Deep well large size casing insertion type cementing device and process method

Abstract

The present application relates to the technical field of cementing device, and is a deep well large size casing insertion type cementing device and process method, the former comprises drill pipe, casing and double ball valve double channel drill pipe cement head, insertion type cementing wellhead sealing circulating device, insertion type cementing rubber plug pressure device arranged from top to bottom in turn. The present application has reasonable and compact structure, and is convenient to use. The double ball valve double channel drill pipe cement head of the present application realizes insertion type cementing rubber plug replacement, carries out accurate replacement, avoids the risk of traditional insertion type cementing tool replacement amount only through theoretical calculation to cause insufficient replacement, internal pipe ash plug or excessive replacement to cause external pipe replacement empty, which leads to the occurrence of cementing accident, can shorten the cementing construction time and cement slurry thickening time, save the cementing time, reduce the construction risk, and effectively solve the deep well large size casing cementing problem.

Description

Technical Field

[0001] This invention relates to the field of cementing equipment technology, and is a deep well large-size casing insertion cementing device and process. Background Technology

[0002] With the development of the petroleum industry, there are more and more deep wells and multiple wells being opened. As a result, the number of wells with long cementing (2000m-4000m) and large-size casing (473.1mm, 365.13mm, 339.7mm) is also increasing. Conventional cementing technology and conventional insertion cementing technology will bring risks to cementing construction. The main problems with conventional cementing techniques are large displacement volume, long construction time, long cement slurry thickening time, and difficulty in ensuring cementing quality. Conventional insertion cementing is prone to problems such as bending or retraction of long drill strings, leading to insertion head seal failure, cement slurry entering the casing, and a high risk of "flagpole" accidents. For deep wells with large-diameter casing insertion cementing or tailpipe cementing, conventional drill pipe cement heads cannot be pre-inserted with rubber plugs, preventing rubber plug displacement and pressure application. Displacement volume can only be calculated theoretically, increasing the risk of insufficient displacement resulting in cement plugs inside the casing or excessive displacement leading to empty casing outside, causing cementing accidents and numerous inconveniences. Because deep wells with large-diameter casing insertion cementing technology is immature, conventional cementing techniques are the only option, resulting in low cementing quality pass rates, high construction risks, and severely restricting oil and gas field production and development. Summary of the Invention

[0003] This invention provides a deep well large-size casing insertion cementing device and process method, which overcomes the shortcomings of the above-mentioned prior art, proposes a new process method, and solves the problems of high safety risks and poor cementing quality when using conventional cementing processes for deep well large-size casing, and the inability to use insertion cementing. It achieves accurate slurry replacement and wellhead plus downhole double sealing for deep well large-size casing insertion cementing, ensuring cementing quality and construction safety.

[0004] One of the technical solutions of this invention is achieved through the following measures: a deep well large-size casing insertion cementing device, comprising a drill pipe, a casing, and a double-ball-valve double-channel drill pipe cement head, an insertion cementing wellhead sealing circulation device, and an insertion cementing rubber plug pressing device arranged sequentially from top to bottom. The double-ball-valve double-channel drill pipe cement head includes an upper connector, an upper connecting pipe, a lower connecting pipe, and a lower connector threaded together sequentially from top to bottom. A first ball valve and a second ball valve are respectively provided on the inner side of the lower part of the upper connecting pipe and the lower connecting pipe. A first rotating pin and a second rotating pin are respectively provided on the upper connecting pipe and the lower connecting pipe corresponding to the positions of the first ball valve and the second ball valve. The upper part of the upper connecting pipe and the upper part of the lower connector are connected by a connecting pipe. The through pipe is equipped with a first plug valve, and the lower connector is threadedly connected to the top of the drill pipe at the uppermost end. The insertion-type cementing wellhead sealing circulation device includes a sealing sub, an end cap, and a rubber sleeve. The sealing sub is fixedly installed with the end cap. The upper inner side of the sealing sub is equipped with a rubber sleeve whose upper end is fixedly installed with the end cap. The end cap has a through hole in the middle, and the rubber sleeve is funnel-shaped with its opening facing upwards. The lower outer side of the sealing sub is threadedly connected to the upper end of the casing at the uppermost end. The insertion-type cementing wellhead sealing circulation device can seal the annulus between the casing and the drill pipe. The insertion-type cementing rubber plug pressing device is located inside the wellbore and connected to the lower casing. The insertion-type cementing rubber plug pressing device can perform rubber plug pressing.

[0005] The following are further optimizations and / or improvements to the above-mentioned technical solution: The aforementioned insert-type cementing plug pressing device may include an insert-type pressing sub, an insert head, a support cylinder, a self-locking plug, an insert seat, a pressing seat, a six-tooth claw ring, and a one-way valve. The insert-type pressing sub is connected to the casing on both its upper inner side and lower outer side. A support cylinder is fixedly installed on the upper inner side of the insert-type pressing sub. The upper outer side of the insert seat is fixedly installed together with the inner side of the support cylinder. The insert seat has a vertically penetrating installation channel in the middle. A one-way valve is located at the lower end of the installation channel, and a valve located above it is located on the upper inner side of the installation channel. The insert head has a grouting channel running vertically through the middle. A pressing seat is fixedly installed in the insert seat below the insert head. A support ring platform is provided in the insert seat below the pressing seat. A six-tooth claw ring is provided between the upper side of the support ring platform and the lower side of the pressing seat. A self-locking rubber plug is provided in the insert head. The self-locking rubber plug includes a rubber plug and a self-locking head. The self-locking head with its lower end located below it is installed in the rubber plug. The lower outer side of the self-locking head is tapered, wider at the top and narrower at the bottom. A groove is provided on the lower outer side of the self-locking head that can be locked by the six-tooth claw ring.

[0006] The aforementioned insertion-type cementing wellhead sealing circulation device may be equipped with a circulation pipe on its sealing short section, and the circulation pipe is equipped with a second plug valve and a pressure gauge.

[0007] The aforementioned insertable cementing plug pressing device may also include a centralizing block, with the centralizing block fixedly installed on the outer side of the middle part of the insert head.

[0008] The upper inner side of the aforementioned insertion seat may be provided with a guide cone surface, and the corresponding position on the lower outer side of the insertion head matches the guide cone surface.

[0009] The above may also include sealing rings, with a sealing ring provided between the support cylinder and the insert-type pressing short section, a sealing ring provided between the support cylinder and the insert seat, at least one sealing ring provided vertically between the insert seat and the insert head, and a sealing ring provided between the pressing seat and the insert seat.

[0010] The aforementioned insertion-type cementing wellhead sealing circulation device may also include lifting rings, with two lifting rings on the end cap for hoisting.

[0011] The second technical solution of the present invention is achieved through the following measures: a process method for a deep well large-size casing insertion cementing device, which is carried out according to the following steps. (1) Run the casing, connect the insert-type pressing short section to the casing and run it into the well. Run the casing to the predetermined bottom position. Then remove the end cap and rubber sleeve of the insert-type cementing wellhead sealing circulation device, thread the lower end of the sealing short section to the upper end of the casing located at the top, and close the second plug valve on the circulation port to complete the casing running operation. (2) Lower the drill string. Thread the insert head to the bottom end of the lowest drill pipe. When the drill pipe is lowered, it passes through the sealing short section of the insert cementing wellhead sealing circulation device. Connect the drill pipes in sequence. The insert drill string is relatively long and requires circulation in the middle. Install the rubber sleeve and end cap to form a wellhead seal. Open the second plug valve at the circulation pipe to circulate the drilling fluid. After circulation is complete, remove the rubber sleeve and end cap, lower the insert head to the bottom of the well, and lower it to the last drill pipe. Install the rubber sleeve and end cap, and then lower the last drill pipe to form a wellhead seal. Insert the insert head into the installation channel of the insert seat to complete the lowering of the insert drill string. (3) Insert the self-locking rubber plug, rotate the second rotating pin of the double ball valve double channel drill rod cement head to rotate the second ball valve to the closed position, rotate the first rotating pin to rotate the first ball valve to the open position, insert the self-locking rubber plug from the inlet of the upper connector, at this time the self-locking rubber plug falls to the upper end of the second ball valve, rotate the first rotating pin to rotate the first ball valve to the closed position, at this time the self-locking rubber plug is in the sealed space, and the liquid cannot enter, close the first plug valve, connect the lower connector to the upper end of the drill rod at the top thread to complete the connection of the drill rod and cement head, and connect the top drive or square drill rod on the upper connector; (4) During cementing operations, close the first ball valve and the second ball valve, open the first plug valve, and inject the isolation fluid and cement slurry from the top drive or screed. The liquid flows out from the connecting pipe into the drill pipe and the insertion head, flows out from the grouting channel and the check valve, and enters the annulus between the casing and the wellbore for cementing. After the cement slurry is injected, close the first plug valve, open the first ball valve and the second ball valve respectively, and continue to inject the replacement fluid. The self-locking rubber plug moves down into the insertion head under the push of the replacement fluid and engages with the six-tooth claw ring, presses and forms a self-locking, and seals the grouting channel in the middle of the insertion head together with the check valve. (5) Lift up the drill string, pull out the insert head and drill pipe, disassemble the double ball valve double channel drill pipe cement head and the insert cementing wellhead sealing circulation device to complete the cementing.

[0012] This invention features a reasonable and compact structure, making it easy to use. Its dual-ball valve and dual-channel drill pipe cement head enables precise slurry replacement via an insert-type cementing plug. This avoids the risks associated with traditional insert-type cementing tools where the slurry volume can only be theoretically calculated, leading to insufficient slurry replacement and the risk of cementing accidents caused by either leaving cement plugs inside the pipe or excessive slurry removal resulting in empty pipes outside the pipe. It can shorten cementing construction time and cement slurry thickening time, save cementing efficiency, reduce construction risks, and effectively solve the problem of cementing large-size casing in deep wells. Attached Figure Description

[0013] Appendix Figure 1 This is a schematic diagram of the main sectional view of the cement head of the double ball valve and double channel drill pipe of the present invention.

[0014] Appendix Figure 2 For the appendix Figure 1 A schematic diagram of the three-dimensional structure.

[0015] Appendix Figure 3 This is a schematic diagram of the main cross-sectional structure of an insert-type cementing wellhead sealing circulation device.

[0016] Appendix Figure 4 For the appendix Figure 3 A schematic diagram of the three-dimensional structure.

[0017] Appendix Figure 5 This is a schematic diagram of the front cross-sectional structure of an insert-type cementing plug pressing device.

[0018] Appendix Figure 6 A schematic diagram of the front sectional view of the present invention in use.

[0019] The codes in the attached diagram are as follows: 1 is the upper connector, 2 is the upper connecting pipe, 3 is the lower connecting pipe, 4 is the lower connector, 5 is the first ball valve, 6 is the second ball valve, 7 is the first rotating pin, 8 is the second rotating pin, 9 is the connecting pipe, 10 is the first plug valve, 11 is the sealing section, 12 is the end cap, 13 is the rubber cylinder, 14 is the insertion-type pressing section, 15 is the insertion head, 16 is the support cylinder, 17 is the rubber plug, 18 is the self-locking head, 19 is the insertion seat, 20 is the pressing seat, 21 is the six-tooth claw ring, 22 is the one-way valve, 23 is the grouting channel, 24 is the second plug valve, 25 is the straightening block, 26 is the sealing ring, 27 is the lifting ring, 28 is the pressure gauge, 29 is the circulation pipe, 30 is the drill rod, and 31 is the casing. Detailed Implementation

[0020] The present invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of the present invention.

[0021] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0022] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 2As shown in Figures 3, 4, 5, and 6, this deep well large-size casing insertion cementing device includes a drill pipe 30, a casing 31, and a double-ball valve double-channel drill pipe 30 cement head, an insertion cementing wellhead sealing circulation device, and an insertion cementing rubber plug pressing device arranged sequentially from top to bottom. The double-ball valve double-channel drill pipe 30 cement head includes an upper connector 1, an upper connecting pipe 2, a lower connecting pipe 3, and a lower connector 4, which are threaded together sequentially from top to bottom. The lower inner sides of the upper connecting pipe 2 and the lower connecting pipe 3 are respectively provided with a first ball valve 5 and a second ball valve 6. The upper connecting pipe 2 and the lower connecting pipe 3 are respectively provided with a first rotating pin 7 and a second rotating pin 8 at the positions of the first ball valve 5 and the second ball valve 6. The upper part of the upper connecting pipe 2 and the upper part of the lower connector 4 are connected by a connecting pipe 9, and a first plug valve 10 is provided on the connecting pipe 9. The lower connector 4 is threadedly connected to the top of the drill pipe 30 at the uppermost end; the insertion-type cementing wellhead sealing circulation device includes a sealing sub 11, an end cap 12, and a rubber sleeve 13. The sealing sub 11 is fixedly installed with the end cap 12. The upper inner side of the sealing sub 11 is provided with a rubber sleeve 13, which is fixedly installed with the end cap 12 at the upper end. The end cap 12 is provided with a through hole in the middle. The rubber sleeve 13 is funnel-shaped with the opening facing upward. The lower outer side of the sealing sub 11 is threadedly connected to the upper end of the casing 31 at the uppermost end. The insertion-type cementing wellhead sealing circulation device can seal the annulus between the casing 31 and the drill pipe 30; the insertion-type cementing rubber plug pressing device is located inside the wellbore and connected to the lower casing 31. The insertion-type cementing rubber plug pressing device can press the rubber plug 17.

[0023] In use, the double-ball valve double-channel drill pipe cement head of this invention can pre-place a rubber plug 17, which presses against the inlet of the insert cementing rubber plug pressing device, enabling precise slurry replacement and avoiding cementing accidents caused by excessive or insufficient slurry replacement. By setting an insert cementing wellhead sealing circulation device to seal the annulus between the casing 31 and the drill pipe 30, the insertion length of the drill string can easily extend and damage the sealing structure of the insert cementing rubber plug pressing device, or shrink and cause the seal of the insert cementing rubber plug pressing device to fail. If the annulus space between the casing 31 and the drill string is open-pressurized, when injecting isolation fluid and cement slurry, the liquid will enter the annulus space between the casing 31 and the drill string from the insert cementing rubber plug pressing device, resulting in a cement plug accident inside the pipe. At this time, because the rubber sleeve 13 closes the annulus space between the drill pipe 30 and the casing 31, the liquid cannot flow into the space, which plays a role in wellhead sealing and can effectively avoid cement plug accidents inside the pipe.

[0024] The above-mentioned deep well large-size casing insertion cementing device can be further optimized and / or improved according to actual needs: As attached Figure 5 , 6As shown, the insert-type cementing plug pressing device includes an insert pressing sub 14, an insert head 15, a support cylinder 16, a self-locking plug, an insert seat 19, a pressing seat 20, a six-tooth claw ring 21, and a one-way valve 22. The inner side of the upper end and the outer side of the lower end of the insert pressing sub 14 are connected to the casing 31. The support cylinder 16 is fixedly installed on the inner side of the upper part of the insert pressing sub 14. The outer side of the upper part of the insert seat 19 is fixedly installed together with the inner side of the support cylinder 16. The middle part of the insert seat 19 has a vertically penetrating installation channel. The lower end of the installation channel is equipped with a one-way valve 22. The inner side of the upper part of the installation channel has an insert head positioned above it. The head 15 has a grouting channel 23 that runs vertically through the middle of the insertion head 15. A pressing seat 20 is fixedly installed in the insertion seat 19 below the insertion head 15. A support ring platform is provided in the insertion seat 19 below the pressing seat 20. A six-tooth claw ring 21 is provided between the upper side of the support ring platform and the lower side of the pressing seat 20. A self-locking rubber plug is provided in the insertion head 15. The self-locking rubber plug includes a rubber plug 17 and a self-locking head 18. The self-locking head 18 with its lower end located below it is installed in the rubber plug 17. The lower outer side of the self-locking head 18 is tapered with a larger upper end and a smaller lower end. The lower outer side of the self-locking head 18 has a groove that can be locked by the six-tooth claw ring 21.

[0025] The insertable cementing plug pressing device of the present invention can achieve self-locking. After the grouting is completed, the self-locking plug can work with the one-way valve 22 to block the grouting channel 23, prevent downhole liquid from entering, and work with the one-way valve 22 to ensure the safety of the bottom of the well.

[0026] As attached Figure 3 , 4 As shown in Figure 6, the sealing section 11 of the insertion-type cementing wellhead sealing circulation device is equipped with a circulation pipe 29, and the circulation pipe 29 is equipped with a second plug valve 24 and a pressure gauge 28. During use, the long static time of the drilling mud in the well results in poor fluidity, leading to high construction pressure and easy leakage of the bottom layer. The plug valve at the circulation pipe can be opened to circulate the drilling fluid.

[0027] As attached Figure 5 , 6 As shown, the insert-type cementing plug pressing device also includes a centralizing block 25, which is fixedly installed on the outer side of the middle part of the insert head 15. By setting the centralizing block 25, the position of the insert head 15 in the middle of the casing 31 can be maintained.

[0028] As attached Figure 5 , 6 As shown, the upper inner side of the insertion seat 19 is provided with a guide cone surface, and the corresponding position on the lower outer side of the insertion head 15 matches the guide cone surface. This facilitates the positioning of the insertion seat 19 and better completes the pressing action. As attached Figure 5 , 6As shown, it also includes sealing rings 26. A sealing ring 26 is provided between the support cylinder 16 and the insertion-type pressing sub 14, a sealing ring 26 is provided between the support cylinder 16 and the insertion seat 19, at least one sealing ring 26 is provided vertically between the insertion seat 19 and the insertion head 15, and a sealing ring 26 is provided between the pressing seat 20 and the insertion seat 19. The sealing rings 26 are used to prevent fluid from flowing through the bottom of the well.

[0029] As attached Figure 5 , 6 As shown, the insertion-type cementing wellhead sealing circulation device also includes lifting rings 27, and the end cap 12 is provided with two lifting rings 27 for lifting. The lifting rings 27 facilitate lifting.

[0030] Example 2: As shown in the attached document Figure 1 , 2 As shown in Figures 3, 4, 5, and 6, the process method for this deep well large-size casing insertion cementing device is carried out according to the following steps. (1) Run the casing 31, connect the insert-type pressing short section 14 to the casing 31 and run it into the well. Run the casing 31 to the predetermined bottom position. Then remove the end cap 12 and rubber sleeve 13 of the insert-type cementing wellhead sealing circulation device. Thread the lower end of the sealing short section 11 to the upper end of the casing 31 located at the uppermost end, and close the second plug valve 24 on the circulation port to complete the casing 31 running operation. (2) Lower the drill string. Connect the insert head 15 to the lower end of the drill pipe 30. When the drill pipe 30 is lowered, it passes through the sealing short section 11 of the insert cementing wellhead sealing circulation device. Connect the drill pipes 30 in sequence. The drill string is long and needs to be circulated in the middle. Install the rubber sleeve 13 and the end cap 12 to form a wellhead seal. Open the second plug valve 24 at the circulation pipe 29 to circulate the drilling fluid. After circulation is completed, remove the rubber sleeve 13 and the end cap 12. Lower the insert head 15 to the bottom of the well. Before the last drill pipe 30, install the rubber sleeve 13 and the end cap 12. Then lower the last drill pipe 30 to form a wellhead seal. Insert the insert head 15 into the installation channel of the insert seat 19 to complete the lowering of the drill string. (3) Insert the self-locking rubber plug, rotate the second rotating pin 8 of the cement head of the double ball valve double channel drill rod 30 to rotate the second ball valve 6 to the closed position, rotate the first rotating pin 7 to rotate the first ball valve 5 to the open position, insert the self-locking rubber plug from the inlet of the upper connector 1, at this time the self-locking rubber plug falls to the upper end of the second ball valve 6, rotate the first rotating pin 7 to rotate the first ball valve 5 to the closed position, at this time the self-locking rubber plug is in a sealed space and the liquid cannot enter, close the first plug valve 10, connect the lower connector 4 to the upper end of the drill rod 30 at the top, and complete the connection of the drill rod 30 and the cement head, connect the top drive or square drill rod 30 on the upper connector 1; (4) During cementing operations, close the first ball valve 5 and the second ball valve 6, open the first plug valve 10, and inject the isolation fluid and cement slurry from the top drive or square drill pipe 30 respectively. The liquid flows out from the connecting pipe 9 and enters the drill pipe 30 and the insertion head 15, flows out from the grouting channel 23 and the one-way valve 22, and enters the annulus between the casing 31 and the wellbore for cementing. After the cement slurry is injected, close the first plug valve 10, open the first ball valve 5 and the second ball valve 6 respectively, and continue to inject the replacement slurry. The self-locking rubber plug moves down to the insertion head 15 under the push of the replacement slurry and engages with the six-tooth claw ring 21, pressing and forming a self-locking, which together with the one-way valve 22 seals the grouting channel 23 in the middle of the insertion head 15. (5) Lift up the drill string, remove the insert head 15 and drill pipe 30, disassemble the cement head of the double ball valve double channel drill pipe 30 and the insert cementing wellhead sealing circulation device to complete the cementing.

[0031] This process can be used for cementing of various sizes of casing in shallow or deep wells. It can effectively solve the problem of cementing large-size casing in deep wells, shorten construction time and cement slurry thickening time, save cementing efficiency, reduce construction risks, and meet the needs of oilfield production and development.

[0032] When this process is applied to large-size casing in deep wells, it can effectively shorten the slurry replacement time by about 90% compared to conventional cementing (taking a 4000m deep well with 339.7mm casing as an example, the slurry replacement volume of conventional cementing is about 300m³, while that of inner-tube insertion cementing is about 35m³). Compared to conventional insertion tools, the sealing pressure can be increased by more than 2 times (the sealing pressure of conventional insertion cementing tools is about 9MPa, while the target sealing pressure of the new tool reaches 15-20MPa). At the same time, the insertion cementing wellhead sealing circulation device can be used alone in the insertion cementing operation of large-size surface casing 31. By using wellhead sealing to seal the space between drill pipe 30 and casing 31, the lower part no longer needs to use a pressure-bearing device, allowing cement slurry to directly enter the annulus, which can save cementing tool costs and effectively shorten the drilling plug time of the well team.

[0033] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A deep well large-size casing insertion cementing device, characterized in that... The system includes drill pipe, casing, and, from top to bottom, a double-ball-valve double-channel drill pipe cement head, an insertion-type cementing wellhead sealing circulation device, and an insertion-type cementing rubber plug pressing device. The double-ball-valve double-channel drill pipe cement head comprises, from top to bottom, an upper connector, an upper connecting pipe, a lower connecting pipe, and a lower connector, all threaded together. The lower inner sides of the upper and lower connecting pipes are respectively equipped with a first ball valve and a second ball valve. Corresponding to the positions of the first and second ball valves, the upper and lower connecting pipes are respectively equipped with a first rotating pin and a second rotating pin. The upper part of the upper connecting pipe and the upper part of the lower connector are connected by a connecting pipe, which is equipped with a first... The plug valve's lower connector is threaded to the top of the drill pipe at the uppermost end. The insert-type cementing wellhead sealing circulation device includes a sealing sub, an end cap, and a rubber sleeve. The sealing sub is fixedly installed with the end cap. The inner side of the upper end of the sealing sub has a rubber sleeve whose upper end is fixedly installed with the end cap. The end cap has a through-hole in the middle. The rubber sleeve is funnel-shaped with its opening facing upwards. The outer side of the lower end of the sealing sub is threaded to the upper end of the casing at the uppermost end. The insert-type cementing wellhead sealing circulation device can seal the annulus between the casing and the drill pipe. The insert-type cementing rubber plug pressing device is located inside the wellbore and connected to the lower casing. The insertion-type cementing plug pressing device is used for plug pressing. It includes an insertion pressing sub, an insert head, a support cylinder, a self-locking plug, an insert seat, a pressing seat, a six-tooth claw ring, and a one-way valve. The upper inner side and lower outer side of the insertion pressing sub are connected to the casing. The support cylinder is fixedly installed on the upper inner side of the insertion pressing sub. The upper outer side of the insert seat is fixedly installed together with the inner side of the support cylinder. The middle of the insert seat has a through-hole installation channel. A one-way valve is located at the lower end of the installation channel. The upper inner side of the installation channel has an insert head positioned above it. The middle of the insert head has... The grouting channel runs vertically through the insertion head. A pressure seat is fixedly installed in the insertion seat below the insertion head. A support ring platform is provided in the insertion seat below the pressure seat. A six-tooth claw ring is provided between the upper side of the support ring platform and the lower side of the pressure seat. A self-locking rubber plug is provided in the insertion head. The self-locking rubber plug includes a rubber plug and a self-locking head. The self-locking head with its lower end located below it is installed in the rubber plug. The lower outer side of the self-locking head is tapered, wider at the top and narrower at the bottom. A groove is provided on the lower outer side of the self-locking head that can be locked by the six-tooth claw ring. Or / and, the sealing short section of the insertion cementing wellhead sealing circulation device is provided with a circulation pipe. A second plug valve and a pressure gauge are provided on the circulation pipe.

2. The deep well large-size casing insertion cementing device according to claim 1, characterized in that... The insert-type cementing plug pressing device also includes a centering block, which is fixedly installed on the outer side of the middle part of the insert head.

3. The deep well large-size casing insertion cementing device according to claim 1 or 2, characterized in that... The upper inner side of the insertion seat is provided with a guide cone surface, and the corresponding position on the lower outer side of the insertion head matches the guide cone surface.

4. The deep well large-size casing insertion cementing device according to claim 1 or 2, characterized in that... It also includes sealing rings, with a sealing ring between the support cylinder and the insert-type pressing section, a sealing ring between the support cylinder and the insert seat, at least one sealing ring spaced vertically between the insert seat and the insert head, and a sealing ring between the pressing seat and the insert seat.

5. The deep well large-size casing insertion cementing device according to claim 3, characterized in that... It also includes sealing rings, with a sealing ring between the support cylinder and the insert-type pressing section, a sealing ring between the support cylinder and the insert seat, at least one sealing ring spaced vertically between the insert seat and the insert head, and a sealing ring between the pressing seat and the insert seat.

6. The deep well large-size casing insertion cementing device according to claim 1, 2, or 5, characterized in that... The insertion-type cementing wellhead sealing circulation device also includes lifting rings, with two lifting rings on the end cap for hoisting.

7. The deep well large-size casing insertion cementing device according to claim 3, characterized in that... The insertion-type cementing wellhead sealing circulation device also includes lifting rings, with two lifting rings on the end cap for hoisting.

8. The deep well large-size casing insertion cementing device according to claim 4, characterized in that... The insertion-type cementing wellhead sealing circulation device also includes lifting rings, with two lifting rings on the end cap for hoisting.

9. A process method for using the deep well large-size casing insertion cementing device according to any one of claims 1 to 8, characterized in that... Follow these steps. (1) Run the casing, connect the insert-type pressing short section to the casing and run it into the well. Run the casing to the predetermined bottom position. Then remove the end cap and rubber sleeve of the insert-type cementing wellhead sealing circulation device, thread the lower end of the sealing short section to the upper end of the casing located at the top, and close the second plug valve on the circulation port to complete the casing running operation. (2) Lower the drill string. Thread the insert head to the bottom end of the lowest drill pipe. When the drill pipe is lowered, it passes through the sealing short section of the insert cementing wellhead sealing circulation device. Connect the drill pipes in sequence. The insert drill string is relatively long and requires circulation in the middle. Install the rubber sleeve and end cap to form a wellhead seal. Open the second plug valve at the circulation pipe to circulate the drilling fluid. After circulation is complete, remove the rubber sleeve and end cap, lower the insert head to the bottom of the well, and lower it to the last drill pipe. Install the rubber sleeve and end cap, and then lower the last drill pipe to form a wellhead seal. Insert the insert head into the installation channel of the insert seat to complete the lowering of the insert drill string. (3) Insert the self-locking rubber plug, rotate the second rotating pin of the double ball valve double channel drill rod cement head to rotate the second ball valve to the closed position, rotate the first rotating pin to rotate the first ball valve to the open position, insert the self-locking rubber plug from the inlet of the upper connector, at this time the self-locking rubber plug falls to the upper end of the second ball valve, rotate the first rotating pin to rotate the first ball valve to the closed position, at this time the self-locking rubber plug is in the sealed space, and the liquid cannot enter, close the first plug valve, connect the lower connector to the upper end of the drill rod at the top thread to complete the connection of the drill rod and cement head, and connect the top drive or square drill rod on the upper connector; (4) During cementing operations, close the first ball valve and the second ball valve, open the first plug valve, and inject the isolation fluid and cement slurry from the top drive or screed. The liquid flows out from the connecting pipe into the drill pipe and the insertion head, flows out from the grouting channel and the check valve, and enters the annulus between the casing and the wellbore for cementing. After the cement slurry is injected, close the first plug valve, open the first ball valve and the second ball valve respectively, and continue to inject the replacement fluid. The self-locking rubber plug moves down into the insertion head under the push of the replacement fluid and engages with the six-tooth claw ring, presses and forms a self-locking, and seals the grouting channel in the middle of the insertion head together with the check valve. (5) Lift up the drill string, pull out the insert head and drill pipe, disassemble the double ball valve double channel drill pipe cement head and the insert cementing wellhead sealing circulation device to complete the cementing.

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