Continuous flexible pipe secondary well cementation integrated device and well cementation process

Abstract

The invention belongs to the technical field of oil and gas field development, and discloses a continuous flexible pipe secondary well cementation integrated device and a well cementation process. Comprising a bottom plate, a stirring barrel is arranged on the bottom plate, a rotary crane is arranged beside the stirring barrel, the stirring barrel is connected with a high-pressure tee joint on a plunger pump through a mortar hose, the high-pressure tee joint is connected with a large roller on a large roller mounting frame and a small roller on a small roller mounting frame through hoses, and a cable roller welding frame, a water pump and a control box are further arranged on the bottom plate. The control box is connected with each component through a cable of a cable roller on the cable roller welding frame to control operation, and the water pump is connected with the stirring barrel through a pipeline. The method has important significance in solving the problem of oil-gas well casing damage and improving the production capacity of an oil-gas well and the integrity of a shaft, the operation construction efficiency is improved, and potential safety hazards of operation are eliminated.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, specifically relating to a continuous flexible pipe secondary cementing integrated device and cementing process. Background Technology

[0002] As oil and gas field development at home and abroad gradually enters the middle and late stages, wells put into production in the early stages are generally facing the severe challenge of casing damage due to long-term production and repeated production enhancement and modification. Although existing secondary cementing technology can be used to repair damaged casing to some extent, it still has many obvious technical limitations and structural defects in practical applications, which restrict the reliability and economy of the repair effect.

[0003] Currently widely used conventional secondary cementing processes often rely on rigid working strings (such as drill pipe or casing), which have poor throughput and adaptability. In complex conditions such as severe wellbore deformation, reduced diameter, or doglegs, the string may be difficult to lower smoothly to the target formation, potentially leading to stuck pipe and workover failure. Furthermore, traditional cementing methods are prone to problems such as channeling and discontinuous sealing during cement slurry injection, especially in high-permeability or fractured formations. The low precision in controlling the flow direction of the cement slurry makes accurate sealing difficult, resulting in insufficient annular seal integrity and a short effective period after repair.

[0004] In terms of straightening and centering, existing straightening tools have relatively limited functions and are unable to effectively center and repair tubing in severely deformed casing sections. This results in uneven thickness and poor bonding quality of the newly formed cement sheath, severely affecting the interlayer sealing efficiency. At the same time, conventional cement slurry systems also have insufficient compatibility with aging wellbores and complex geological environments: cement stone is prone to volume shrinkage after solidification, forming micro-annular gaps; its corrosion resistance and toughness are poor, making it prone to brittle fracture and failure under stress fluctuations during subsequent production and injection operations.

[0005] More notably, existing technologies are characterized by "single-process, multi-step construction," lacking continuity and integration in repair operations. For example, corrosion protection, radial reinforcement, and sealing often need to be completed in multiple stages, significantly increasing well dwell time and construction costs, and exacerbating the potential risk of damage to the producing formation. Furthermore, existing processes lack real-time, visual monitoring and evaluation methods for repair effectiveness, relying excessively on experience-based judgment for construction quality, making it difficult to reliably verify and guarantee the long-term sealing performance and durability of the wellbore after repair.

[0006] Overall, existing secondary cementing technologies are limited by tool adaptability, material performance, and process integration. When dealing with complex casing damage, they generally suffer from incomplete repair, limited effectiveness, and high overall costs, making it difficult to meet the urgent needs of high-quality development in old oil and gas fields. There is an urgent need to develop new integrated repair technologies that are more adaptable and reliable.

[0007] Patent application CN118855415A discloses a small-casing secondary cementing device and its construction method. The device includes a connecting sleeve, a central tube, and a setting hydraulic cylinder. Both the sliding sleeve (capable of inserting a sealing ball) and the central tube have pressure transmission holes. The sliding sleeve and the central tube are connected via circulating shear pins. The upper part of the connecting sleeve, which has cement injection holes, is connected to the central tube, and the lower part is connected to the piston of the setting hydraulic cylinder via connecting shear pins. The cement injection holes form a cement injection channel with the circulating shear pin installation holes in the central tube. A rubber sleeve and a spacer ring are installed below the setting hydraulic cylinder via a rubber sleeve seat and the central tube. The secondary cementing device is made of easily drillable material, and its upper part can be connected to the lower end of the small casing and can be drilled out after cementing. It can be widely used in oilfield production wells with damaged casing in long or full sections. By using a suspended small casing for secondary cementing, damaged wells can be thoroughly repaired, and oil production can be completed using the small casing, significantly improving the service life of production wells.

[0008] However, the application could not repair the casing while completing the secondary cementing operation, and the complex problem of casing damage in oil and gas wells remained unresolved. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention provides a continuous flexible tube secondary cementing integrated device and cementing process. This process offers a simple structure, small footprint, improved cementing safety, casing repair capabilities, increased productivity, enhanced wellbore integrity, extended well service life, adaptability to complex working conditions, and protection of wellbore and personnel safety.

[0010] The above-mentioned objective of this invention is achieved through the following technical solution: a continuous flexible tubing secondary cementing integrated device, comprising:

[0011] The base plate has a mixing tank on it. A rotating crane is located next to the mixing tank. The mixing tank is connected to a high-pressure tee on a plunger pump via a mortar hose. The high-pressure tee is also connected to a large roller on a large roller mounting frame and a small roller on a small roller mounting frame via hoses. The base plate also has a cable roller welding frame, a water pump, and a control box. The control box is connected to each component via cables from the cable rollers on the cable roller welding frame to control their operation. The water pump is connected to the mixing tank via pipeline.

[0012] Furthermore, the control box is equipped with a flow meter display, which can simultaneously display parameters such as flow rate and pump pressure and automatically save the data, making it convenient to adjust the construction parameters in a timely manner and avoid safety hazards caused by parameter malfunction.

[0013] Furthermore, the control box controls the speed of the water pump and the plunger pump through a frequency converter inside the control box.

[0014] Furthermore, the mixing tank includes a tank body, with a stirring motor located at the center of the top of the tank body that penetrates into the tank body. The stirring motor is connected to a rotating rod that penetrates into the tank body, and a stirring umbrella is provided on the rotating rod.

[0015] Furthermore, the tank body is connected to the mortar hose as a mortar outlet, and a filter cover is provided on the mortar outlet.

[0016] Furthermore, a filter screen block is provided on the top of the tank, and a filter screen covering the top of the tank is provided below the filter screen block.

[0017] Furthermore, the tank is also equipped with an open cleaning port.

[0018] In a further preferred embodiment of the present invention, the cleaning port is equipped with a cleaning port plug.

[0019] Furthermore, the rotating crane includes a bracket fixedly connected to the base plate, a movable frame connected to the top of the bracket, the movable frame being movably connected to the cantilever, a winch being provided on the cantilever, the winch being connected to a lifting ring also provided on the cantilever, the lifting ring being controlled to move up and down by the winch, and the lifting ring being controlled to move left and right by the cantilever.

[0020] Another objective of this invention is to protect the cementing process using the aforementioned continuous flexible tube secondary cementing integrated device. The steps are as follows: the cable on the cable drum connects the control box, mixing tank, rotary crane, water pump, and plunger pump. The control box controls the water pump to pump water into the mixing tank and controls the rotary crane to lift mortar into the mixing tank. After the water and mortar of the corresponding proportion enter the mixing tank, the control box controls the mixing tank to stir. The stirred mortar enters the high-pressure tee through the mortar hose and then enters the plunger pump. The hoses on the large drum and small drum are simultaneously lowered into the annulus of the casing and oil casing through the high-pressure tee. The controller controls the plunger pump speed to inject mortar into the annulus of the casing and oil casing to complete the cementing.

[0021] The beneficial effects of this invention compared to existing technologies are as follows: This invention effectively solves the complexity brought about by secondary cementing operations, improves the timeliness of secondary cementing, eliminates the risk of well blowout and runaway, and improves the safety and efficiency of cementing. Furthermore, this invention is of great significance in solving the problem of casing damage in oil and gas wells, improving the production capacity and wellbore integrity of oil and gas wells, increasing operational efficiency, and eliminating potential safety hazards. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 This is a schematic diagram of the structure of the continuous flexible tube secondary cementing integrated device of the present invention;

[0024] Figure 2 This is a schematic diagram of the mixing tank structure of the continuous flexible tube secondary cementing integrated device of the present invention;

[0025] Figure 3 This is a top view of the mixing tank of the continuous flexible tube secondary cementing integrated device of the present invention;

[0026] Figure 4 This is a schematic diagram of the rotating crane structure of the continuous flexible tube secondary cementing integrated device of the present invention.

[0027] In the diagram: 1. Base plate; 2. Rotary crane; 3. Mixing tank; 4. Plunger pump; 5. High-pressure tee; 6. Hoist; 7. Large drum mounting bracket; 8. Small drum mounting bracket; 9. Cable drum welding bracket; 10. Mortar hose; 11. Water pump; 12. Large drum; 13. Small drum; 14. Cable drum; 15. Tank body; 16. Mixing motor; 17. Rotating rod; 18. Mixing umbrella; 19. Filter cover; 20. Filter screen block; 21. Filter screen; 22. Cleaning port; 23. Cleaning port plug; 24. Support; 25. Movable frame; 26. Cantilever; 27. Winch; 28. Lifting ring; 29. ​​Control box. Detailed Implementation

[0028] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0029] Example 1

[0030] A continuous flexible tube secondary solidification integrated device includes:

[0031] The base plate 1 has a mixing tank 3 mounted on it. A rotating crane 2 is located next to the mixing tank 3. The mixing tank 3 is connected to a high-pressure tee 5 on a plunger pump 4 via a mortar hose 10. The high-pressure tee 5 is also connected to a large roller 12 on a large roller mounting frame 7 and a small roller 13 on a small roller mounting frame 8 via a hose 6. The base plate 1 also has a cable roller welding frame 9, a water pump 11, and a control box 29. The control box 29 is connected to each component via a cable on a cable roller 14 on the cable roller welding frame 9 to control its operation. The water pump 11 is connected to the mixing tank 3 via a pipeline. The control box 29 has a flow meter display that can simultaneously display parameters such as flow rate and pump pressure and automatically save the data, facilitating timely adjustment of construction parameters and avoiding safety hazards caused by parameter malfunction.

[0032] The control box 29 controls the speed of the water pump 11 and the plunger pump 4 through the frequency converter inside the control box 29.

[0033] The mixing tank 3 includes a tank body 15. A stirring motor 16 is provided at the center of the top of the tank body 15 and penetrates into the interior of the tank body 15. The stirring motor 16 is connected to a rotating rod 17 that penetrates into the interior of the tank body 15. A stirring umbrella 18 is provided on the rotating rod 17.

[0034] The tank body 15 is connected to the mortar hose 10 as a mortar outlet, and a filter cover 19 is provided on the mortar outlet.

[0035] The tank body 15 is provided with a filter screen block 20 on top, and a filter screen 21 covering the top of the tank body 15 is provided below the filter screen block 20.

[0036] The tank body 15 is also provided with an open cleaning port 22, and a cleaning port plug 23 is installed on the cleaning port 22.

[0037] The rotating crane 2 includes a support 24 fixedly connected to the base plate 1. A movable frame 25 is attached to the top of the support 24. The movable frame 25 is movably connected to the cantilever 26. A winch 27 is provided on the cantilever 26. The winch 27 is connected to a lifting ring 28 provided on the cantilever 26. The winch 27 controls the lifting ring 28 to move up and down, and the cantilever 26 controls the lifting ring 28 to move left and right.

[0038] The upper plate of the large roller 12 has a 150m tube with a diameter of 32mm, and the upper plate of the small roller 13 has a 150m tube with a diameter of 25mm.

[0039] The device can control the liquid flow direction through a three-way valve. No pipeline connection is required during construction. The hose 6 can be installed by inserting it into the annulus of the gauge sleeve and oil sleeve through the straight pipe device. The frequency converter precisely controls the speed of the water pump 11 and the plunger pump 4. The injection rate can be dynamically adjusted according to the geological conditions to ensure that the cement slurry returns to the ground. The maximum construction depth can reach 200 meters.

[0040] Example 2

[0041] The solidification process using the device in Example 1 involves the following steps: The cable on the cable drum 14 connects the control box 29 to the mixing tank 3, the rotary crane 2, the water pump 11, and the plunger pump 4. The control box 29 controls the water pump 11 to pump water into the mixing tank 3, and controls the rotary crane 2 to lift mortar into the mixing tank 3. After the water and mortar of the corresponding ratio enter the mixing tank 3, the control box 29 controls the mixing tank 3 to stir. The stirred mortar enters the high-pressure tee 5 through the mortar hose 10 and then enters the plunger pump 4. The hoses 6 on the large drum 12 and the small drum 13 simultaneously enter the annulus of the gauge sleeve and the oil sleeve through the high-pressure tee 5. The controller controls the speed of the plunger pump 4 to inject mortar into the annulus of the gauge sleeve and the oil sleeve to complete the solidification.

[0042] Advantages:

[0043] The use of automatic mixing tanks and simple electric hoists eliminates the need for manual labor such as lifting and mixing ash, thus reducing operational risks.

[0044] Once the integrated device arrives at the construction site, the hose 6 is directly lowered into the annulus. After the water pump 11, electric hoist, and automatic mixing tank complete the mortar mixing work, the mortar is injected into the annulus of the gauge sleeve and oil sleeve through the plunger pump 4 to complete the solidification of the spring.

[0045] The real-time monitoring system (flow meter display) can simultaneously display parameters such as flow rate and pump pressure and automatically save the data, making it easy to adjust construction parameters in a timely manner and avoid safety hazards caused by uncontrolled parameters.

[0046] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A continuous flexible pipe secondary cementing integrated device, characterized in that, include: The base plate (1) is equipped with a mixing tank (3). A rotating crane (2) is located next to the mixing tank (3). The mixing tank (3) is connected to the high-pressure tee (5) on the plunger pump (4) through a mortar hose (10). The high-pressure tee (5) is also connected to the large roller (12) on the large roller mounting frame (7) and the small roller (13) on the small roller mounting frame (8) through a hose (6). The base plate (1) is also equipped with a cable roller welding frame (9), a water pump (11) and a control box (29). The control box (29) is connected to each component through the cable of the cable roller (14) on the cable roller welding frame (9) to control its operation. The water pump (11) is connected to the mixing tank (3) through a pipeline.

2. The continuous flexible tubing secondary cementing integrated device according to claim 1, characterized in that, The control box (29) is equipped with a flow meter display.

3. The continuous flexible tubing secondary cementing integrated device according to claim 1, characterized in that, The control box (29) controls the speed of the water pump (11) and the plunger pump (4) through the frequency converter inside the control box (29).

4. The continuous flexible tubing secondary cementing integrated device according to claim 1, characterized in that, The mixing tank (3) includes a tank body (15), and a stirring motor (16) is provided at the center of the top of the tank body (15) and penetrates into the interior of the tank body (15). The stirring motor (16) is connected to a rotating rod (17) that penetrates into the interior of the tank body (15), and a stirring umbrella (18) is provided on the rotating rod (17).

5. The continuous flexible tubing secondary cementing integrated device according to claim 4, characterized in that, The tank (15) is connected to the mortar hose (10) as a mortar outlet, and a filter cover (19) is provided on the mortar outlet.

6. The continuous flexible tubing secondary cementing integrated device according to claim 4, characterized in that, The tank (15) is provided with a filter screen block (20) on top, and a filter screen (21) covering the top of the tank (15) is provided below the filter screen block (20).

7. The continuous flexible tubing secondary cementing integrated device according to claim 4, characterized in that, The tank (15) is also provided with an open cleaning port (22).

8. The continuous flexible tubing secondary cementing integrated device according to claim 7, characterized in that, The cleaning port (22) is equipped with a cleaning port plug (23).

9. The continuous flexible tubing secondary cementing integrated device according to claim 1, characterized in that, The rotating crane (2) includes a bracket (24) fixedly connected to the base plate (1), a movable frame (25) connected to the top of the bracket (24), the movable frame (25) being movably connected to the cantilever (26), a winch (27) being provided on the cantilever (26), the winch (27) being wire-connected to a lifting ring (28) provided on the cantilever (26), the lifting ring (28) being moved up and down by the winch (27), and the cantilever (26) controlling the lifting ring (28) to move left and right.

10. The cementing process using the continuous flexible tubing secondary cementing integrated device as described in claim 1, characterized in that, The steps are as follows: the cable on the cable drum (14) connects the control box (29) and the mixing drum (3), the rotary crane (2), the water pump (11), and the plunger pump (4). The control box (29) controls the water pump (11) to pump water to the mixing drum (3) and controls the rotary crane (2) to lift the ash into the mixing drum (3). After the water and ash of the corresponding proportion enter the mixing drum (3), the control box (29) controls the mixing drum (3) to stir. The stirred slurry enters the high-pressure tee (5) through the slurry hose (10) and then enters the plunger pump (4). The hoses (6) on the large drum (12) and the small drum (13) are simultaneously lowered into the annulus of the casing and the oil casing through the high-pressure tee (5). The controller controls the plunger pump (4) to rotate and inject slurry into the annulus of the casing and the oil casing to complete the cementing.

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