A method of cementing a carbon dioxide injection well

Abstract

The application discloses a carbon dioxide reinjection well cementing method and belongs to the technical field of well cementing in oil drilling and production engineering. The carbon dioxide reinjection well cementing method sequentially carries out casing cementing, liner cementing and liner tieback cementing processes for different well sections, can improve the corrosion resistance of the wellbore cement sheath and the casing, can strengthen the pressure-bearing capacity of the well, can reduce the risk of cementing leakage, can prevent the formation of carbon dioxide leakage channels and can ensure long-term reliable operation of the well in the marine environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of well cementing in petroleum drilling engineering, and particularly relates to a well cementing method for a carbon dioxide reinjection well. BACKGROUND

[0002] CO2 capture, utilization and storage (CCUS) is an important technical choice for realizing large-scale fossil energy zero emission at present, and is a main carbon emission reduction means for future electric power, steel, cement and chemical industries.

[0003] Carbon storage technology includes three contents in specific practice: capture, transportation and storage. Carbon capture and storage, as the core of carbon storage technology, has been widely concerned worldwide. In carbon dioxide geological storage, storage wells (burial wells) include injection wells, production wells and abandoned wells. After the injection of carbon dioxide into the well, the cement sheath and casing in the storage area will be corroded under the condition of water, thereby forming a channel for carbon dioxide leakage, and resulting in imperfect integrity of the storage system. Offshore extended reach wells as reinjection wells face problems such as low cementing quality, shallow burial depth of reinjection layer, poor pressure-bearing capacity of stratum, risk of fault, cementing leakage, difficulty in casing centralization in large dogleg build-up and long build-up section, and poor corrosion resistance of casing and tailpipe due to the presence of CO2.

[0004] In view of the above problems, the present application provides a well cementing method for a carbon dioxide reinjection well. SUMMARY

[0005] The present application provides a well cementing method for a carbon dioxide reinjection well, which solves the above problems.

[0006] The present application provides the following technical solutions:

[0007] A well cementing method for a carbon dioxide reinjection well, comprising the following steps:

[0008] S1, casing cementing;

[0009] S1.1, preparation work before cementing;

[0010] S1.2, pumping cementing fluid;

[0011] S1.3, switching to mud pump for displacement;

[0012] S1.4, pressure control and detection;

[0013] S1.5, waiting for setting;

[0014] S2, tailpipe cementing;

[0015] S2.1, repeating step S1.1;

[0016] S2.2, tailing pump in, filling the wellbore bottom;

[0017] S2.3, switching to mud pump for displacement;

[0018] S2.4, pressure control and detection;

[0019] S2.5, setting top packer, pulling out the running tool, and circulating cement slurry;

[0020] S2.6, conducting cementing;

[0021] S3, liner tieback cementing;

[0022] S3.1, preparing for liner tieback cementing work and conducting liner tieback sealing test;

[0023] S3.2, cleaning mud in the wellbore and cleaning and preparing after testing the ground pipeline pressure;

[0024] S3.3, mixing the mixed slurry and cementing fluid through the cementing pump, and filling the wellbore bottom with the tailing slurry mixed by the cementing pump;

[0025] S3.4, quickly dismounting the circulating head, putting in the casing top plug, and quickly connecting the variable buckle and the casing, and connecting the top drive to send the casing into the wellbore;

[0026] S3.5, increasing additional pressure on the basis of the final displacement pressure to meet the design requirements, and then stabilizing the pressure for 5 minutes to ensure the safe installation of the casing and the tight sealing with the wellbore wall;

[0027] S3.6, slowly lowering the insertion seal until it is fully inserted into the tieback sleeve, and when the second seal is inserted into the tieback sleeve, releasing all the pressure in the casing and keeping the ground pressure relief valve open, continuing to lower and fully insert the insertion seal into the tieback sleeve while applying a certain downward pressure;

[0028] S3.7, checking whether the casing mark is consistent with the mark when the first test is inserted, if consistent, continue to press down to the design load to set the casing packer and hanger, and keep for a certain period of time to ensure the correct installation depth and position of the casing, and the effectiveness of the hanger and the packer;

[0029] S3.8, releasing the pressure of the cementing pump and checking the backflow, if there is backflow, replacing the backflow pressure holding to ensure that the cementing fluid in the casing has no leakage, and conducting cementing.

[0030] In one possible design, the step S1.1 specifically comprises the following steps:

[0031] S1.1.1, determining the size of the casing centralizer, sequentially running in the casing and adding the centralizer;

[0032] S1.1.2, water is passed through the ground pipeline by the cementing pump, and the pressure should meet the requirement of the highest pump pressure in the cementing method to ensure that the pipeline is firm and available during the cementing process;

[0033] S1.1.3, the impurities are flushed out of the well hole by flushing the flushing fluid through the cementing pump to sufficiently clean the well wall surface of the well hole.

[0034] In a possible design, the step S1.2 specifically includes the following steps:

[0035] S1.2.1, stop the cementing pump, and open the bottom plug release block pin of the cement head;

[0036] S1.2.2, pump the mixed water plug of the spacer into the cementing pump, and the spacer mixed with water pumped into the bottom plug pushes the bottom plug to the bottom of the well hole, so that the cementing fluid fills the well hole from the bottom of the casing;

[0037] S1.2.3, mix the mixed spacer and cementing fluid uniformly by the cementing pump;

[0038] S1.2.4, mix the tailing slurry by the cementing pump, and pump the tailing slurry into the well hole to fill the bottom of the well hole.

[0039] In a possible design, the step S1.3 specifically includes the following steps:

[0040] S1.3.1, stop the cementing pump, and open the top plug release block pin of the cement head to release the top plug;

[0041] S1.3.2, pump the tailing slurry mixed with water plug by the cementing pump;

[0042] S1.3.3, switch to the mud pump for displacement, and finally change to small displacement displacement.

[0043] In a possible design, the step S1.4 specifically includes the following steps:

[0044] S1.4.1, on the basis of reaching the final displacement pressure, increase the additional pressure to meet the design requirement, and maintain the pressure for a certain period of time to ensure the reliability of the cementing, and detect whether there is a pressure drop to ensure that the cementing fluid does not leak;

[0045] S1.4.2, open the pressure relief valve of the cementing pump, and check the backflow, and then replace the backflow pressure holding and condensation.

[0046] In a possible design, the step S2.2 specifically includes the following steps:

[0047] S2.2.1, pump the spacer by the mud pump, pump the flushing fluid by the cementing pump, and pump the drilling water by the cementing pump;

[0048] S2.2.2, mixing the mixed slurry and cementing fluid uniformly by the cementing pump;

[0049] S2.2.3, mixing the tail slurry by the cementing pump, and pumping the tail slurry into the wellbore to fill the bottom of the wellbore.

[0050] In a possible design, the step S2.3 specifically includes the following steps:

[0051] S2.3.1, stopping the cementing pump from working, and opening the blocking pin on the cement head to release the top plug to release the top plug;

[0052] S2.3.2, pumping the tail slurry mixed water pressure plug by the cementing pump;

[0053] S2.3.3, switching to the mud pump for displacement, and finally switching to small displacement displacement.

[0054] In a possible design, the step S2.4 specifically includes the following steps:

[0055] S2.4.1, on the basis of reaching the final displacement pressure, increasing the additional pressure to meet the design requirements, and maintaining the pressure for a certain period of time to ensure the reliability of cementing, while detecting whether there is a pressure drop to ensure that the cementing fluid does not leak;

[0056] S2.4.2, opening the pressure relief valve of the cementing pump, and checking the backflow to replace the backflow pressure holding and condensation.

[0057] In a possible design, the step S3.1 specifically includes the following steps:

[0058] S3.1.1, during the wellbore, a certain volume of thick slurry is filled below the back connection cylinder to fill the bottom of the back connection cylinder;

[0059] S3.1.2, checking the integrity of the insertion seal and the packer, including the number of packer shear pins, while using double floating collars to ensure the integrity of the insertion seal and the packer, and correctly using the double floating collars to provide effective sealing and sealing;

[0060] S3.1.3, replacing the long elevator before casing, sequentially lowering the casing and adding the centralizer, coating the thread glue below the casing with the floating collar, and checking the float valve performance by grouting;

[0061] S3.1.4, the cementing pump tests the back connection seal, tests the sealing performance of the back connection seal, and ensures the normal sealing system;

[0062] S3.1.5, after the circulating hole is brought out to the top of the back-connection cylinder, the cementing pump is turned on to confirm that the circulation channel is unobstructed, then the cementing pump is stopped, the casing slips are installed, and the cementing circulation head and the cementing pipeline are connected to establish the circulation channel, and the well is prepared for cementing operation.

[0063] In one possible design, the step S3.2 specifically includes the following steps:

[0064] S3.2.1, before cementing, mud in the wellbore is removed by starting small-displacement circulation, gradually increasing to the designed displacement, to ensure that the wellbore is clean;

[0065] S3.2.2, the cementing pump is watered to the ground pipeline and pressure tested to test the sealing performance of the ground pipeline and ensure that the cementing fluid does not leak;

[0066] S3.2.3, the wellbore is cleaned by pumping flushing fluid through the cementing pump, preparing for the following cementing fluid pumping.

[0067] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application.

[0068] The present application is directed to the process of casing cementing, liner cementing and liner back-connection cementing in different well sections, which can improve the corrosion resistance of the wellbore cement sheath and the casing, strengthen the pressure-bearing capacity of the well, reduce the risk of cementing leakage, prevent the formation of carbon dioxide leakage channels, and ensure the long-term reliable operation of the well in the marine environment. DETAILED DESCRIPTION

[0069] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0070] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a sufficient understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0071] EMBODIMENT

[0072] This embodiment is based on a certain offshore extended reach well in a certain place, and the wellbore and casing data are shown in the following table:

[0073]

[0074] The present embodiment provides a carbon dioxide reinjection well cementing method, which includes the following steps:

[0075] Step one, casing cementing

[0076] 1. Preparation:

[0077] 1.1. Check the cement head of the casing and install the rubber plug according to the relevant procedures.

[0078] 1.2. Determine the size of the casing centralizer.

[0079] 1.3. Before starting the cementing operation, reserve samples of cement for cementing, mixed water, drilling water, seawater, etc.

[0080] 1.4. Lower the casing and install the centralizer in sequence, apply thread sealant to the thread of the casing below the float collar, and check the performance of the float valve by grouting.

[0081] 1.5. After the casing enters the open hole, control the lowering speed to be greater than 30 seconds per root; if resistance is encountered, move the pipe string and establish circulation.

[0082] 1.6. After the casing is lowered into position, set the safety slips, connect the cement head, cementing pipeline, and exhaust pipeline, punch the floating collar, and exhaust.

[0083] 1.7. Circulate before cementing, punch and establish circulation at a small displacement, and gradually increase to the design displacement; if there is a leak, reduce the displacement and perform plugging.

[0084] 1.8. Adjust the drilling fluid properties under the premise of ensuring safety downhole, reduce the density, viscosity, shear force, and yield value; the recommended drilling fluid properties are FV ≤ 50, PV ≤ 20, and YP ≤ 5.

[0085] 1.9. Circulate the drilling fluid for at least 2 weeks, and observe that there are no obvious drill cuttings in the shaker and the gas measurement value is <5%.

[0086] 2. Centralizer placement: plan to install 190-200 resin centralizers to ensure the centralization of the casing; install rigid centralizers at about 3 meters above the float collar and float shoe, and fix them with a stop ring; then install one resin centralizer for each casing.

[0087] 3. Start the operation:

[0088] 3.1. The cementing pump is connected to the surface pipeline and pressure tested, with a low pressure of 300 psi for 5 minutes and a high pressure of 3000 psi for 15 minutes.

[0089] 3.2. The cementing pump pumps in the flushing fluid.

[0090] 3.3. The mud pump pumps in the spacer fluid with a density of 1.10 g / cm 3 and a displacement of 12 bpm.

[0091] 3.4. The cementing pump pumps in the flushing fluid.

[0092] 3.5. Stop the pump and release the bottom plug.

[0093] 3.6, Pump the mixed water pressure plug into the annulus by the cementing pump.

[0094] 3.7, Pump the mixed plug into the annulus by the cementing pump.

[0095] 3.8, Pump the mixed tail plug into the annulus by the cementing pump.

[0096] 3.9, Stop pumping and release the double plugs. (Pump 1 bbls of water between the two plugs.)

[0097] 3.10, Pump the mixed water pressure plug into the annulus by the cementing pump.

[0098] 3.11, Switch to the mud pump for displacement, fast displacement at 12 bpm, and slow displacement at 2 bpm for the last 100 bbls. (The maximum displacement shall not exceed half of the volume of the shoe plug.)

[0099] 3.12, Pressure bumping, add 500 psi to the final displacement pressure, and stabilize for 5 minutes. (Do not require pressure bumping to prevent displacement.) Bleed off the cementing pump and check the backflow. (If the backflow does not stop, pump in the entire backflow volume and check again. If it still does not work after 2 attempts, wait for the cement to set under pressure.)

[0100] 3.13, Wait for the cement to set for ≥24 hours.

[0101] Specifically, the embodiment adopts:

[0102] Additional volume: The additional volume is not less than 20% of the electric logging annulus volume; when there is no electric logging data, the additional volume is not less than 50% of the standard annulus volume; the casing overlap section is not added.

[0103] Rinse formula: 30% PC-W21L + 70% drilling water.

[0104] Cement slurry return height: the lead slurry returns to the mud line, and the tail slurry returns to 300 m above the 9-5 / 8 pipe shoe.

[0105] Preflush: 150 bbls of rinse + 1200 bbls of spacer + 60 bbls of rinse.

[0106] Cement slurry: PC-Corro CEM cement slurry system is used, which is a special research achievement and has good CO2 corrosion resistance; the lead slurry density is 1.50 g / cm 3 , and the tail slurry density is 1.90 g / cm 3 .

[0107] Displacement: The mud pump is used for displacement of seawater throughout the process.

[0108] Check backflow: After pressure relief, check backflow. If backflow continues, pump back all the backflow volume. If it still fails after 2 attempts, hold pressure and wait for setting. The setting time is based on the test formula.

[0109] Thickening time: The thickening time of the slurry should consider the safety time of the wellhead operation.

[0110] The cement slurry formula is shown in the following table:

[0111]

[0112]

[0113] Step two, liner cementing

[0114] 1. Preparation:

[0115] 1.1. Communicate with the liner engineer in advance to confirm the cementing process and key operations.

[0116] 1.2. Determine the size of the liner centralizer.

[0117] 1.3. Before starting the cementing operation, reserve samples of cement, mixed water, drilling water, seawater, etc. for cementing.

[0118] 1.4. Lower the liner and the centralizer in order, and coat the threads of the casing below the float collar with thread compound. Check the performance of the float valve by grouting.

[0119] 1.5. After the casing enters the open hole, control the lowering speed to be greater than 30 seconds per root. If resistance is encountered, move the pipe string and establish circulation.

[0120] 1.6. Circulate before cementing, and gradually increase the design discharge rate after small discharge rate is used to clear the hole and establish circulation. If there is a leak, reduce the discharge rate and perform plugging.

[0121] 1.7. Adjust the drilling fluid properties under the premise of ensuring safety downhole, reduce the density, viscosity, shear force, and yield value. The recommended drilling fluid properties are FV≤50, PV≤20, and YP≤5.

[0122] 1.8. Circulate the drilling fluid for at least 2 weeks, and observe that there are no obvious drill cuttings in the shaker and the gas measurement value is <5%.

[0123] 2. Centralizer placement:

[0124] Plan to install 90-100 resin centralizers to ensure the centralization of the casing. Install rigid centralizers at the stop collar, float collar, and float shoe, and fix them with a stop ring. Then install a resin centralizer on each liner.

[0125] 3. Start the operation:

[0126] 3.1, use batch mixing tank to mix cement slurry in advance.

[0127] 3.2, cementing pump is connected to surface line and pressure tested, low pressure 300 psi / 5 min, high pressure 4500 psi / 15 min.

[0128] 3.3, cementing pump pumps in flushing fluid.

[0129] 3.4, mud pump pumps in spacer fluid, density 1.10 g / cm 3 , displacement 8 bpm.

[0130] 3.5, cementing pump pumps in flushing fluid.

[0131] 3.6, cementing pump pumps in drilling water.

[0132] 3.7, cementing pump pumps in lead slurry.

[0133] 3.8, cementing pump pumps in tail slurry.

[0134] 3.9, stop pumping, release shear plug.

[0135] 3.10, cementing pump pumps in drilling water pressure plug.

[0136] 3.11, switch to mud pump for displacement, fast displacement 8 bpm, slow displacement 2 bpm in the last 100 bbls, and the maximum displacement is not more than half the volume of the shoe plug.

[0137] 3.12, pressure bumping, add 500 psi to the final displacement pressure, and stabilize for 5 minutes, and strictly prohibit the requirement of pressure bumping to prevent displacement.

[0138] 3.13, cementing pump pressure relief, check backflow; if the backflow does not stop, pump in all the backflow amount and check again, and if it still does not work after 2 attempts, directly set the packer.

[0139] 3.14, set the top packer according to the instructions of the tailpipe engineer, pull out the running tool, and circulate the cement slurry.

[0140] 3.15, conduct a waiting period, and the waiting period is ≥72 hours.

[0141] Specifically, the embodiment adopts:

[0142] Additional amount: the additional amount is not less than 20% of the electric logging annulus volume; when there is no electric logging data, the additional amount is not less than 50% of the standard annulus volume; the casing overlap section is not added.

[0143] Pre-flush fluid: 90 bbls of flushing fluid + 450 bbls of spacer fluid + 60 bbls of flushing fluid.

[0144] Spacer fluid formulation: Drilling water + PC-X60L + PC-G86L + PC-S32S, weighted to 1.10 g / cm 3 .

[0145] Flushing fluid formulation: 30% PC-W21L + 70% drilling water.

[0146] Cement slurry return: lead slurry returns to 50 m above the liner hanger, and tail slurry returns to 400 m above the liner shoe.

[0147] Pre-flush fluid: 90 bbls of flushing fluid + 450 bbls of spacer fluid + 60 bbls of flushing fluid.

[0148] Cement slurry: a phosphoaluminate cement slurry system is used, which is a special research achievement, is not affected by CO2 corrosion, and can theoretically achieve permanent sealing of the CO2 injection layer; lead slurry density 1.82 g / cm 3 , tail slurry density 1.82 g / cm 3 .

[0149] Displacement: mud pump displacement is used throughout the seawater.

[0150] Check backflow: after pressure relief, check backflow. If the backflow continues, pump back the entire backflow volume, and if it still does not work after repeated attempts 2 times, directly set the packer.

[0151] Specifically, the cement slurry formulation is shown in the following table:

[0152]

[0153]

[0154] Step three, liner back-connection cementing

[0155] 1. Preparation:

[0156] 1.1. During the wellbore passing period, pad at least 100 m of thick slurry below the back-connection cylinder.

[0157] 1.2. Lower the back-connection cylinder scraper to clean the back-connection cylinder.

[0158] 1.3. Check the insertion seal integrity, the number of packer shear pins, and preferably use a double float collar.

[0159] 1.4. Before starting the cementing operation, reserve samples of cement, mixed water, drilling water, seawater, etc. for cementing.

[0160] 1.5. Replace the long elevator before lowering the liner, lower the casing and the centralizer in order, coat the casing threads with thread sealant below the float collar, and check the float valve performance by grouting.

[0161] 1.6, cementing pump to back-connection sealing pressure test, specifically 500 psi / 3 min, 1000 psi / 5 min.

[0162] 1.7, after the circulation hole is put out of the top of the back-connection cylinder, the pump is started to confirm the circulation channel, the pump is stopped, the casing slips are seated, the cementing circulation head and the cementing pipeline are connected.

[0163] 1.8, pre-cementing circulation, small displacement to open and establish circulation, gradually increase to design displacement.

[0164] 1.9, thickening time: the thickening time of the lead slurry should consider the safety time of the liner hanging and setting and circulating cleaning cement slurry.

[0165] 2, centralizer placement: one resin centralizer is planned to be installed on one casing to ensure the centralization of the casing.

[0166] 3, start operation:

[0167] 3.1, cementing pump to ground pipeline water and pressure test, low pressure 300 psi / 5 min, high pressure 3000 psi / 15 min.

[0168] 3.2, cementing pump to pump in flushing fluid.

[0169] 3.3, cementing pump to pump in lead slurry mixed water.

[0170] 3.4, cementing pump to mix and pump lead slurry.

[0171] 3.5, cementing pump to mix and pump tail slurry.

[0172] 3.6, quickly remove the circulation head, put in the casing top plug, quickly connect the variable buckle + send into the casing, connect the top drive.

[0173] 3.7, switch to mud pump for displacement, fast displacement 8 bpm, last 20 bbls slow displacement, slow displacement 3 bpm, and the maximum displacement is not more than half of the shoe plug volume.

[0174] 3.8, pressure bumping, additional 500 psi based on the final displacement pressure, stable pressure for 5 minutes, and it is required to bump pressure to prevent displacement.

[0175] 3.9, slowly lower the insert seal into the back-connection cylinder, when the second seal is inserted into the back-connection cylinder, all the pressure inside the casing is released, and the ground pressure relief valve is kept open. Continue to lower the insert seal into the back-connection cylinder, lower 5-8 klbs.

[0176] 3.10, check if the casing mark is consistent with the mark when the first test is inserted, if it is consistent, continue to lower to the design hanging weight to set the casing packer and hanger, and keep for 5 minutes.

[0177] 3.11 Depressurize the cementing pump and check the backflow.

[0178] 3.12. Allow the mixture to solidify for at least 24 hours.

[0179] Specifically, this embodiment uses:

[0180] Additional quantity: No additional quantity is added for the overlapping section of the sleeve.

[0181] Cement grout return height: The lead grout returns to the mud line, and the tail grout returns to 1000m above the return pipe.

[0182] Pre-flushing solution: 90bbls flushing solution.

[0183] Cement grout: The PC-CorroCEM cement grout system is used. This system is a specialized research achievement and has excellent resistance to CO2 corrosion; the grout density is 1.90 g / cm³. 3 Tailings density 1.90 g / cm³ 3 .

[0184] Replacement: The entire process uses mud pumps to replace seawater.

[0185] Check reflux: After depressurization, check the reflux. If reflux continues, pump back the entire reflux volume. If this is ineffective after two attempts, pressurize and wait for condensation. The condensation time should be based on the test formula.

[0186] Thickening time: The thickening time of the slurry should take into account the safe time for wellhead operations.

[0187] The pre-flushing solution is 90bbls of flushing fluid;

[0188] Flushing fluid formulation: 30% PC-W21L + 70% drilling water.

[0189] Specifically, the cement slurry formulation design is shown in the table below:

[0190]

[0191] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. In the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cementing method for carbon dioxide reinjection wells, characterized in that, Includes the following steps: S1, casing cementing; S1.1 Preparations before cementing; S1.2, Pump in cementing fluid; S1.3, Switch to mud pump for replacement; S1.4, Perform pressure control and testing; S1.5, proceed with condensation; S2, tailpipe cementing; S2.1, Repeat step S1.1; S2.2, Tailings slurry is pumped in to fill the bottom of the wellbore; S2.3, Switch to mud pump for replacement; S2.4, Perform pressure control and testing; S2.5 Set the top packer, remove the feeding tool, and circulate and clean the cement slurry; S2.6, Proceed to condensation; S3, Tailpipe reconnection cementing; S3.1 Prepare for the reconnection cementing work and conduct a reconnection sealing test; S3.2 Remove the mud from the wellbore and perform pre-cleaning preparations after pressure testing the surface pipelines; S3.

3. The cementing pump is used to mix the cementing slurry and cementing fluid evenly, and the cementing pump tail slurry is used to fill the bottom of the wellbore. S3.4 Quickly disconnect the circulation head, drop the casing top plug, and quickly connect the variable thread and the delivery casing, and connect the top drive to send the casing into the wellbore. S3.

5. Add additional pressure to the final displacement pressure to meet the design requirements, and then stabilize the pressure for 5 minutes to ensure that the casing is installed safely and forms a tight seal with the wellbore wall. S3.

6. Slowly lower the insertion seal until it is fully inserted into the return sleeve. When the second seal is inserted into the return sleeve, release all the pressure in the sleeve and keep the ground pressure relief valve open. Continue to lower the seal until it is fully inserted into the return sleeve, while applying a certain downward pressure. S3.7 Check whether the casing markings match the markings during the first trial insertion. If they match, continue pressing down until the designed suspension weight sets the casing packer and hanger, and maintain this position for a certain period of time to ensure the correct depth and position of the casing installation, as well as the effectiveness of the hanger and packer. S3.8 Depressurize the cementing pump and check for backflow. If there is backflow, replace it with the backflow flow rate, pressurize and allow it to solidify to ensure that there is no leakage of cementing fluid in the casing, and allow it to solidify. Step S1.3 specifically includes the following steps: S1.3.1 Stop the cementing pump and open the stop pin on the cement head to release the top plug; S1.3.2, The cementing pump pumps tail slurry into the hydraulic plug for mixing; S1.3.3 Switch to mud pump for replacement, and finally replace with small displacement pump in the final stage; Step S1.4 specifically includes the following steps: S1.4.

1. After reaching the final displacement pressure, add additional pressure to meet the design requirements and maintain this pressure for a certain period of time to ensure the reliability of cementing. At the same time, check for pressure drop to ensure that there is no leakage of cementing fluid. S1.4.2 Open the cementing pump pressure relief valve and check for backflow. If there is backflow, replace it with the backflow flow to hold the pressure and wait for it to solidify. Step S2.2 specifically includes the following steps: S2.2.

1. Use a mud pump to pump in isolation fluid, a cementing pump to pump in flushing fluid, and a cementing pump to pump in drilling water. S2.2.2, Mix the cementing slurry and cementing fluid evenly using a cementing pump; S2.2.3 Utilize a cementing pump to mix the tailings slurry and pump the tailings slurry into the wellbore to fill the bottom of the wellbore; Step S2.3 specifically includes the following steps: S2.3.1 Stop the cementing pump and open the stop pin on the cement head to release the top plug; S2.3.2, Cementing pump injects tail slurry mixed with water pressure rubber plug; S2.3.3, Switch to mud pump for replacement, and finally replace with small displacement pump in the final stage; Step S2.4 specifically includes the following steps: S2.4.

1. After reaching the final displacement pressure, add additional pressure to meet the design requirements and maintain this pressure for a certain period of time to ensure the reliability of cementing. At the same time, check for pressure drop to ensure that there is no leakage of cementing fluid. S2.4.2 Open the cementing pump pressure relief valve and check for backflow. If there is backflow, replace it with the backflow flow to hold the pressure and wait for it to solidify.

2. The carbon dioxide reinjection well cementing method according to claim 1, characterized in that, Step S1.1 specifically includes the following steps: S1.1.1 Determine the dimensions of the casing centralizer, and install the casing and centralizer in sequence; S1.1.

2. Water is pumped through the cementing pump to the surface pipeline and pressure is tested. The pressure should meet the highest pump pressure required in the cementing method to ensure that the pipeline is secure and usable during the cementing process. S1.1.

3. Flushing fluid is injected through a cementing pump to flush out impurities from the wellbore, thereby thoroughly cleaning the wellbore surface.

3. The carbon dioxide reinjection well cementing method according to claim 1, characterized in that, Step S1.2 specifically includes the following steps: S1.2.1 Stop the cementing pump and open the bottom stop pin of the cement head to release the bottom rubber plug; S1.2.

2. Use a cementing pump to pump in the cementing fluid mixed with water to pressurize the rubber plug. The pumped cementing fluid mixed with water pushes the bottom rubber plug to the bottom of the wellbore, so that the cementing fluid fills the wellbore from the bottom of the casing. S1.2.

3. Mix the cementing slurry and cementing fluid evenly using a cementing pump; S1.2.

4. Use a cementing pump to mix the tailings slurry and pump the tailings slurry into the wellbore to fill the bottom of the wellbore.

4. The carbon dioxide reinjection well cementing method according to claim 1, characterized in that, Step S3.1 specifically includes the following steps: S3.1.1 During well cleaning, a certain volume of thick slurry is inserted below the return pipe to fill the bottom of the return pipe; S3.1.2 Check the integrity of the insert seal and packer, including the number of packer shear pins. At the same time, use double float hoops to ensure the integrity of the insert seal and packer, and use double float hoops correctly to provide an effective seal and packer. S3.1.3 Before lowering the casing, replace the long hanging clamp, lower the casing and add the stabilizer in sequence, apply thread glue to the casing below the float hoop, and grout to check the performance of the float valve. S3.1.

4. Perform a pressure test on the reconnection seal of the cementing pump to test its sealing performance and ensure that the sealing system is functioning properly. S3.1.5 After raising the circulation hole to the top of the return sleeve, turn on the cementing pump to confirm that the circulation channel is unobstructed. Then stop the cementing pump, install the casing slips, and connect the cementing circulation head and cementing pipeline to establish the circulation channel in preparation for cementing operations.

5. A carbon dioxide reinjection well cementing method according to claim 1, characterized in that, Step S3.2 specifically includes the following steps: S3.2.1 Before cementing, start by removing the mud from the wellbore through small-volume circulation, and gradually increase to the designed displacement to ensure the wellbore is clean; S3.2.2 The cementing pump is used to pump water through the surface pipeline and pressure test is performed to test the sealing performance of the surface pipeline and ensure that the cementing fluid will not leak. S3.2.

3. Use a cementing pump to pump flushing fluid to clean the wellbore and prepare for the next cementing fluid pumping.

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