A core assembly for cementing

Abstract

The utility model relates to a kind of core filling assembly for cementing, including two core filling components, connecting seat and two well cementing plugs;Two core filling components are connected by connecting seat and form main structure, and there is the installation cavity of columnar and two ends opening in core filling component, and two well cementing plugs are respectively arranged in the installation cavity in two core filling components;Main structure can be installed in the inner bag of cement head horizontally sliding, and main structure can be horizontally slid to the installation cavity of core filling component and is connected cement head's grouting passage and casing joint to carry out cementing operation.It has beneficial effect, through the combination of transverse layout, sliding switching, double plug integrated design, overcome the problem, such as low efficiency, complex operation, poor space adaptability, insufficient versatility etc. in single cementing operation of traditional core filling assembly, provide structural guarantee for the efficient collaborative work of double plug in once cementing operation.

Description

Technical Field

[0001] This utility model relates to the field of cementing technology in oil and gas fields, and in particular to a cementing core repair assembly. Background Technology

[0002] In oil and gas cementing operations, the filler assembly, as the core component of the cement head, plays a crucial role in supporting the cement plug, controlling its release timing, and guiding the cement plug into the tubing. Its structural rationality directly affects the efficiency and safety of cementing operations. With the increasing number of deep and complex wells, cementing operations place higher demands on the stability, adaptability, and ease of operation of the filler assembly.

[0003] Existing cementing plug assemblies mostly adopt a single plug design or a double plug longitudinal arrangement structure, which has significant limitations: a single plug cementing plug assembly can only support one cement plug, which cannot meet the complex cementing requirements that require two isolations (such as drilling fluid and cement slurry, cement slurry and clean water), requiring the replacement of the cementing plug midway, resulting in operation interruption and low efficiency; a double plug longitudinal arrangement cementing plug assembly, due to its stacked layout, increases the overall height of the cement head, making it difficult to install in space-constrained scenarios such as offshore platforms and cluster well groups, and the release path of the cement plug in the longitudinal structure is easily affected by gravity and mud flow field, resulting in deflection or jamming, affecting the isolation effect. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a cementing core filling assembly, which solves the technical problem of insufficient spatial adaptability of the prior art.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0008] This utility model provides a cementing core filling assembly, including two core filling components, a connecting seat, and two cementing plugs; the two core filling components are connected by the connecting seat to form a main structure, and each core filling component has a columnar installation cavity with open ends. The two cementing plugs are respectively disposed in the installation cavities of the two core filling components; the main structure can be horizontally slidably installed in the inner liner of the cement head, and the main structure can be horizontally slid to the installation cavity of the core filling component to connect the grouting channel of the cement head and the casing joint for cementing operations.

[0009] Optionally, the core filling assembly includes a core filling seat and a core filling cylinder; the core filling cylinder is coaxially disposed within the core filling seat, and the cementing plug is disposed within the core filling cylinder; the core filling seats of the two core filling assemblies are connected by a connecting seat.

[0010] Optionally, an elastic element that continuously provides axial force is provided between the core support and the core cylinder, so that the bottom of the core support and the top of the core cylinder are tightly attached to the inner wall of the cement head.

[0011] Optionally, the elastic element is a wave spring.

[0012] Optionally, a sealing ring is provided between the core support and the core cylinder.

[0013] Optionally, the outer diameter of the cement plug is larger than the inner diameter of the filler core.

[0014] Optionally, a first limiting ring is provided on the inner wall of the core support; a second limiting ring is provided on the outer side of the core cylinder; and the bottom of the second limiting ring abuts against the top of the first limiting ring.

[0015] Optionally, the spacing between the two core-filling components is the same as the diameter of the grouting channel of the cement head.

[0016] Optionally, the cementing plug is a rubber plug.

[0017] (III) Beneficial Effects

[0018] The beneficial effects of this utility model are:

[0019] This utility model provides a cementing core assembly, which uses two core-filling components connected by a connecting seat to form the main structure. Two cement plugs are placed in the installation cavity of the core-filling components, allowing for the loading and releasing of two cement plugs in a single operation without mid-operation disassembly or replacement. This avoids the cumbersome process of stopping the machine to replace the traditional single-plug core-filling component, significantly improving the continuity and efficiency of a single cementing operation. The main structure can be horizontally slidably installed in the cement head liner. Lateral sliding allows the installation cavity of the core-filling component to precisely connect the grouting channel and the casing joint, replacing the multi-layer operation of the traditional longitudinal structure, simplifying the switching steps for dual-plug release, and significantly improving operational convenience. The horizontally arranged dual core-filling component design, compared to the traditional dual-plug design... The vertically stacked structure effectively reduces the overall height of the cementing head assembly, making it more suitable for space-constrained environments such as offshore platforms and cluster well groups, thus enhancing installation flexibility. The columnar, open-end installation cavity guides the mud to form a straight flow path when connecting the grouting channel and casing joint, reducing eddy current interference with the cement plug and ensuring smooth descent of both cement plugs under mud impact, avoiding jamming due to path deviation and improving the stability and reliability of cement plug release. Furthermore, the modular dual-core assembly design facilitates flexible replacement of the core assembly according to the needs of different stages in a cementing operation (such as different sized cement plugs), enhancing the equipment's versatility. Simultaneously, the disassembly and maintenance of individual components are more convenient, reducing operating costs. Compared to existing technologies, this design, through a combination of lateral layout, sliding switching, and dual-plug integrated design, overcomes the problems of low efficiency, complex operation, poor spatial adaptability, and insufficient versatility of traditional core assemblies in a single cementing operation, providing structural assurance for the efficient collaborative work of the two plugs in a single cementing operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cementing core-filling assembly in Embodiment 1 of this utility model;

[0021] Figure 2 This is a cross-sectional schematic diagram of the cementing core-filling assembly in Embodiment 1 of this utility model;

[0022] Figure 3 This is a front view schematic diagram of the cementing core repair assembly in Embodiment 1 of this utility model;

[0023] Figure 4 This is a side view schematic diagram of the cementing core repair assembly in Embodiment 1 of this utility model;

[0024] Figure 5 This is a schematic diagram of the cement head structure in Embodiment 2 of this utility model;

[0025] Figure 6 This is a schematic diagram of the cementing core assembly in Embodiment 2 of this utility model during the process of setting it in the inner liner.

[0026] [Explanation of Labels in the Attached Image]

[0027] 1: Connecting seat; 2: Cementing plug; 3: Filler seat; 4: Filler cylinder; 5: Elastic element; 6: Sealing ring; 7: First limiting ring; 8: Second limiting ring; 9: Main body; 10: Inner liner; 11: Translation drive assembly. Detailed Implementation

[0028] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0029] Example 1:

[0030] like Figure 1 As shown, this embodiment provides a cementing filler assembly, including two filler components, a connecting seat 1, and two cement plugs 2. The two filler components are connected by the connecting seat 1 to form a main structure. Each filler component has a cylindrical mounting cavity with openings at both ends. The two cement plugs 2 are respectively disposed in the mounting cavities within the two filler components. The main structure can be horizontally slidably installed in the inner liner of the cement head, and the main structure can slide horizontally to the mounting cavity of the filler component to connect the grouting channel of the cement head and the casing joint for cementing operations. In this embodiment, the cement plug 2 is a rubber plug. The rubber plug has good elasticity and wear resistance, and can tightly adhere to the inner wall of the casing during the descent process, scraping away residual mud and achieving a reliable seal, ensuring the isolation effect between the cementing fluid and the drilling fluid. At the same time, the rubber plug material is soft, which can reduce impact wear on the casing joint and extend the service life of the casing.

[0031] Specifically, the main structure is formed by connecting two core-filling components via a connecting seat 1. Two cement plugs 2 are placed within the mounting cavities of the core-filling components. This allows for the loading and releasing of the cement plugs 2 twice in a single operation without the need for mid-operation disassembly or replacement, avoiding the cumbersome process of stopping the machine for replacement required by traditional single-plug core-filling. This significantly improves the continuity and efficiency of a single cementing operation. The main structure can be horizontally slidably installed within the cement head liner. Lateral sliding allows for precise connection between the mounting cavity of the core-filling components and the grouting channel and casing joint, replacing the multi-layer operation of the traditional longitudinal structure. This simplifies the switching steps for dual-plug release and significantly improves operational convenience. The horizontally arranged dual core-filling component design, compared to the traditional longitudinal stacked dual-plug structure… The overall height of the filler assembly is effectively reduced, making the cement head more suitable for space-constrained scenarios such as offshore platforms and cluster well groups, enhancing installation flexibility. The cylindrical installation cavity with open ends guides the mud to form a straight flow path when connecting the grouting channel and the casing joint, reducing eddy current interference on the cement plug 2 and ensuring that the two cement plugs 2 fall smoothly under the impact of mud, avoiding jamming due to path deviation, and improving the stability and reliability of cement plug 2 release. In addition, the modular dual filler assembly design facilitates flexible replacement of filler assemblies according to the needs of different stages in a cementing operation (such as cement plugs 2 of different sizes), enhancing the equipment's versatility. At the same time, the disassembly and maintenance of individual components are more convenient, reducing operating costs. Compared with existing technologies, this design, through the combination of lateral layout, sliding switching, and dual-plug integrated design, overcomes the problems of low efficiency, complex operation, poor spatial adaptability, and insufficient versatility of traditional filler assemblies in a single cementing operation, providing structural guarantee for the efficient collaborative work of the two plugs in a single cementing operation.

[0032] Furthermore, such as Figures 1-4 As shown, the filler assembly includes a filler seat 3 and a filler cylinder 4; the filler cylinder 4 is coaxially disposed within the filler seat 3, and the cement plug 2 is disposed within the filler cylinder 4; the filler seats 3 of the two filler assemblies are connected by a connecting seat 1, and the installation cavity is opened within the filler cylinder 4. The core advantage of the split design is that the filler cylinder 4 can be replaced individually according to the size requirements of the cement plug 2. When the operation requires adaptation to different specifications of cement plug 2, only the filler cylinder 4 of the corresponding size needs to be replaced, which greatly improves the adaptability of the equipment to different wellbores and different cementing processes; at the same time, as a vulnerable part that directly contacts the cement plug 2, the individual replacement design of the filler cylinder 4 also reduces maintenance costs and avoids overall scrapping due to local wear; in addition, the coaxial cooperation between the filler seat 3 and the filler cylinder 4 ensures the stability of the installation posture of the cement plug 2, avoids release jamming due to skew, and further improves the accuracy of dual plug positioning and release.

[0033] Furthermore, such as Figure 2As shown, an elastic element 5 is provided between the core-filling seat 3 and the core-filling cylinder 4 to continuously provide axial force. This ensures that the bottom of the core-filling seat 3 and the top of the core-filling cylinder 4 are tightly attached to the bottom and top of the inner wall of the cement head's inner liner, respectively. Two stable radial channels are formed between the bottom and top of the inner wall of the inner liner, allowing for maximum contact and connection with the grouting channel when the core-filling assembly slides below it. This concentrates the impact force axially onto the cement plug 2, maximizing the pushing efficiency and maintaining the concentration of the mud's pushing force on the cement plug 2. Simultaneously, the buffering effect of the elastic element 5 absorbs the vibration generated by the mud impact, reducing rigid collisions between the core-filling assembly and the inner liner, and extending equipment life. Furthermore, it allows the core-filling assembly to adaptively compensate for installation tolerances or minor unevenness of the inner wall of the inner liner during sliding, ensuring that the sealing and coaxiality remain stable throughout the entire stroke, providing reliable structural protection for double-plug cementing operations. In this embodiment, the elastic element 5 is a wave spring. Compared to ordinary springs, wave springs can provide greater axial force under the same compression and have smaller axial dimensions, making them suitable for the narrow installation space between the core support 3 and the core cylinder 4. Their multi-peak structure can achieve uniform force distribution, avoid the tilting caused by uneven force on the core cylinder 4, and ensure the stability of the elastic effect.

[0034] Furthermore, such as Figure 2 As shown, a sealing ring 6 is provided between the core filler seat 3 and the core filler cylinder 4. The sealing ring 6 is in close contact with the contact surfaces of the core filler seat 3 and the core filler cylinder 4, which can effectively prevent mud from seeping through the gap between them. It forms a double protection of elastic pre-tightening and physical sealing with the elastic element 5, which further enhances the sealing performance of the core filler assembly, avoids pressure loss caused by mud leakage, and ensures that the impact force of mud is concentrated on the cement plug 2. At the same time, the sealing ring 6 can reduce the direct friction between the core filler cylinder 4 and the core filler seat 3, reduce the wear caused by the relative slight movement between the two (such as the fine adjustment under the action of the elastic element 5), and extend the service life of the components. In addition, the elastic deformation capability of the sealing ring 6 can compensate for the machining tolerance or assembly error between the core filler seat 3 and the core filler cylinder 4, ensuring that a good sealing state is always maintained under different working conditions, providing additional protection for the stability of the two radial channels, and indirectly improving the concentration and reliability of mud pushing the cement plug 2.

[0035] Furthermore, in this embodiment, the outer diameter of the cement plug 2 is larger than the inner diameter of the filler cylinder 4. The interference fit ensures that the cement plug 2 is reliably fixed inside the filler cylinder 4 when not subjected to mud impact, preventing the cement plug 2 from accidentally falling off during the sliding of the filler assembly; when the mud pressure reaches the design threshold, the cement plug 2 can break through the interference constraint and fall smoothly, taking into account both the reliability of fixation and the controllability of release.

[0036] Furthermore, such as Figure 2As shown, the inner wall of the core-filling seat 3 is provided with a first limiting ring 7; the outer side of the core-filling cylinder 4 is provided with a second limiting ring 8; the core-filling cylinder 4 is installed into the core-filling seat 3 from top to bottom, and the bottom of the second limiting ring 8 abuts against the top of the first limiting ring 7. The abutting structure of the first limiting ring 7 and the second limiting ring 8 provides a clear axial positioning reference for the installation of the core-filling cylinder 4 in the core-filling seat 3, ensuring that its installation depth is consistent each time the core-filling cylinder 4 is replaced, avoiding the difference in the height of the cement plug 2 of the two core-filling components due to manual assembly errors, ensuring the uniformity of the initial position when the double plugs are released, and improving operational stability. The supporting effect of the first limiting ring 7 on the second limiting ring 8 can effectively limit the maximum downward movement of the core-filling cylinder 4 in the core-filling seat 3, preventing excessive displacement caused by excessive compression of the elastic element 5 (such as the instantaneous load during mud impact) or the self-weight of the core-filling cylinder 4, avoiding rigid collision between the bottom of the core-filling cylinder 4 and the inner wall of the core-filling seat 3, and reducing the risk of component deformation or damage. The limiting fit ensures that the relative positions of the core-filling cylinder 4 and the core-filling seat 3 are fixed, keeping the sealing ring 6 between them at a preset compression level and preventing seal failure due to core-filling cylinder 4 offset. Simultaneously, the fixed axial position ensures precise alignment between the mounting cavity of the core-filling cylinder 4 and the flow channel port of the core-filling seat 3, maintaining the integrity of the radial channel, ensuring a stable mud flow path, and further enhancing the concentration of impact force. The abutting fit of the first limiting ring 7 and the second limiting ring 8 achieves precise positioning and protection of the core-filling cylinder 4, further optimizing the performance of the core-filling assembly in terms of assembly consistency, structural durability, and sealing reliability, providing a stable structural foundation for the efficient release of the dual plugs.

[0037] Furthermore, in this embodiment, the spacing between the two core-filling components is the same as the diameter of the grouting channel of the cement head. When the core-filling assembly slides horizontally to the working position, the mounting cavity of the first core-filling component can be completely aligned with the grouting channel and the casing joint, forming a straight flow channel without offset. When switching to the second core-filling component, because the spacing is consistent with the diameter of the grouting channel, the mounting cavity of the second core-filling component can take over and achieve coaxial communication with the grouting channel and the casing joint in the same way. This zero-misalignment connection avoids the turning or eddying of mud in the flow channel, ensuring that the mud impacts the cement plug 2 axially, minimizing energy loss and improving propulsion efficiency. The matching of the spacing with the diameter of the grouting channel ensures that the relative position of the edge of the core-filling component with the grouting channel remains stable during the sliding process. The area and force of the mud impacting the sidewall of the core-filling component are significantly reduced, avoiding lateral mud erosion caused by excessive spacing or local stress concentration caused by excessive spacing, reducing the wear rate of the core-filling component and extending its service life.

[0038] The following is an example of the use of a cementing filler assembly provided in this embodiment: Before operation, based on the cementing requirements of the two stages in a single cementing operation, select a first cement plug 2 and a second cement plug 2 of corresponding specifications. Install the filler cylinder 4 of matching dimensions into the two filler seats 3 respectively. Confirm the filler cylinder 4 is in place by the contact of the first limiting ring 7 and the second limiting ring 8. Then, press the first cement plug 2 and the second cement plug 2 into the two filler cylinders 4 respectively (using interference fit for pre-fixation). Next, push the main structure into the cement head inner liner and adjust the filler assembly to its initial position, aligning the installation cavity of the first filler component with the grouting channel and the casing joint. During operation, mud is injected through the grouting channel and impacts the first cement plug 2 along the installation cavity of the first core-filling assembly. When the mud pressure exceeds the constraint force of the interference fit, the first cement plug 2 disengages from the core-filling cylinder 4 and falls into the casing through the casing joint, completing the first cementing isolation. Subsequently, the core-filling assembly is driven to slide horizontally, precisely replacing the installation cavity of the second core-filling assembly and aligning it with the grouting channel and casing joint. The mud continues to impact the second cement plug 2, causing it to fall and completing the second cementing isolation.

[0039] Example 2:

[0040] like Figure 5 and Figure 6 As shown, this embodiment provides a cement head, which includes a main body 9, an inner liner 10, a translational drive assembly 11, and the cementing core-filling assembly described in Embodiment 1. The inner liner 10 is disposed within the main body 9 and has a horizontally extending cavity. The main structure of the cementing core-filling assembly is horizontally slidably disposed inside the inner liner 10. The main body 9 has a coaxially arranged grouting channel and a casing joint, which are respectively connected to the inner liner 10. The grouting channel is located above the inner liner 10, and the casing joint is located below the inner liner 10. The translational drive assembly 11 passes through one side of the inner liner 10 and connects to the main structure.

[0041] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0043] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A cementing core patching assembly, characterized in that, It includes two core-filling assemblies, a connecting seat (1), and two cementing plugs (2); The two core-filling components are connected by a connecting seat (1) to form the main structure. The core-filling component has a columnar installation cavity with open ends. Two cementing plugs (2) are respectively set in the installation cavities of the two core-filling components. The main structure can be horizontally slidably installed in the inner liner of the cement head, and the main structure can also be horizontally slid to the installation cavity of the core-filling assembly to connect the grouting channel of the cement head and the casing joint for cementing operations.

2. The cementing core patching assembly as described in claim 1, characterized in that, The core-filling assembly includes a core-filling base (3) and a core-filling cylinder (4); The core filler tube (4) is coaxially arranged inside the core filler seat (3), and the cementing plug (2) is arranged inside the core filler tube (4); The two core-filling assemblies are connected by a connecting seat (1) between their core-filling seats (3).

3. The cementing core patching assembly as described in claim 2, characterized in that, An elastic element (5) is provided between the core support (3) and the core cylinder (4) to continuously provide axial force, so that the bottom of the core support (3) and the top of the core cylinder (4) are respectively in close contact with the inner wall of the cement head.

4. The cementing core patching assembly as described in claim 3, characterized in that, The elastic element (5) is a wave spring.

5. The cementing core patching assembly as described in claim 2, characterized in that, A sealing ring (6) is provided between the core support (3) and the core cylinder (4).

6. The cementing core patching assembly as described in claim 2, characterized in that, The outer diameter of the cement plug (2) is larger than the inner diameter of the filler core (4).

7. The cementing core patching assembly as described in claim 2, characterized in that, The inner wall of the core support (3) is provided with a first limiting ring (7); the outer side of the core cylinder (4) is provided with a second limiting ring (8); The bottom of the second limiting ring (8) abuts against the top of the first limiting ring (7).

8. The cementing core patching assembly as described in claim 1, characterized in that, The spacing between the two core-filling components is the same as the diameter of the grouting channel of the cement head.

9. The cementing core patching assembly as described in claim 1, characterized in that, Cement plug (2) is a rubber plug.

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