Cement head special for tail pipe tie-back well cementation

Abstract

The invention relates to the technical field of heads, in particular to a tail pipe tie-back well cementation special cement head which comprises an upper shell, a lower shell, a rubber plug and a rubber plug stop pin, the bottom of the upper shell is detachably connected with the top of the lower shell, the lower shell and the upper shell are connected to form a containing cavity, and the rubber plug stop pin is arranged in the containing cavity. The rubber plug is located in the containing cavity and can slide along the axis of the containing cavity, and the outer side wall of the rubber plug is tightly attached to the inner side wall of the containing cavity; the rubber plug stop pin is installed on the lower shell and can stretch into the containing cavity to be used for limiting the rubber plug. According to the scheme, the problems that the casing buckle is damaged due to repeated disassembly and reassembly and the tie-back plug cannot be smoothly inserted into the tie-back barrel after well cementation can be solved.

Description

Technical Field

[0001] This invention relates to the technical field of cement heads, and more specifically, to a cement head specifically designed for tailpipe reconnection cementing. Background Technology

[0002] Tail pipe reconnection cementing is an important procedure in oil drilling engineering. Tail pipe reconnection is a process in which a casing string with a reconnection plug tool connected to the bottom end is run back from the tail pipe hanger position to the wellhead after the tail pipe cementing is completed.

[0003] To ensure the sealing of the reconnector and meet the requirements of circulating cementing, three steps are often required after the reconnected casing string is lowered into place: trial insertion and length adjustment, circulation, pumping cement slurry, and displacing with a rubber plug. To ensure the smooth operation of these three steps, corresponding variable-thread casings need to be prepared in advance for each step. This can lead to discontinuous cementing operations, multiple disassembly and reassembly, and risks such as casing thread damage and thixotropic or abnormally thickened cement slurry at high temperatures. Furthermore, although the reconnector is inside the reconnector barrel before cementing, the pressure changes in the fluid columns inside and outside the casing string due to the pumping of fluids of different specific gravities during cementing can cause the tubing string to move, pulling the reconnector out of the reconnector barrel. Due to the limitations of the reconnector structure and the buckling of the casing string, the reconnector may not be able to be smoothly inserted into the reconnector barrel after cementing. Such reconnection cementing problems are often fatal, and in severe cases, can even lead to the abandonment of the entire wellbore, causing serious losses to the entire project. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art, such as discontinuous cementing operations, damage to casing threads caused by repeated disassembly and reassembly, and the inability of the reconnection plug to be smoothly inserted into the reconnection cylinder after cementing. This invention provides a special cement head for tailpipe reconnection cementing. The cement head in this solution can solve the problems of damage to casing threads caused by repeated disassembly and reassembly and the inability of the reconnection plug to be smoothly inserted into the reconnection cylinder after cementing.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A cement head for tailpipe reconnection cementing is provided, comprising an upper shell, a lower shell, a rubber plug, and a rubber plug stop pin. The bottom of the upper shell is detachably connected to the top of the lower shell. The lower shell and the upper shell, when connected, form a receiving cavity. The rubber plug is located within the receiving cavity and can slide along the axis of the receiving cavity. The outer side wall of the rubber plug is tightly fitted with the inner side wall of the receiving cavity. The rubber plug stop pin is installed on the lower shell and can extend into the receiving cavity to limit the rubber plug.

[0006] The cement head of this invention features a split design with upper and lower housings. During use, the lower housing is fixedly installed on top of the cementing casing. Even if the pressure of the fluid columns inside and outside the casing changes due to pumping in fluids of different specific gravities, causing the reconnector plug to rise, the reconnector plug cannot extend out of the casing because the lower housing is fixed on top of the cementing casing. This avoids the problem of the reconnector plug being unable to be inserted into the reconnector sleeve after extending out of the casing. Furthermore, the detachable upper and lower housing structure allows for the addition of rubber plugs by disassembling the upper and lower housings, eliminating the need for repeated disassembly and assembly of the casing and preventing damage to the casing threads. Additionally, the overall length of the cement head can be made smaller, effectively avoiding the adverse effects of a longer cement head, resulting in better performance and facilitating its industrial promotion and use.

[0007] Furthermore, the upper housing and the lower housing are threadedly connected. The upper housing and the lower housing are detachably connected by a threaded connection. The threaded connection has a simple structure, high connection strength, and is easy to disassemble and maintain.

[0008] Furthermore, it also includes an anti-detachment structure, which comprises an anti-detachment part and a first slot located at the top of the side wall of the lower housing. The anti-detachment part is detachably installed at the bottom of the side wall of the upper housing and can be embedded in the first slot. The anti-detachment structure can prevent the upper and lower housings from loosening due to sleeve vibration after threaded connection. The anti-detachment part can be a metal sheet or block with a certain thickness that can be embedded in the first slot. After the anti-detachment part installed on the upper housing is embedded in the first slot on the lower housing, it can effectively prevent relative rotation between the upper and lower housings.

[0009] Furthermore, the anti-detachment structure also includes a second slot located at the bottom of the side wall of the upper housing. The anti-detachment part can be embedded in the second slot, which has a threaded hole. The anti-detachment part is provided with a positioning bolt, which can pass through the anti-detachment part and be threadedly connected to the threaded hole. After the anti-detachment part is embedded in the second slot, it can be fixed to the upper housing by the positioning bolt. The design of the second slot and the positioning bolt makes it easier to fix the anti-detachment part to the upper housing.

[0010] Furthermore, there are multiple anti-detachment structures, which are arranged equidistantly in a circle with the axis of the receiving cavity as the center. Having multiple anti-detachment structures provides better protection against relative rotation between the upper and lower shells.

[0011] Furthermore, the number of anti-detachment structures is 2-4. Too many anti-detachment structures will increase the dismantling process when removing the upper and lower shells, thus increasing the labor intensity of workers; too few anti-detachment structures will result in an ineffective effect in preventing the relative rotation of the upper and lower shells. Experiments have shown that setting 2-4 anti-detachment structures can effectively prevent the relative rotation of the upper and lower shells while avoiding the cumbersome dismantling process.

[0012] Furthermore, a handle is provided at the end of the rubber stopper pin away from the receiving cavity. The handle makes it easier to slide the rubber stopper pin on the lower housing, facilitating the removal or insertion of the rubber stopper pin from the lower housing.

[0013] Furthermore, the top of the upper housing is provided with a first through hole communicating with the receiving cavity, and the inner sidewall of the first through hole is provided with an internal thread for connecting with the sleeve drive device. The internal thread on the top of the upper housing facilitates the connection between the cement head and the sleeve drive device.

[0014] Furthermore, the outer side wall of the upper housing is provided with a clamping groove for the lifting clamp to hold the upper housing. The clamping groove is located at the top of the side wall of the upper housing, and the lifting clamp can lift the upper housing by clamping the clamping groove.

[0015] Furthermore, the side wall of the lower housing is provided with a second through hole for connecting a high-pressure fluid pipeline, and the bottom of the outer side wall of the lower housing is provided with an external thread for connecting to the casing. The high-pressure fluid pipeline communicates with the inner cavity of the lower housing through the second through hole, thereby allowing all major fluids, such as pre-fluid, cement slurry, and displacement drilling fluid, to enter the casing through this port. The lower housing is connected to the casing via external threads; the threaded connection has a simple structure, high connection strength, and is easy to disassemble and maintain.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The cement head of this invention features a split design with upper and lower housings. During use, the lower housing is fixedly installed on top of the cementing casing. Even if the pressure of the fluid columns inside and outside the casing changes due to pumping in fluids of different specific gravities, causing the reconnector plug to rise, the reconnector plug cannot extend out of the casing because the lower housing is fixed on top of the cementing casing. This avoids the problem of the reconnector plug being unable to be inserted into the reconnector sleeve after extending out of the casing. Furthermore, the detachable upper and lower housing structure allows for the addition of rubber plugs by disassembling the upper and lower housings, eliminating the need for repeated disassembly and assembly of the casing and preventing damage to the casing threads. Additionally, the overall length of the cement head can be made smaller, effectively avoiding the adverse effects of a longer cement head, resulting in better performance and facilitating its industrial promotion and use. Attached Figure Description

[0017] Figure 1A schematic diagram of a cement head specifically designed for tailpipe reconnection cementing; Figure 2 A schematic diagram of the internal structure of a cement head specifically designed for tailpipe reconnection cementing; Figure 3 for Figure 1 Enlarged view of part A.

[0018] In the attached diagram: 1. Upper housing; 2. Lower housing; 3. Rubber plug; 4. Rubber plug stop pin; 5. Receiving cavity; 6. Anti-detachment structure; 601. First slot; 602. Anti-detachment part; 603. Second slot; 621. Positioning bolt; 401. Handle; 101. First through hole; 102. Clamping groove; 201. Second through hole; 202. External thread. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0020] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0021] Example 1 This embodiment is a first embodiment of a cement head specifically designed for tailpipe reconnection cementing, such as... Figure 1 and Figure 2 As shown, the device includes an upper housing 1, a lower housing 2, a rubber plug 3, and a rubber plug stop pin 4. The bottom of the upper housing 1 is detachably connected to the top of the lower housing 2. After the lower housing 2 and the upper housing 1 are connected, they form a receiving cavity 5. The rubber plug 3 is located in the receiving cavity 5 and can slide along the axis of the receiving cavity 5. The outer side wall of the rubber plug 3 is tightly fitted with the inner side wall of the receiving cavity 5. The rubber plug stop pin 4 is installed on the lower housing 2 and can extend into the receiving cavity 5 to limit the rubber plug 3.

[0022] Specifically, the upper housing 1 and the lower housing 2 are threaded together.

[0023] The beneficial effects of this embodiment are as follows: In this embodiment, the cement head features a split design with upper and lower housings. During use, the lower housing 2 is fixedly installed on top of the cementing casing. Even if the pressure of the fluid columns inside and outside the casing changes due to pumping in fluids of different specific gravities, causing the reconnector plug to rise, the lower housing 2, fixed to the top of the cementing casing, prevents the reconnector plug from extending out of the casing. This avoids the problem of the reconnector plug being unable to be inserted into the reconnector sleeve after extending out of the casing. Furthermore, the detachable upper and lower housing structure allows for the addition of the rubber plug 3 by disassembling the upper and lower housings, eliminating the need for repeated casing disassembly and assembly, thus preventing damage to the casing threads. Additionally, the overall length of the cement head can be kept relatively short, effectively avoiding the adverse effects of a longer cement head, resulting in better performance and facilitating its promotion and use in the industry.

[0024] The upper housing 1 and the lower housing 2 are detachably connected by a threaded connection. The threaded connection has a simple structure, high connection strength, and is easy to disassemble and maintain.

[0025] Example 2 This embodiment is a second embodiment of a cement head specifically designed for tailpipe reconnection cementing, such as... Figures 1-3 As shown, the device includes an upper housing 1, a lower housing 2, a rubber plug 3, and a rubber plug stop pin 4. The bottom of the upper housing 1 is detachably connected to the top of the lower housing 2. After the lower housing 2 and the upper housing 1 are connected, they form a receiving cavity 5. The rubber plug 3 is located in the receiving cavity 5 and can slide along the axis of the receiving cavity 5. The outer side wall of the rubber plug 3 is tightly fitted with the inner side wall of the receiving cavity 5. The rubber plug stop pin 4 is installed on the lower housing 2 and can extend into the receiving cavity 5 to limit the rubber plug 3.

[0026] Specifically, the anti-detachment structure 6 includes an anti-detachment part 602 and a first slot 601 located at the top of the side wall of the lower housing 2. The anti-detachment part 602 is detachably installed at the bottom of the side wall of the upper housing 1, and the anti-detachment part 602 can be embedded in the first slot 601. The anti-detachment part 602 is a metal sheet or block with a certain thickness that can be embedded in the first slot 601.

[0027] Specifically, the anti-detachment structure 6 also includes a second slot 603 located at the bottom of the side wall of the upper housing 1. The anti-detachment part 602 can be embedded in the second slot 603. The second slot 603 is provided with a threaded hole. The anti-detachment part 602 is provided with a positioning bolt 621. The positioning bolt 621 can pass through the anti-detachment part 602 and be threadedly connected to the threaded hole.

[0028] Specifically, there are multiple anti-detachment structures 6, which are arranged equidistantly in a circle with the axis of the receiving cavity 5 as the center. Furthermore, the number of anti-detachment structures 6 is 2-4.

[0029] The beneficial effects of this embodiment are as follows: The anti-detachment structure 6 prevents the upper housing 1 and lower housing 2 from loosening due to sleeve vibration after threaded connection. After the anti-detachment part 602 is embedded in the second slot 603, it can be fixed to the upper housing 1 by the positioning bolt 621. The second slot 603 and the positioning bolt 621 facilitate fixing the anti-detachment part 602 to the upper housing 1. Multiple anti-detachment structures 6 provide better protection against relative rotation between the upper and lower housings. Using 2-4 anti-detachment structures 6 effectively prevents relative rotation between the upper and lower housings while avoiding the cumbersome process of disassembling them.

[0030] Example 3 This embodiment is a third embodiment of a cement head specifically designed for tailpipe reconnection cementing, such as... Figures 1-3 As shown, the device includes an upper housing 1, a lower housing 2, a rubber plug 3, and a rubber plug stop pin 4. The bottom of the upper housing 1 is detachably connected to the top of the lower housing 2. After the lower housing 2 and the upper housing 1 are connected, they form a receiving cavity 5. The rubber plug 3 is located in the receiving cavity 5 and can slide along the axis of the receiving cavity 5. The outer side wall of the rubber plug 3 is tightly fitted with the inner side wall of the receiving cavity 5. The rubber plug stop pin 4 is installed on the lower housing 2 and can extend into the receiving cavity 5 to limit the rubber plug 3.

[0031] Specifically, the anti-detachment structure 6 includes an anti-detachment part 602 and a first slot 601 located at the top of the side wall of the lower housing 2. The anti-detachment part 602 is detachably installed at the bottom of the side wall of the upper housing 1, and the anti-detachment part 602 can be embedded in the first slot 601. The anti-detachment part 602 is a metal sheet or block with a certain thickness that can be embedded in the first slot 601.

[0032] Specifically, the anti-detachment structure 6 also includes a second slot 603 located at the bottom of the side wall of the upper housing 1. The anti-detachment part 602 can be embedded in the second slot 603. The second slot 603 is provided with a threaded hole. The anti-detachment part 602 is provided with a positioning bolt 621. The positioning bolt 621 can pass through the anti-detachment part 602 and be threadedly connected to the threaded hole.

[0033] Specifically, there are multiple anti-detachment structures 6, which are arranged equidistantly in a circle with the axis of the receiving cavity 5 as the center. Furthermore, the number of anti-detachment structures 6 is 2-4.

[0034] Specifically, a handle 401 is provided on the end of the rubber stopper pin 4 that is away from the receiving cavity 5.

[0035] Specifically, the top of the upper housing 1 is provided with a first through hole 101 that connects to the receiving cavity 5, and the inner sidewall of the first through hole 101 is provided with an internal thread for connecting to the sleeve drive device.

[0036] Specifically, the outer side wall of the upper housing 1 is provided with a clamping groove 102 for clamping the hanging clamp.

[0037] Specifically, the side wall of the lower housing 2 is provided with a second through hole 201 for connecting a high-pressure fluid pipeline, and the bottom of the outer side wall of the lower housing 2 is provided with an external thread 202 for connecting with a sleeve.

[0038] The beneficial effects of this embodiment are as follows: The handle 401 facilitates the sliding of the rubber stopper pin 4 on the lower housing 2, making it easier to remove or insert the rubber stopper pin 4 from the lower housing 2. The internal thread on the top of the upper housing 1 facilitates the connection between the cement head and the casing drive device. The clamping groove 102 is located on the top of the side wall of the upper housing 1, and the lifting clamp can be used to lift the upper housing 1 by clamping the clamping groove 102. The high-pressure fluid pipeline is connected to the inner cavity of the lower housing 2 through the second through hole 201, thereby allowing all major fluids such as pre-fluid, cement slurry, and displacement drilling fluid to enter the casing through this port. The lower housing 2 is connected to the casing through the external thread 202. The threaded connection has a simple structure, high connection strength, and is easy to disassemble and maintain.

[0039] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A cement head for liner tieback cementing, characterized in that, The utility model provides a kind of high-pressure fluid pipe connector, including upper shell (1), lower shell (2), rubber plug (3), rubber plug stop pin (4), the bottom of the upper shell (1) is detachably connected with the top of the lower shell (2), the lower shell (2) and the upper shell (1) form containing cavity (5) after being connected, the rubber plug (3) is located in the containing cavity (5) and can slide along the axis of the containing cavity (5), the outer side wall of the rubber plug (3) is tightly combined with the inner side wall of the containing cavity (5);The rubber plug stop pin (4) is installed to the lower shell (2) and the rubber plug stop pin (4) can extend into the containing cavity (5) to limit the rubber plug (3).

2. The liner tieback cement head of claim 1, wherein, The upper shell (1) is threadedly connected with the lower shell (2).

3. The liner tieback cement head of claim 2, wherein, Further comprising anti-dropping structure (6), the anti-dropping structure (6) includes anti-dropping part (602) and first clamping groove (601) located at the top of the side wall of the lower shell (2), the anti-dropping part (602) is detachably installed at the bottom of the side wall of the upper shell (1), and the anti-dropping part (602) can be embedded in the first clamping groove (601).

4. The liner tieback cement head of claim 3, wherein, The anti-dropping structure (6) further comprises a second clamping groove (603) located at the bottom of the side wall of the upper shell (1), the anti-dropping part (602) can be embedded in the second clamping groove (603), the second clamping groove (603) is provided with a threaded hole, the anti-dropping part (602) is provided with a positioning bolt (621), and the positioning bolt (621) can be threadedly connected with the threaded hole through the anti-dropping part (602).

5. The liner tieback cement head of claim 3, wherein, The anti-dropping structure (6) has a plurality of anti-dropping structures (6) arranged at equal distances in a circle with the axis of the containing cavity (5) as the center.

6. A liner tieback cement head according to claim 5, characterized in that The number of the anti-dropping structure (6) is 2-4.

7. The liner tieback cement head of claim 1, wherein, The rubber plug stop pin (4) is provided with a handle (401) at one end away from the containing cavity (5).

8. The liner tieback cement head of claim 1, wherein, The top of the upper shell (1) is provided with a first through hole (101) communicating with the containing cavity (5), and the inner side wall of the first through hole (101) is provided with an internal thread for connecting with a sleeve driving device.

9. The method of claim 1, wherein, The outer side wall of the upper shell (1) is provided with a clamping groove (102) for clamping by a lifting clamp.

10. The liner tieback cement head of claim 1, wherein, The side wall of the lower shell (2) is provided with a second through hole (201) for connecting a high-pressure fluid pipeline, and the bottom of the outer side wall of the lower shell (2) is provided with an external thread (202) for connecting with a sleeve.

Images