Cementing dust removal pressure stabilizing device

Abstract

The application discloses a dust removal and pressure stabilizing device for well cementation, which comprises a metering tank, a plunger pump, a slurry mixing tank and a constant pressure recovery tank. A mixer is arranged on the slurry mixing tank, and an ash inlet, an ash outlet, a water inlet and a secondary slurry mixing inlet are formed in the mixer. The outlet of the slurry mixing tank is communicated with the plunger pump, the inlet of the metering tank is connected with a feeding pipe, and the outlet of the metering tank is respectively communicated with the plunger pump, a sampling port and the water inlet of the mixer. The outlet of the plunger pump is respectively communicated with a well bore and the metering tank. The dust removal and pressure stabilizing device for well cementation has reasonable manifold arrangement, compact structure and small space occupation in well site during construction. The ash conveying stability is good, the well cementation construction operation density is stable, and the well cementation construction efficiency and quality are greatly improved. Meanwhile, the cement ash particles from the ash outlet of the mixer are recovered, the environmental pollution is reduced, and the on-site operation environment is greatly improved.

Description

Technical Field

[0001] This invention belongs to the technical field of oilfield cementing equipment and relates to a dust removal and pressure stabilizing device for cementing. Background Technology

[0002] Cementing is an essential part of drilling operations, encompassing casing installation and cementing. Excellent cementing quality is crucial for ensuring drilling safety and efficiency, and dust control is an important aspect of guaranteeing cementing quality.

[0003] The existing cementing dust removal equipment has the following problems: (1) During cementing operations, cement ash is transported to the mixer by a ash conveying truck through the ash conveying pipeline. Since the gas-solid ratio in the ash conveying pipeline is a variable, simply using conventional conveying equipment not only occupies working space, but also makes it difficult to adapt to the requirements of gas-solid changes, resulting in inconsistent cement ash delivery to the mixer, the cementing operation density cannot be guaranteed, and the overflowing cement ash cannot be recycled, which wastes resources, pollutes the environment, and reduces economic benefits; (2) The mixing tank is usually a single tank layout, and the mud does not stay in the tank for a sufficient time, and the water in the mixing tank... Due to insufficient mixing time, the cement slurry delivered into the wellbore is not uniform, which affects the quality of cementing construction. In addition, when the mixing tank is a single tank, the position of the agitator in the mixing tank is one of the important factors affecting the mixing effect. In severe cases, some cement slurry in the mixing tank is not mixed and is pumped into the wellbore by the plunger pump. (3) The metering water tank has a relatively simple function and can only store the clean water required for cementing operations. The additives required for cementing operations need to be prepared in advance, which is inconvenient to transport. In addition, the preparation of cementing additives requires a lot of equipment, and the space of the cementing truck (skid) is limited. Multiple trucks and multiple transportations are required, resulting in high transportation costs.

[0004] To address the aforementioned problems, this application proposes a dust removal and pressure stabilization device for cementing. Summary of the Invention

[0005] The purpose of this invention is to provide a dust removal and pressure stabilization device for cementing, which solves the problems of inconsistent gas-solid ratio in the ash conveying pipeline, uneven mixing of cement slurry, and high transportation costs of cementing additives in existing cementing dust removal devices.

[0006] The technical solution adopted in this invention is a dust removal and pressure stabilizing device for cementing, including a metering tank, a plunger pump, a mixing tank, a constant pressure recovery tank, and a control system.

[0007] The mixing tank is equipped with a mixer, which has an ash inlet, an ash outlet, a water inlet, and a secondary mixing inlet. The outlet of the mixing tank is connected to a plunger pump.

[0008] The metering tank inlet is connected to the feed pipe, and the metering tank outlet is connected to the plunger pump, the sampling port, and the water inlet of the mixer, respectively; the plunger pump outlet is connected to the well shaft and the metering tank, respectively.

[0009] The constant pressure recovery tank includes a filter device, a recovery tank, and a constant pressure tank. The filter device is located at the top of the recovery tank and is connected to the recovery tank. The constant pressure tank is located at the bottom of the recovery tank. A separation mechanism is provided between the recovery tank and the constant pressure tank. The outlet of the constant pressure tank is connected to the ash inlet of the mixer. A feed inlet is provided on the outer wall of the constant pressure tank.

[0010] The invention is further characterized in that,

[0011] The separation mechanism includes an inverted V-shaped structure at the bottom of the recycling tank, a second spring, and a dust-blocking cover. The bottom of the inverted V-shaped structure has a notch. One end of the second spring is fixed to the inner wall of the recycling tank, and the other end of the second spring extends out of the notch of the inverted V-shaped structure to connect with the dust-blocking cover. The lateral width of the dust-blocking cover is not less than the width of the notch.

[0012] The bottom of the inverted V-shaped structure is also equipped with a buffer tube. The recovery tank is connected to the buffer tube through a notch. A baffle is installed at the opening of the buffer tube to control the closure of the opening.

[0013] The constant pressure recovery tank is also equipped with a special-shaped pipe on its exterior, and the recovery tank and the constant pressure tank are connected by the special-shaped pipe;

[0014] A connecting pipe is also provided on the side wall of the constant pressure tank. The connecting pipe is connected to the special-shaped pipe. One end of the connecting pipe is set on the outer wall of the constant pressure tank, and the other end of the connecting pipe is closed. A first spring is set inside the connecting pipe. The end of the first spring near the constant pressure tank is fixed on the inner wall of the connecting pipe, and a stop ball is set on the other end of the first spring.

[0015] A density meter is also installed on the outside of the mixing tank. The outlet of the mixing tank is connected to the density meter. The mixing tank is also connected to the inlet of the mixer.

[0016] A butterfly valve and a pump are installed between the ash outlet of the mixer and the recovery tank. The recovery tank, the butterfly valve, the pump and the ash outlet of the mixer are connected in sequence.

[0017] The constant pressure tank is equipped with an exhaust valve on its side wall, an inlet control valve on its inlet, and an outlet on its bottom with an outlet control valve. An overflow valve is installed at the inlet of the filter device.

[0018] An air hammer is installed on the outer wall of the buffer tube, and the baffle is connected to the buffer tube by a pin.

[0019] The metering tank includes a first tank and a second tank, which are connected by a first conduit. A first control valve is installed on the first conduit. The mixing tank includes a third tank and a fourth tank, which are connected by a second conduit. A second control valve is installed on the second conduit. A stirrer is installed in each of the first, second, third, and fourth tanks.

[0020] The tops of the first and second tanks are respectively equipped with an eighteenth butterfly valve and a twenty-third butterfly valve, and the bottoms of the first and second tanks are respectively equipped with a first butterfly valve and a second butterfly valve. The first tank, the first butterfly valve, and the sampling port are connected in sequence, as are the second tank and the second butterfly valve. A third butterfly valve is also installed between the first tank and the plunger pump. The first tank, the first butterfly valve, and the third butterfly valve are connected in sequence to the plunger pump, as are the second tank, the second butterfly valve, and the third butterfly valve. A first water supply pump, a second water supply pump, and a fourth butterfly valve are installed between the first tank and the inlet of the mixer. The first tank is sequentially connected to the inlet of the first water supply pump, the fourth butterfly valve, and the mixer. The second tank is sequentially connected to the inlet of the first water supply pump, the fourth butterfly valve, and the mixer. The first and second water supply pumps are also connected to sampling ports. A fifteenth butterfly valve is installed between the first water supply pump and the sampling port, and a sixteenth butterfly valve is installed between the second water supply pump and the sampling port.

[0021] An eighth butterfly valve, a first centrifugal pump, a ninth butterfly valve, and a tenth butterfly valve are installed between the third tank and the plunger pump. The third tank, the eighth butterfly valve, and the plunger pump are sequentially connected. The third tank, the ninth butterfly valve, the first centrifugal pump, and the tenth butterfly valve are sequentially connected to the plunger pump. An eleventh butterfly valve, a second centrifugal pump, a twelfth butterfly valve, and a nineteenth butterfly valve are also installed between the metering tank and the mixing tank. The first tank, the nineteenth butterfly valve, the second centrifugal pump, the eleventh butterfly valve, and the third tank are connected. The first tank, the nineteenth butterfly valve, the second centrifugal pump, the twelfth butterfly valve, and the fourth tank are connected. The second tank, the nineteenth butterfly valve, the second centrifugal pump, the eleventh butterfly valve, and the third tank are connected. The second tank, the nineteenth butterfly valve, the second centrifugal pump, the twelfth butterfly valve, and the fourth tank are connected.

[0022] A seventh butterfly valve and a seventeenth butterfly valve are installed between the feed pipe and the inlet of the mixer. The feed pipe, the seventh butterfly valve, the seventeenth butterfly valve and the inlet of the mixer are connected in sequence. The feed pipe, the seventh butterfly valve, the first water supply pump, the fourth butterfly valve and the inlet of the mixer are connected in sequence. The feed pipe, the seventh butterfly valve, the fifth butterfly valve, the second water supply pump, the sixth butterfly valve and the inlet of the mixer are connected in sequence. The first tank, the first butterfly valve, the seventeenth butterfly valve and the inlet of the mixer are connected in sequence. The second tank, the second butterfly valve, the seventeenth butterfly valve and the inlet of the mixer are connected in sequence.

[0023] A thirteenth butterfly valve and a fourteenth butterfly valve are installed between the third tank and the fourth tank. The third tank, the first centrifugal pump, the ninth butterfly valve, the thirteenth butterfly valve, the density meter and the fourth tank are connected in sequence. The third tank, the ninth butterfly valve, the first centrifugal pump, the fourteenth butterfly valve and the inlet of the mixer are connected in sequence.

[0024] The beneficial effects of this invention are:

[0025] 1) In the dust removal and pressure stabilizing device for cementing of the present invention, the metering tank and the mixing tank are set to a dual-tank mode. If one tank fails, the other tank is quickly started to continue working, ensuring the cementing operation continues, reducing the risk of cementing operation and avoiding accidents.

[0026] 2) The cementing dust removal and pressure stabilizing device of the present invention is equipped with a densitometer, which can accurately control the density of cementing mud and further improve the cementing effect;

[0027] 3) The manifold layout of the cementing dust removal and pressure stabilization device of this invention is reasonable, the structure is compact, and it occupies little space at the well site during construction;

[0028] 4) The dust removal and pressure stabilization device for cementing of the present invention has multiple alternative schemes for each line, which has good ash conveying stability and stable cementing operation density, thus greatly improving the cementing operation efficiency and cementing operation quality.

[0029] 5) The cement ash particles at the ash outlet of the mixer in the cementing dust removal and pressure stabilization device of the present invention are recovered, reducing environmental pollution and greatly improving the on-site working environment. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the cementing dust removal and pressure stabilizing device of the present invention;

[0031] Figure 2 This is a schematic diagram of the metering tank part of the cementing dust removal and pressure stabilizing device of the present invention;

[0032] Figure 3 This is a schematic diagram of the mixing tank part of the dust removal and pressure stabilization device for cementing of the present invention;

[0033] Figure 4 This is a schematic diagram of the constant pressure recovery tank part of the cementing dust removal and pressure stabilization device of the present invention;

[0034] Figure 5 This is a schematic diagram of the mixer part of the cementing dust removal and pressure stabilization device of the present invention.

[0035] In the diagram, 1. Metering tank, 2. Plunger pump, 3. Mixing tank, 4. Constant pressure recovery tank, 5. Feed pipe, 6. Sampling port, 7. Well shaft, 8. Densitometer, 9. Ash conveying butterfly valve, 10. Ash conveying pump, 11. First butterfly valve, 12. Second butterfly valve, 13. Third butterfly valve, 14. First water supply pump, 15. Second water supply pump, 16. Fourth butterfly valve, 17. Fifth butterfly valve, 18. Sixth butterfly valve, 19. Seventh butterfly valve, 20. Eighth butterfly valve, 21. First centrifugal pump, 22. Ninth butterfly valve, 23. Tenth butterfly valve, 24. Eleventh butterfly valve, 25. Second centrifugal pump, 26. Twelfth butterfly valve, 27. Thirteenth butterfly valve, 28. Fourteenth butterfly valve, 29. Twenty-third butterfly valve, 30. Fifteenth butterfly valve, 31. Sixteenth butterfly valve, 32. Seventeenth butterfly valve, 33. Eighteenth butterfly valve; 34. Nineteenth butterfly valve, 35. Twentieth butterfly valve, 36. Twenty-first butterfly valve, 37. Twenty-second butterfly valve;

[0036] 1-1. First tank body; 1-2. Second tank body; 1-3. First conduit; 1-4. First control valve;

[0037] 3-1. Mixer; 3-2. Third tank; 3-3. Fourth tank; 3-4. Second conduit; 3-5. Second control valve.

[0038] 3-1-1. Ash inlet, 3-1-2. Ash outlet, 3-1-3. Water inlet, 3-1-4. Secondary mixing slurry inlet;

[0039] 4-1. Recycling tank; 4-2. Constant pressure tank; 4-3. Filter device; 4-4. Separation mechanism; 4-5. Feed inlet; 4-6. Special-shaped pipe; 4-7. Connecting pipe; 4-8. First spring; 4-9. Ball plug; 4-10. Exhaust valve; 4-11. Feed inlet control valve; 4-12. Discharge port; 4-13. Discharge port control valve; 4-14. Overflow valve;

[0040] 4-4-1. V-shaped structure, 4-4-2. Second spring, 4-4-3. Dust shield, 4-4-4. Notch, 4-4-5. Buffer tube, 4-4-6. Baffle, 4-4-7. Air hammer, 4-4-8. Pin. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0042] The dust removal and pressure stabilizing device for cementing of the present invention has the following structure: Figure 1 As shown, it includes a metering tank 1, a plunger pump 2, a mixing tank 3, a constant pressure recovery tank 4, and a control system; a mixer 3-1 is installed on the mixing tank 3, and the structure of the mixer 3-1 is as follows. Figure 5As shown, the mixer 3-1 has an ash inlet 3-1-1, an ash outlet 3-1-2, a water inlet 3-1-3, and a secondary mixing inlet 3-1-4. The outlet of the mixing tank 3 is connected to the plunger pump 2. The clean water and additives in the metering tank 1 enter the mixing tank 3 through the water inlet 3-1-3 of the mixer 3-1. The ash from the ash conveying car enters the mixing tank 3 through the constant pressure recovery tank 4 and the ash inlet 3-1-1 of the mixing tank 3. The mixing tank 3 mixes the materials (including clean water, ash, or additives) that enter it.

[0043] The inlet of metering tank 1 is connected to feed pipe 5, and the outlet of metering tank 1 is connected to plunger pump 2, sampling port 6 and water inlet 3-1-3 of mixer 3-1 respectively; the outlet of plunger pump 2 is connected to well 7 and metering tank 1 respectively, and the sampling port is used to observe the composition and density of additives from feed pipe 5 and metering tank 1.

[0044] The structure of constant pressure recovery tank 4 is as follows Figure 4 As shown, the constant pressure recovery tank 4 includes a filter device 4-3, a recovery tank 4-1, and a constant pressure tank 4-2. The filter device 4-3 is located at the upper end of the recovery tank 4-1 and is connected to the recovery tank 4-1. The constant pressure tank 4-2 is located at the bottom of the recovery tank 4-1. A separation mechanism 4-4 is provided between the recovery tank 4-1 and the constant pressure tank 4-2. The outlet of the constant pressure tank 4-2 is connected to the ash inlet 3-1-1 of the mixer 3-1. An inlet 4-5 is provided on the outer wall of the constant pressure tank 4-2. Ash from the ash conveying vehicle enters the constant pressure tank 4-2 through the inlet 4-5.

[0045] The separating mechanism 4-4 includes an inverted V-shaped structure 4-4-1 located at the bottom of the recycling tank 4-1, a second spring 4-4-2, and a dust-blocking cover 4-4-3. The bottom of the inverted V-shaped structure 4-4-1 has a notch 4-4-4. One end of the second spring 4-4-2 is fixed to the inner wall of the recycling tank 4-1, and the other end of the second spring 4-4-2 extends out of the notch 4-4-4 of the inverted V-shaped structure 4-4-1 and connects to the dust-blocking cover 4-4-3. The lateral width of the dust-blocking cover 4-4-3 is not less than the width of the notch 4-4-4. A buffer tube 4-4-5 is also provided at the bottom of the inverted V-shaped structure 4-4-1. The recycling tank 4-1 is connected to the buffer tube 4-4-5 through the notch 4-4-4. A baffle 4-4-6 is provided at the opening of the buffer tube 4-4-5. The baffle 4-4-6 is used to control the closing of the opening of the buffer tube 4-4-5. The constant pressure recovery tank 4 is also provided with a special-shaped pipe 4-6 on the outside, and the recovery tank 4-1 and the constant pressure tank 4-2 are connected by the special-shaped pipe 4-6; a connecting pipe 4-7 is also provided on the side wall of the constant pressure tank 4-2, and the connecting pipe 4-7 is connected to the special-shaped pipe 4-6. One end of the connecting pipe 4-7 is provided on the outer wall of the constant pressure tank 4-2, and the other end of the connecting pipe 4-7 is closed. A first spring 4-8 is provided inside the connecting pipe 4-7. The end of the first spring 4-8 near the constant pressure tank 4-2 is fixed on the inner wall of the connecting pipe 4-7, and a stop ball 4-9 is provided on the other end of the first spring 4-8.

[0046] A density meter 8 is also installed on the outside of the mixing tank 3. The outlet of the mixing tank 3 is connected to the density meter 8. The mixing tank 3 is also connected to the inlet 3-1-3 of the mixer 3-1.

[0047] A butterfly valve 9 and a pump 10 are also installed between the ash outlet 3-1-2 of the mixer 3-1 and the recovery tank 4-1. The recovery tank 4-1, the butterfly valve 9, the pump 10 and the ash outlet 3-1-2 of the mixer 3-1 are connected in sequence.

[0048] The constant pressure tank 4-2 is equipped with an exhaust valve 4-10 on its side wall, an inlet control valve 4-11 on its inlet 4-5, and an outlet 4-12 on its bottom. An outlet control valve 4-13 is installed on the outlet 4-12. An overflow valve 4-14 is installed at the inlet of the filter device 4-3.

[0049] An air hammer 4-4-7 is installed on the outer wall of the buffer tube 4-4-5, and the baffle 4-4-6 is connected to the buffer tube 4-4-5 by a pin 4-4-8.

[0050] Metering tank 1 includes a first tank 1-1 and a second tank 1-2, which are connected by a first conduit 1-3. A first control valve 1-4 is installed on the first conduit 1-3. Mixing tank 3 includes a third tank 3-2 and a fourth tank 3-3, which are connected by a second conduit 3-4. A second control valve 3-5 is installed on the second conduit 3-4. Agitators are installed in the first tank 1-1, the second tank 1-2, the third tank 3-2, and the fourth tank 3-3.

[0051] The piping connections of metering tank 1 are as follows: Figure 2As shown, the tops of the first tank 1-1 and the second tank 1-2 are respectively equipped with an eighteenth butterfly valve 33 and a twenty-third butterfly valve 29, and the bottoms of the first tank 1-1 and the second tank 1-2 are respectively equipped with a first butterfly valve 11 and a second butterfly valve 12. The first tank 1-1 and the first butterfly valve 11 are sequentially connected to the sampling port 6, and the second tank 1-2 and the second butterfly valve 12 are sequentially connected to the sampling port 6. A third butterfly valve 13 is also provided between the first tank 1-1 and the plunger pump 2. The first tank 1-1, the first butterfly valve 11, and the third butterfly valve 13 are sequentially connected to the plunger pump 2, and the second tank 1-2, the second butterfly valve 12, and the third butterfly valve 13 are sequentially connected to the plunger pump 2. A first water supply pump 14, a second water supply pump 15, a fourth butterfly valve 16, and a fifth butterfly valve are provided between the first tank 1-1 and the inlet 3-1-3 of the mixer 3-1. Valve 17 and the sixth butterfly valve 18 are connected in sequence to the inlet 3-1-3 of the first tank 1-1, the first water supply pump 14, the fourth butterfly valve 16, and the mixer 3-1. The first tank 1-1 is connected in sequence to the inlet 3-1-3 of the fifth butterfly valve 17, the second water supply pump 15, the sixth butterfly valve 18, and the mixer 3-1. The second tank 1-2 is connected in sequence to the inlet 3-1-3 of the first water supply pump 14, the fourth butterfly valve 16, and the mixer 3-1. The second tank 1-2 is connected in sequence to the inlet 3-1-3 of the fifth butterfly valve 17, the second water supply pump 15, the sixth butterfly valve 18, and the mixer 3-1. The first water supply pump 14 and the second water supply pump 15 are also connected to the sampling port 6. A fifteenth butterfly valve 30 is installed between the first water supply pump 14 and the sampling port 6, and a sixteenth butterfly valve 31 is installed between the second water supply pump 15 and the sampling port 6.

[0052] The piping connections of mixing tank 3 are as follows: Figure 3 As shown, an eighth butterfly valve 20, a first centrifugal pump 21, a ninth butterfly valve 22, and a tenth butterfly valve 23 are installed between the third tank 3-2 and the plunger pump 2. The third tank 3-2, the eighth butterfly valve 20, and the plunger pump 2 are connected in sequence. The third tank 3-2, the ninth butterfly valve 22, the first centrifugal pump 21, and the tenth butterfly valve 23 are also connected in sequence to the plunger pump 2. An eleventh butterfly valve 24, a second centrifugal pump 25, a twelfth butterfly valve 26, and a nineteenth butterfly valve 34 are also installed between the metering tank 1 and the mixing tank 3. The first tank... 1-1, the nineteenth butterfly valve 34, the second centrifugal pump 25, the eleventh butterfly valve 24, and the third tank 3-2 are connected; the first tank 1-1, the nineteenth butterfly valve 34, the second centrifugal pump 25, the twelfth butterfly valve 26, and the fourth tank 3-3 are connected; the second tank 1-2, the nineteenth butterfly valve 34, the second centrifugal pump 25, the eleventh butterfly valve 24, and the third tank 3-2 are connected; the second tank 1-2, the nineteenth butterfly valve 34, the second centrifugal pump 25, the twelfth butterfly valve 26, and the fourth tank 3-3 are connected.

[0053] A seventh butterfly valve 19 and a seventeenth butterfly valve 32 are installed between the feed pipe 5 and the water inlet 3-1-3 of the mixer 3-1. The feed pipe 5, the seventh butterfly valve 19, the seventeenth butterfly valve 32 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence. The feed pipe 5, the seventh butterfly valve 19, the first water supply pump 14, the fourth butterfly valve 16 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence. The feed pipe 5, the seventh butterfly valve 19, the fifth butterfly valve 17, the second water supply pump 15, the sixth butterfly valve 18 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence. The first tank 1-1, the first butterfly valve 11, the seventeenth butterfly valve 32 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence. The second tank 1-2, the second butterfly valve 12, the seventeenth butterfly valve 32 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence.

[0054] A thirteenth butterfly valve 27 and a fourteenth butterfly valve 28 are provided between the third tank 3-2 and the fourth tank 3-3. The third tank 3-2, the ninth butterfly valve 22, the first centrifugal pump 21, the thirteenth butterfly valve 27, the hydrometer 8 and the fourth tank 3-3 are connected in sequence. The third tank 3-2, the ninth butterfly valve 22, the first centrifugal pump 21, the fourteenth butterfly valve 28 and the water inlet 3-1-3 of the mixer 3-1 are connected in sequence.

[0055] The control system of the cementing dust removal and pressure stabilization device of the present invention can be a conventional control system, which is used to control the mixing tank 3, the mixer 3-1, the metering tank 1, the constant pressure recovery tank 4, the plunger pump 2, and the valves and pumps in this application.

[0056] The components and their interactions in the cementing dust removal and pressure stabilization device of the present invention are explained below:

[0057] A: Metering tank 1 is set as the first tank 1-1 and the second tank 1-2, which facilitates the mixing of various additives, and the normal use of metering tank 1 is not affected when the first tank 1-1 or the second tank 1-2 fails.

[0058] B: The mixing tank 3 is configured as a third tank 3-2 and a fourth tank 3-3. On the one hand, if either the third tank 3-2 or the fourth tank 3-3 malfunctions, the normal use of the mixing tank 3 will not be affected. On the other hand, due to insufficient mixing time, the cement slurry in the mixing tank 3 is not uniformly delivered to the wellbore 7, affecting the quality of cementing operations. Furthermore, when the mixing tank 3 is a single tank, the position of the agitator within the tank is a crucial factor affecting the mixing effect. In severe cases, some cement slurry in the mixing tank 3 may not be mixed and may be pumped into the wellbore 7 by the plunger pump 2. This invention divides the mixing tank 3 into a third tank 3-2 and a fourth tank 3-3, and connects the third tank 3-2 and the fourth tank 3-3 with a second conduit 3-4, extending the time the cement slurry spends in the mixing tank 3 and improving its mixing effect.

[0059] C: The plunger pump is used to pump the uniformly mixed cement slurry in the mixing tank 3 into the well shaft 7;

[0060] D: Densitometer 8 is used to detect the density of cement slurry in mixing tank 3;

[0061] E: The special-shaped pipe 4-6 is used to connect the recovery tank 4-1 and the constant pressure tank 4-2;

[0062] F: The first spring 4-8 is used to push the ball 4-9 to move in the connecting pipe 4-7. When the pressure in the constant pressure tank 4-2 is higher than 1MPa, the first spring 4-8 in the special tube 4-6 breaks the original balance and is in a stretched state. The pressure in the constant pressure tank 4-2 applies pressure to the first spring 4-8 through the special tube 4-6, causing the first spring 4-8 to move towards the constant pressure tank 4-2, driving the ball 4-9 away from the intersection of the special tube 4-6 and the connecting pipe 4-7, thus realizing the connection between the recovery tank 4-1 and the constant pressure tank 4-2.

[0063] G: The ball stopper 4-9 is used to control the connection between the recovery tank 4-1 and the constant pressure tank 4-2. Under normal pressure conditions, the ball stopper 4-9 is at the intersection of the shaped pipe 4-6 and the connecting pipe 4-7, so that the recovery tank 4-1 and the constant pressure tank 4-2 are not connected. When the pressure inside the constant pressure tank 4-2 is higher than 1MPa, the ball stopper 4-9 moves away from the intersection of the shaped pipe 4-6 and the connecting pipe 4-7, so that the recovery tank 4-1 and the constant pressure tank 4-2 are connected.

[0064] H: The second spring 4-4-2 is used to control the movement of the dust baffle 4-4-3. When there are a lot of cement dust particles accumulated on the dust baffle 4-4-3, the second spring 4-4-2 breaks the original balance and extends. The dust baffle 4-4-3 temporarily detaches from the bottom of the recycling tank 4-1, and the cement dust particles remaining in the lower part of the recycling tank 4-1 quickly fall into the buffer tube 4-4-5. The second spring 4-4-2 returns to the original balance and sticks to the bottom of the recycling tank 4-1.

[0065] I: Dust cover 4-4-3 is used to collect cement dust particles in recycling tank 4-1;

[0066] J: The inverted V-shaped structure 4-4-1 facilitates the accumulation of cement ash particles inside the collection tank 4-1;

[0067] K: Air hammer 4-4-7 is used to vibrate buffer tube 4-4-5, causing cement dust particles inside buffer tube 4-4-5 to accumulate at baffle 4-4-6.

[0068] L: Filter device 4-3 is used to prevent cement ash particles in recycling tank 4-1 from being released into the atmosphere;

[0069] The working principle of the cementing dust removal and pressure stabilizing device of the present invention is as follows: Before the cementing operation begins, the corresponding pipelines are connected to ensure that each component moves flexibly. The entire working manifold is cleaned with clean water from metering tank 1. The specific cleaning operation is as follows:

[0070] The control system opens the eighteenth butterfly valve 33, the twenty-third butterfly valve 29, the first butterfly valve 11, the second butterfly valve 12, the fourth butterfly valve 16, the fifth butterfly valve 17, the sixth butterfly valve 18, the eleventh butterfly valve 24, the twelfth butterfly valve 26, the nineteenth butterfly valve 34, the ninth butterfly valve 22, the thirteenth butterfly valve 27, and the fourteenth butterfly valve 28. Clean water enters the first tank 1-1 and the second tank 1-2 of the metering tank 1 through the feed pipe 5. The second centrifugal pump 25 then pumps the clean water into the third tank 3-2 and the fourth tank 3-3, respectively. The agitators in the third tank 3-2 and the fourth tank 3-3 are activated to clean the tanks. During washing, clean water flows through the third tank 3-2-ninth butterfly valve 22-first centrifugal pump 21-thirteenth butterfly valve 27 to the densitometer 8 to clean it. The water then flows through the third tank 3-2-ninth butterfly valve 22-first centrifugal pump 21-fourteenth butterfly valve 28 to the mixer inlet 3-1-3 to clean the mixer. After cleaning, the eleventh butterfly valve 24, thirteenth butterfly valve 27, and fourteenth butterfly valve 28 are closed. The washing waste liquid flows through the third tank 3-2-eighth butterfly valve 20 or through the third tank 3-2-tenth butterfly valve 23 to the plunger pump 2, which then pumps it into the metering tank 1 for recycling.

[0071] After cleaning, cementing operations begin. Water or cementing additives are injected into metering tank 1 through feed pipe 5. Metering tank 1 is then started. The start-up of metering tank 1's first tank 1-1 and second tank 1-2 depends on whether additives need to be mixed during the on-site operation. When mixing cementing additives using metering tank 1 is necessary, the agitator in the first tank 1-1 or second tank 1-2 is activated. Samples are taken through sampling port 6 to test the additives and determine if they meet the requirements for cementing operations. Once the additives are mixed evenly, the first water supply pump 14 or the second water supply pump 15 pressurizes and accelerates the water or additives in the first tank 1-1 or second tank 1-2 to the inlet 3-1-3 of mixer 3-1. If the cementing operation does not require the use of metering tank 1 to store water or mix additives, the seventeenth butterfly valve 32 can be opened to directly pump water or additives into the inlet 3-1-3 of mixer 3-1 using pressurization equipment. If there is no pressurization equipment at the cementing operation site, the pressure and speed are increased by the first water supply pump 14 or the second water supply pump 15 by opening the seventh butterfly valve 19, and then delivered to the inlet 3-1-3 of the mixer 3-1. The cement ash truck transports cement ash particles through the feed inlet 4-5 to the constant pressure tank 4-2 below the constant pressure recovery tank 4. Simultaneously, pressurized air is introduced into the constant pressure tank 4-2, and the pressurized air transports the cement ash particles in the constant pressure tank 4-2 to the ash inlet 3-1-1 of the mixer 3-1 through the opening of the twenty-second butterfly valve 37. When the branch entering the constant pressure recovery tank 4 is blocked, the twenty-first butterfly valve 36 can be opened, allowing the cement ash transported by the ash truck to bypass the constant pressure recovery tank 4 and directly reach the ash inlet 3-1-1 of the mixer 3-1. During cementing operations, the branch that bypasses the constant pressure recovery tank 4 is often used as a backup. To replenish the pressure in the constant pressure tank 4-2 caused by leakage, the pressurized air supply is kept open. When the pressure inside the constant pressure tank 4-2 exceeds 1 MPa, the blocking ball 4-9 moves towards the constant pressure tank 4-2, and the first spring 4-8 breaks its original equilibrium and is stretched. At this time, the constant pressure tank 4-2 is connected to the recovery tank 4-1, and the pressure inside the constant pressure tank 4-2 is released into the recovery tank 4-1. Simultaneously, the cement ash particles carried by the pressurized air inside the constant pressure tank 4-2 reach the recovery tank 4-1 via the special-shaped pipe 4-6. At this time, the first spring 4-8 returns to its original equilibrium state, and the blocking ball 4-9 moves to the intersection of the special-shaped pipe 4-6 and the connecting pipe 4-7, and the constant pressure tank 4-2 and the recovery tank 4-1 are no longer connected through the special-shaped pipe 4-6. Most of the cement ash particles carried by the pressurized air inside the recovery tank 4-2, as well as the cement ash particles recovered from the ash outlet 3-1-2 of the mixer 3-1, fall into the ash baffle 4-4-3 at the bottom of the recovery tank 4-1. A small portion of cement ash particles are discharged into the atmosphere through the filter device 4-3 and overflow valve 4-14 (set pressure 1MPa) at the top of the recovery tank 4-1. When a significant amount of cement ash particles accumulate at the ash baffle 4-4-3, the second spring 4-4-2 breaks the original balance, and the ash baffle 4-4-3 temporarily detaches from the bottom of the recovery tank 4-1. The cement ash particles remaining at the bottom of the recovery tank 4-1 quickly fall into the buffer tube 4-4-5.The second spring 4-4-2 returns to its original equilibrium state, and the dust-blocking cover 4-4-3 re-enters contact with the bottom of the recovery tank 4-1. Cement ash particles in the buffer tube 4-4-5 accumulate at the baffle 4-4-6 under the vibration of the air hammer 4-4-7. At this time, the baffle 3-2-5 is closed, preventing cement ash particles in the buffer tube 4-4-5 from falling into the constant pressure tank 4-2. When too much cement ash accumulates in the buffer tube 4-4-5, the baffle 4-4-6 opens, allowing the cement ash particles in the buffer tube 4-4-5 to fall into the constant pressure tank 4-2. Subsequently, the baffle 3-2-5 closes again, preventing cement ash particles in the constant pressure tank 4-2 from entering the recovery tank 4-1 through the buffer tube 4-4-5.

[0072] In mixer 3-1, water and cement ash particles are initially mixed. The resulting cement slurry, insufficient for cementing operations, falls into the fourth tank 3-3 of mixing tank 3. There, it is further mixed by an agitator. The slurry from the fourth tank 3-3 enters the third tank 3-2 via the second conduit 3-4. The slurry from the third tank 3-2 is divided into two streams. One stream returns to the third tank 3-2 via densitometer 8. Densitometer 8 continuously feeds back the actual density of the cement slurry to the control system, which displays the data. The other stream passes through the secondary mixing inlet 3-1-4 of mixer 3-1, forming a high-speed jet stream and creating a vacuum that draws cement ash into mixer 3-1, facilitating the initial mixing of water and cement ash into mixing tank 3. After thorough mixing and reaching the required density, the cement slurry is pumped through the eleventh butterfly valve 24 to the suction port of the plunger pump 2 via the second centrifugal pump 25. The plunger pump 2 then pumps the slurry into the wellbore 7 to complete the cementing operation. Due to the poor fluidity of the cement slurry, to prevent cavitation in the plunger pump 2, the eighth butterfly valve 20 is opened, allowing the cement slurry in the third tank 3-2 of the mixing tank 3 to reach the suction port of the plunger pump 2 via this branch. Any remaining cement slurry in the fourth tank 3-3 of the mixing tank 3 can be removed by the second centrifugal pump 25 by opening the twelfth butterfly valve 26. After the cementing operation is completed, the entire manifold is cleaned using clean water from the metering tank 1.

Claims

1. A dust removal pressure stabilizing device for cementing, characterized by, Including metering tank (1), plunger pump (2), mixed slurry tank (3), constant pressure recovery tank (4) and control system; The mixed slurry tank (3) is provided with a mixer (3-1), the mixer (3-1) is provided with an ash inlet (3-1-1), an ash outlet (3-1-2), a water inlet (3-1-3) and a secondary mixed slurry inlet (3-1-4), and the outlet of the mixed slurry tank (3) is communicated with the plunger pump (2); The inlet of the metering tank (1) is connected with a feeding pipe (5), the outlet of the metering tank (1) is respectively communicated with the plunger pump (2), a sampling port (6) and the water inlet (3-1-3) of the mixer (3-1), and the outlet of the plunger pump (2) is respectively communicated with a shaft lining (7) and the metering tank (1); The constant pressure recovery tank (4) comprises a filtering device (4-3), a recovery tank (4-1) and a constant pressure tank (4-2), the filtering device (4-3) is arranged on the upper end of the recovery tank (4-1) and is communicated with the recovery tank (4-1), the constant pressure tank (4-2) is arranged at the bottom of the recovery tank (4-1), and a separation mechanism (4-4) is arranged between the recovery tank (4-1) and the constant pressure tank (4-2); the outlet of the constant pressure tank (4-2) is communicated with the ash inlet (3-1-1) of the mixer (3-1); and the outer wall of the constant pressure tank (4-2) is provided with a feeding port (4-5); The separation mechanism (4-4) comprises an inverted V-shaped structure (4-4-1) arranged at the bottom of the recovery tank (4-1), a second spring (4-4-2) and a dust cover (4-4-3), the bottom of the inverted V-shaped structure (4-4-1) is provided with a notch (4-4-4), one end of the second spring (4-4-2) is fixed to the inner wall of the recovery tank (4-1), the other end of the second spring (4-4-2) extends out of the notch (4-4-4) of the inverted V-shaped structure (4-4-1) and is connected with the dust cover (4-4-3), and the transverse width of the dust cover (4-4-3) is not less than the width of the notch (4-4-4); The bottom of the inverted V-shaped structure (4-4-1) is further provided with a buffer pipe (4-4-5), the recovery tank (4-1) is communicated with the buffer pipe (4-4-5) through the notch (4-4-4), and the buffer pipe (4-4-5) is provided with a baffle (4-4-6) at the opening, and the baffle (4-4-6) is used for controlling the closure of the opening of the buffer pipe (4-4-5); The constant pressure recovery tank (4) is further provided with a special-shaped pipe (4-6) outside, and the recovery tank (4-1) and the constant pressure tank (4-2) are communicated through the special-shaped pipe (4-6); The sidewall of the constant pressure tank (4-2) is further provided with a communication pipe (4-7), the communication pipe (4-7) is communicated with the special-shaped pipe (4-6), one end of the communication pipe (4-7) is arranged on the outer wall of the constant pressure tank (4-2), the other end of the communication pipe (4-7) is closed, the communication pipe (4-7) is provided with a first spring (4-8) inside, one end of the first spring (4-8) is fixed to the inner wall of the communication pipe (4-7) and close to the constant pressure tank (4-2), and the other end of the first spring (4-8) is provided with a plug ball (4-9).

2. The dust removal pressure stabilizing device for cementing as claimed in claim 1, wherein The density meter (8) is arranged outside the slurry tank (3), the outlet of the slurry tank (3) is communicated with the density meter (8), and the slurry tank (3) is also communicated with the water inlet (3-1-3) of the mixer (3-1). The ash conveying butterfly valve (9) and the ash conveying pump (10) are arranged between the ash outlet (3-1-2) of the mixer (3-1) and the recovery tank (4-1), and the recovery tank (4-1), the ash conveying butterfly valve (9), the ash conveying pump (10) and the ash outlet (3-1-2) of the mixer (3-1) are sequentially communicated.

3. The pressure stabilizing device for cementing according to claim 1, wherein The exhaust valve (4-10) is arranged on the side wall of the constant pressure tank (4-2), the feed inlet control valve (4-11) is arranged on the feed inlet (4-5) of the constant pressure tank (4-2), the discharge outlet (4-12) is further arranged on the bottom of the constant pressure tank (4-2), the discharge outlet control valve (4-13) is arranged on the discharge outlet (4-12), and the overflow valve (4-14) is arranged at the inlet of the filtering device (4-3).

4. The pressure stabilizing device for cementing according to claim 1, wherein The air hammer (4-4-7) is arranged on the outer wall of the buffer pipe (4-4-5), and the baffle (4-4-6) and the buffer pipe (4-4-5) are connected through the pin shaft (4-4-8).

5. The pressure stabilizing device for cementing according to claim 1, wherein The metering tank (1) comprises a first tank body (1-1) and a second tank body (1-2), the first tank body (1-1) and the second tank body (1-2) are communicated through a first conduit (1-3), and the first control valve (1-4) is arranged on the first conduit (1-3); the slurry tank (3) comprises a third tank body (3-2) and a fourth tank body (3-3), the third tank body (3-2) and the fourth tank body (3-3) are communicated through a second conduit (3-4), the second control valve (3-5) is arranged on the second conduit (3-4), and the first tank body (1-1), the second tank body (1-2), the third tank body (3-2) and the fourth tank body (3-3) are all provided with stirrers.

6. The pressure stabilizing device for cementing according to claim 5, wherein The first tank body (1-1) and the second tank body (1-2) are respectively provided with an eighteenth butterfly valve (33) and a twenty-third butterfly valve (29) at the top, and are respectively provided with a first butterfly valve (11) and a second butterfly valve (12) at the bottom, the first tank body (1-1), the first butterfly valve (11) and the sampling port (6) are sequentially communicated, the second tank body (1-2), the second butterfly valve (12) and the sampling port (6) are sequentially communicated; the first tank body (1-1) and the plunger pump (2) are further provided with a third butterfly valve (13), the first tank body (1-1), the first butterfly valve (11), the third butterfly valve (13) and the plunger pump (2) are sequentially communicated, the second tank body (1-2), the second butterfly valve (12), the third butterfly valve (13) and the plunger pump (2) are sequentially communicated; the first tank body (1-1) and the water inlet (3-1-3) of the mixer (3-1) are provided with a first water supply pump (14), a second water supply pump (15), a fourth butterfly valve (16), a fifth butterfly valve (17) and a sixth butterfly valve (18), the first tank body (1-1) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated through the first water supply pump (14), the fourth butterfly valve (16), the first tank body (1-1) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated through the fifth butterfly valve (17), the second water supply pump (15) and the sixth butterfly valve (18), the second tank body (1-2) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated through the first water supply pump (14), the fourth butterfly valve (16), the second tank body (1-2) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated through the fifth butterfly valve (17), the second water supply pump (15) and the sixth butterfly valve (18); the first water supply pump (14) and the second water supply pump (15) are further communicated with the sampling port (6), the first water supply pump (14) and the sampling port (6) are provided with a fifteenth butterfly valve (30), and the second water supply pump (15) and the sampling port (6) are provided with a sixteenth butterfly valve (31).

7. The pressure stabilizing device for cementing according to claim 6, wherein The eighth butterfly valve (20), the first centrifugal pump (21), the ninth butterfly valve (22) and the tenth butterfly valve (23) are arranged between the third tank body (3-2) and the plunger pump (2), the third tank body (3-2), the eighth butterfly valve (20) and the plunger pump (2) are sequentially communicated, the third tank body (3-2), the ninth butterfly valve (22), the first centrifugal pump (21), the tenth butterfly valve (23) and the plunger pump (2) are sequentially communicated, the eleventh butterfly valve (24), the second centrifugal pump (25), the twelfth butterfly valve (26) and the nineteenth butterfly valve (34) are further arranged between the metering tank (1) and the mixing tank (3), the first tank body (1-1), the nineteenth butterfly valve (34), the second centrifugal pump (25), the eleventh butterfly valve (24) and the third tank body (3-2) are communicated, the first tank body (1-1), the nineteenth butterfly valve (34), the second centrifugal pump (25), the twelfth butterfly valve (26) and the fourth tank body (3-3) are communicated, the second tank body (1-2), the nineteenth butterfly valve (34), the second centrifugal pump (25), the eleventh butterfly valve (24) and the third tank body (3-2) are communicated, and the second tank body (1-2), the nineteenth butterfly valve (34), the second centrifugal pump (25), the twelfth butterfly valve (26) and the fourth tank body (3-3) are communicated.

8. The pressure stabilizing device for cementing according to claim 7, wherein The seventh butterfly valve (19) and the seventeenth butterfly valve (32) are arranged between the feed pipe (5) and the water inlet (3-1-3) of the mixer (3-1), the feed pipe (5), the seventh butterfly valve (19), the seventeenth butterfly valve (32) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated, the feed pipe (5), the seventh butterfly valve (19), the first water supply pump (14), the fourth butterfly valve (16) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated, the feed pipe (5), the seventh butterfly valve (19), the fifth butterfly valve (17), the second water supply pump (15), the sixth butterfly valve (18) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated, the first tank body (1-1), the first butterfly valve (11), the seventeenth butterfly valve (32) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated, and the second tank body (1-2), the second butterfly valve (12), the seventeenth butterfly valve (32) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated; The thirteenth butterfly valve (27) and the fourteenth butterfly valve (28) are arranged between the third tank body (3-2) and the fourth tank body (3-3), the third tank body (3-2), the ninth butterfly valve (22), the first centrifugal pump (21), the thirteenth butterfly valve (27), the density meter (8) and the fourth tank body (3-3) are sequentially communicated, and the third tank body (3-2), the ninth butterfly valve (22), the first centrifugal pump (21), the fourteenth butterfly valve (28) and the water inlet (3-1-3) of the mixer (3-1) are sequentially communicated.

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