Top drive type tail pipe cementing head, tail pipe cementing system and cementing process

Abstract

This invention discloses a top-drive type tailpipe cementing head, a tailpipe cementing system, and a cementing process. The cement head body comprises a cement head body, a rubber plug pre-installation mechanism, and a drill pipe tandem connector. The cement head body is used to connect to the top drive system at its upper end. At least one union joint is milled on the cement head body. The cement head body has an internal cavity. The rubber plug pre-installation mechanism is installed within the cavity. The rubber plug pre-installation mechanism includes a rubber plug sleeve and a drill pipe rubber plug. A fluid channel is provided on the side wall of the rubber plug sleeve. The drill pipe rubber plug is installed inside the rubber plug sleeve. The drill pipe rubber plug is used to scrape the drill pipe under the action of displacement fluid. The drill pipe tandem connector is connected to the lower end of the cement head body. The drill pipe tandem connector is used to connect the drill pipe string. This invention solves the problem of the need for multiple connection and disassembly of conventional cement heads in tailpipe cementing; solves the circulation problem of the top drive system under drill pipe rubber plug pre-installation; and solves the problem of continuity of tailpipe cementing construction throughout the entire process.

Description

Technical Field

[0001] This invention relates to the field of oilfield drilling tailpipe cementing technology, and particularly to top-drive tailpipe cementing head, tailpipe cementing system and cementing process. Background Technology

[0002] With the rapid development of exploration drilling technology, drilling depths are constantly increasing, leading to a rise in deep well tailpipe cementing and raising the technical requirements for tailpipe cementing. In tailpipe cementing processes, the tailpipe cement head is a key tool for ensuring the quality of deep well tailpipe cementing. However, existing tailpipe cement heads have several drawbacks: First, installation and disassembly operations are complex in the field, increasing labor intensity. Second, they cannot be connected to the top drive system, thus preventing the use of the top drive system for processes such as ball-dropping and hand-dropping. Third, construction is discontinuous; for example, during the later stages of cementing, flushing the flared end requires disassembling the conventional cement head to connect the angular drill pipe, causing discontinuous operation and affecting construction efficiency. Fourth, conventional cement heads primarily use welding between different components, resulting in poor pressure resistance, tensile strength, and torsional resistance, making them unsuitable for high-pressure conditions and later-stage pressure-pressurization and drill pipe string lifting operations. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a top-drive tailpipe cement head, a tailpipe cementing system and cementing process that overcomes or at least partially solves the above problems.

[0004] In a first aspect, embodiments of the present invention provide a top-drive tailpipe cementing head, comprising:

[0005] Cement head body, rubber plug pre-positioning mechanism and drill pipe joint;

[0006] The cement head body is used to connect the top drive system at the upper end;

[0007] The cement head body is milled with at least one joint;

[0008] The cement head body has an internal cavity; the cavity is equipped with the rubber plug pre-positioning mechanism; the rubber plug pre-positioning mechanism includes a rubber plug sleeve and a drill rod rubber plug; the side wall of the rubber plug sleeve is provided with a fluid channel; the drill rod rubber plug is disposed inside the rubber plug sleeve; the drill rod rubber plug is used to clean the drill rod under the action of the displacement fluid.

[0009] The drill pipe string connector is connected to the lower end of the cement head body; the drill pipe string connector is used to connect the drill pipe string.

[0010] In one embodiment, the fluid channel is disposed on the upper part of the rubber stopper sleeve;

[0011] The drill pipe plug is positioned below the fluid channel.

[0012] In one embodiment, the top end of the drill pipe connector is sleeved inside the cement head body;

[0013] The bottom of the rubber stopper sleeve is wedge-shaped;

[0014] The top of the drill pipe tandem joint is wedge-shaped.

[0015] In one embodiment, it further includes: a latch assembly;

[0016] The stop pin assembly is connected to the side wall of the cement head body and is located below the rubber stopper sleeve.

[0017] In one embodiment, it further includes: a rubber stopper indicator assembly;

[0018] The rubber plug indicator assembly is located on the drill pipe joint.

[0019] It also includes: multiple anti-torsion components;

[0020] The anti-torsion component is connected to the cement head body and the drill pipe joint, respectively.

[0021] In one embodiment, the port is located below the cavity.

[0022] In one embodiment, the renkou includes:

[0023] The first union port is used for throwing the ball, and / or the second union port is used for connecting the injection plug valve.

[0024] In one embodiment, the components of the cement head are made of high-strength alloy steel and are manufactured by machining.

[0025] Secondly, embodiments of the present invention provide a top-drive tailpipe cementing system, comprising: the aforementioned cement head, a top drive system, a drill pipe plug valve, a drill pipe string, a dispensing plug valve, a cleaning plug valve, and a tee connector.

[0026] The upper part of the cement head body is sequentially connected to the drill pipe plug valve, the drill string and the top drive system; the top drive system is used to lift and lower the drill pipe string, and to pump in the pre-fluid, the plugging fluid and the displacement fluid.

[0027] The lower part of the drill string connector is connected to the drill string;

[0028] The injection replacement stopcock valve is connected to the cement head body;

[0029] The main pipeline of the tee connector is connected to the injection plug valve; one branch pipeline of the tee connector is connected to the cleaning plug valve, and the other branch pipeline is used to pump in cement slurry and spare displacement fluid.

[0030] Thirdly, embodiments of the present invention provide a cementing process based on the above-described top-drive tailpipe cementing system, comprising:

[0031] Open the drill pipe plug valve, close the injection plug valve and the cleaning plug valve, and use the top drive system to perform circulation well cleaning;

[0032] Close the drill pipe stop valve, throw the ball through the junction, and set the tailpipe;

[0033] Reverse and release the tailpipe hanger;

[0034] Open the drill pipe stop valve and pump in the pre-flush fluid; close the drill pipe stop valve and open the injection stop valve to pump in cement slurry through the other branch pipeline for cement cementing.

[0035] Close the injection valve and release the rubber stopper pre-positioning mechanism so that it falls onto the top of the drill pipe joint;

[0036] Open the drill pipe stop valve and inject the plugging fluid and the displacement fluid until pressure is applied;

[0037] The drill string is pulled up by pressurization to flush the tailpipe hanger and circulate excess cement slurry out of the casing.

[0038] In one embodiment, it also includes:

[0039] While closing the dispensing stopcock valve and releasing the pre-positioned rubber stopper mechanism inside the cement head body, open the cleaning stopcock valve to clean the cement slurry inside the tee joint. After cleaning, close the cleaning stopcock valve and open the dispensing stopcock valve.

[0040] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0041] The top-drive stub cementing head provided in this invention has two main advantages: First, it solves the problem of conventional cement heads requiring multiple connection and disassembly in stub cementing, saving manual operation time and reducing labor intensity. The stub cementing head of this invention only requires connecting its upper part to the top drive system and its lower part to the drill string before construction; no further disassembly and reinstallation are needed during construction. Furthermore, the installation of this stub cementing head before construction is quick and convenient. Second, it solves the circulation problem of the top drive system with pre-installed drill pipe rubber plugs. The stub cementing head body has a pre-installed rubber plug structure, and there is a side circulation channel between the rubber plug pre-installation mechanism and the cement head body. This allows the mud pump to be directly turned on, allowing fluid to flow through the top drive system, across the upper part of the cement head body, through the fluid channel on the rubber plug sleeve, into the drill string, and into the external annulus to form a circulation operation. This eliminates the need for a separate water hose or wellhead gate assembly connection for conventional cement head cementing operations, saving circulation time, reducing labor intensity, and improving construction efficiency. Thirdly, it solves the problem of continuity in the entire tailpipe cementing process, improving construction efficiency and reducing the risk of errors or accidents. Based on this tailpipe cement head, a complete series of tailpipe cementing construction processes can be easily and quickly implemented, including circulating well washing, ball placement and mounting, reverse clamping and release, pumping pre-fluid and cement slurry, placing drill pipe plugs, injecting plugging fluid and displacement fluid, pressurizing and flushing, and circulating excess cement. This significantly shortens the construction connection time between each process and ensures the quality of tailpipe cementing construction.

[0042] Furthermore, the cement head body is milled with a nut for throwing the ball, so as to carry out the subsequent tailpipe hanger mounting operation.

[0043] Furthermore, the tailpipe cement head of this embodiment of the invention has no welding process and is made of high-strength alloy steel through integral machining processes such as turning and milling. Therefore, it has high tensile strength, torsional strength, and high pressure resistance. The tensile strength ensures that the tailpipe cement head can resist tensile force without damage during pressure-induced lifting operations after impact; the torsional strength ensures that it can resist torque without damage during forward and reverse rotation operations of the tailpipe hanger; and the high pressure resistance addresses the problem of high construction pressure within the tailpipe cement head during tailpipe cementing construction.

[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0046] Figure 1This is a schematic diagram of the top-drive tailpipe cement head structure in an embodiment of the present invention;

[0047] Figure 2 This is a photograph of the top-drive tailpipe cement head in an embodiment of the present invention.

[0048] Figure 3 This is a top view of the rubber stopper indicator assembly in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of the top-drive tailpipe cementing system in an embodiment of the present invention;

[0050] Figure 5 This is section AA in the schematic diagram of the top-drive tailpipe cementing system in an embodiment of the present invention;

[0051] Figure 6 This is a flowchart of the top-drive tailpipe cementing process in an embodiment of the present invention;

[0052] Figure 7 This is a photograph of a conventional cement head as described in an embodiment of the present invention.

[0053] Figures 8-9 This is a field construction diagram of the square drill pipe tailpipe cementing method in an embodiment of the present invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1. Cement head body; 2. Rubber plug sleeve; 3. Drill rod rubber plug; 4. Drill rod connector; 5. Stop pin assembly; 6. Rubber plug indicator assembly; 7. Anti-torsion component; 8. Protective sleeve; 9. Groove pin rod; 10. Rubber plug indicator rod; 11. Rotary shaft; 12. Top drive system; 13. Drill rod stop valve; 14. Injection stop valve; 15. Cleaning stop valve; 16. T-connector; 17. First cement truck; 18. Second cement truck; 19. Injection pipeline; 20. Sewage pipeline; 21. First union joint; 22. Second union joint; 23. Union blockage; 24. Sewage equipment. Detailed Implementation

[0056] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0057] Reference Figure 1 and Figure 2 and Figure 4 This invention provides a top-drive tailpipe cementing head ( Figure 2 The blue device includes:

[0058] 1. Cement head body, 4. Rubber plug pre-positioning mechanism and drill rod connector;

[0059] The cement head body 1 is used to connect the top drive system 12 at its upper end;

[0060] At least one joint is milled on the cement head body 1;

[0061] The cement head body 1 has an internal cavity; the cavity is equipped with the rubber plug pre-positioning mechanism; the rubber plug pre-positioning mechanism includes a rubber plug sleeve 2 and a drill rod rubber plug 3; the side wall of the rubber plug sleeve 2 is provided with a fluid channel; the drill rod rubber plug 3 is disposed inside the rubber plug sleeve 2; the drill rod rubber plug 3 is used to clean and scrape the drill rod under the action of the displacement fluid.

[0062] The drill pipe string connector 4 is connected to the lower end of the cement head body 1; the drill pipe string connector 4 is used to connect the drill pipe string.

[0063] In one embodiment, the fluid channel is located at the upper part of the rubber stopper cylinder; the drill pipe rubber stopper 3 is placed below the fluid channel to avoid blocking it. Specifically, refer to... Figure 1 The rubber stopper sleeve is hollow inside, and multiple fluid channels are opened on the upper side wall. For example, four fluid channels can be opened circumferentially. The number of fluid channels is not limited in the embodiments of the present invention.

[0064] In one embodiment, the top end of the drill pipe tandem connector 4 is fitted inside the cement head body 1; the bottom of the rubber plug sleeve 2 is wedge-shaped; the top end of the drill pipe tandem connector 4 is wedge-shaped. For example, refer to... Figure 1 The drill pipe connector 4 has an external thread at its upper end, and the cement head body 1 has an internal thread at its lower end. The drill pipe connector 4 and the cement head body 1 are connected together by the threads. The outer side of the bottom end of the rubber plug sleeve 2 is wedge-shaped, and correspondingly, the inner side of the top end of the drill pipe connector 4 is also wedge-shaped. When the rubber plug sleeve falls from the stop assembly, its bottom end contacts the top end of the drill pipe connector 4 in the cement head body 1. Due to the wedge-shaped design of both, the connection between the bottom end of the rubber plug sleeve and the top end of the drill pipe connector 4 can be sealed tightly.

[0065] In one embodiment, it further includes: a stop pin assembly 5; the stop pin assembly 5 is connected to the side wall of the cement head body 1 and is located below the rubber plug sleeve. The stop pin assembly 5 is used to support the rubber plug sleeve 2 before cementing operations are performed by pumping in cement slurry, and to release the rubber plug sleeve during displacement operations. For example, see reference... Figure 1 At this time, the rubber stopper sleeve 2 is placed on the stop pin rod that extends into the cement head body 1 from the stop pin assembly 5. During subsequent construction, the stop pin rod can be retracted by shaking the handwheel on the stop pin assembly 5, thereby releasing the rubber stopper sleeve 2.

[0066] In one embodiment, it further includes: a rubber plug indicator assembly 6; the rubber plug indicator assembly 6 is disposed on the drill pipe tandem joint 4. Specifically, refer to... Figure 1 and Figure 3 The rubber stopper indicator assembly 6 includes a rubber stopper indicator rod 10 and a rotating shaft 11 sleeved on the rubber stopper indicator rod 10. The rubber stopper indicator rod 10 is located inside the drill pipe tandem joint 4, and the rotating shaft 11 is located outside the drill pipe tandem joint 4. At this time, the rubber stopper indicator rod 10 is in a horizontal position. (Refer to...) Figure 3 The angle between the rubber stopper indicator rod 10 and the rotating shaft 11 is 90°. When the drill pipe rubber stopper 3 moves downward until its bottom touches the rubber stopper indicator rod 10, the rubber stopper indicator rod 10, pushed by the drill pipe rubber stopper 3, gradually folds towards the inner wall of the drill pipe joint 4 until it folds 90° and adheres to the inner wall of the drill pipe joint 4, so that the drill pipe rubber stopper 3 can pass smoothly. At the same time, the rotating shaft 11 connected to the rubber stopper indicator rod 10 will also rotate 90° synchronously. Therefore, engineers can determine whether the drill pipe rubber stopper 3 has passed smoothly by observing the change of the rotating shaft 11.

[0067] In one embodiment, the system further includes: a plurality of anti-torsion components 7; the anti-torsion components 7 are respectively connected to the cement head body 1 and the drill pipe tandem joint 4, and the anti-torsion components 7 are used to enhance the overall torsional resistance of the cement head body 1 after it is connected to the drill pipe tandem joint 4. Specifically, refer to... Figure 1 At least one anti-twist block is circumferentially arranged within the area where the lower end of the cement head body 1 is threadedly connected to the upper end of the drill rod string. However, the embodiments of the present invention do not limit the number or shape of the anti-twist blocks. To prevent the anti-twist blocks from slipping, a protective sleeve 8 is also provided outside the anti-twist blocks.

[0068] In one embodiment, the union opening on the cement head body 1 is located below the upper cavity of the cement head body 1.

[0069] Reference Figure 4 and Figure 5 In one embodiment, the union port includes: a first union port 21 for throwing the ball, and / or a second union port 22 for connecting the dispensing stopcock valve 14. For example, the cement head body 1 includes a first union port 21 and a second union port 22, and the first union port 21 is sealed with a union plug 23. This embodiment of the invention does not limit the number of union ports, but at least one is required. If one union port is used, it can be used to complete the throwing and connecting to the dispensing stopcock valve 14 operations in different processes. For example, the first union port 21, with a diameter of 50-60 mm, is milled into the cement head body 1. The first union port 21 is sealed with a union plug 23 before throwing the ball. When throwing the ball, the plug can be broken off with a hammer, and then the ball is thrown in for the hanging operation. Since the union ports in conventional cement heads are welded, while the union ports in this embodiment of the invention are directly milled into the cement head body 1 and are integral with the cement head body 1, they have higher mechanical strength.

[0070] In one embodiment, the components of the tailpipe cementing head of this invention are made of high-strength alloy steel and manufactured through machining. These components include the cementing head body 1, drill pipe connector 4, stop pin assembly 5, rubber plug indicator assembly 6, anti-torsion component 7, and protective sleeve 8. All components are manufactured using integral turning, milling, and other machining processes, eliminating the use of welding. Therefore, it possesses high tensile, torsional, and high-pressure resistance. The tensile strength ensures that the tailpipe cementing head can resist tensile forces without damage during pressure-induced lifting operations; the torsional strength ensures that it can resist torque without damage during forward and reverse rotation operations of the tailpipe hanger; and the high-pressure resistance addresses the high construction pressure issues during tailpipe cementing operations. For example, the pressure resistance of a conventional cementing head is only about 35 MPa, while the pressure resistance of the tailpipe cementing head of this embodiment can reach about 70 MPa.

[0071] The installation steps for the tailpipe cement head in this embodiment of the invention can be as follows:

[0072] 1. Install the stop pin assembly 5 onto the cement head body 1, and shake the handwheel of the stop pin assembly 5 to retract the stop pin rod; insert the rubber plug sleeve 2 into the cavity from the lower end of the cement head body 1, and shake out the stop pin rod 9; insert the drill rod rubber plug 3 into the rubber plug sleeve 2 from the upper end of the cement head body 1.

[0073] 2. Connect the drill pipe connector 4 to the cement head body 1, and install the anti-torsion component 7 and the protective sleeve 8;

[0074] 3. Install the rubber plug indicator assembly 6 onto the drill pipe connector 4.

[0075] This invention also provides a top-drive tailpipe cementing system, including: the aforementioned tailpipe cementing head, as well as a top drive system 12, a drill pipe plug valve 13, a drill pipe string, a dispensing plug valve 14, a cleaning plug valve 15, and a three-way connector 16.

[0076] The upper part of the cement head body 1 is connected in sequence to the drill pipe plug valve 13, the drill string and the top drive system 12; the top drive system 12 is used to lift and lower the drill pipe string, and to pump in the pre-fluid, the plugging fluid and the displacement fluid.

[0077] The lower part of drill pipe string connector 4 is connected to the drill pipe string;

[0078] The second dispensing plug valve 14 is connected to the cement head body 1;

[0079] The main pipeline of the tee connector 16 is connected to the injection plug valve 14; one branch pipeline of the tee connector 16 is connected to the cleaning plug valve 15, and the other branch pipeline is used for pumping cement slurry and standby displacement fluid.

[0080] Specifically, refer to Figure 4 and Figure 5 The top drive system 12 is connected to the tailpipe cementing head, and the lower end of the tailpipe cementing head is connected to the drill pipe string. The top drive system 12 is connected to the first cement truck 17, and another branch of the tee connector 16 is connected to the second cement truck 18. Before cement slurry cementing, during the circulation well washing process, the well washing fluid can be directly injected through the first cement truck 17 and the top drive system 12 for circulation well washing operation. During the ball-dropping and reverse-release processes, the tailpipe cementing head can be rotated through the top drive system 12 to lift and lower the drill pipe string for tailpipe suspension setup and release operations. During cement slurry cementing construction, the pre-filling fluid can be pumped in through the first cement truck 17 and the top drive system 12, and the cement slurry can be pumped in through the second union joint 22 through the second cement truck 18 for cement slurry injection into the annulus; and after the designed cement slurry is injected into the annulus, the plugging fluid and displacement fluid can be pumped in through the first cement truck 17 and the top drive system 12 until pressure is applied. After cementing, during the process of flushing and circulating excess cement slurry by lifting the drill string under pressure, the top drive system 12 can be used to rotate the tee box cementing head to lift and lower the drill string, flush the tee box hanger, and circulate excess cement slurry out of the casing. Here, the first cement truck 17 and the second cement truck 18 refer to the fluids pumped in different tee box cementing operations; the pumped fluid is determined based on the actual project. Additionally, a branch line of the tee joint 16 connects to a cleaning stopcock valve 15, which is connected to a sludge discharge device 24. This valve is used to clean residual cement slurry in the tee joint 16 and discharge it into the sludge discharge device 24.

[0081] This invention also provides a cementing process based on the above-described top-drive tailpipe cementing system, referring to... Figure 6 The process includes the following steps:

[0082] S61. Open the drill pipe plug valve 13, close the injection plug valve 14 and the cleaning plug valve 15, and use the top drive system 12 to perform circulation well cleaning.

[0083] S62. Close the drill pipe stop valve 13, throw the ball through the junction, and set the tailpipe.

[0084] S63. Reverse and release the tailpipe hanger.

[0085] S64. Open the drill pipe stop valve 13 and pump in the pre-flush fluid; close the drill pipe stop valve 13, open the injection stop valve 14, and pump in cement slurry through the other branch pipeline to cement the well.

[0086] S65. Close the injection plug valve 14 and release the rubber plug pre-positioning mechanism so that it falls on the top of the drill pipe joint 4.

[0087] S66. Open the drill pipe stop valve 13 and inject the plugging fluid and the displacement fluid until they are pressed together;

[0088] S67. Pressurize and lift the drill string to flush the tailpipe hanger and circulate out excess cement slurry from the casing.

[0089] In one embodiment, the tailpipe cementing process further includes: while closing the injection plug valve 14 and releasing the rubber plug pre-positioning mechanism in the cement head body 1, opening the cleaning plug valve 15 to clean the cement slurry in the tee joint 16, and after cleaning, closing the cleaning plug valve 15 and opening the injection plug valve 14.

[0090] Typically, tailpipe cementing involves the most complex and numerous processes among all cementing projects, thus posing the greatest risks. The tailpipe cementing process described in this invention comprehensively considers almost every possible step in tailpipe cementing, achieving continuous construction throughout the entire process. This significantly reduces manpower consumption, lowers the probability of errors and failure risks, and increases construction efficiency. The following is a detailed description of the continuous tailpipe cementing process.

[0091] In one embodiment, necessary installation and inspection work is performed before construction, including:

[0092] 1. Install the tailpipe cement head.

[0093] 2. Check whether the groin pin 9 in the groin pin assembly is in the extended state, and check whether the rubber plug indicator 10 in the rubber plug indicator assembly 6 is in the horizontal position. If not, it needs to be adjusted. Check whether the fluid channel on the side wall of the rubber plug sleeve 2 can be observed. If it cannot be observed, the position of the drill rod rubber plug 3 in the rubber plug sleeve 2 needs to be adjusted.

[0094] 3. Lift the tailpipe cement head to the rat hole, and use hydraulic tongs to connect the drill pipe plug, drill string and top drive system 12 in sequence to the upper end of the tailpipe cement head, and connect the drill pipe string to the lower end of the tailpipe cement head.

[0095] IV. Connect the injection plug valve 14, the three-way connector 16, and the cleaning plug valve 15.

[0096] In one embodiment, after the pre-construction work is completed, the tailpipe cementing construction is completed in sequence according to the following procedures:

[0097] (1) Circulation well washing. Close the injection plug valve 14 and the cleaning plug valve 15, open the drill pipe plug valve 13, connect the top drive system 12 to the first cement truck 17, start the mud pump, and use the top drive system 12 to directly perform circulation well washing operation until the design requirements are met.

[0098] (2) Ball Drop and Sealing. Close the drill pipe plug valve 13, open the union deadbolt 23, and drop a ball through the first union port 21. For example, a copper ball, stainless steel ball, aluminum ball, or bakelite ball can be used. After dropping the ball, reinstall the union deadbolt 23, pump the ball to the ball seat to pressurize, and use the top drive system 12 to lower the drill pipe string for tailpipe seating. After confirming successful seating, pressurize the ball seat at the wellhead. Because the tailpipe cement head is connected to the drill pipe string, the lifting and lowering operations can be performed simultaneously.

[0099] (3) Reverse release. The top drive system 12 rotates forward a certain number of times. When the effective number of rotations exceeds the designed reverse release number, the drill string is lifted to determine if release is possible. During release, the tailpipe cement head rotates and moves up and down along with the drill string below. After successful release, the tee connector 16 connects to the second cement truck 18 and the sewage discharge equipment 24 via the injection pipeline 19 and the sewage discharge pipeline 20, respectively.

[0100] (4) Inject pre-fluid and cement slurry. Open the drill pipe stop valve 13 and use the first cement truck 17 to pump in the designed amount of pre-fluid; close the drill pipe stop valve 13 and open the injection stop valve 14 and use the second cement truck 18 to pump in the designed amount of cement slurry.

[0101] (5) Place the drill pipe rubber plug 3. Close the injection plug valve 14, and swing out the ferrule rod 9 to allow the rubber plug pre-positioning mechanism (containing the drill pipe rubber plug 3) to fall freely to the wedge-shaped position at the top of the drill pipe joint 4. At the same time, open the cleaning plug valve 15, use the second cement truck 18 to clean the cement slurry in the pipeline of the tee joint 16, and discharge it into the sewage discharge equipment 24. After cleaning, close the cleaning plug valve 15 and open the injection plug valve 14 for standby replacement.

[0102] (6) Inject plugging fluid and displacement fluid. Open the drill pipe plug valve 13 and use the first cement truck 17 to pump in the plugging fluid and displacement fluid until pressure is applied.

[0103] (7) Pressurization and flushing. After pressurization, monitor the return water flow interruption, close the injection plug valve 14, remove the injection pipeline 19 and the sewage pipeline 20, and use the first cement truck 17 to pressurize and lift the drill rod string to flush the tailpipe hanger.

[0104] (8) Rotate and circulate excess cement. Start the mud pump and use the first cement truck 17 and the top drive system 12 to circulate the excess cement in the annulus. During this process, the tailpipe cement head is raised, lowered and rotated with the drill string.

[0105] In one embodiment, construction continuity refers to completing the connection operations between the above eight procedures within a preset short time. Specifically, for the first three procedures before cement slurry cementing, a connection time of less than 5 minutes between each procedure can be considered construction continuity; for the last five procedures during and after cement slurry cementing, a connection time of less than 2 minutes between each procedure can be considered construction continuity. The tailpipe cementing process of this embodiment can not only participate in the above eight construction procedures throughout the entire process, but also the connection time of each procedure can be controlled within 2 minutes, realizing continuous construction of the entire tailpipe cementing process.

[0106] If using a standard cement head, refer to... Figure 7 If the conventional cement head cannot be connected to the top drive, the top drive system 12 cannot be used to carry out the construction of process (1) circulating well washing, process (2) ball dropping and hanging, and process (3) reverse release. If process (1) circulating well washing is carried out with the conventional cement head connected, the water hose needs to be connected to the conventional cement head separately at the wellhead, which will undoubtedly increase manpower. After the water hose is connected, it needs to be removed again during process (3) reverse release to rotate, lift and lower the drill string. Then the water hose needs to be connected again to carry out process (4) injection of pre-fluid and process (6) injection of plugging fluid and displacement fluid. Although steps (4) of injecting pre-flush fluid and cement slurry, (5) of placing drill pipe plug 3, and (6) of injecting plugging fluid and displacement fluid can be achieved by installing a conventional cement head, the conventional cement head needs to be removed when performing step (7) of pressurizing and flushing. Then, the drill pipe string needs to be connected to the top drive or angular drill pipe for operation, which delays the operation by about 10 to 15 minutes. Then, when performing step (8) of rotating and circulating to remove excess cement, since the conventional cement head has been removed, this step cannot be performed under the current circumstances. Therefore, using a conventional cement head for tailpipe cementing is not only cumbersome and complicated, increasing the workload and labor intensity, but also causes discontinuous construction, seriously affecting the construction progress.

[0107] The inventors also discovered that the method of using angular drill pipe tailpipe cementing, which abandons conventional cement heads due to their numerous defects, also has many shortcomings. (See reference...) Figure 8 and Figure 9 The drill pipe tailpipe cementing method is a method of cementing operations that does not use conventional cement heads for tailpipe cementing. Instead, it connects the drill pipe series to the top drive system 12 or the angular drill pipe, and the cementing injection line 19 is directly connected to the angular drill pipe circulation system. Figure 8 These are on-site photos of rubber plugs being dropped during the kerf cementing method using square drill pipe. Figure 9This is a field photo of the flushing pipeline during the kerb cementing method. The main drawbacks of this method are: 1. After pumping cement slurry, the kerb needs to be disassembled and drill pipe plug 3 driven in. Disassembling the kerb introduces a large amount of air into the tailings slurry, affecting the quality of bottom cementing. 2. On-site manual connection of the coupling is required. After flushing the cement slurry from the kerb, the kerb needs to be reconnected to the drill pipe before cementing replacement can be performed, causing discontinuity in the cementing replacement process. 3. On-site disassembly and installation of the kerb, driving in the drill pipe plug 3, and manual connection of the coupling increase labor intensity and safety risks, as well as the inherent safety risks of the drill pipe plug 3, significantly reducing the quality of tail pipe cementing.

[0108] The embodiments of the present invention have at least the following beneficial effects:

[0109] The top-drive tailpipe cementing head provided in this invention has two main advantages: First, it solves the problem of conventional cementing heads requiring multiple connection and disassembly in tailpipe cementing, saving manual operation time and reducing labor intensity. The tailpipe cementing head of this invention only requires connecting its upper part to the top drive system 12 and its lower part to the drill string before construction; no further disassembly and reinstallation are needed during construction. Furthermore, the installation of this tailpipe cementing head before construction is quick and convenient. Second, it solves the circulation problem of the top drive system 12 under the pre-installed drill pipe rubber plug 3. The cement head body 1 of this tailpipe cementing head has a pre-installed rubber plug structure installed inside. There is a side circulation channel between the rubber plug pre-installation mechanism and the cement head body 1, allowing the mud pump to be directly turned on, allowing fluid to flow through the top drive system 12, through the upper part of the cement head body 1, through the fluid channel on the rubber plug sleeve 2, into the drill string, and into the external annulus to form a circulation operation. This eliminates the need for a separate water hose or wellhead gate assembly connection for conventional cement head cementing operations, saving circulation time, reducing labor intensity, and improving construction efficiency. Thirdly, it solves the problem of continuity in the entire tailpipe cementing process, improving construction efficiency and reducing the risk of errors or accidents. Based on this tailpipe cement head, a complete series of tailpipe cementing construction processes can be easily and quickly implemented, including circulating well washing, ball placement and setting, reverse clamping and release, pumping pre-fluid and cement slurry, placing drill pipe plugs, injecting plugging fluid and displacement fluid, pressurizing and flushing, and circulating excess cement. This significantly shortens the construction connection time between each process and ensures the quality of tailpipe cementing construction.

[0110] Furthermore, a port is opened on the cement head body 1 for throwing balls, so as to carry out subsequent tailpipe hanger mounting operations.

[0111] Furthermore, the tailpipe cement head of this embodiment of the invention has no welding process and is made of high-strength alloy steel through integral machining processes such as turning and milling. Therefore, it has high tensile strength, torsional strength, and high pressure resistance. The tensile strength ensures that the tailpipe cement head can resist tensile force without damage during pressure-induced lifting operations after impact; the torsional strength ensures that it can resist torque without damage during forward and reverse rotation operations of the tailpipe hanger; and the high pressure resistance addresses the problem of high construction pressure within the tailpipe cement head during tailpipe cementing construction.

[0112] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A top drive liner cement head, characterized by, include: Cement head body, rubber plug pre-positioning mechanism and drill pipe joint; The cement head body is used to connect the top drive system at the upper end; The cement head body is milled with at least one joint; The cement head body has an internal cavity; the cavity is equipped with the rubber plug pre-positioning mechanism; the rubber plug pre-positioning mechanism includes a rubber plug sleeve and a drill rod rubber plug; the side wall of the rubber plug sleeve is provided with a fluid channel; the drill rod rubber plug is disposed inside the rubber plug sleeve; the drill rod rubber plug is used to clean the drill rod under the action of the displacement fluid. The drill pipe string connector is connected to the lower end of the cement head body; the drill pipe string connector is used to connect the drill pipe string.

2. The cement head as described in claim 1, characterized in that, The fluid channel is located on the upper part of the rubber stopper sleeve; The drill pipe plug is positioned below the fluid channel.

3. The cement head as described in claim 2, characterized in that, The top end of the drill pipe connector is sleeved inside the cement head body; The bottom of the rubber stopper sleeve is wedge-shaped; The top of the drill pipe tandem joint is wedge-shaped.

4. The cement head as described in claim 3, characterized in that, Also includes: Gearbox assembly; The stop pin assembly is connected to the side wall of the cement head body and is located below the rubber stopper sleeve.

5. The cement head as described in claim 4, characterized in that, Also includes: Rubber stopper indicator assembly; The rubber plug indicator assembly is located on the drill pipe joint.

6. The cement head as described in any one of claims 1-5, characterized in that, Also includes: Multiple anti-torsion components; The anti-torsion component is connected to the cement head body and the drill pipe joint, respectively.

7. The cement head as described in claim 6, characterized in that, The opening is located below the cavity.

8. The cement head as described in claim 7, characterized in that, The Renkou includes: The first union port is used for throwing the ball, and / or the second union port is used for connecting the injection plug valve.

9. The cement head as described in any one of claims 1-8, characterized in that, The components of the cement head are made of high-strength alloy steel and are manufactured through machining.

10. A top-drive tailpipe cementing system, characterized in that, Includes the cement head as described in any one of claims 1-9, as well as the top drive system, drill pipe plug valve, drill pipe string, injection plug valve, cleaning plug valve, and tee connector; The upper part of the cement head body is sequentially connected to the drill pipe plug valve, the drill string and the top drive system; the top drive system is used to lift and lower the drill pipe string, and to pump in the pre-fluid, the plugging fluid and the displacement fluid. The lower part of the drill string connector is connected to the drill string; The injection replacement stopcock valve is connected to the cement head body; The main pipeline of the tee connector is connected to the injection plug valve; one branch pipeline of the tee connector is connected to the cleaning plug valve, and the other branch pipeline is used to pump in cement slurry and spare displacement fluid.

11. A cementing process based on the top-drive tailpipe cementing system as described in claim 10, characterized in that, include: Open the drill pipe plug valve, close the injection plug valve and the cleaning plug valve, and use the top drive system to perform circulation well cleaning; Close the drill pipe stop valve, throw the ball through the junction, and set the tailpipe; Reverse and release the tailpipe hanger; Open the drill pipe stop valve and pump in the pre-flush fluid; Close the drill pipe plug valve, open the injection plug valve, and pump cement slurry into the well through the other branch pipeline to cement slurry cementing; Close the injection valve and release the rubber stopper pre-positioning mechanism so that it falls onto the top of the drill pipe joint; Open the drill pipe stop valve and inject the plugging fluid and the displacement fluid until pressure is applied; The drill string is pulled up by pressurization to flush the tailpipe hanger and circulate excess cement slurry out of the casing.

12. The cementing process as described in claim 11, characterized in that, Also includes: While closing the dispensing stopcock valve and releasing the pre-positioned rubber stopper mechanism inside the cement head body, open the cleaning stopcock valve to clean the cement slurry inside the tee joint. After cleaning, close the cleaning stopcock valve and open the dispensing stopcock valve.

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