An elongated cement head structure

Abstract

The utility model discloses a lengthen cement head structure, solved the technical problem that current cement head body can not accommodate lengthen top plug. The lengthen cement head structure includes: cement head body for and sleeve connection, cement paste pump injection pipe group is connected in the cement head body, upper top plug is arranged in the cement head body, lower top plug is arranged in the cement head body, the upper top plug is located the upper top plug length is greater than the length of lower top plug above the lower top plug. The utility model discloses through lengthen cement head body length, make cement head body can accommodate lengthen top plug, when carrying out well cementation injection cement operation, need not carry out drilling platform dismounting etc. operation, can improve construction efficiency, can reduce well control risk.

Description

Technical Field

[0001] This utility model belongs to the field of cement head technology, specifically relating to an extended cement head structure. Background Technology

[0002] A cement head is a cementing device installed at the top of the casing during cementing operations, connecting the casing to the surface manifold. The cement head has a gate valve for connecting to the circulation pipeline and contains a rubber stopper for cement injection; it is the main hub of the surface manifold wellhead for cementing operations.

[0003] Traditional cement heads, due to their short length (typically ≤1.1 meters), cannot directly accommodate extended top plugs. This necessitates frequent disassembly of the drill rig to install rubber plugs, taking over an hour per well, severely slowing down construction progress and increasing well control risks. Furthermore, conventional top plug rubber wings experience continuous friction with the casing inner wall during long horizontal sections, resulting in a wear rate as high as 20%-30%. This reduces scraping efficiency and easily leads to cement "hanging" in sections with high dogleg (>30° / 30 meters), causing drilling obstruction or even stuck pipe accidents. Moreover, worn top plugs lead to seal failure, causing pressure fluctuations of ±2MPa during lubrication, making it difficult to maintain stable pressure and posing a risk of casing shoe emptying. The cementing quality failure rate exceeds 15%.

[0004] While existing technologies attempt to improve the top plug by increasing the number of rubber wings, the length of the cement head limits the ability to directly deploy the extended top plug, severely impacting on-site operational efficiency and requiring further improvement. Utility Model Content

[0005] In order to solve all or some of the above problems, the purpose of this utility model is to provide an extended cement head structure. By extending the length of the cement head body, the cement head body can accommodate an extended top plug. When performing cementing operations, there is no need to perform drilling platform disassembly and assembly, which can improve construction efficiency and reduce well control risks.

[0006] This utility model provides an extended cement head structure, including:

[0007] The cement head body is used for connection with the sleeve;

[0008] A cement slurry pump injection pipe assembly is connected to the cement head body;

[0009] The top plug is disposed within the cement head body;

[0010] The lower plug is disposed within the cement head body;

[0011] The upper plug is located above the lower plug, and the length of the upper plug is greater than the length of the lower plug.

[0012] Optionally, the cement head body includes:

[0013] The cement head cylinder is vertically arranged, and the upper plug and the lower plug are respectively disposed inside the cement head cylinder;

[0014] The cement head cap is detachably connected to the top of the cement head cylinder.

[0015] A quick connector is attached to the bottom of the cement head cylinder and is used to connect to a sleeve.

[0016] An upper limit stop is provided on the cement head cylinder and is used to restrict the downward movement of the upper plug;

[0017] A lower limit component is provided on the cement head cylinder and is used to restrict the downward movement of the lower top plug.

[0018] Optionally, a top plug release indicator is provided at the bottom of the cement head cylinder so that workers can observe and determine whether the top plug has descended into the sleeve.

[0019] Optionally, the upper limit member and the lower limit member each include a limiting pin. One end of the limiting pin is fixedly connected to a control handle, and the other end passes through the cement head cylinder and is threadedly connected to the cement head cylinder. The limiting pin is arranged radially along the cement head cylinder to prevent the upper plug or the lower plug from moving downward.

[0020] Optionally, the top of the quick connector is threaded to the cement head cylinder, and the bottom of the quick connector is provided with a connecting thread, which is used to connect with the sleeve thread.

[0021] Optionally, two limit locks are symmetrically arranged at the bottom of the cement head cylinder, and the wedge-shaped teeth of the limit locks are engaged with the quick connector with an engagement depth of 5-8mm.

[0022] Optionally, the cement slurry pumping pipe assembly includes a main pumping pipe, a pumping connector, an upper pumping branch pipe, a middle pumping branch pipe, and a lower pumping branch pipe. The pumping connector is connected to the main pumping pipe and is used to connect to external pumping equipment. One end of the upper pumping branch pipe, the middle pumping branch pipe, and the lower pumping branch pipe are respectively connected to the cement head cylinder, and the other end is respectively connected to the main pumping pipe. A high-pressure plug valve is connected to each of the upper pumping branch pipe, the middle pumping branch pipe, and the lower pumping branch pipe.

[0023] The upper pumping branch pipe, the middle pumping branch pipe, and the lower pumping branch pipe are arranged sequentially along the axial direction of the cement head cylinder. The cement slurry discharge port of the upper pumping branch pipe is located above the upper top plug, the cement slurry discharge port of the middle pumping branch pipe is located between the upper top plug and the lower top plug, and the cement slurry discharge port of the lower pumping branch pipe is located below the lower top plug.

[0024] Optionally, the upper plug and the lower plug each include a rubber plug body and a plurality of annular thickened rubber wings. The thickened rubber wings are integrally formed on the rubber plug body, and the gap between the outer diameter of the thickened rubber wings and the inner wall of the cement head cylinder does not exceed 2mm.

[0025] Optionally, the lower plug has three thickened rubber wings, and the three thickened rubber wings are arranged at equal intervals along the axial direction of the plug body.

[0026] Optionally, the upper plug has six thickened rubber wings, two of which are located at the upper part of the plug body, and the other four are located at the lower middle part of the plug body.

[0027] Optionally, a flexible buffer section is provided in the middle of the rubber plug body of the upper plug, and the compression ratio of the rubber plug body is not less than 30% to adapt to the curved wellbore trajectory of a large-displacement well.

[0028] As can be seen from the above technical solution, the extended cement head structure provided by this utility model has the following advantages:

[0029] This extended cement head structure, by lengthening the cement head body, allows the cement head body to accommodate an extended top plug. When performing cementing operations, there is no need for drilling platform disassembly and assembly, which can improve construction efficiency and reduce well control risks.

[0030] Other features and advantages of this invention will be set forth in the following description. Attached Figure Description

[0031] The accompanying drawings are provided to further understand the technical solution of this utility model and constitute a part of the specification. They are used together with the embodiments of this utility model to explain the technical solution of this utility model, and do not constitute a limitation on the technical solution of this utility model.

[0032] Figure 1 This is a schematic diagram of the overall structure of the extended cement head structure in an embodiment of this utility model;

[0033] Figure 2 This is a cross-sectional view of the extended cement head structure in an embodiment of this utility model;

[0034] Figure 3This is a front view of the long top plug in an embodiment of this utility model.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Cement head body; 101. Cement head cylinder; 102. Cement head top cover; 103. Quick connector; 104. Upper limit stop; 105. Lower limit stop; 106. Upper receiving chamber; 107. Lower receiving chamber; 108. Top plug release indicator; 109. Limit stop pin; 110. Control handle; 111. Connecting thread; 112. Limit lock; 2. Cement slurry pumping pipe assembly; 201. Pumping main pipe; 202. Pumping connector; 203. Upper pumping branch pipe; 204. Middle pumping branch pipe; 205. Lower pumping branch pipe; 206. High-pressure plug valve; 3. Upper top plug; 4. Lower top plug; 5. Rubber plug body; 6. Thickened rubber wings. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described herein can be arbitrarily combined with each other.

[0038] like Figure 1 , Figure 2 , Figure 3 The illustration shows an embodiment of the present invention, which discloses an extended cement head structure, including a cement head body 1. The bottom of the cement head body 1 is used to connect with a sleeve. A cement slurry pumping pipe assembly 2 is connected to the cement head body 1, and the cement slurry pumping pipe assembly 2 is used to connect with external pumping equipment. An upper plug 3 and a lower plug 4 are provided inside the cement head body 1. The upper plug 3 is located above the lower plug 4, and the length of the upper plug 3 is greater than the length of the lower plug 4.

[0039] In one embodiment, such as Figure 1 , Figure 2 As shown, the cement head body 1 includes a vertically arranged cement head cylinder 101. A cement head top cover 102 is detachably connected to the top of the cement head cylinder 101, and a quick connector 103 is connected to the bottom. The quick connector 103 is used to connect with a sleeve. In this embodiment, the cement head top cover 102 is threadedly connected to the cement head body 1 so that the cement head top cover 102 can be quickly installed and removed.

[0040] In one embodiment, such as Figure 1 , Figure 2 As shown, the upper plug 3 and the lower plug 4 are coaxially and movably disposed inside the cement head cylinder 101. The cement head cylinder 101 is provided with an upper limit member 104 and a lower limit member 105. The upper limit member 104 is used to restrict the upper plug 3 from moving downward, and the lower limit member 105 is used to restrict the lower plug 4 from moving downward.

[0041] In one embodiment, such as Figure 1 , Figure 2 As shown, the area between the upper limit member 104 and the cement head top cover 102 of the cement head cylinder 101 is the upper receiving chamber 106, and the area between the upper limit member 104 and the lower limit member 105 of the cement head cylinder 101 is the lower receiving chamber 107. The upper top plug 3 is located in the upper receiving chamber 106, and the lower top plug 4 is located in the lower receiving chamber 107.

[0042] In this embodiment, the total length of the cement head cylinder 101 is 1.3m, the length of the upper receiving chamber 106 is 0.35-0.5m, the length of the lower receiving chamber 107 is 0.15-0.4m, the length of the upper top plug 3 is 0.3-0.4m, and the length of the lower top plug 4 is 0.2-0.3m.

[0043] In this embodiment, the cement head cylinder 101 is integrally forged from high-strength alloy steel. The inner wall of the cement head cylinder 101 is covered with a tungsten carbide wear-resistant coating with a thickness of 0.5-1.0 mm, so that the cement head cylinder 101 has a pressure resistance ≥15MPa. The tungsten carbide wear-resistant coating is an alumina-silicon carbide composite material, and the surface roughness Ra of the tungsten carbide wear-resistant coating is ≤0.8μm, and the coefficient of friction is ≤0.12.

[0044] In one embodiment, such as Figure 1 , Figure 2 As shown, a top plug release indicator 108 is provided at the bottom of the cement head cylinder 101 to monitor the top plug release status in real time, so that the staff can observe and judge whether the upper top plug 3 has descended into the sleeve. In this embodiment, the shell of the top plug release indicator 108 is made of titanium alloy frame to improve structural strength. The top plug release indicator 108 is existing technology and will not be described in detail here.

[0045] In one embodiment, such as Figure 1 , Figure 2 As shown, the upper limit member 104 and the lower limit member 105 each include a limiting pin 109. One end of the limiting pin 109 is fixedly connected to the control handle 110, and the other end passes into the cement head cylinder 101 and is threadedly connected to the cement head cylinder 101. At the same time, the limiting pin 109 is arranged radially along the cement head cylinder 101 to prevent the upper plug 3 or the lower plug 4 from moving downward.

[0046] In one embodiment, such as Figure 1 , Figure 2As shown, the top of the quick connector 103 is inserted into the lower port of the cement head cylinder 101, and the top of the quick connector 103 is threadedly connected to the cement head cylinder 101, while the bottom is integrally formed with a connecting thread 111. At the same time, the connecting thread 111 is used to connect with the sleeve thread to realize the quick connection between the cement head cylinder 101 and the sleeve.

[0047] In one embodiment, such as Figure 1 , Figure 2 As shown, two limit locks 112 are symmetrically arranged at the bottom of the cement head cylinder 101. The wedge-shaped teeth of the limit locks 112 engage with the quick connector 103, and the engagement depth is 5-8mm, so as to improve the connection stability between the cement head cylinder 101 and the quick connector 103.

[0048] In this embodiment, the top and bottom of the quick connector 103 are respectively provided with double rubber rings to ensure the sealing effect, so that the sealing pressure reaches 15MPa.

[0049] In one embodiment, such as Figure 1 , Figure 2 As shown, the cement slurry pumping pipe assembly 2 includes a main pumping pipe 201, a pumping connector 202, an upper pumping branch pipe 203, a middle pumping branch pipe 204, and a lower pumping branch pipe 205. The pumping connector 202 is connected to the main pumping pipe 201 and is used to connect to external pumping equipment. One end of the upper pumping branch pipe 203, the middle pumping branch pipe 204, and the lower pumping branch pipe 205 is connected to the cement head cylinder 101, and the other end is connected to the main pumping pipe 201. High-pressure stopcock valves 206 are connected to the upper pumping branch pipe 203, the middle pumping branch pipe 204, and the lower pumping branch pipe 205, respectively.

[0050] In one embodiment, such as Figure 1 , Figure 2 As shown, the upper pumping branch pipe 203, the middle pumping branch pipe 204, and the lower pumping branch pipe 205 are arranged sequentially along the axial direction of the cement head cylinder 101, with the upper pumping branch pipe 203 located at the top. Simultaneously, the cement slurry discharge port of the upper pumping branch pipe 203 is located above the upper top plug 3, the cement slurry discharge port of the middle pumping branch pipe 204 is located between the upper top plug 3 and the lower top plug 4, and the cement slurry discharge port of the lower pumping branch pipe 205 is located below the lower top plug 4.

[0051] When cement slurry is injected through the middle pump injection branch pipe 204, the cement slurry pushes the lower top plug 4 downward, so that the lower top plug 4 scrapes and cleans the mud on the inner wall of the well. When cement slurry is injected through the upper pump injection branch pipe 203, the cement slurry pushes the upper top plug 3 downward. At this time, the upper top plug 3 replaces the cement slurry and scrapes and cleans the inner wall of the well.

[0052] In one embodiment, such as Figure 2, Figure 3 As shown, the upper plug 3 and the lower plug 4 each include a rubber plug body 5 and multiple annular thickened rubber wings 6. The thickened rubber wings 6 are integrally formed on the rubber plug body 5, and the gap between the outer diameter of the thickened rubber wings 6 and the inner wall of the cement head cylinder 101 does not exceed 2mm.

[0053] In one embodiment, such as Figure 2 , Figure 3 As shown, the lower plug 4 has three thickened rubber wings 6, which are arranged at equal intervals along the axial direction of the plug body 5. The upper plug 3 has six thickened rubber wings 6, two of which are located at the upper part of the plug body 5, and the other four are located at the lower middle part of the plug body 5, and are arranged at equal intervals along the axial direction of the plug body 5.

[0054] In one embodiment, such as Figure 2 , Figure 3 As shown, a flexible buffer section is provided in the middle of the rubber plug body 5 of the upper plug 3, and the compression ratio of the rubber plug body 5 is not less than 30% to adapt to the curved wellbore trajectory of the large-displacement well, so that the upper plug 3 can pass smoothly through the casing.

[0055] As can be seen from the above, the use of this extended cement head structure has the following advantages:

[0056] (1) Improve work efficiency: The extended cement head cylinder 101 can accommodate the extended glue plug, avoiding repeated disassembly of the cement head top cover 102, and shortening the single-layer operation time by 0.5h.

[0057] (2) Adaptable to complex well conditions: The flexible buffer section of the top plug 3 can absorb the lateral stress of the well section with a dogleg degree ≤45° / 30m, and the scraping efficiency is ≥90%.

[0058] (3) Safety and economy: The quick connector 103 is threaded to the cement head cylinder 101 and works in conjunction with the limit lock 112 to achieve a 100% connection sealing qualification rate and reduce maintenance costs by 50%.

[0059] (4) Improve the cementing quality qualification rate: The top plug 3 adopts a six-section thickened rubber wing 6 structure, which is lengthened as a whole, improves the ability to scrape cement slurry from the inner wall of the casing, and reduces the wear rate of long-distance transport. It also provides a guarantee for normal cementing pressure, avoids the occurrence of high plug and empty displacement accidents, and effectively avoids the risk of cement hanging on the wall and drilling obstruction. It is suitable for the development of large displacement wells in complex blocks in Bohai.

[0060] It should be noted that, unless otherwise stated, the technical or scientific terms used in this utility model shall have the ordinary meaning as understood by those skilled in the art to which this utility model pertains.

[0061] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An extended cement head structure, characterized in that, include: Cement head body (1), used for connection with sleeve; Cement slurry pump injection pipe assembly (2) is connected to the cement head body (1); The top plug (3) is installed inside the cement head body (1); The lower plug (4) is disposed inside the cement head body (1); The upper plug (3) is located above the lower plug (4), and the length of the upper plug (3) is greater than the length of the lower plug (4).

2. The extended cement head structure according to claim 1, characterized in that, The cement head body (1) includes: The cement head cylinder (101) is vertically arranged, and the upper plug (3) and the lower plug (4) are respectively arranged inside the cement head cylinder (101); A cement head cap (102) is detachably connected to the top of the cement head cylinder (101); A quick connector (103) is connected to the bottom of the cement head cylinder (101), and the quick connector (103) is used to connect with the sleeve; An upper limit stop (104) is provided on the cement head cylinder (101) and is used to restrict the downward movement of the upper plug (3); A lower limit member (105) is provided on the cement head cylinder (101) and is used to restrict the downward movement of the lower top plug (4).

3. The extended cement head structure according to claim 2, characterized in that, The bottom of the cement head cylinder (101) is provided with a top plug release indicator (108) so that the staff can observe and judge whether the top plug (3) has descended into the sleeve.

4. The extended cement head structure according to claim 2, characterized in that, The upper limit member (104) and the lower limit member (105) each include a limit stop pin (109). One end of the limit stop pin (109) is fixedly connected to a control handle (110), and the other end is inserted into the cement head cylinder (101) and threadedly connected to the cement head cylinder (101). The limit stop pin (109) is arranged radially along the cement head cylinder (101) to prevent the upper plug (3) or the lower plug (4) from moving downward.

5. The extended cement head structure according to claim 2, characterized in that, The top of the quick connector (103) is threaded to the cement head cylinder (101), and the bottom of the quick connector (103) is provided with a connecting thread (111), which is used to connect with the sleeve thread.

6. The extended cement head structure according to claim 4, characterized in that, Two limiting locks (112) are symmetrically arranged at the bottom of the cement head cylinder (101). The wedge-shaped teeth of the limiting locks (112) are engaged with the quick connector (103) with an engagement depth of 5-8mm.

7. The extended cement head structure according to claim 2, characterized in that, The cement slurry pumping pipe assembly (2) includes a main pumping pipe (201), a pumping connector (202), an upper pumping branch pipe (203), a middle pumping branch pipe (204), and a lower pumping branch pipe (205). The pumping connector (202) is connected to the main pumping pipe (201) and is used to connect to external pumping equipment. One end of the upper pumping branch pipe (203), the middle pumping branch pipe (204), and the lower pumping branch pipe (205) are respectively connected to the cement head cylinder (101), and the other end is respectively connected to the main pumping pipe (201). High-pressure plug valves (206) are respectively connected to the upper pumping branch pipe (203), the middle pumping branch pipe (204), and the lower pumping branch pipe (205). The upper pumping branch pipe (203), the middle pumping branch pipe (204), and the lower pumping branch pipe (205) are arranged sequentially along the axial direction of the cement head cylinder (101). The cement slurry discharge port of the upper pumping branch pipe (203) is located above the upper top plug (3), the cement slurry discharge port of the middle pumping branch pipe (204) is located between the upper top plug (3) and the lower top plug (4), and the cement slurry discharge port of the lower pumping branch pipe (205) is located below the lower top plug (4).

8. The extended cement head structure according to claim 2, characterized in that, The upper plug (3) and the lower plug (4) each include a rubber plug body (5) and a plurality of annular thickened rubber wings (6). The thickened rubber wings (6) are integrally formed on the rubber plug body (5), and the gap between the outer diameter of the thickened rubber wings (6) and the inner wall of the cement head cylinder (101) does not exceed 2mm.

9. The extended cement head structure according to claim 8, characterized in that, The lower plug (4) has three thickened rubber wings (6), and the three thickened rubber wings (6) are arranged at equal intervals along the axial direction of the plug body (5).

10. The extended cement head structure according to claim 8, characterized in that, The upper plug (3) has six thickened rubber wings (6), two of which are located at the upper part of the plug body (5), and the other four are located at the lower middle part of the plug body (5).

11. The extended cement head structure according to claim 8, characterized in that, The upper plug (3) has a flexible buffer section in the middle of the rubber plug body (5), and the compression ratio of the rubber plug body (5) is not less than 30% to adapt to the curved wellbore trajectory of the large displacement well.

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