a limit rod and a guide rod in sequence, the baffle is provided with a first guide hole matching the guide rod, the diameter of the limit rod is larger than the diameter of the guide rod, and the guide rod is installed on the inner side of the first guide hole;

[0017] A first annular sealing groove is provided inside the first guide hole, and a first sealing ring is provided inside the first annular sealing groove.

[0018] Furthermore, both ends of the outer tube are provided with mounting grooves, the diameter of the mounting grooves is larger than the inner diameter of the outer tube, and the mounting grooves are provided with internal threads;

[0019] The outer diameter of the sealing ring matches the inner diameter of the outer cylinder, and an annular clamping boss is fixedly arranged on the upper end of the sealing ring, and the diameter of the annular clamping boss matches the diameter of the mounting groove. A pressing ring is arranged in the mounting groove, and the pressing ring is threadedly connected to the inner side of the mounting groove, and the pressing ring presses the upper end surface of the annular clamping boss;

[0020] A second annular sealing groove is formed on the lower end surface of the annular pressing boss, and a second sealing ring is arranged in the second annular sealing groove;

[0021] An annular positioning boss is fixedly arranged at the lower end of the pressure ring, a positioning groove matching the annular positioning boss is opened at the upper end of the sealing ring, the annular positioning boss is located at the inner side of the positioning groove, and the annular positioning boss presses tightly against the bottom end of the positioning groove.

[0022] Furthermore, the lower end of the discharge pipe is an inverted tapered pipe, and the outer side wall of the inverted tapered pipe is provided with a discharge hole;

[0023] An external threaded portion is provided at the upper end of the discharge pipe, and the external threaded portion is threadedly connected to the inner side of the lower end of the outer cylinder.

[0024] Furthermore, a threaded groove is formed at the lower end of the bottom ring, a mounting ring is provided in the threaded groove, the mounting ring is threadedly connected to the threaded groove, the inner diameter of the mounting ring is smaller than the inner diameter of the bottom ring, and the first compression spring is installed between the mounting ring and the baffle.

[0025] Furthermore, the outer side of the bottom ring is provided with an external thread, the bottom ring thread is connected to the mounting groove at the lower end of the outer tube, the upper end of the bottom ring is provided with a third annular sealing groove corresponding to the bottom end of the mounting groove, and a third sealing ring is provided in the third annular sealing groove.

[0026] Furthermore, an annular plate is fixedly provided on the outer side of the lower end of the outer sleeve, a second guide hole is formed on the annular plate, a guide column corresponding to the second guide hole is formed on the bottom ring, the guide column is installed on the inner side of the second guide hole, and a water permeable hole corresponding to the annular plate is formed on the bottom ring;

[0027] When in working state, the positions of through hole 1 and through hole 2 correspond;

[0028] When in a sealed state, there is no overlapping portion between the positions of through hole 1 and through hole 2, and the upper end of the outer sleeve seals through hole 1.

[0029] Furthermore, a fourth annular sealing groove is formed on the outer side wall of the annular plate, and a fourth sealing ring is provided in the fourth annular sealing groove.

[0030] Compared with the prior art, the floating collar and floating shoe for cementing a large diameter well described in the utility model has the following beneficial effects:

[0031] (1) The utility model discloses a floating hoop and a floating shoe for cementing a large-diameter well. When grouting is stopped, the pressure in the well is greater than the pressure on the upper end of the valve core, and the outer casing moves upward. At this time, the second through hole and the first through hole do not overlap, completing the first seal. The valve core moves upward to press against the conical hole to complete the second seal. The multi-sealing form ensures the sealing effect. When one sealing structure is stuck by a stone, the other sealing structure can still play a sealing role.

[0032] (2) The floating collar and floating shoe for cementing a large-diameter well described in the utility model has an annular positioning boss corresponding to the position of the tapered hole, which plays a role in supporting the tapered hole and ensuring the sealing effect. The threaded connection setting of the pressure ring facilitates the installation and removal of the sealing ring, thereby improving the maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0034] Figure 1 This is a schematic diagram of the three-dimensional structure of a floating hoop and a floating shoe according to the first embodiment of the utility model;

[0035] Figure 2 This is a schematic diagram of the exploded three-dimensional structure of the floating hoop and floating shoe of the first embodiment of the utility model;

[0036] Figure 3 This is a schematic diagram of the three-dimensional structure of the discharge pipe of Example 1 described in the embodiment of the utility model;

[0037] Figure 4 This is a schematic cross-sectional structure diagram of a floating hoop and a floating shoe according to a first embodiment of the utility model;

[0038] Figure 5 For the embodiment of the utility model Figure 4 Schematic diagram of the structure at A in the middle;

[0039] Figure 6 For the embodiment of the utility model Figure 4 Schematic diagram of the structure at B in the middle;

[0040] Figure 7 For the embodiment of the utility model Figure 4 Schematic diagram of the structure at C in the middle;

[0041] Figure 8 This is a schematic diagram of the three-dimensional structure of the inner tube of the first embodiment of the utility model;

[0042] Fig. 9 This is a schematic diagram of the three-dimensional structure of the outer sleeve of the first embodiment of the utility model;

[0043] Fig.10 This is a schematic diagram of the three-dimensional structure of a sealing ring in Example 1 of the embodiment of the utility model;

[0044] Fig.11 This is a schematic diagram of the three-dimensional structure of the pressure ring in the first embodiment of the utility model;

[0045] Fig.12 This is a schematic diagram of the three-dimensional structure of the valve core in Example 1 of the embodiment of the utility model;

[0046] Fig.13 This is a schematic diagram of the cross-sectional structure of the second floating hoop and floating shoe according to an embodiment of the utility model;

[0047] Fig.14 It is a schematic diagram of the cross-sectional structure of a float shoe with three float hoops as described in an embodiment of the utility model.

[0048] Description of reference numerals:

[0049] 1. Outer tube; 2. Discharge pipe; 3. Pressing ring; 4. Sealing ring; 5. Valve core; 6. Outer sleeve; 7. Inner tube; 8. Mounting ring; 9. First compression spring; 10. Second compression spring; 11. Second sealing ring; 12. Third sealing ring; 13. Fourth sealing ring; 14. First sealing ring; 101. Mounting groove; 201. Discharge hole; 301. Annular positioning boss; 401. Conical hole; 402. Annular clamping boss; 403. Positioning groove; 501. Guide rod; 502. Limit rod; 601. Annular plate; 602. Fourth annular sealing groove; 603. Second guide hole; 604. Through hole two; 605. Baffle; 701. Bottom ring; 702. Third annular sealing groove; 703. Guide column; 704. Through hole one; 705. Water permeable hole. DETAILED DESCRIPTION

[0050] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0051] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0053] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0054] Embodiment 1:

[0055] like Figures 1 to 12 As shown, a floating collar and a floating shoe for cementing a large diameter well include:

[0056] An outer cylinder 1, a discharge pipe 2 is provided at the lower end of the outer cylinder 1;

[0057] The sealing ring 4 is installed on the inner side of the upper end of the outer tube 1, and the lower end of the inner side of the sealing ring 4 is a tapered hole 401;

[0058] The valve core 5 has a conical structure at its upper end, and the conical structure of the valve core 5 matches the conical hole 401, and the conical structure of the valve core 5 fits the inner side of the conical hole 401;

[0059] Bottom ring 701, bottom ring 701 is installed on the inner side of the lower end of outer tube 1, inner tube 7 is fixed on bottom ring 701, and a through hole 704 is opened on the side wall of inner tube 7;

[0060] An outer sleeve 6, the inner diameter of the outer sleeve 6 matches the outer diameter of the inner tube 7, a second through hole 604 is opened on the side wall of the outer sleeve 6, the inner tube 7 is installed on the inner side of the outer sleeve 6, a baffle 605 is provided at the upper end of the outer sleeve 6, the baffle 605 closes the upper end opening of the outer sleeve 6, and the valve core 5 is connected to the baffle 605;

[0061] The first compression spring 9 is installed between the baffle 605 and the bottom ring 701 .

[0062] The valve core 5, the outer sleeve 6 and the inner tube 7 are all structural parts made of wear-resistant steel, and the sealing ring 4 is made of but not limited to the existing high-temperature resistant rubber material.

[0063] The lower end of the valve core 5 is connected to the limit rod 502 and the guide rod 501 in sequence. The baffle plate 605 is provided with a first guide hole matching the guide rod 501. The diameter of the limit rod 502 is larger than that of the guide rod 501. The guide rod 501 is installed inside the first guide hole.

[0064] A first annular sealing groove is provided inside the first guide hole, and a first sealing ring 14 is provided inside the first annular sealing groove. The first sealing ring 14 improves the sealing performance between the first guide hole and the guide rod 501 .

[0065] Both ends of the outer tube 1 are provided with mounting grooves 101, the diameter of the mounting grooves 101 is larger than the inner diameter of the outer tube 1, and the mounting grooves 101 are provided with internal threads;

[0066] The outer diameter of the sealing ring 4 matches the inner diameter of the outer tube 1, and an annular clamping boss 402 is fixedly provided at the upper end of the sealing ring 4. The diameter of the annular clamping boss 402 matches the diameter of the mounting groove 101, and a pressing ring 3 is provided in the mounting groove 101. The pressing ring 3 is threadedly connected to the inner side of the mounting groove 101, and the pressing ring 3 presses the upper end surface of the annular clamping boss 402; a second annular sealing groove is opened on the lower end surface of the annular clamping boss 402, and a second sealing ring 11 is provided in the second annular sealing groove; the second sealing ring 11 improves the sealing between the annular clamping boss 402 and the bottom end of the mounting groove 101. An annular positioning boss 301 is fixed at the lower end of the pressure ring 3, and a positioning groove 403 matching the annular positioning boss 301 is opened at the upper end of the sealing ring 4. The annular positioning boss 301 is located on the inner side of the positioning groove 403, and the annular positioning boss 301 presses against the bottom end of the positioning groove 403. The annular positioning boss 301 corresponds to the position of the tapered hole 401, which supports the tapered hole 401 and ensures the sealing effect. The threaded connection setting of the pressure ring 3 facilitates the installation and removal of the sealing ring 4, thereby improving the maintenance efficiency.

[0067] The lower end of the discharge pipe 2 is an inverted tapered pipe, which plays a guiding role during the movement in the well. The outer wall of the inverted tapered pipe is provided with a discharge hole 201; the upper end of the discharge pipe 2 is provided with an external threaded portion, which is connected to the inner thread of the lower end of the outer tube 1.

[0068] A threaded groove is formed at the lower end of the bottom ring 701, and a mounting ring 8 is disposed in the threaded groove. The mounting ring 8 is threadedly connected to the threaded groove. The inner diameter of the mounting ring 8 is smaller than the inner diameter of the bottom ring 701. The first compression spring 9 is installed between the mounting ring 8 and the baffle 605. The first compression spring 9 can be replaced or cleaned by disassembling the mounting ring 8.

[0069] An external thread is provided on the outer side of the bottom ring 701, and the bottom ring 701 is threadedly connected to the mounting groove 101 at the lower end of the outer tube 1. A third annular sealing groove 702 corresponding to the bottom end of the mounting groove 101 is provided on the upper end of the bottom ring 701, and a third sealing ring 12 is provided in the third annular sealing groove 702. The third sealing ring 12 improves the sealing between the bottom ring 701 and the bottom end of the mounting groove 101.

[0070] An annular plate 601 is fixedly provided on the outer side of the lower end of the outer sleeve, a second guide hole 603 is opened on the annular plate 601, a guide column 703 corresponding to the second guide hole 603 is opened on the bottom ring 701, a retaining ring is fixedly provided on the upper end of the guide column 703, the retaining ring is used to limit the annular plate 601, the guide column 703 is installed on the inner side of the second guide hole 603, and a water-permeable hole 705 corresponding to the annular plate 601 is opened on the bottom ring 701; the second guide hole 603 and the guide column 703 are installed in coordination with each other, and can also prevent relative rotation between the sleeve and the inner tube 7, thereby ensuring that the through hole 1 704 is aligned with the through hole 2 604.

[0071] When in working state, the positions of through hole 1 704 and through hole 2 604 correspond to each other; when in sealing state, there is no overlapping part between the positions of through hole 1 704 and through hole 2 604, and the upper end of the outer sleeve seals through hole 1 704.

[0072] A fourth annular sealing groove 602 is formed on the outer wall of the annular plate 601 . A fourth sealing ring 13 is disposed in the fourth annular sealing groove 602 . The fourth sealing ring 13 improves the sealing performance between the annular plate 601 and the bottom ring 701 .

[0073] Assembly process:

[0074] Install the sealing ring 4 to the inner side of the outer tube 1, then tighten the pressure ring 3 in the installation groove 101 at the upper end of the outer tube 1, install the second compression spring 10 on the outer side of the guide rod 501, install the guide rod 501 of the valve core 5 on the inner side of the first guide hole of the baffle 605, then sleeve the outer sleeve 6 on the outer side of the inner tube 7, and thread the bottom ring 701 into the installation groove 101 at the lower end of the outer tube 1. During this process, the second compression spring 10 is compressed, the first compression spring 9 is installed on the inner side of the inner tube 7, and the installation ring 8 is tightened in the threaded groove. During this process, the first compression spring 9 is compressed, and the discharge pipe 2 is installed. The assembly process is convenient, easy to assemble and disassemble, and the maintenance efficiency is improved.

[0075] Working process:

[0076] The upper end of the outer tube 1 is connected to the grouting equipment through the casing string. When the slurry flows out, the pressure at the upper end of the valve core 5 is greater than the pressure at the lower end. At this time, the valve core 5 moves downward, and the second compression spring 10 compresses the slurry to flow in from the tapered hole 401. After the limit tube at the lower end of the valve core 5 presses the baffle 605, the outer sleeve moves downward to align the through hole 2 604 with the through hole 1 704. The slurry flows from the through hole 2 604, the through hole 1 704, the inner tube 7, the bottom ring 701 to the discharge pipe 2 in sequence, and finally enters the well through the discharge hole 201 on the lower end and side wall of the discharge pipe 2.

[0077] When grouting is stopped, the pressure in the well is greater than the pressure on the upper end of the valve core 5. Under the elastic force of the compression spring one and the pressure of the liquid in the well, the outer sleeve 6 moves upward. At this time, the through hole 2 604 and the through hole 1 704 do not overlap, completing the first seal. Under the elastic force of the compression spring two and the pressure of the liquid in the well, the valve core 5 moves upward to press against the conical hole 401 to complete the second seal. The multi-sealing form ensures the sealing effect. When one sealing structure is stuck by a stone, the other seal can still play a sealing role.

[0078] The sealing form of the through hole 1 704 and the through hole 2 604 is less likely to be stuck by stones than the valve core 5, and the sealing structure of the valve core 5 has a better sealing effect.

[0079] Embodiment 2:

[0080] like Fig.13 As shown, a floating collar and a floating shoe for cementing a large diameter well include:

[0081] An outer cylinder 1, a discharge pipe 2 is provided at the lower end of the outer cylinder 1;

[0082] The sealing ring 4 is installed on the inner side of the upper end of the outer tube 1, and the lower end of the inner side of the sealing ring 4 is a tapered hole 401;

[0083] The valve core 5 has a conical structure at its upper end, and the conical structure of the valve core 5 matches the conical hole 401, and the conical structure of the valve core 5 fits the inner side of the conical hole 401;

[0084] Bottom ring 701, bottom ring 701 is installed on the inner side of the lower end of outer tube 1, inner tube 7 is fixed on bottom ring 701, and a through hole 704 is opened on the side wall of inner tube 7;

[0085] An outer sleeve 6, the inner diameter of the outer sleeve 6 matches the outer diameter of the inner tube 7, a second through hole 604 is opened on the side wall of the outer sleeve 6, the inner tube 7 is installed on the inner side of the outer sleeve 6, a baffle 605 is provided at the upper end of the outer sleeve 6, the baffle 605 closes the upper end opening of the outer sleeve 6, and the valve core 5 is connected to the baffle 605;

[0086] The first compression spring 9 is installed between the baffle 605 and the bottom ring 701 , and the lower end of the valve core 5 is fixedly connected to the baffle 605 .

[0087] Working process:

[0088] The upper end of the outer tube 1 is connected to the grouting equipment through the casing string. When the slurry flows out, the pressure at the upper end of the valve core 5 is greater than the pressure at the lower end. At this time, the valve core 5 and the outer casing 6 move downward, and the slurry flows in from the tapered hole 401. The outer casing moves downward so that the second through hole 604 is aligned with the first through hole 704. The slurry flows through the second through hole 604, the first through hole 704, the inner tube 7, the bottom ring 701, and into the discharge pipe 2 in sequence, and finally enters the well through the discharge hole 201 on the lower end and side wall of the discharge pipe 2.

[0089] When grouting is stopped, the pressure in the well is greater than the pressure on the upper end of the valve core 5. Under the action of the elastic force of the compression spring 1 and the pressure of the liquid in the well, the outer sleeve and the valve core 5 tube move upward. At this time, the through hole 2 604 and the through hole 1 704 do not overlap, completing the first seal. The valve core 5 moves upward to press against the conical hole 401 to complete the second seal. The multi-sealing form ensures the sealing effect.

[0090] Embodiment three:

[0091] like Fig.14 As shown, a floating collar and a floating shoe for cementing a large diameter well include:

[0092] An outer cylinder 1, a discharge pipe 2 is provided at the lower end of the outer cylinder 1;

[0093] The sealing ring 4 is installed on the inner side of the upper end of the outer tube 1, and the lower end of the inner side of the sealing ring 4 is a tapered hole 401;

[0094] The valve core 5 has a conical structure at its upper end, and the conical structure of the valve core 5 matches the conical hole 401, and the conical structure of the valve core 5 fits the inner side of the conical hole 401;

[0095] Bottom ring 701, bottom ring 701 is installed on the inner side of the lower end of outer tube 1, inner tube 7 is fixed on bottom ring 701, and a through hole 704 is opened on the side wall of inner tube 7;

[0096] An outer sleeve 6, the inner diameter of the outer sleeve 6 matches the outer diameter of the inner tube 7, a second through hole 604 is opened on the side wall of the outer sleeve 6, the inner tube 7 is installed on the inner side of the outer sleeve 6, a baffle 605 is provided at the upper end of the outer sleeve 6, the baffle 605 closes the upper end opening of the outer sleeve 6, and the valve core 5 is connected to the baffle 605;

[0097] The first compression spring 9 is installed between the baffle 605 and the bottom ring 701 .

[0098] A guide rod 501 is fixedly disposed at the lower end of the valve core 5, and a guide tube matching the guide rod 501 is fixedly disposed at the upper end of the baffle 605, and the guide rod 501 is installed on the inner side of the guide tube;

[0099] A second compression spring 10 is provided between the valve core 5 and the baffle 605 .

[0100] Working process:

[0101] The upper end of the outer tube 1 is connected to the grouting equipment through the casing string. When the slurry flows out, the pressure at the upper end of the valve core 5 is greater than the pressure at the lower end. At this time, the valve core 5 moves downward, and the second compression spring 10 compresses the slurry to flow in from the tapered hole 401. After the limit tube at the lower end of the valve core 5 presses the baffle 605, the outer sleeve moves downward to align the through hole 2 604 with the through hole 1 704. The slurry flows from the through hole 2 604, the through hole 1 704, the inner tube 7, the bottom ring 701 to the discharge pipe 2 in sequence, and finally enters the well through the discharge hole 201 on the lower end and side wall of the discharge pipe 2.

[0102] When grouting is stopped, the pressure in the well is greater than the pressure on the upper end of the valve core 5. Under the elastic force of the compression spring one and the pressure of the liquid in the well, the outer sleeve 6 moves upward. At this time, the through hole 2 604 and the through hole 1 704 do not overlap, completing the first seal. Under the elastic force of the compression spring two and the pressure of the liquid in the well, the valve core 5 moves upward to press against the conical hole 401 to complete the second seal. The multi-sealing form ensures the sealing effect. When one sealing structure is stuck by a stone, the other seal can still play a sealing role.

[0103] The sealing form of the through hole 1 704 and the through hole 2 604 is less likely to be stuck by stones than the valve core 5, and the sealing structure of the valve core 5 has a better sealing effect.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the utility model, and they should all be included in the scope of the claims and specification of the utility model.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A floating collar and floating shoe for cementing a large diameter well, characterized in that: include: An outer cylinder (1), wherein a discharge pipe (2) is provided at the lower end of the outer cylinder (1); A sealing ring (4), the sealing ring (4) being mounted on the inner side of the upper end of the outer cylinder (1), the inner lower end of the sealing ring (4) being a tapered hole (401); A valve core (5), wherein the upper end of the valve core (5) is a conical structure, the conical structure of the valve core (5) matches the conical hole (401), and the conical structure of the valve core (5) fits the inner side of the conical hole (401); A bottom ring (701), the bottom ring (701) being mounted on the inner side of the lower end of the outer tube (1), an inner tube (7) being fixedly mounted on the bottom ring (701), and a through hole (704) being formed on the side wall of the inner tube (7); An outer sleeve (6), the inner diameter of the outer sleeve (6) matches the outer diameter of the inner tube (7), a second through hole (604) is opened on the side wall of the outer sleeve (6), the inner tube (7) is installed on the inner side of the outer sleeve (6), a baffle (605) is provided at the upper end of the outer sleeve (6), the baffle (605) closes the upper end opening of the outer sleeve (6), and the valve core (5) is connected to the baffle (605); A first compression spring (9), wherein the first compression spring (9) is installed between the baffle (605) and the bottom ring (701).

2. The floating collar and floating shoe for cementing a large diameter well according to claim 1, characterized in that: The lower end of the valve core (5) is fixedly connected to the baffle (605).

3. The floating collar and floating shoe for cementing a large diameter well according to claim 1, characterized in that: A guide rod (501) is fixedly provided at the lower end of the valve core (5), a guide tube matching the guide rod (501) is fixedly provided at the upper end of the baffle (605), and the guide rod (501) is installed on the inner side of the guide tube; A second compression spring (10) is provided between the valve core (5) and the baffle (605).

4. The floating collar and floating shoe for cementing a large diameter well according to claim 1, characterized in that: The lower end of the valve core (5) is connected to a limit rod (502) and a guide rod (501) in sequence, the baffle plate (605) is provided with a first guide hole matching the guide rod (501), the diameter of the limit rod (502) is larger than the diameter of the guide rod (501), and the guide rod (501) is installed on the inner side of the first guide hole; A first annular sealing groove is provided inside the first guide hole, and a first sealing ring (14) is provided inside the first annular sealing groove.

5. The floating collar and floating shoe for cementing a large diameter well according to claim 1, characterized in that: Both ends of the outer cylinder (1) are provided with mounting grooves (101), the diameter of the mounting groove (101) is larger than the inner diameter of the outer cylinder (1), and an internal thread is provided in the mounting groove (101); The outer diameter of the sealing ring (4) matches the inner diameter of the outer cylinder (1); an annular clamping boss (402) is fixedly provided at the upper end of the sealing ring (4); the diameter of the annular clamping boss (402) matches the diameter of the mounting groove (101); a pressing ring (3) is provided in the mounting groove (101); the pressing ring (3) is threadedly connected to the inner side of the mounting groove (101); the pressing ring (3) presses the upper end surface of the annular clamping boss (402); A second annular sealing groove is formed on the lower end surface of the annular pressing boss (402), and a second sealing ring (11) is arranged in the second annular sealing groove; An annular positioning boss (301) is fixedly arranged at the lower end of the pressure ring (3), and a positioning groove (403) matching the annular positioning boss (301) is opened at the upper end of the sealing ring (4). The annular positioning boss (301) is located on the inner side of the positioning groove (403), and the annular positioning boss (301) is pressed tightly against the bottom end of the positioning groove (403).

6. The floating collar and floating shoe for cementing a large diameter well according to claim 5, characterized in that: The lower end of the discharge pipe (2) is an inverted conical pipe, and the outer side wall of the inverted conical pipe is provided with a discharge hole (201); The upper end of the discharge pipe (2) is provided with an external threaded portion, and the external threaded portion is threadedly connected to the inner side of the lower end of the outer cylinder (1).

7. The floating collar and floating shoe for cementing a large diameter well according to claim 5, characterized in that: A thread groove is formed at the lower end of the bottom ring (701), a mounting ring (8) is provided in the thread groove, the mounting ring (8) is threadedly connected to the thread groove, the inner diameter of the mounting ring (8) is smaller than the inner diameter of the bottom ring (701), and the first compression spring (9) is installed between the mounting ring (8) and the baffle (605).

8. The floating collar and floating shoe for cementing a large diameter well according to claim 5, characterized in that: The outer side of the bottom ring (701) is provided with an external thread, and the bottom ring (701) is threadedly connected to the mounting groove (101) at the lower end of the outer tube (1). The upper end of the bottom ring (701) is provided with a third annular sealing groove (702) corresponding to the bottom end of the mounting groove (101), and a third sealing ring (12) is provided in the third annular sealing groove (702).

9. The floating collar and floating shoe for cementing a large diameter well according to claim 5, characterized in that: An annular plate (601) is fixedly provided on the outer side of the lower end of the outer sleeve, a second guide hole (603) is formed on the annular plate (601), a guide column (703) corresponding to the second guide hole (603) is formed on the bottom ring (701), the guide column (703) is installed on the inner side of the second guide hole (603), and a water permeable hole (705) corresponding to the annular plate (601) is formed on the bottom ring (701); When in working state, the positions of through hole 1 (704) and through hole 2 (604) correspond; When in a sealed state, there is no overlapping portion between the positions of through hole 1 (704) and through hole 2 (604), and the upper end of the outer sleeve seals through hole 1 (704).

10. The floating collar and floating shoe for cementing a large diameter well according to claim 9, characterized in that: A fourth annular sealing groove (602) is formed on the outer side wall of the annular plate (601), and a fourth sealing ring (13) is arranged in the fourth annular sealing groove (602).

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