A cement mixing method and mixing device suitable for low density cementing

Abstract

The application discloses a cement mixing method and mixing device suitable for low-density cementing, which comprises a lower ring support, a plurality of supporting rods vertically fixed on the upper periphery of the lower ring support, a machine base installed on the upper side of the supporting rods, the machine base being constructed on the ground through the lower ring support, a mixing assembly installed on the lower side of the machine base, a stirring vane rotationally arranged at the shaft center of the machine base, and a low-position baffle coaxially fixed on the lower ring support; the supporting rods are mutually constructed to form a cement feeding and discharging port for feeding cement shovels into the lower ring support; an annular water tank is fixed in the machine base, a water pipe is transversely connected to one end of the annular water tank, a plurality of water supply nozzles are vertically and uniformly distributed on the lower side of the machine base, and one end of the water supply nozzles is in communication with the annular water tank.

Description

Technical Field

[0001] This invention belongs to the field of cement mixing technology, specifically a cement mixing method and mixing device suitable for low-density cementing. Background Technology

[0002] The main purpose of cement cementing is to isolate underground oil and gas layers and water layers, preventing cross-contamination and establishing a long-term, stable, and safe channel for oil and gas production. Currently, cementing mainly uses high-density cement slurry systems (oil well cement mud) and low-density cement slurry systems. In low-density cement production, lightweight aggregates, hollow microspheres, or other lightweight materials are often added. Existing cement mixers mostly use complex mixing blades to achieve cement mixing. However, in low-density cement mixing, lightweight aggregates are difficult to uniformly integrate into the cement slurry, and during cement pumping, lightweight aggregates are prone to agglomeration or pipe blockage. Furthermore, significant residue remains on the cylinder wall afterward, making cleaning difficult and easily leading to cement slurry waste. Therefore, it is necessary to provide a cement mixing method and mixing device suitable for low-density cementing to solve the problems mentioned in the background technology. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution:

[0004] A cement mixing method suitable for low-density cementing includes the following steps:

[0005] Step 1. Raw material preparation: Select lightweight aggregates, such as cenospheres and expanded perlite, and prepare low-density special cement. Also prepare additives, such as water-reducing agents and retarders, according to the cement mixing process requirements. Accurately calculate and mix the proportions of cement, lightweight aggregates, and water to achieve the required low-density cement paste with good fluidity and bonding properties.

[0006] Step 2. Mix evenly, turn on the annular water tank water supply system to ensure that the cement slurry is continuously and stably supplied with the required water throughout the mixing process, and operate the hydraulic telescopic rod control system to make the telescopic arm on the mixing component continuously retract and extend according to the mixing requirements.

[0007] The first and second actions of the material feeding mechanism are activated to move the low-density cement material piled at the bottom of the device in layers, so as to break the aggregation between the materials and promote the uniform mixing of the materials.

[0008] Step 3. Mid-section mixing: The driving device starts the mixing blades to rotate, further agitating the cement slurry located in the middle of the mixing device, ensuring that the lightweight aggregate is evenly distributed in the cement slurry. At this time, under the action of the telescopic arm and the material feeding mechanism, the cement slurry at the outer ring is fully mixed with the cement slurry at the center point, so that the material in the entire mixing area is uniform.

[0009] Step 4. Add additives. Add water-reducing agents and other additives at appropriate times during the mixing process to improve the fluidity, thickening time and strength characteristics of the cement slurry. At the same time, monitor and adjust the mixing speed, time and slurry state in real time to ensure that the final cement slurry meets the various technical indicators of low-density cementing.

[0010] Step 5. Injection and subsequent treatment: The mixed low-density cement slurry is injected into the predetermined location through a dedicated pipeline system for cementing operations.

[0011] A cement mixing device suitable for low-density cementing includes: a lower ring frame with multiple support rods vertically fixed on its upper circumference, a machine base installed above the support rods, the machine base being constructed on the ground via the lower ring frame, a mixing assembly installed below the machine base, a stirring blade rotatably mounted at the axis of the machine base, and a low-position baffle coaxially fixed on the lower ring frame;

[0012] The supporting rods are interconnected to form a cement feeding and discharging port, which is used to shovel cement into the lower ring frame;

[0013] An annular water tank is fixed inside the base. One end of the annular water tank is horizontally connected to a water pipe. Multiple water supply nozzles are vertically and evenly distributed below the base, and one end of each water supply nozzle is connected to the annular water tank.

[0014] Furthermore, preferably, the mixing assembly includes:

[0015] The rotating shaft tube is coaxially rotatably disposed below the machine base;

[0016] A drive gear seat is installed inside the machine base, and one end of the rotating shaft tube passes through the drive gear seat and is driven to rotate by the drive gear seat;

[0017] The telescopic arms are multiple in number and distributed circumferentially, and each telescopic arm is laterally fixed to the outside of the rotating shaft tube;

[0018] A material feeding mechanism is installed at the lower end of each of the telescopic arms. The material feeding mechanism is capable of mixing low-density cement by means of a first action and a second action.

[0019] Furthermore, as a preferred embodiment, a shaft is rotatably disposed below the base, the shaft is rotatably connected to the rotating shaft tube, a drive motor is mounted on the base, one end of the shaft is fixed to the output end of the drive motor, the stirring blade is fixed to the lower end of the shaft, and multiple spiral blades are also fixed on the shaft.

[0020] Furthermore, preferably, the feeding mechanism includes:

[0021] A rotating base is fixed below the telescopic arm, and a rotating shaft is rotatably installed inside the rotating base;

[0022] A connecting arm is fixed to the lower end of the rotating shaft. A rotating arm is rotatably connected to the connecting arm. One end of the connecting arm is connected to an adjusting rod, and the telescopic end of the adjusting rod is connected to the rotating arm.

[0023] The lower connector is rotatably connected below the rotating arm. The rotating arm is provided with an adjusting rod two connected to the lower connector. A lever is fixed on the lower connector, and a lever plate is detachably provided on the lever.

[0024] Furthermore, preferably, the deflection angle of the rotating arm in the vertical direction ranges from 12° to 48°, and the deflection angle of the lower connector in the vertical direction ranges from 5° to 28°.

[0025] Furthermore, as a preferred embodiment, the first action of the feeding mechanism is as follows: the rotating shaft deflects 40° in the positive direction, while the first adjusting rod gradually shortens to cause the rotating arm to deflect laterally, and the second adjusting rod extends synchronously to cause the lower connecting piece to deflect in the same direction;

[0026] The second action of the feeding mechanism is as follows: the rotating shaft deflects back to its original position in the opposite direction, while the first adjusting rod gradually extends to make the rotating arm return to its original position in the opposite direction, and the second adjusting rod shortens simultaneously to make the lower connecting piece return to its original position in the same direction.

[0027] Furthermore, preferably, a frame rod is fixed outside the rotating shaft tube between adjacent telescopic arms. A hydraulic telescopic rod is arranged parallel above one of the telescopic arms on the rotating shaft tube. One end of the hydraulic telescopic rod is connected to the rotating shaft tube, and the telescopic end of the hydraulic telescopic rod is connected to one end of the telescopic arm. A double-headed telescopic frame is rotatably connected to the frame rod. The two ends of the double-headed telescopic frame are respectively connected to the corresponding telescopic arms, so that when the hydraulic telescopic rod drives the telescopic arm to extend or retract, the adjacent telescopic arms retract synchronously in opposite directions.

[0028] Furthermore, preferably, when the telescopic arm retracts under the drive of the hydraulic telescopic rod, the material feeding mechanism performs a first action; when the telescopic arm extends under the drive of the hydraulic telescopic rod, the material feeding mechanism performs a second action.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] In this invention, the mixing components can be directly mounted on the ground via the lower ring structure, so that they can be put into use directly on the construction site. The material feeding mechanism on multiple mixing components uses the first action and the second action to mix low-density cement, so that the cement can be piled up and mixed, thereby avoiding unevenness in the mixing process. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the mixing component in this invention;

[0033] Figure 3 This is a schematic diagram of the material feeding mechanism in this invention;

[0034] Figure 4 This is a schematic diagram of the structure of the double-headed telescopic frame in this invention;

[0035] Figure 5 This is a schematic diagram of the trajectory of the first action of the material feeding mechanism below the telescopic arm in this invention;

[0036] Figure 6 This is a schematic diagram of the trajectory of the second action of the material feeding mechanism below the telescopic arm in this invention;

[0037] In the diagram: 1. Lower ring frame; 11. Low-position baffle; 12. Support rod; 13. Base; 14. Mixing blade; 15. Annular water tank; 16. Water pipe; 17. Water supply nozzle; 2. Mixing assembly; 21. Rotary shaft tube; 22. Drive gear seat; 23. Telescopic arm; 24. Hydraulic telescopic rod; 25. Shaft; 26. Spiral blade; 3. Material feeding mechanism; 31. Rotating seat; 32. Connecting arm; 33. Rotating arm; 34. Adjusting rod one; 35. Lower connecting piece; 36. Adjusting rod two; 37. Feeding frame; 4. Frame rod; 41. Double-headed telescopic frame. Detailed Implementation

[0038] Please see Figure 1-6 In this embodiment of the invention, a cement mixing method suitable for low-density cementing includes the following steps:

[0039] Step 1. Raw material preparation: Select lightweight aggregates, such as cenospheres and expanded perlite, and prepare low-density special cement. Also prepare additives, such as water-reducing agents and retarders, according to the cement mixing process requirements. Accurately calculate and mix the proportions of cement, lightweight aggregates, and water (determine the specific dosage ratios of cement, lightweight aggregates, water, and various additives based on geological conditions, well depth, construction requirements, etc.) to achieve the required low-density cement slurry with good fluidity and bonding properties.

[0040] Step 2. Mix evenly, turn on the water supply system of the annular water tank 15 to ensure that the cement slurry is continuously and stably supplied with the required water throughout the mixing process, and operate the hydraulic telescopic rod control system to make the telescopic arm 23 on the mixing component 2 continuously retract and extend according to the mixing requirements.

[0041] The first and second actions of the material feeding mechanism 3 are activated to move the low-density cement material piled at the bottom of the device in layers, so as to break the aggregation between the materials and promote the uniform mixing of the materials.

[0042] Step 3. Mid-section mixing: The driving device starts the mixing blade 14 to rotate, further agitating the cement slurry located in the middle of the mixing device. This ensures that the lightweight aggregate is evenly distributed in the cement slurry. At this time, under the action of the telescopic arm 23 and the material feeding mechanism 3, the cement slurry at the outer ring is fully mixed with the cement slurry at the center point, achieving uniform material distribution throughout the entire mixing area.

[0043] Step 4. Add additives. Add water-reducing agents and other additives at appropriate times during the mixing process to improve the fluidity, thickening time and strength characteristics of the cement slurry. At the same time, monitor and adjust the mixing speed, time and slurry state (such as viscosity, rheology, etc.) in real time to ensure that the final cement slurry meets the various technical indicators of low-density cementing.

[0044] Step 5. Injection and subsequent treatment: The mixed low-density cement slurry is injected into the predetermined location through a dedicated pipeline system for cementing operations.

[0045] A cement mixing device suitable for low-density cementing includes: a lower ring frame 1 with multiple support rods 12 vertically fixed on its upper circumference; a base 13 is installed above the support rods 12; the base 13 is constructed on the ground via the lower ring frame 1; a mixing component 2 is installed below the base 13; a stirring blade 14 is rotatably installed at the axis of the base 13; and a low-position baffle 11 is coaxially fixed on the lower ring frame 1. The lower ring frame can have a bottomed or bottomless end cap structure, and the low-position baffle can obstruct the flow of low-density cement during mixing, allowing the low-density cement to be relatively flat within the lower ring frame. This achieves high mixing uniformity during mixing, ensuring uniform distribution of cement and aggregate. It is typically suitable for large-scale concrete production, enabling continuous production of large quantities of concrete. Compared to existing cylindrical mixing systems, it facilitates observation of the mixing process and convenient material replenishment. Furthermore, the lightweight aggregate in the flatly piled low-density cement is less prone to agglomeration and accumulation, ensuring uniform mixing.

[0046] The supporting rods 12 are interconnected to form a cement feeding and discharging port, which is used to shovel cement into the lower ring frame 1;

[0047] An annular water tank 15 is fixed inside the base 13. One end of the annular water tank 15 is horizontally connected to a water pipe 16. Multiple water supply nozzles 17 are vertically and evenly distributed below the base 13. One end of each water supply nozzle 17 is connected to the annular water tank 15 to achieve uniform water supply.

[0048] In this embodiment, the mixing component 2 includes:

[0049] The rotating shaft tube 21 is coaxially rotatably disposed below the base 13;

[0050] A drive gear seat 22 is installed inside the base 13. One end of the rotating shaft tube 21 passes through the drive gear seat 22 and is driven to rotate by the drive gear seat 22.

[0051] The telescopic arms 23 are multiple in number and distributed circumferentially, and each of the telescopic arms 23 is laterally fixed to the outside of the rotating shaft tube 21;

[0052] The material feeding mechanism 3 is installed at the lower end of each of the telescopic arms 23. The material feeding mechanism 3 can mix low-density cement by means of a first action and a second action. The telescopic arms can achieve radial displacement of the material feeding mechanism under telescopic adjustment, so as to achieve mixing of cement slurry at the outer ring and cement slurry at the center point in the mixing of low-density cement in a flat and piled state.

[0053] In a preferred embodiment, a shaft 25 is rotatably disposed below the base 13, the shaft 25 is rotatably connected to the rotating shaft tube 21, a drive motor is mounted on the base 13, one end of the shaft 25 is fixed to the output end of the drive motor, the stirring blade 14 is fixed to the lower end of the shaft 25, and multiple spiral blades 26 are also fixed on the shaft 25. The spiral blades 26 can realize the upward polymerization and transport of low-density cement under rotation.

[0054] In this embodiment, the feeding mechanism 3 includes:

[0055] A rotating base 31 is fixed below the telescopic arm 23, and a rotating shaft is rotatably provided inside the rotating base 31;

[0056] A connecting arm 32 is fixed to the lower end of the rotating shaft. A rotating arm 33 is rotatably connected to the connecting arm 32. An adjusting rod 34 is connected to one end of the connecting arm 32. The telescopic end of the adjusting rod 34 is connected to the rotating arm 33.

[0057] The lower connector 35 is rotatably connected below the rotating arm 33. The rotating arm 33 is provided with an adjusting rod 36 connected to the lower connector 35. A lever 37 is fixed on the lower connector 35, and a lever plate is detachably provided on the lever 37.

[0058] In this embodiment, the deflection angle of the rotating arm 33 in the vertical direction ranges from 12° to 48°, and the deflection angle of the lower connector 35 in the vertical direction ranges from 5° to 28°.

[0059] In this embodiment, the first action of the material feeding mechanism 3 is: the rotating shaft deflects 40° in the positive direction, while the first adjusting rod 34 gradually shortens to make the rotating arm 33 deflect laterally, and the second adjusting rod 36 extends synchronously to make the lower connecting piece 35 deflect in the same direction; that is, the first action can push the low-density cement on the relatively outer side toward the center to polymerize.

[0060] The second action of the material feeding mechanism 3 is as follows: the rotating shaft deflects back to its original position in the opposite direction, while the first adjusting rod 34 gradually extends to make the rotating arm 33 return to its original position in the opposite direction, and the second adjusting rod 36 shortens simultaneously to make the lower connecting piece 35 return to its original position in the same direction; that is, the second action can move and disperse the low-density cement that is piled up in the relatively central part to the outside.

[0061] In a preferred embodiment, a support rod 4 is fixed outside the pivot tube 21 between adjacent telescopic arms 23. A hydraulic telescopic rod 24 is arranged parallel above one of the telescopic arms 23 on the pivot tube 21. One end of the hydraulic telescopic rod 24 is connected to the pivot tube 21, and the telescopic end of the hydraulic telescopic rod 24 is connected to one end of the telescopic arm 23. A double-headed telescopic frame 41 is rotatably connected to the support rod 4. The two ends of the double-headed telescopic frame 41 are respectively connected to the corresponding telescopic arms 23, so that when the hydraulic telescopic rod 24 drives the telescopic arm 23 to extend or retract, the adjacent telescopic arms 23 synchronously retract in opposite directions. That is, when the hydraulic telescopic rod drives the corresponding telescopic arm to extend or retract, the other telescopic arms can extend or retract synchronously, which provides high controllability.

[0062] In this embodiment, when the telescopic arm 23 retracts under the drive of the hydraulic telescopic rod 24, the material feeding mechanism 3 performs a first action; when the telescopic arm 23 extends under the drive of the hydraulic telescopic rod 24, the material feeding mechanism 3 performs a second action, that is, the rotating shaft tube continuously rotates at medium and high speed. The telescopic arm that is synchronously radially retracting can push the low-density cement that is relatively on the outside towards the center to aggregate during the first action of the material feeding mechanism, while the telescopic arm that is synchronously radially extending outward can push the low-density cement that is relatively accumulated in the center outward to disperse during the second action of the material feeding mechanism.

[0063] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A cement mixing device suitable for low-density cementing, characterized in that, include: The lower ring frame (1) has multiple support rods (12) vertically fixed on its upper circumference. A machine base (13) is installed above the support rods (12). The machine base (13) is constructed on the ground through the lower ring frame (1). A mixing assembly (2) is installed below the machine base (13). A stirring blade (14) is also rotatably installed at the axis of the machine base (13). A low baffle (11) is coaxially fixed on the lower ring frame (1). The supporting rods (12) are constructed together to form a cement feeding and discharging port, which is used to shovel cement into the lower ring frame (1); An annular water tank (15) is fixed inside the base (13). A water pipe (16) is horizontally connected to one end of the annular water tank (15). Multiple water supply nozzles (17) are vertically and evenly distributed below the base (13). One end of each water supply nozzle (17) is connected to the annular water tank (15). The mixing component (2) includes: The rotating shaft tube (21) is coaxially rotatably disposed below the base (13); A drive gear seat (22) is installed inside the base (13). One end of the rotating shaft tube (21) passes through the drive gear seat (22) and is driven to rotate by the drive gear seat (22). The telescopic arms (23) are multiple in a circumferentially distributed manner, and each of the telescopic arms (23) is laterally fixed outside the rotating shaft tube (21); The material feeding mechanism (3) is installed at the lower end of each of the telescopic arms (23). The material feeding mechanism (3) can mix low-density cement by using the first action and the second action. The feeding mechanism (3) includes: A rotating seat (31) is fixed below the telescopic arm (23), and a rotating shaft is rotatably provided inside the rotating seat (31); A connecting arm (32) is fixed to the lower end of the rotating shaft. A rotating arm (33) is rotatably connected to the connecting arm (32). One end of the connecting arm (32) is connected to an adjusting rod (34). The telescopic end of the adjusting rod (34) is connected to the rotating arm (33). The lower connector (35) is rotatably connected below the rotating arm (33). The rotating arm (33) is provided with an adjusting rod (36) connected to the lower connector (35). The lower connector (35) is fixed with a lever (37), and the lever (37) is detachably provided with a lever plate. The first action of the feeding mechanism (3) is: the rotating shaft deflects 40° in the positive direction, and at the same time the first adjusting rod (34) gradually shortens so that the rotating arm (33) deflects laterally, and the second adjusting rod (36) extends synchronously so that the lower connecting piece (35) deflects in the same direction; The second action of the feeding mechanism (3) is as follows: the rotating shaft deflects back to its original position, and at the same time, the first adjusting rod (34) gradually extends to make the rotating arm (33) return to its original position in the reverse direction, and the second adjusting rod (36) shortens synchronously to make the lower connecting piece (35) return to its original position in the same direction.

2. A cement mixing device suitable for low-density cementing according to claim 1, characterized in that: A shaft (25) is rotatably disposed below the base (13). The shaft (25) is rotatably connected to the rotating shaft tube (21). A drive motor is installed on the base (13). One end of the shaft (25) is fixed to the output end of the drive motor. The stirring blade (14) is fixed to the lower end of the shaft (25). Multiple spiral blades (26) are also fixed on the shaft (25).

3. A cement mixing device suitable for low-density cementing according to claim 1, characterized in that: The deflection angle of the rotating arm (33) in the vertical direction ranges from 12° to 48°, and the deflection angle of the lower connector (35) in the vertical direction ranges from 5° to 28°.

4. A cement mixing device suitable for low-density cementing according to claim 1, characterized in that: A support rod (4) is fixed outside the pivot tube (21) between adjacent telescopic arms (23). A hydraulic telescopic rod (24) is arranged parallel above one of the telescopic arms (23) on the pivot tube (21). One end of the hydraulic telescopic rod (24) is connected to the pivot tube (21), and the telescopic end of the hydraulic telescopic rod (24) is connected to one end of the telescopic arm (23). A double-headed telescopic frame (41) is rotatably connected to the support rod (4). The two ends of the double-headed telescopic frame (41) are respectively connected to the corresponding telescopic arms (23), so that when the hydraulic telescopic rod (24) drives the telescopic arm (23) to extend or retract, the adjacent telescopic arms (23) retract synchronously in opposite directions.

5. A cement mixing device suitable for low-density cementing according to claim 4, characterized in that: When the telescopic arm (23) retracts under the drive of the hydraulic telescopic rod (24), the material feeding mechanism (3) performs a first action; when the telescopic arm (23) extends under the drive of the hydraulic telescopic rod (24), the material feeding mechanism (3) performs a second action.

6. A cement mixing method suitable for low-density cementing, employing a cement mixing device suitable for low-density cementing as described in any one of claims 1-5, characterized in that: Includes the following steps: Step 1. Raw material preparation: Select lightweight aggregates, such as cenospheres and expanded perlite, and prepare low-density special cement. Also prepare additives, such as water-reducing agents and retarders, according to the cement mixing process requirements. Accurately calculate and mix the proportions of cement, lightweight aggregates, and water to achieve the required low-density cement paste with good fluidity and bonding properties. Step 2. Mix evenly, turn on the water supply system of the annular water tank (15) to ensure that the cement slurry is continuously and stably supplied with the required water throughout the mixing process, and operate the hydraulic telescopic rod control system to make the telescopic arm (23) on the mixing component (2) continuously contract and extend according to the mixing requirements; The first and second actions of the material feeding mechanism (3) are activated to move the low-density cement material piled at the bottom of the device in layers to break the aggregation between the materials and promote uniform mixing of the materials. Step 3. Mid-section mixing: The mixing blade (14) is started to rotate by the driving device to further agitate the cement slurry located in the middle of the mixing device, ensuring that the lightweight aggregate is evenly distributed in the cement slurry. At this time, under the action of the telescopic arm (23) and the material feeding mechanism (3), the cement slurry at the outer ring and the cement slurry at the center point are fully mixed, so that the material in the entire mixing area is uniform. Step 4. Add additives. Add water-reducing agents and other additives at appropriate times during the mixing process to improve the fluidity, thickening time and strength characteristics of the cement slurry. At the same time, monitor and adjust the mixing speed, time and slurry state in real time to ensure that the final cement slurry meets the various technical indicators of low-density cementing. Step 5. Injection and subsequent treatment: The mixed low-density cement slurry is injected into the predetermined location through a dedicated pipeline system for cementing operations.

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