Reinforced connection structure of float shoe

Abstract

The utility model relates to the technical field of float shoe, disclose a kind of float shoe reinforced connection structure, comprising: float shoe shell and oil bushing, the oil bushing is connected with the bottom of float shoe shell thread, the bottom end opening of float shoe shell is equipped with several limit notches around, the periphery outer wall of the connecting end of the oil bushing and the float shoe shell is equipped with several limit grooves, when the oil bushing is connected in place after the float shoe shell thread, the limit notches and the limit grooves correspond, and at this time, each limit notches and its corresponding limit grooves are inserted into the limit plate of clamping, the limit plate is fixed on the oil bushing by bolt installation. In the utility model, limit plate is used to prevent float shoe shell and oil bushing from rotating relatively under running vibration, effectively transmit loose rotation torque from float shoe shell to oil bushing, so as to completely eliminate the risk of back-off, and strengthen connection.

Description

Technical Field

[0001] This utility model belongs to the field of floating shoe technology, specifically a floating shoe reinforcement connection structure. Background Technology

[0002] Float shoes are one of the key tools in cementing operations during oil and gas drilling, and are usually installed at the bottom of the casing string. Their main function is to guide the casing smoothly into the wellbore during the casing running process, and through their internal one-way valve structure, to prevent cement slurry from flowing back into the casing after cementing operations, thus ensuring cementing quality.

[0003] In existing technologies, float shoes are typically connected to the casing and tubing below via threads. While this connection method meets basic pressure-bearing and sealing requirements, it faces challenges in real-world operating conditions. Especially in complex environments such as deep wells, ultra-deep wells, or horizontal wells, the tubing string is subjected to severe vibration, impact, and torsional loads downhole. Under prolonged alternating loads, relying solely on thread friction to prevent loosening is far from sufficient, easily leading to loosening or even stripping of the threads. If the connection between the float shoe and the casing fails, it will not only severely impact cementing operations, potentially causing serious accidents such as cement slurry backflow and casing jamming, but also result in significant economic losses and engineering risks.

[0004] To address the aforementioned issues, a floating shoe reinforcement connection structure is proposed. Utility Model Content

[0005] The purpose of this invention is to provide a floating shoe reinforcement connection structure in order to solve the problems mentioned above.

[0006] The technical solution adopted by this utility model is as follows: a floating shoe reinforced connection structure, comprising: a floating shoe shell and an oil sleeve, wherein the oil sleeve is threadedly connected to the bottom of the floating shoe shell; The bottom opening of the floating shoe shell is provided with several limiting slots around its perimeter, and the outer wall of the connection end between the oil sleeve and the floating shoe shell is provided with several limiting grooves. When the floating shoe shell and the oil sleeve are threadedly connected in place, the limiting slots correspond to the limiting grooves, and at this time, a limiting plate is embedded and engaged between each limiting slot and its corresponding limiting groove. The limiting plate is fixedly installed on the oil sleeve by bolts.

[0007] In a preferred embodiment, a floating shoe cover is fixedly connected to the top of the floating shoe shell.

[0008] In a preferred embodiment, the floating shoe cover has a plurality of top holes.

[0009] In a preferred embodiment, the upper outer wall of the floating shoe shell is provided with a plurality of side holes.

[0010] In a preferred embodiment, a one-way valve is installed inside the floating shoe shell. The one-way valve includes a valve seat, which is fixedly installed on the inner wall of the floating shoe shell. A valve hole is opened on the valve seat. A basket is threadedly connected to the upper part of the valve seat. A guide rod is slidably connected to the top of the basket. A valve core adapted to the valve hole is fixedly connected to the bottom end of the guide rod. A spring is sleeved on the guide rod.

[0011] In a preferred embodiment, the limiting plate has two recessed holes, and the bottom of the limiting groove has two threaded holes. A fixing bolt is threaded into the threaded hole and passes through the recessed hole.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are: 1. In this utility model, after the float shoe shell and the oil casing are threadedly connected, the limiting groove and the limiting recess correspond to each other, the limiting plate is inserted, and it is fixed to the oil casing with bolts. The limiting plate prevents the float shoe shell and the oil casing from rotating relative to each other under operating vibration, effectively transferring the loosening torque from the float shoe shell to the oil casing, thus completely eliminating the risk of uncoupling, strengthening the connection, and greatly improving the vibration resistance, impact resistance and fatigue resistance of the connection point under harsh working conditions. It provides reliable hardware protection for cementing operations under complex working conditions such as deep wells and ultra-deep wells, and significantly reduces the probability of engineering accidents caused by connection failure. Attached Figure Description

[0013] Figure 1 This is a simplified schematic diagram of the three-dimensional structure of this utility model; Figure 2 This is a simplified schematic diagram of the internal structure of this utility model from the front view; Figure 3 This is a simplified schematic diagram of the exploded three-dimensional structure of this utility model.

[0014] The markings in the diagram are: 1-Float shoe shell; 2-Oil casing; 3-Limiting groove; 4-Limiting groove; 5-Limiting plate; 6-Float shoe top cover; 7-Top hole; 8-Side hole; 9-One-way valve; 10-Valve seat; 11-Valve hole; 12-Cartridge; 13-Guide rod; 14-Valve core; 15-Spring; 16-Sinkhole; 17-Threaded hole; 18-Fixing bolt. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0016] The following will combine Figures 1-3 A detailed description of a floating shoe reinforcement connection structure according to an embodiment of this utility model is provided.

[0017] Example: This utility model provides a floating shoe reinforcement connection structure, referencing... Figures 1 to 3 As shown, it includes: a floating shoe housing 1 and an oil sleeve 2, with the oil sleeve 2 threadedly connected to the bottom of the floating shoe housing 1; The bottom opening of the floating shoe shell 1 is provided with several limiting slots 3 around the perimeter, and the outer wall of the oil sleeve 2 connected to the floating shoe shell 1 is provided with several limiting grooves 4. When the floating shoe shell 1 and the oil sleeve 2 are threadedly connected in place, the limiting slots 3 and the limiting grooves 4 correspond to each other. At this time, each limiting slot 3 and its corresponding limiting groove 4 are embedded and snapped together with a limiting plate 5. The limiting plate 5 is fixedly installed on the oil sleeve 2 by bolts. In this embodiment, when the float shoe housing 1 and the oil casing 2 are screwed to the designed position, the limiting groove 3 and the limiting recess 4 on both are aligned to form a common slot. The limiting plate 5 is embedded in this slot and fastened to the oil casing 2 with bolts. At this time, the limiting plate 5 is simultaneously embedded in the slots of the float shoe housing 1 and the oil casing 2, which restricts the relative rotation of the two in the radial direction. This provides an absolutely reliable anti-loosening guarantee for the threaded connection, strengthens the connection, and ensures the stability of the float shoe in the harsh downhole environment.

[0018] refer to Figures 1 to 3 As shown, a floating shoe cover 6 is fixedly connected to the top of the floating shoe shell 1; In this embodiment, the float shoe cover 6, together with the float shoe shell 1, constitutes a complete pressure vessel to seal the upper end of the float shoe shell 1, and together with the shell, forms the outline of the guide shoe toe, ensuring the overall structural integrity and pressure bearing capacity of the float shoe, and providing good well-drilling guidance.

[0019] refer to Figures 1 to 3 As shown, the top cover 6 of the floating shoe has several top holes 7; In this embodiment, the top hole 7 is the main outflow channel for cement slurry in the later stage of cementing operation. The function of this structure is to allow cement slurry to be discharged from the top of the float shoe after filling the annulus. It is a key flow path to achieve effective replacement of cement slurry and full filling of the annulus, and to ensure the quality of cementing.

[0020] refer to Figures 1 to 3 As shown, the upper outer wall of the floating shoe shell 1 is provided with several side holes 8; In this embodiment, the side hole 8 is the main outflow channel of cement slurry in the early stage of cement injection operation. The function of this structure is to increase the flow area, reduce the flow resistance of cement slurry, and improve the cement injection efficiency. It works in conjunction with the top hole 7 to ensure that cement slurry can be injected into the wellbore annulus quickly and smoothly, and reduce the impact on the formation and casing.

[0021] refer to Figures 1 to 3 As shown, a one-way valve 9 is installed inside the floating shoe shell 1. The one-way valve 9 includes a valve seat 10, which is fixedly installed on the inner wall of the floating shoe shell 1. A valve hole 11 is opened on the valve seat 10. A basket 12 is threadedly connected to the upper part of the valve seat 10. A guide rod 13 is slidably connected to the top of the basket 12. A valve core 14 that matches the valve hole 11 is fixedly connected to the bottom end of the guide rod 13. A spring 15 is sleeved on the guide rod 13. In this embodiment, under the preload of spring 15, valve core 14 and valve hole 11 of valve seat 10 remain normally closed and sealed. During casing installation, drilling fluid can push open valve core and enter casing; after cementing is completed, spring force pushes valve core to reset, preventing backflow of cement slurry in the annulus, thus achieving unidirectional flow of drilling fluid and effective isolation of cement slurry.

[0022] refer to Figures 1 to 3 As shown, the limiting plate 5 has two recessed holes 16, and the bottom of the limiting groove 4 has two threaded holes 17. The threaded holes 17 are internally threaded with fixing bolts 18, which pass through the recessed holes 16. In this embodiment, the countersunk hole 16 allows the head of the fixing bolt 18 to be recessed into the limiting plate 5 to avoid protrusion. The fixing bolt 18 is screwed into the threaded hole 17 on the oil sleeve 2, which presses the limiting plate 5 tightly against the bottom surface of the limiting groove 4. This provides a firm and compact fixing method for the limiting plate 5, ensuring that the limiting plate 5 will not loosen or fall off when subjected to torque. At the same time, it maintains the smooth shape of the connection part and avoids unnecessary stress concentration or scratches.

[0023] It should be noted that the above threaded hole 17 is not a through hole design.

[0024] The implementation principle of a float shoe reinforced connection structure according to an embodiment of this application is as follows: In use, the float shoe shell 1 and the oil casing 2 are first screwed together by threads, and a special tool is used to tighten it to the specified torque value to ensure that the threaded connection itself reaches the optimal state. At this time, the limiting groove 3 at the bottom of the float shoe shell 1 and the limiting groove 4 on the oil casing 2 will automatically align. Then, the limiting plate 5 is embedded in the slot formed by the corresponding limiting groove 3 and the limiting groove 4. Next, the fixing bolt 18 is passed through the countersunk hole 16 on the limiting plate 5 and screwed into the threaded hole 17 of the oil casing 2. The fixing bolt 18 is tightened with a wrench so that the limiting plate 5 is firmly locked on the oil casing 2. Thus, the reinforced connection is completed. During well operation, the traditional threaded connection is responsible for bearing the axial tensile and compressive loads and providing the main seal, while the limiting plate 5 acts as an independent mechanical defense line, specifically responsible for resisting the circumferential torque and vibration that may cause the threads to loosen.

Claims

1. A floating shoe reinforcement connection structure, characterized in that, include: The floating shoe shell (1) and the oil casing (2) are threaded to the bottom of the floating shoe shell (1); The bottom opening of the floating shoe shell (1) is provided with several limiting slots (3), and the outer wall of the connection end of the oil sleeve (2) and the floating shoe shell (1) is provided with several limiting grooves (4). When the floating shoe shell (1) and the oil sleeve (2) are threadedly connected, the limiting slots (3) correspond to the limiting grooves (4), and at this time, each limiting slot (3) and its corresponding limiting groove (4) are embedded and snapped together with a limiting plate (5). The limiting plate (5) is fixedly installed on the oil sleeve (2) by bolts.

2. The floating shoe reinforcement connection structure as described in claim 1, characterized in that: The top of the floating shoe shell (1) is fixedly connected to the floating shoe cover (6).

3. The floating shoe reinforcement connection structure as described in claim 2, characterized in that: The floating shoe cover (6) has several top holes (7).

4. The floating shoe reinforcement connection structure as described in claim 1, characterized in that: The upper outer wall of the floating shoe shell (1) is provided with several side holes (8).

5. The floating shoe reinforcement connection structure as described in claim 1, characterized in that: The floating shoe shell (1) is equipped with a one-way valve (9). The one-way valve (9) includes a valve seat (10). The valve seat (10) is fixedly installed on the inner wall of the floating shoe shell (1). The valve seat (10) has a valve hole (11). The upper part of the valve seat (10) is threaded with a basket (12). The top of the basket (12) is slidably connected with a guide rod (13). The bottom end of the guide rod (13) is fixedly connected with a valve core (14) that matches the valve hole (11). A spring (15) is sleeved on the guide rod (13).

6. The floating shoe reinforcement connection structure as described in claim 1, characterized in that: The limiting plate (5) has two recessed holes (16), and the bottom of the limiting groove (4) has two threaded holes (17). The threaded holes (17) are threaded with fixing bolts (18), and the fixing bolts (18) pass through the recessed holes (16).

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