A foamed cement slurry well cementing device

Abstract

This invention belongs to the technical field of cementing devices, specifically relating to a foamed cement slurry cementing device. It aims to solve the problem of uneven foam distribution within the foamed cement slurry that ultimately settles on the wellbore, reducing cementing quality. The invention includes a reinforcement pipe, a delivery pipe, an external wellbore base, a return assembly, a drive assembly, and an injection head. This invention can introduce foamed cement slurry from well sections with higher foam content back into well sections with lower foam content for circulation, thereby ensuring the uniformity of foam distribution and size within the foamed cement slurry during its flow through the delivery pipe and return cavity, thus improving cementing quality.

Description

Technical Field

[0001] This invention belongs to the technical field of cementing devices, and specifically relates to a foamed cement slurry cementing device. Background Technology

[0002] During the cementing process, foamed cement slurry is first introduced into the bottom of the wellbore through the casing, and then released onto the outer wall of the casing. The slurry then flows upwards between the casing and the wellbore wall, reinforcing the wellbore. Different well depths have varying well pressures and temperatures, which can affect the distribution of foam within the slurry. Specifically, as the slurry flows downwards through the casing, increased pressure and temperature can lead to reduced foam volume, increased density, and decreased stability, accelerating foam breakage and disappearance. Conversely, as it flows upwards between the casing and the wellbore wall, decreased pressure and temperature can cause the foam to fuse and form uneven shapes. This results in an uneven distribution of foam within the slurry that ultimately remains on the wellbore wall, reducing cementing quality. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, namely the uneven distribution of foam in the foamed cement slurry that ultimately remains on the well wall, thus reducing cementing quality, this invention provides a foamed cement slurry cementing device.

[0004] This application discloses a foamed cement slurry cementing device, which adopts the following technical solution:

[0005] A foamed cement slurry cementing device, characterized in that it includes a reinforcement pipe, a slurry delivery pipe, an external well base, a return assembly, a drive assembly, and a slurry injection head;

[0006] The reinforcement tube includes an outer tube arranged in the cementing cavity and an inner tube inserted through the outer tube and rotatably connected to it; the outer tube has multiple equally spaced external windows through its wall; the inner tube has multiple equally spaced internal windows through its wall; the internal windows are connected to or blocked by the rotation of the inner tube to align with the external windows.

[0007] The slurry delivery pipe is installed inside the inner cylinder, and a slurry return cavity is formed between the inner cylinder and the slurry delivery pipe.

[0008] The reflux assembly is arranged in the slurry reflux chamber; the reflux assembly includes a rotating frame fixedly connected to the outer wall of the slurry delivery pipe, and inclined external agitator blades are rotatably connected to the rotating frame; multiple external agitator blades are provided;

[0009] The drive assembly is arranged on the slurry pipe and drives the external agitator blades to rotate.

[0010] The grouting head is fixedly connected to the lower end of the reinforcing pipe and the lower end of the grout delivery pipe. The grouting head is provided with a first discharge hole coaxial with the grout delivery pipe, a plurality of second discharge holes communicating with the first discharge hole, and a third discharge hole for communicating the external space of the grouting head and the grout return cavity.

[0011] By adopting the above technical solution, the drive component drives the external agitator blades to rotate in the slurry return chamber, so that the external agitator blades in this section guide the slurry back to the section with increased resistance. This allows the foam cement slurry in the section with higher foam content to be introduced back to the section with lower foam cement slurry content for circulation. This ensures the uniformity of foam distribution and size in the foam cement slurry during its flow in the delivery pipe and slurry return chamber, thereby improving the cementing quality.

[0012] Optionally, the rotating frame includes a fixed pipe, a connecting pipe, and a connecting rod that fixes the fixed pipe and the connecting pipe together. The fixed pipe is sleeved and fixedly connected to the outer wall of the slurry delivery pipe, the connecting pipe is sleeved on the fixed pipe, and there is a gap between the inner wall of the connecting pipe and the inner wall of the fixed pipe. The connecting rod is arranged between the fixed pipe and the connecting pipe to fix the fixed pipe and the connecting pipe together.

[0013] An arrangement pipe is fixedly connected to the outer side of the external agitator fan blades. The arrangement pipe connects multiple external agitator fan blades together. The arrangement pipe, together with the external agitator fan blades, is arranged between the connecting pipe and the fixed pipe. The outer wall of the arrangement pipe is in contact with and rotatably connected to the inner wall of the connecting pipe.

[0014] By adopting the above technical solution, it is convenient to install the external agitator fan blades on the rotating ring frame and realize the rotation of the external agitator fan blades on the rotating ring frame.

[0015] Optionally, an installation tube is fixedly connected to the inner side of the external agitator fan blades, and the installation tube connects the inner sides of multiple external agitator fan blades together; multiple fixing holes are opened through the fixing tube, and the multiple fixing holes are arranged at equal intervals along the circumference of the fixing tube; multiple magnetic blocks are fixedly connected to the installation tube, and multiple magnetic blocks are provided, with each magnetic block corresponding to one of the multiple fixing holes, and the magnetic blocks are exposed at the fixing holes.

[0016] The drive assembly includes a sealing ring rotatably connected to the inner wall of the slurry delivery pipe. An electromagnet is fixedly connected to the outer ring surface of the sealing ring. Multiple electromagnets are arranged at equal intervals along the circumference of the outer ring surface of the sealing ring.

[0017] Multiple connection holes are provided through the slurry delivery pipe. The connection holes are arranged at equal intervals along the circumference of the slurry delivery pipe, and the connection holes are aligned with the fixing holes. Multiple inclined internal agitator blades are fixedly connected to the inner ring surface of the sealing rotating ring. The multiple internal AC blades are arranged at equal intervals, and the internal agitator blades and the external agitator blades are arranged at the same height.

[0018] By adopting the above technical solution, the electromagnet controls the generation or dissipation of its magnetic force. When the electromagnet generates magnetic force, it can attract magnetic blocks. At this time, the inner and outer agitator blades rotate synchronously, and the outer agitator blades have the function of guiding the flow towards the bottom of the wellbore. When the magnetic force of the electromagnet dissipates, the inner agitator blades are driven by the fluid in the slurry return cavity to rotate freely, and the outer agitator blades are driven by the fluid in the slurry delivery pipe to rotate freely. In other words, on the one hand, both the inner and outer agitator blades have the function of stirring the foamed cement slurry, which is beneficial to the foamed cement slurry obtaining a certain degree of stirring effect in the slurry delivery pipe and the slurry return cavity. On the other hand, the rotating agitation shape and structure of the inner and outer agitator blades also have the effect of separating and intercepting the flowing foamed cement slurry, preventing unstable flow distribution when the foam is pressurized and depressurized. This is beneficial to maintaining the stability of the foam distribution during the process of introducing the foamed cement slurry through the slurry delivery pipe and exporting it from the cementing cavity, thereby making the foam distribution in the cement slurry more uniform.

[0019] Optionally, a resistance sensor is installed on the outer wall of the slurry delivery pipe.

[0020] By adopting the above technical solution, the resistance sensor monitors the flow resistance of the foamed cement slurry in the slurry return chamber. When the resistance decreases, it indicates that the foam content in the foamed cement slurry of this local section is relatively high. Correspondingly, the resistance sensor at the foamed cement slurry section where the resistance increases will detect an increase in resistance. At this time, the electromagnet in the section where the resistance decreases is activated to generate magnetic attraction to the magnetic block, so that the external agitator in this section guides the flow back to the section where the resistance increases. This allows the foamed cement slurry in the section with a high foam content to be introduced back to the section with a low foam content for circulation. Whenever the resistance sensor of the corresponding section returns to the initial monitoring value, the electromagnet of the corresponding section loses its magnetic force. The real-time dynamic monitoring method is used to monitor the process, thereby ensuring the uniformity of the foam distribution and the uniformity of the size and shape of the foam in the slurry during the flow of the slurry in the delivery pipe and the slurry return chamber.

[0021] Optionally, a resistance monitoring rod is fixedly connected to the outer wall of the slurry delivery pipe, and the resistance sensor is fixedly connected to the resistance monitoring rod.

[0022] By adopting the above technical solution, the installation of the resistance sensor is facilitated.

[0023] Optionally, an extension tube is fixedly connected to the lower side of the mounting tube, the extension tube extends through the mounting tube, and a plurality of agitators are fixedly connected to the extension tube.

[0024] By adopting the above technical solution, the agitator is mainly used to agitate larger foams in foamed cement slurry, thereby improving the uniformity of foam distribution in foamed cement slurry.

[0025] Optionally, a first drive motor for driving the outer cylinder to rotate is installed on the outer well base.

[0026] By adopting the above technical solution, the first drive motor drives the inner cylinder to rotate, so that the inner window and the outer window are aligned and connected, and drilling fluid is introduced into the slurry delivery pipe to flush the cementing cavity.

[0027] Optionally, the reinforcing pipe includes multiple outer cylinders and multiple inner cylinders; multiple grout delivery pipes are provided, and adjacent inner cylinders are connected by a plug-in connection, and adjacent grout delivery pipes are connected by a plug-in connection.

[0028] Two adjacent outer tubes are connected by a connector, which includes a connecting ring. The upper end of the connecting ring is inserted into the lower side of the upper outer tube and engages with it. The lower end of the connecting ring is sleeved on the upper side of the lower outer tube and engages with it.

[0029] By adopting the above technical solution, it is convenient to connect pipes to each other.

[0030] Optionally, trapezoidal protrusions that are fixedly connected to the connecting ring are arranged circumferentially on the outer wall of the connecting ring.

[0031] Optionally, the inclination direction of the inner agitator fan blades is opposite to that of the outer agitator fan blades.

[0032] The beneficial effects of this invention are as follows: In this invention, resistance sensors are distributed at different well sections to monitor the flow resistance of foamed cement slurry in the slurry return cavity. The foam content of the foamed cement slurry in a local well section is determined in real time. By activating the electromagnet in the well section where the resistance decreases, magnetic attraction of the magnetic block is generated, causing the external agitator in this well section to guide the flow back to the well section where the resistance increases. This allows the foamed cement slurry in the well section with a higher foam content to be introduced back to the well section with a lower foamed cement slurry content for circulation. This ensures the uniformity of foam distribution and size of the foamed cement slurry during its flow in the slurry delivery pipe and slurry return cavity, thereby improving the cementing quality. Attached Figure Description

[0033] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 This is a schematic diagram of the foamed cement slurry cementing device in this embodiment;

[0035] Figure 2 This is a schematic diagram of the reinforcing pipe in this embodiment;

[0036] Figure 3 This is a schematic diagram of the connector in this embodiment;

[0037] Figure 4 This is a schematic diagram of the outer well base in this embodiment;

[0038] Figure 5 This is a schematic diagram of the recirculation component in this embodiment;

[0039] Figure 6 This is a schematic diagram of the driving component in this embodiment;

[0040] Figure 7 This is a schematic diagram showing the connection between the recirculation component and the drive component in this embodiment;

[0041] Figure 8 This is a schematic diagram of the rotating connection of the external agitator fan blades in this embodiment;

[0042] Figure 9 This is a schematic diagram of the grouting head in this embodiment.

[0043] Explanation of reference numerals in the attached drawings: 1. Reinforcing pipe; 11. Outer cylinder; 111. Outer window; 12. Inner cylinder; 121. Inner window; 13. Connector; 131. Connecting ring; 132. Trapezoidal protrusion; 2. Grout delivery pipe; 21. Grout return chamber; 22. Receiving annular groove; 23. Connecting hole; 3. Outer well seat; 31. Well seat plate; 32. First sealing ring cover; 321. First guide pipe; 33. First rotating drum ring; 34. Second sealing ring cover; 341. Second guide pipe; 35. Second rotating drum ring; 351. Third guide pipe; 36. First support; 361. 1. Rotary motor; 37. Second bracket; 372. Second rotary motor; 4. Return assembly; 41. Rotary ring frame; 411. Fixed pipe; 412. Connecting pipe; 413. Connecting rod; 42. External agitator blade; 421. Arrangement pipe; 422. Mounting pipe; 423. Fixed hole; 424. Magnetic block; 43. Extension pipe; 44. Agitator rod; 5. Drive assembly; 51. Sealing ring; 52. Electromagnet; 53. Internal agitator blade; 6. Grouting head; 61. First discharge hole; 62. Second discharge hole; 63. Third discharge hole; 7. Resistance monitoring rod. Detailed Implementation

[0044] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] This invention provides a foamed cement slurry cementing device, with reference to Figure 1 The foamed cement slurry cementing device includes a reinforcement pipe 1, a slurry delivery pipe 2, an external well base 3, a return assembly 4, a drive assembly 5, and a slurry injection head 6.

[0047] Reference Figure 2 The reinforcement pipe 1 includes an outer cylinder 11 arranged in the cementing cavity. The upper end of the outer cylinder 11 is connected to the outer well seat 3, and the lower end can be connected to the grouting head 6 or the connector 13. When the outer cylinder 11 is provided in multiple sections, adjacent sections of the outer cylinder 11 are connected by the connector 13. The lowermost outer cylinder 11 is connected to the grouting head 6, and the uppermost outer cylinder 11 is connected to the outer well seat 3. Multiple external windows 111 are provided through the pipe wall of the outer cylinder 11, and the multiple external windows 111 are arranged at equal intervals along the circumference of the pipe wall of the outer cylinder 11.

[0048] An inner tube 12 is inserted through the outer tube 11. The upper end of the inner tube 12 is connected to the outer well seat 3, and the lower end can be connected to the grouting head 6 or another inner tube 12. The outer wall of the inner tube 12 is in contact with the inner wall of the outer tube 11, and an inner window 121 is provided through the tube wall of the inner tube 12. Multiple inner windows 121 are provided and are arranged at equal intervals along the circumference of the inner tube 12. The aperture of the inner window 121 is the same as that of the outer window 111, and the number of inner windows 121 and outer windows 111 is the same. The inner tube 12 can be rotated in the outer tube 11 to align and connect the inner windows 121 with the outer windows 111 or to offset and seal them. When foam cement grouting is performed, the inner windows 121 and outer windows 111 are aligned and connected. When the cementing cavity is filled with foam cement grout, the inner windows 121 and outer windows 111 are controlled to offset and seal them. When multiple outer tubes 11 are provided, two adjacent inner tubes 12 are fixedly connected by insertion. When inserting, the upper end of the lower inner tube 12 is inserted into the lower end of the upper inner tube 12.

[0049] Reference Figure 3 The connector 13 includes a connecting ring 131. The upper end of the connecting ring 131 is inserted into the lower side of the upper outer tube 11 and engages with it. The lower end of the connecting ring 131 is sleeved on the upper side of the lower outer tube 11 and engages with it. Trapezoidal protrusions 132 are circumferentially arranged on the outer wall of the connecting ring 131 and are fixedly connected to the connecting ring 131.

[0050] The grout delivery pipe 2 is installed inside the inner cylinder 12 and is mainly used for injecting drilling fluid, isolation fluid, foamed cement slurry, etc. into the well. The upper end of the grout delivery pipe 2 is connected to the outer well seat 3, and the lower end can be connected to the grouting head 6 or another grout delivery pipe 2. A slurry return cavity 21 is formed between the inner cylinder 12 and the grout delivery pipe 2, and the return assembly 4 is arranged in the slurry return cavity 21.

[0051] Reference Figure 4 The outer well seat 3 includes a well seat plate 31, which is located on the ground surface of the cementing cavity. The well seat plate 31 is mainly used to prevent the outer well seat 3 from entering the well, and to connect with the grouting pipe, the reinforcement pipe 1, and the grout delivery pipe 2. The well seat plate 31 is laid flat on the ground. A through hole is formed on the well seat plate 31 to expose the cementing cavity. A first annular sealing ring cover 32 is fixedly connected to the through hole. The first sealing ring cover 32 can be installed in the through hole on the well seat plate 31 by threaded connection or overlap. A first guide tube 321 passes through the first sealing ring cover 32, with its lower end penetrating the first sealing ring cover 32 and extending between the reinforcement pipe 1 and the wall of the cementing cavity. The lower end of the first sealing ring cover 32 is inserted and fixed to the upper end of the outer cylinder 11, thus connecting the first sealing ring cover 32 to the outer cylinder 11. A first rotating ring 33 is rotatably connected to the inner wall of the first sealing ring cover 32. The lower end of the first rotating ring 33 is inserted and fixed to the upper end of the inner cylinder tube 12, thus connecting the first rotating ring 33 and the inner cylinder tube 12. A second annular sealing ring cover 34 is fixedly connected to the upper end of the first rotating ring cover 33. A second conduit 341 passes through the second sealing ring cover 34, with its lower end penetrating through the second sealing ring cover 34 and entering between the inner cylinder tube 12 and the slurry delivery pipe 2. A second rotating ring 35 is rotatably connected to the inner wall of the second sealing ring cover 34. The lower end of the second rotating ring 35 is inserted and fixed to the upper end of the slurry delivery pipe 2, thus connecting the second rotating ring 35 and the slurry delivery pipe 2. A third conduit 351 passes through the second rotating ring 35 and communicates with the slurry delivery pipe 2.

[0052] The third conduit 351 is connected to the grouting pipe and is used to inject drilling fluid, isolation fluid, foamed cement slurry, etc. into the grouting pipe 2. The first conduit 321 is used for the backflow of drilling fluid, isolation fluid, foamed cement slurry, etc. from between the reinforcement pipe 1 and the cementing cavity wall. The second conduit 341 is used for the backflow of drilling fluid, isolation fluid, foamed cement slurry, etc. from between the inner cylinder 12 and the grouting pipe 2. A first bracket 36 and a second bracket 37 are installed on the well base plate 31. A first rotating motor 361 is installed on the first bracket 36, which drives the first rotating drum ring 33 to rotate. A second rotating motor 372 is installed on the second bracket 37, which drives the second rotating drum ring 35 to rotate. When the first rotating drum ring and the second rotating drum ring 35 rotate, they drive the inner cylinder 12 and the grouting pipe 2 to rotate, which facilitates drilling.

[0053] Reference Figures 5-8 The return assembly 4 is used to extract the foamed cement slurry in the slurry return chamber 21, change the density of the foamed cement slurry in the slurry return chamber 21, and thus change the density of the foamed cement slurry in the cementing cavity, so that the foamed cement slurry is filled more evenly in the cementing cavity.

[0054] The reflux assembly 4 includes a rotating ring frame 41 fixedly connected to the outer wall of the slurry delivery pipe 2, and an external agitator fan blade 42 rotatably connected to the rotating ring frame 41. Specifically, the rotating ring frame 41 includes a fixed pipe 411, a connecting pipe 412, and a connecting rod 413 that fixes the fixed pipe 411 and the connecting pipe 412 together. The fixed pipe 411 is sleeved and fixedly connected to the outer wall of the slurry delivery pipe 2, and the connecting pipe 412 is sleeved on the fixed pipe 411, with a gap between the inner wall of the connecting pipe 412 and the inner wall of the fixed pipe 411. The connecting rod 413 is arranged between the fixed pipe 411 and the connecting pipe 412, fixing the fixed pipe 411 and the connecting pipe 412 together. Multiple external agitator fan blades 42 are provided, arranged at equal intervals and inclined in the horizontal direction. An arrangement pipe 421 is fixedly connected to the outer side of each external agitator fan blade 42, connecting the multiple blades together. The arrangement pipe 421, along with the fan blades 42, is positioned between the connecting pipe 412 and the fixed pipe 411. The outer wall of the arrangement pipe 421 contacts and rotatably connects with the inner wall of the connecting pipe 412. To achieve this rotatable connection, a groove is formed on the contact surface between the arrangement pipe 421 and the connecting pipe 412. A retaining ring is placed in the groove, with its two sides embedded in the outer wall of the arrangement pipe 421 and the inner wall of the connecting pipe 412, thus preventing the arrangement pipe 421 and the fan blades 42 from detaching from the rotating frame 41.

[0055] An installation tube 422 is fixedly connected to the inner side of the outer agitator fan blades 42, and the installation tube 422 connects the inner sides of multiple outer agitator fan blades 42 together. Multiple fixing holes 423 are opened through the fixing tube 411, and the multiple fixing holes 423 are arranged at equal intervals along the circumference of the fixing tube 411. Magnetic blocks 424 are fixedly connected to the installation tube 422, and multiple magnetic blocks 424 are provided. Each magnetic block 424 corresponds to one of the multiple fixing holes 423, and the magnetic blocks 424 are exposed at the fixing holes 423.

[0056] An extension pipe 43 is fixedly connected to the lower side of the installation pipe 422. The extension pipe 43 extends through the installation pipe 422, and multiple agitator rods 44 are fixedly connected to the extension pipe 43. The agitator rods 44 are mainly used to agitate the larger foam aggregates in the foamed cement slurry, thereby improving the uniformity of foam distribution in the foamed cement slurry.

[0057] When the foamed cement slurry flows in the slurry return chamber 21, it impacts the external agitator blades 42, causing them to rotate. As the rotational speed of the external agitator blades 42 increases, the foamed cement slurry from the well section with a higher foam content is introduced back into the well section with a lower foamed cement slurry content.

[0058] The drive assembly 5 includes a sealing ring 51 rotatably connected to the inner wall of the slurry delivery pipe 2. The sealing ring 51 is installed in a receiving annular groove 22 opened in the inner wall of the slurry delivery pipe 2. An electromagnet 52 is fixedly connected to the outer annular surface of the sealing ring 51. Multiple electromagnets 52 are arranged at equal intervals along the circumference of the outer annular surface of the sealing ring 51. Multiple connecting holes 23 are opened through the receiving annular groove 22 of the slurry delivery pipe 2, penetrating the pipe wall of the slurry delivery pipe 2. The connecting holes 23 are arranged at equal intervals along the circumference of the slurry delivery pipe 2, and the connecting holes 23 are aligned with the fixing holes 423. Multiple internal agitator blades 53 are fixedly connected to the inner annular surface of the sealing ring 51. The multiple internal agitator blades are arranged at equal intervals, and the internal agitator blades 53 are inclined in the horizontal direction, with the inclination direction opposite to that of the external agitator blades 42. The internal agitator blades 53 and the external agitator blades 42 are arranged at the same height.

[0059] The generation and dissipation of magnetic force are controlled by the electromagnet 52. When the electromagnet 52 generates magnetic force, it can attract the magnetic block 424. At this time, the inner stirring fan blade 53 and the outer stirring fan blade 42 rotate synchronously, and the outer stirring fan blade 42 has the function of guiding the flow towards the bottom of the wellbore. When the magnetic force of the electromagnet 52 dissipates, the inner stirring fan blade 53 is driven by the fluid in the slurry return chamber 21 to rotate freely, and the outer stirring fan blade 42 is driven by the fluid in the slurry delivery pipe 2 to rotate freely. That is to say, on the one hand, the inner stirring fan blade 53 and the outer stirring fan blade 42 rotate freely. Both the flow fan blades 42 have the function of stirring the foamed cement slurry, which is conducive to the foamed cement slurry achieving a certain degree of stirring effect in the slurry delivery pipe 2 and the slurry return cavity 21. On the other hand, the rotating and stirring shape structure of the inner flow fan blade 53 and the outer flow fan blade 42 also has the effect of separating and intercepting the flowing foamed cement slurry, preventing unstable flow distribution when the foam is pressurized and depressurized. This is conducive to maintaining the stability of the foam distribution during the process of the foamed cement slurry being introduced through the slurry delivery pipe 2 and discharged through the cementing cavity, thereby making the foam distribution in the cement slurry more uniform.

[0060] A resistance monitoring rod 7 is fixedly connected to the outer wall of the slurry delivery pipe 2 below the electromagnet 52. A resistance sensor is installed on the resistance monitoring rod 7, and the resistance sensors are distributed at different locations in the wellbore. The resistance sensors monitor the flow resistance of the foamed cement slurry in the slurry return chamber 21. When a decrease in resistance is detected, it indicates that the foam content in this local well section of the foamed cement slurry is relatively high. Correspondingly, the resistance sensor at the foamed cement slurry location in the local well section will detect an increase in resistance. At this time, the electromagnet 52 in the well section where the resistance decreases will be activated to generate... The magnetic adsorption of the magnetic block 424 causes the external agitator in this section to divert and return the flow to the section with increased resistance. This allows the foamed cement slurry in the section with higher foam content to be introduced and returned to the section with lower foamed cement slurry content for circulation. Whenever the resistance sensor of the corresponding section returns to its initial monitoring value, the electromagnet 52 of the corresponding section loses its magnetic force. Real-time dynamic monitoring is used to ensure the uniformity of foam distribution and size of foam in the flow of foamed cement slurry in the slurry delivery pipe 2 and slurry return chamber 21.

[0061] Reference Figure 9 The grouting head 6 is fixedly connected to the lower end of the reinforcing pipe 1 and the lower end of the grout delivery pipe 2. The grouting head 6 has a first discharge hole 61 coaxial with the grout delivery pipe 2, multiple second discharge holes 62 communicating with the first discharge hole 61 and arranged upwards at an angle, and a third discharge hole 63 connecting the external space of the grouting head 6 and the grout return chamber 21. The rotation of the grouting head 6 is controlled by the second rotating motor 372, which controls the rotation of the second rotating drum ring 35, thereby driving the grout delivery pipe 2 to rotate. In this embodiment, the diameter of the first discharge hole 61 is equal to the diameter of the grout delivery pipe 2.

[0062] In addition, when connecting different pipe sections, a stepped surface is usually set at the pipe-to-pipe connection for the connection.

[0063] The method of using a foamed cement slurry cementing device disclosed in this embodiment is as follows: First, the inner cylinder 12 is rotated by the first drive motor so that the inner window 121 and the outer window 111 are aligned and connected, and drilling fluid is introduced into the slurry delivery pipe 2 to flush the cementing cavity; after the drilling fluid is discharged from the first guide pipe 321, a certain amount of isolation fluid is introduced into the slurry delivery pipe 2; after the isolation fluid is introduced, foamed cement slurry is introduced into the slurry delivery pipe 2; until the foamed cement slurry is discharged from the first guide pipe 321, the thrust piston is installed into the slurry delivery pipe 2, and displacement fluid is introduced to push the thrust piston to press the foamed cement slurry, and the foamed cement slurry discharged from the first guide pipe 321 is collected; when the isolation fluid reaches the bottom of the injection head 6, the inner window 121 and the outer window 111 are adjusted to be misaligned and blocked, and displacement fluid is continuously introduced again to discharge and collect the foamed cement slurry in the slurry return cavity 21, thereby forming a cementing device consisting of an inner cylinder 12, an outer cylinder 11, and solidified foamed cement slurry.

[0064] When the resistance sensor detects a decrease in resistance, it indicates that the foam content in the foamed cement slurry in this local well section is relatively high. Correspondingly, the resistance sensor at the foamed cement slurry section where the resistance is detected to increase will also detect an increase in resistance. At this time, the electromagnet 52 in the well section where the resistance decreases is activated to generate magnetic force to attract the magnetic block 424, causing the external agitator in this well section to guide the flow back to the well section where the resistance increases. This allows the foamed cement slurry in the well section with a higher foam content to be introduced back to the well section with a lower foamed cement slurry content for circulation. Whenever the resistance sensor of the corresponding well section returns to the initial monitoring value, the electromagnet 52 of the corresponding well section will lose its magnetic force. The real-time dynamic monitoring method is used to monitor the process, thereby ensuring the uniformity of the foam distribution and the uniformity of the shape and size of the foam in the foamed cement slurry during the flow of the slurry delivery pipe 2 and the slurry return chamber 21.

[0065] In this invention, resistance sensors are distributed at different well sections to monitor the flow resistance of foamed cement slurry in the slurry return chamber 21. The foam content of the foamed cement slurry in a local well section is determined in real time. By activating the electromagnet 52 in the well section where the resistance decreases, the magnetic force attracts the magnetic block 424, causing the external agitator in this well section to guide the flow back to the well section where the resistance increases. This allows the foamed cement slurry in the well section with a higher foam content to be introduced back to the well section with a lower foamed cement slurry content for circulation. This ensures the uniformity of foam distribution and size of foam in the foamed cement slurry during the flow of the slurry in the slurry delivery pipe 2 and the slurry return chamber 21, thereby improving the cementing quality.

[0066] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0067] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A foamed cement slurry well cementing device, characterized by: It includes a reinforcement pipe (1), a grout delivery pipe (2), an external well base (3), a return assembly (4), a drive assembly (5), and a grouting head (6); The reinforcement pipe (1) includes an outer tube (11) arranged in the cementing cavity and an inner tube (12) rotatably connected to the outer tube (11) through the outer tube (11); the outer tube (11) has multiple equally spaced outer windows (111) through its wall; the inner tube (12) has multiple equally spaced inner windows (121) through its wall; the inner windows (121) are aligned and connected with the outer windows (111) or misaligned and blocked by the rotation of the inner tube (12); The slurry delivery pipe (2) is installed in the inner cylinder (12), and a slurry return cavity (21) is formed between the inner cylinder (12) and the slurry delivery pipe (2); The reflux assembly (4) is arranged in the slurry reflux chamber (21); the reflux assembly (4) includes a rotating ring frame (41) fixedly connected to the outer wall of the slurry delivery pipe (2), and an inclined external agitator fan blade (42) is rotatably connected to the rotating ring frame (41); multiple external agitator fan blades (42) are provided; The drive assembly (5) is arranged on the slurry pipe (2) and drives the external agitator blades (42) to rotate; The grouting head (6) is fixedly connected to the lower end of the reinforcing pipe (1) and the lower end of the grout delivery pipe (2). The grouting head (6) is provided with a first discharge hole (61) coaxial with the grout delivery pipe (2), a plurality of second discharge holes (62) communicating with the first discharge hole (61), and a third discharge hole (63) for communicating with the external space of the grouting head (6) and the grout return cavity (21).

2. A foamed cement slurry well cementing device according to claim 1, characterized in that: The rotating frame (41) includes a fixed pipe (411), a connecting pipe (412), and a connecting rod (413) that fixes the fixed pipe (411) and the connecting pipe (412) together. The fixed pipe (411) is sleeved and fixedly connected to the outer wall of the slurry delivery pipe (2). The connecting pipe (412) is sleeved on the fixed pipe (411), and there is a gap between the inner wall of the connecting pipe (412) and the inner wall of the fixed pipe (411). The connecting rod (413) is arranged between the fixed pipe (411) and the connecting pipe (412) to fix the fixed pipe (411) and the connecting pipe (412) together. An arrangement pipe (421) is fixedly connected to the outside of the external agitator fan blade (42). The arrangement pipe (421) connects multiple external agitator fan blades (42) together. The arrangement pipe (421) together with the external agitator fan blades (42) is arranged between the connecting pipe (412) and the fixed pipe (411). The outer wall of the arrangement pipe (421) and the inner wall of the connecting pipe (412) are in contact and rotatably connected together.

3. A foamed cement slurry well cementing device according to claim 2, characterized in that: An installation tube (422) is fixedly connected to the inner side of the external agitator fan blade (42), and the installation tube (422) connects the inner sides of multiple external agitator fan blades (42) together; multiple fixing holes (423) are opened through the fixing tube (411), and the multiple fixing holes (423) are arranged at equal intervals along the circumference of the fixing tube (411); a magnetic block (424) is fixedly connected to the installation tube (422), and multiple magnetic blocks (424) are provided, with each magnetic block (424) corresponding to one of the multiple fixing holes (423), and the magnetic blocks (424) are exposed at the fixing holes (423); The drive assembly (5) includes a sealing ring (51) rotatably connected to the inner wall of the slurry pipe (2). An electromagnet (52) is fixedly connected to the outer ring surface of the sealing ring (51). Multiple electromagnets (52) are provided, and the multiple electromagnets (52) are arranged at equal intervals along the circumference of the outer ring surface of the sealing ring (51). The slurry delivery pipe (2) has multiple connecting holes (23) through it. The connecting holes (23) are arranged at equal intervals along the circumference of the slurry delivery pipe (2), and the connecting holes (23) are aligned with the fixing holes (423). Multiple inclined internal agitator blades (53) are fixedly connected to the inner ring surface of the sealing ring (51). The multiple internal agitator blades are arranged at equal intervals, and the internal agitator blades (53) and the external agitator blades (42) are arranged at the same height.

4. The foamed cement slurry well cementing device of claim 1, wherein: A resistance sensor is installed on the outer wall of the slurry delivery pipe (2).

5. A foamed cement slurry well cementing device according to claim 4, characterized in that: A resistance monitoring rod (7) is fixedly connected to the outer wall of the slurry delivery pipe (2), and the resistance sensor is fixedly connected to the resistance monitoring rod (7).

6. The foamed cement slurry well cementing device of claim 3, wherein: An extension tube (43) is fixedly connected to the lower side of the mounting tube (422). The extension tube (43) extends through the mounting tube (422) and a plurality of pulverizing rods (44) are fixedly connected to the extension tube (43).

7. The foamed cement slurry well cementing device of claim 1, wherein: The outer well base (3) is equipped with a first drive motor that drives the outer cylinder (11) to rotate.

8. The foamed cement slurry well cementing device of claim 1, wherein: The reinforcing pipe (1) includes multiple outer cylinders (11) and multiple inner cylinders (12); multiple grout delivery pipes (2) are provided, and adjacent two inner cylinders (12) are connected by a plug-in method, and adjacent two grout delivery pipes (2) are connected by a plug-in method. Two adjacent outer tubes (11) are connected by a connector (13). The connector (13) includes a connecting ring (131). The upper end of the connecting ring (131) is inserted into the lower side of the upper outer tube (11) and is engaged with the upper outer tube (11). The lower end of the connecting ring (131) is sleeved on the upper side of the lower outer tube (11) and is engaged with the lower outer tube (11).

9. A foamed cement slurry well cementing device according to claim 8, characterized in that: The outer wall of the connecting ring (131) is circumferentially arranged with trapezoidal protrusions (132) that are fixedly connected to the connecting ring (131).

10. The foamed cement slurry well cementing device of claim 3, wherein: The inclination direction of the inner turbulence fan blade (53) is opposite to that of the outer turbulence fan blade (42).

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