Multi-stage high-speed centrifugal pump driven underground sand blockage prevention jet flow drainage and mining system and using method

Abstract

The invention relates to the technical field of oil and gas field and coal bed gas field mining and drainage engineering, in particular to a multi-stage high-speed centrifugal pump driven underground sand blockage prevention jet flow drainage and drainage system and a using method. According to the technical scheme, the output end of a horizontal centrifugal pump is connected to a well mouth through a pipeline, the sand blocking prevention tubular jet pump is installed on an underground oil production layer through an oil pipe, a plurality of sand setting bearing umbrellas are installed on the small-diameter oil pipe in a segmented mode, and a plurality of sand setting bearing covers are installed on the oil pipe in a segmented mode. The problems that a pump shaft of a multi-stage high-speed centrifugal pump is large in length and high in rotating speed and is in axial fluctuation in the starting and working process of the pump, consequently, a common coupling force transmission and dynamic sealing structure is difficult to adapt to the high-rotating-speed working condition, and the fault rate is high are solved. In addition, the sand blockage prevention tubular jet pump is improved, the sand blockage prevention performance of the sand blockage prevention tubular jet pump is enhanced, the sand blockage prevention tubular jet pump is novel and simple in structure, safe and reliable, a plurality of sand setting bearing umbrellas are installed on a small-diameter oil pipe in a segmented mode, and sand blockage of an underground pump and a tubular column caused by the fact that setting sand sinks into a pump cylinder is avoided.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field and coalbed methane field development and drainage engineering technology, and in particular to a multi-stage high-speed centrifugal pump driven downhole sand-blocking jet drainage system and its usage method. Background Technology

[0002] Downhole jet pumps have demonstrated significant advantages in oil and gas well production with sand, drainage gas production, and coalbed methane well drainage gas production. However, existing jet pump power hydraulic systems, due to their high injection pressure, are mostly driven by plunger pumps. Plunger pumps require frequent maintenance and frequent shutdowns to replace seals. In wells with high sand or coal dust content, sand blockage during pump shutdowns can lead to difficulties in well restarting, sometimes even forcing the tubing to be pulled out for unblocking before production can resume, causing significant inconvenience and increasing production costs. Secondly, significant adjustments to the injection / discharge rate require replacing the plunger and cylinder liner, further increasing the frequency of well shutdowns. Thirdly, in cold regions during winter, plunger pumps require indoor installation with necessary insulation and heating facilities, making fully automated unmanned control systems difficult to implement, resulting in high management and maintenance costs. Fourthly, the high noise and large space requirements of plunger pumps limit their use in areas near residential areas and offshore platform well sites.

[0003] In addition, the pump pressure of existing surface centrifugal pumps is limited by the small number of stages and low speed (less than 1500 rpm), while the existing downhole multi-stage high-pressure high-speed (greater than 2700 rpm) submersible centrifugal electric pumps have large pump shaft length, high speed, and axial fluctuation during pump start-up and operation. This makes it difficult for commonly used coupling transmission and dynamic sealing structures to adapt to high speed conditions, resulting in high temperature, high failure rate, and easy leakage at dynamic seals. As a result, such high-speed high-pressure multi-stage centrifugal pumps are still in the research and development stage in China.

[0004] Furthermore, existing downhole jet pump systems with sand production suffer from severe wear and erosion due to the complex and tortuous internal flow channels. The significant difference between the centrifugal force, impact, and shear force of sand particles during their turning flow and the fluid flow makes it difficult to maintain a long working life. When there is a power outage or the well needs to be shut down to replace the pump core, the sand in the fluid inside the wellbore will accumulate and block the pump core or flow channel. Therefore, it is necessary to invent a new type of jet pump system with a wear-resistant and sand-blocking structure. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in existing technologies by providing a multi-stage high-speed centrifugal pump-driven downhole sand-blocking jet drainage system and its usage method. This solves the problem that the large pump shaft length, high speed, and axial fluctuation during pump start-up and operation of multi-stage high-speed centrifugal pumps make commonly used coupling transmission and dynamic sealing structures unsuitable for high-speed conditions, resulting in a high failure rate. Furthermore, the invention improves the sand-blocking jet pump, enhancing its anti-sand-blocking performance. Its structure is novel, simple, safe, and reliable. Multiple sand-support umbrellas are also installed in sections on the small-diameter tubing to prevent sand from sinking into the pump barrel and causing sand blockage in the downhole pump and tubing.

[0006] The present invention discloses a multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system. The technical solution includes a wellhead and a water tank, with the water tank installed on one side of the wellhead. The system also includes a horizontal centrifugal pump, a sand-supporting umbrella, and a sand-control jet pump. The horizontal centrifugal pump is installed next to the water tank on the ground. The output end of the horizontal centrifugal pump is connected to the wellhead via a pipeline. The sand-control jet pump is installed in the oil-producing layer downhole via tubing. A small-diameter tubing is installed inside the tubing, with its lower end connected to the upper end of the sand-control jet pump. Multiple sand-supporting umbrellas are installed in sections on the small-diameter tubing, and multiple sand-supporting covers are also installed in sections on the tubing. Each sand-supporting umbrella is located within the inner cavity of a sand-supporting cover, and an annular space is formed between the upper outer wall of the sand-supporting umbrella and the inner wall of the sand-supporting cover. Sand is collected by the sand-supporting umbrella, and as the liquid rises through the annular space, it carries the sand within the sand-supporting umbrella to the surface.

[0007] Preferably, the above-mentioned horizontal centrifugal pump includes a drive motor, a coupling, a discharge pipe, a high-speed vibration damping seal protector, a pump body, a foundation support, and a check valve. The foundation support is installed at the lower part of the pump body and the high-speed vibration damping seal protector. The output end of the drive motor is connected to the high-speed vibration damping seal protector through the coupling. The output end of the high-speed vibration damping seal protector is connected to one end of the pump body. The other end of the pump body is equipped with a check valve and a discharge pipe. A multi-stage impeller is installed inside the pump body.

[0008] Preferably, the aforementioned high-speed vibration damping sealing protector includes a protector body, a lubrication chamber housing, a centering bearing, a first dynamic seal, a centrifugal pump coupling, a water inlet, a lubricating oil injector, an oil injection through hole, a gland, a second dynamic seal, and a water passage hole. The lubrication chamber housing is installed at the center of the inner cavity of the protector body. The annular space formed between the lubrication chamber housing and the protector body is a water-cooled cavity. The right side of the drive shaft is installed inside the lubrication chamber housing, and one or more centering bearings are installed on the drive shaft. The drive shaft is connected to the left end of the protector body through the first dynamic seal. The right end of the protector body is equipped with a second dynamic seal. An oil injection through hole is provided inside the right end of the protector body, and a lubricating oil injector is installed above the oil injection through hole. A water inlet is provided on the upper right side of the protector body. The left side of the protector body is connected to the inlet end of the pump body through a centrifugal pump coupling.

[0009] Preferably, multiple water passage holes are provided at the left end of the protector body to connect the water-cooled cavity with the inner cavity of the centrifugal pump coupling. Water is connected to the inlet end of the pump body through the annular space formed between the drive shaft and the inner wall of the centrifugal pump coupling.

[0010] Preferably, the aforementioned sand-proof, pipe-plugging jet pump includes a pump barrel, a pump core, an accelerating annular seam, a flow conversion hole, a mixing chamber, a deceleration chamber, a mixed liquid flow conversion hole, a ball valve, and a retrieval head. The pump barrel has a double-layer structure, with mixed liquid flow conversion holes at the bottom of both the inner and outer barrels. A small-diameter oil pipe is connected to the top of the inner barrel, and an oil pipe is connected to the top of the outer barrel. The pump core is installed in the inner cavity of the inner barrel, and the middle part of the pump core is a hollow structure. The lower end of the pump core communicates with the lower connector of the pump barrel, and a ball valve is installed in the lower connector. The upper end of the pump core is equipped with a retrieval head; an acceleration annular slit is formed between the pump core and the inner wall of the inner cylinder as a nozzle, and a flow conversion hole is provided below the acceleration annular slit. A mixing chamber and a deceleration chamber are provided below the flow conversion hole. The power fluid is sprayed downward along the acceleration annular slit, which drives the formation fluid to enter the flow conversion hole through the ball valve, the inner cavity of the pump core and the outlet hole. Then, it enters the annulus between the outer cylinder and the inner cylinder through the mixing chamber, the deceleration chamber and the mixed fluid flow conversion hole, and continues to rise along the annulus between the oil pipe and the small diameter oil pipe.

[0011] Preferably, a pump initiation cup is installed on the upper part of the pump core, and a pressure cap is installed on the upper part of the pump initiation cup. The lower outer diameter of the pump initiation cup is larger than the outer diameter of the pump core. The lower end of the pump core sits at the upper center of the lower connector.

[0012] Preferably, the aforementioned sand-supporting umbrella includes a central tube, a supporting umbrella body, an upper coupling, and a lower coupling. The upper end of the central tube is connected to the upper coupling, and the lower end of the central tube is connected to the lower coupling. The central tube is connected to a small-diameter oil pipe through the upper and lower couplings. The outer wall of the central tube is fitted with an umbrella-shaped supporting umbrella body with the opening facing upward.

[0013] Preferably, the aforementioned sand-supporting cover includes a cover body, an upper connector, and a lower connector. The upper end of the cover body is connected to the upper connector, and the lower end of the cover body is connected to the lower connector. The cover body adopts a conical cover structure, and the inner diameter of the cover body is larger than the outer diameter of the umbrella body.

[0014] The method of using the multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system mentioned in this invention includes the following process: 1. Start the drive motor of the horizontal centrifugal pump. The drive motor drives the transmission shaft to rotate through the coupling. The transmission shaft is installed in the high-speed damping seal protector on the right side. The circulating water in the water tank is sent to the water inlet of the high-speed damping seal protector. The circulation of the circulating water in the water-cooled cavity cools down the lubrication chamber shell. In addition, the first and second dynamic seals reduce the axial fluctuation of the transmission shaft. Then, the circulating water enters the pump body and is gradually pressurized under the action of centrifugal force through multi-stage impellers. Then, it enters the small-diameter oil pipe through the single-flow valve, the outlet pipe and the wellhead as the power fluid to drive the sand-blocking jet pump in the well for drainage. 2. The power fluid enters the acceleration annular gap through the annulus between the inner cylinder and the outer wall of the pump core of the sand-proof plugging jet pump. The ejected power fluid drives the formation fluid in the inner cavity of the pump core to enter the transfer hole along the outlet hole. After being mixed with the power fluid in the mixing chamber, it enters the annulus between the outer cylinder and the inner cylinder through the deceleration chamber and the mixing fluid transfer hole. It then continues to rise along the annulus between the tubing and the small-diameter tubing until it is discharged to the wellhead. 3. When the drive motor loses power or the well needs to be shut down, the sand-containing mixture in the annulus between the tubing and the small-diameter tubing stops rising, and the sand particles in the mixture will sink. When passing through each sand-sinking support umbrella and sand-sinking support cover, the sand particles sink to the bottom of the sand-sinking support umbrella and are collected. In this way, the sand in the annulus is collected in sections, avoiding the sand from sinking into the pump barrel and causing sand blockage of the downhole pump and tubing. When the well is restarted for production, the rising mixture flows through the annulus between the support cover body and the support umbrella body and sprays upward, and carries the sand in the sand-sinking support umbrella upward with the liquid flow, thereby achieving the function of preventing sand blockage. 4. When it is necessary to lift the pump core, inject power fluid into the annulus between the tubing and the small-diameter tubing at the wellhead on the ground. The power fluid flows down along the annulus between the tubing and the small-diameter tubing to the mixing fluid transfer hole of the sand-proof plugging jet pump, enters the annulus between the inner cylinder of the pump barrel and the pump core, and then passes through the deceleration chamber, mixing chamber and acceleration annulus in sequence. The power fluid pushes the pump cup, which in turn drives the pump core to move upward along the small-diameter tubing to the wellhead on the ground for removal.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The horizontal centrifugal pump used in this invention has the advantages of low noise, simple and easy adjustment of pressure and displacement parameters, no need to add heating and antifreeze facilities when used in cold regions, minimal daily maintenance, long equipment life, and reduced production costs. It has outstanding advantages over the currently used plunger pump. Among them, the high-speed shock-absorbing seal protector has the functions of transmitting high-speed torque, balancing axial thrust, lubricating and protecting the high-speed rotating dynamic sealing components, preventing overheating and shaft seizure, thermal expansion and cracking of rigid sealing rings, and preventing vibration. 2. In the event of a sudden power outage or when well shutdown is required, the sand-containing mixture in the annulus between the tubing and the small-diameter tubing stops rising, and the sand particles in the mixture sink. As they pass through each sand-supporting umbrella and sand-supporting cover, the sand particles sink to the bottom of the sand-supporting umbrella and are collected. In this way, the sand in the annulus is collected in sections, preventing the sand from sinking into the pump barrel and causing sand blockage of the downhole pump and tubing. When well production resumes, the rising mixture flows through the annulus between the support cover body and the support umbrella body and sprays upward, carrying the sand in the sand-supporting umbrella upward with the liquid flow, thereby achieving the function of preventing sand blockage. 3. The internal fluid flow channels of the anti-sand plugging jet pump of the present invention are all longitudinally parallel straight annular and columnar flow channels. There is no space for sand to accumulate in the straight flow channels, so sand particles in the formation fluid and mixed fluid are not easy to accumulate and deposit, which reduces the wear on the internal flow channels of the anti-sand plugging jet pump and enhances its anti-sand plugging performance. Its structure is novel, simple, safe and reliable. The present invention can safely and reliably pump formation fluid with sand content of 1%-12% to the surface without sand plugging and difficulty in opening the well after pump shutdown. It is more suitable for applications in quicksand formations with high sand content, oil and gas wells with unstable sand production intensity, and coalbed methane wells with high coal powder content. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the horizontal centrifugal pump of the present invention; Figure 3 This is a structural schematic diagram of a high-speed shock absorber and sealing protector; Figure 4 This is a schematic diagram of the structure of a sand-proof, pipe-plugging jet pump; Figure 5 This is a schematic diagram of the structure of the sand-supporting umbrella; Figure 6 This is a structural schematic diagram of the sedimentation support cover; In the diagram: 1. Wellhead; 2. Horizontal centrifugal pump; 3. Water tank; 4. Casing; 5. Tubing; 6. Small-diameter tubing; 7. Sand-proof jet pump; 8. Oil-producing layer; 9. Sand-proof support cover; 10. Drive motor; 2.1. Coupling; 2.2. Discharge pipe; 2.3. High-speed vibration damping seal protector; 2.4. Pump body; 2.5. Foundation support; 2.6. Check valve; 2.7. Protector body; 2.4.1. Lubrication chamber housing; 2.4.2. Centralizing bearing; 2.4.3. First dynamic seal; 2.4.4. Centrifugal pump coupling; 2.4.5. Water injection port; 2.4.6. Lubrication injector; 2.4.7. Oil injection through hole; 2.4.8. Pressure... 2.4.9 Cover, 2.4.10 Second dynamic seal, 2.4.11 Drive shaft, 2.4.12 Water passage hole, 2.4.13 Thrust bearing, 7.1 Center tube, 7.2 Support umbrella body, 7.3 Upper coupling, 7.4 Lower coupling, 8.1 Pump barrel, 8.2 Pump core, 8.3 Pump starter cup, 8.4 Pressure cap, 8.5 Accelerating ring seam, 8.6 Conversion hole, 8.7 Mixing chamber, 8.8 Deceleration chamber, 8.9 Mixed liquid conversion hole, 8.10 Ball valve, 8.11 Retrieval head, 8.12 Lower connector, 8.13 Liquid outlet, 10.1 Support cover body, 10.2 Upper connector, 10.3 Lower connector. Detailed Implementation

[0017] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0018] Example 1, referring to Figures 1-6 The present invention discloses a multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system, comprising a wellhead 1 and a water tank 3, with the water tank 3 installed on one side of the wellhead 1. The system also includes a horizontal centrifugal pump 2, a sand-supporting umbrella 7, and a sand-control and plugging-pipe jet pump 8. The horizontal centrifugal pump 2 is installed next to the water tank 3 on the ground. The output end of the horizontal centrifugal pump 2 is connected to the wellhead 1 via a pipeline. The sand-control and plugging-pipe jet pump 8 is installed in the oil-producing layer 9 downhole through an oil pipe 5 within the casing 4. Install a small-diameter oil pipe 6, with the lower end of the small-diameter oil pipe 6 connected to the upper end of the anti-sand plugging jet pump 8. Install multiple sand-collecting umbrellas 7 in sections on the small-diameter oil pipe 6, and install multiple sand-collecting covers 10 in sections on the oil pipe 5. Each sand-collecting umbrella 7 is located in the inner cavity of the sand-collecting cover 10, and an annular space is formed between the upper outer wall of the sand-collecting umbrella 7 and the inner wall of the sand-collecting cover 10. The sand is collected by the sand-collecting umbrella 7, and when the liquid rises through the annular space, it drives the sand in the sand-collecting umbrella 7 to be discharged to the ground.

[0019] Reference Figure 2The horizontal centrifugal pump 2 mentioned in this invention includes a drive motor 2.1, a coupling 2.2, a discharge pipe 2.3, a high-speed vibration damping seal protector 2.4, a pump body 2.5, a foundation support 2.6, and a check valve 2.7. The foundation support 2.6 is installed at the lower part of the pump body 2.5 and the high-speed vibration damping seal protector 2.4. The output end of the drive motor 2.1 is connected to the high-speed vibration damping seal protector 2.4 through the coupling 2.2. The output end of the high-speed vibration damping seal protector 2.4 is connected to one end of the pump body 2.5. The check valve 2.7 and the discharge pipe 2.3 are installed at the other end of the pump body 2.5. A multi-stage impeller is installed inside the pump body 2.5.

[0020] Reference Figure 3 The high-speed shock-absorbing sealing protector 2.4 mentioned in this invention includes a protector body 2.4.1, a lubrication chamber housing 2.4.2, a centering bearing 2.4.3, a first dynamic seal 2.4.4, a centrifugal pump coupling 2.4.5, a water inlet 2.4.6, a lubrication injector 2.4.7, an oil injection through hole 2.4.8, a gland 2.4.9, a second dynamic seal 2.4.10, and a water passage hole 2.4.12. The lubrication chamber housing 2.4.2 is installed in the center of the inner cavity of the protector body 2.4.1. The annular space formed between the lubrication chamber housing 2.4.2 and the protector body 2.4.1 is a water-cooled cavity. The right side of the drive shaft 2.4.11 is installed inside the lubrication chamber housing 2.4.2, and the drive shaft 2.4.11... One or more sets of centering bearings 2.4.3 are installed on the upper part. The drive shaft 2.4.11 is connected to the left end of the protector body 2.4.1 through the first dynamic seal 2.4.4. The right end of the protector body 2.4.1 is installed with the second dynamic seal 2.4.10. An oil injection hole 2.4.8 is provided in the right end of the protector body 2.4.1. A lubricating oil injector 2.4.7 is installed on the upper part of the oil injection hole 2.4.8. A water injection port 2.4.6 is provided on the upper right side of the protector body 2.4.1. Pressure caps 2.4.9 are installed on the outer sides of both ends of the protector body 2.4.1. The outer side of the left end of the protector body 2.4.1 is connected to the inlet end of the pump body 2.5 through a centrifugal pump coupling 2.4.5.

[0021] The protector body 2.4.1 has multiple water passage holes 2.4.12 at its left end, which connect the water-cooled cavity to the inner cavity of the centrifugal pump coupling 2.4.5. Water is connected to the inlet end of the pump body 2.5 through the annular space formed between the drive shaft 2.4.11 and the inner wall of the centrifugal pump coupling 2.4.5.

[0022] In addition, thrust bearings 2.4.13 are installed on the drive shafts 2.4.11 at the inner ends of the first dynamic seal 2.4.4 and the second dynamic seal 2.4.10, respectively.

[0023] Reference Figure 4The sand-proof, pipe-plugging jet pump 8 mentioned in this invention includes a pump barrel 8.1, a pump core 8.2, an accelerating annular seam 8.5, a flow conversion hole 8.6, a mixing chamber 8.7, a deceleration chamber 8.8, a mixed liquid flow conversion hole 8.9, a ball valve 8.10, and a retrieval head 8.11. The pump barrel 8.1 adopts a double-layer structure, with mixed liquid flow conversion holes 8.9 provided at the bottom of the inner and outer barrels. A small-diameter oil pipe 6 is connected to the top of the inner barrel, and an oil pipe 5 is connected to the top of the outer barrel. The pump core 8.2 is installed in the inner cavity of the inner barrel, and the middle part of the pump core 8.2 is a hollow structure. The lower end of the pump core 8.2 is connected to the lower connector 8.12 of the pump barrel 8.1, and a ball valve 8 is installed in the lower connector 8.12. 10. A retrieval head 8.11 is provided at the upper end of the pump core 8.2; an acceleration annular gap 8.5 is formed between the pump core 8.2 and the inner wall of the inner cylinder as a nozzle. A flow conversion hole 8.6 is provided below the acceleration annular gap 8.5. A mixing chamber 8.7 and a deceleration chamber 8.8 are provided below the flow conversion hole 8.6. The power fluid is sprayed downward along the acceleration annular gap 8.5, which drives the formation fluid to enter the flow conversion hole 8.6 through the ball valve 8.10, the inner cavity of the pump core 8.2 and the outlet hole 8.13. Then, it enters the annulus between the outer cylinder and the inner cylinder through the mixing chamber 8.7, the deceleration chamber 8.8 and the mixed fluid flow conversion hole 8.9, and continues to rise along the annulus between the oil pipe 5 and the small diameter oil pipe 6.

[0024] The pump core 8.2 is equipped with a pump lifting cup 8.3 on its upper part, and a pressure cap 8.4 is installed on the upper part of the pump lifting cup 8.3. The lower outer diameter of the pump lifting cup 8.3 is larger than the outer diameter of the pump core 8.2. The lower end of the pump core 8.2 is located at the upper center of the lower connector 8.12.

[0025] Reference Figure 5 The sediment support umbrella 7 mentioned in this invention includes a central tube 7.1, a support umbrella body 7.2, an upper coupling 7.3, and a lower coupling 7.4. The upper end of the central tube 7.1 is connected to the upper coupling 7.3, and the lower end of the central tube 7.1 is connected to the lower coupling 7.4. It is connected to the small-diameter oil pipe 6 through the upper coupling 7.3 and the lower coupling 7.4. The umbrella-shaped support umbrella body 7.2 is installed on the outer wall of the central tube 7.1, and the opening faces upward.

[0026] Reference Figure 6 The sediment support cover 10 mentioned in this invention includes a support cover body 10.1, an upper connector 10.2, and a lower connector 10.3. The upper end of the support cover body 10.1 is connected to the upper connector 10.2, and the lower end of the support cover body 10.1 is connected to the lower connector 10.3. The support cover body 10.1 adopts a conical cover structure, and the inner diameter of the support cover body 10.1 is larger than the outer diameter of the support umbrella body 7.2.

[0027] The method of using the multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system mentioned in this invention includes the following process: 1. Start the drive motor 2.1 of the horizontal centrifugal pump 2. The drive motor 2.1 drives the transmission shaft 2.4.11 to rotate through the coupling 2.2. The transmission shaft 2.4.11 is installed in the high-speed damping seal protector 2.4 on the right side. The circulating water in the water tank 3 is sent to the water inlet 2.4.6 of the high-speed damping seal protector 2.4. The flow of circulating water in the water-cooled cavity cools down the lubrication chamber shell 2.4.2. In addition, the first dynamic seal 2.4.4 and the second dynamic seal 2.4.10 reduce the axial fluctuation of the transmission shaft 2.4.11. Then, the circulating water enters the pump body 2.5 and is gradually pressurized under the action of centrifugal force through the multi-stage impeller. Then, it enters the small diameter oil pipe 6 through the single-flow valve 2.7, the liquid outlet pipe 2.3 and the wellhead 1 as the power fluid to drive the sand-blocking jet pump 8 downhole for drainage. 2. The power fluid enters the acceleration annular gap 8.5 through the annular space between the inner cylinder of the sand-proof plugging jet pump 8 and the outer wall of the pump core 8.2. The ejected power fluid drives the formation fluid in the inner cavity of the pump core 8.2 to enter the transfer hole 8.6 along the outlet hole 8.13. After being mixed with the power fluid in the mixing chamber 8.7, it enters the annular space between the outer cylinder and the inner cylinder through the deceleration chamber 8.8 and the mixing fluid transfer hole 8.9. It then continues to rise along the annular space between the oil pipe 5 and the small diameter oil pipe 6 until it is discharged to the wellhead 1. 3. When the drive motor 2.1 loses power or the well needs to be shut down, the sand-containing mixture in the annulus between the tubing 5 and the small-diameter tubing 6 stops rising, and the sand particles in the mixture will sink. When passing through each sand-sinking support umbrella 7 and sand-sinking support cover 10, the sand particles sink to the bottom of the sand-sinking support umbrella 7 and are collected. In this way, the sand in the annulus is collected in sections, avoiding the sand from sinking into the pump barrel 8.1 and causing sand blockage of the downhole pump and tubing. When the well is restarted for production, the rising mixture flows through the annulus between the support cover body 10.1 and the support umbrella body 7.2 and sprays upward, and drives the sand in the sand-sinking support umbrella 7 to rise with the liquid flow, thereby realizing the function of preventing sand blockage. 4. When it is necessary to lift the pump core 8.2, inject power fluid into the annulus between the tubing 5 and the small-diameter tubing 6 at the wellhead 1 on the ground. The power fluid flows down along the annulus between the tubing 5 and the small-diameter tubing 6 to the mixing fluid transfer hole 8.9 of the sand-proof plugging jet pump 8, enters the annulus between the inner cylinder of the pump barrel 8.1 and the pump core 8.2, and then passes through the deceleration chamber 8.8, the mixing chamber 8.7 and the acceleration annulus 8.5 in sequence. The power fluid pushes the pump cup 8.3, which in turn drives the pump core 8.2 upward, and it rises along the small-diameter tubing 6 to the wellhead 1 on the ground for removal.

[0028] Example 2: The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system mentioned in this invention includes a wellhead 1 and a water tank 3. The water tank 3 is installed on one side of the wellhead 1. The system also includes a horizontal centrifugal pump 2, a sand-supporting umbrella 7, and a sand control and jet pump 8. The horizontal centrifugal pump 2 is installed next to the water tank 3 on the ground. The output end of the horizontal centrifugal pump 2 is connected to the wellhead 1 via a pipeline. The sand control and jet pump 8 is installed in the oil-producing layer 9 downhole via an oil pipe 5. A small-diameter oil pipe 6 is connected to the upper end of a sand-blocking jet pump 8. Multiple sand-collecting umbrellas 7 are installed in sections on the small-diameter oil pipe 6, and multiple sand-collecting covers 10 are installed in sections on the oil pipe 5. Each sand-collecting umbrella 7 is located inside the sand-collecting cover 10, and an annular space is formed between the upper outer wall of the sand-collecting umbrella 7 and the inner wall of the sand-collecting cover 10. Sand is collected by the sand-collecting umbrella 7, and when the liquid rises through the annular space, it drives the sand in the sand-collecting umbrella 7 to be discharged to the ground.

[0029] The difference from Example 1 is: In this embodiment, the outer wall of the central tube 7.1 of the sediment support umbrella 7 is equipped with multiple sets of support umbrella bodies 7.2, and the openings face upwards, which can better achieve the collection and reception of sediment.

[0030] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system, comprising a wellhead (1) and a water tank (3), wherein the water tank (3) is installed on one side of the wellhead (1), characterized in that: It also includes a horizontal centrifugal pump (2), a sand-supporting umbrella (7), and a sand-blocking jet pump (8). The horizontal centrifugal pump (2) is installed next to the water tank (3) on the ground. The output end of the horizontal centrifugal pump (2) is connected to the wellhead (1) through a pipeline. The sand-blocking jet pump (8) is installed in the oil-producing layer (9) downhole through the oil pipe (5). A small-diameter oil pipe (6) is installed inside the oil pipe (5), and the lower end of the small-diameter oil pipe (6) is connected to the sand-blocking jet pump (8). At the upper end of the pipe (6), multiple sand-supporting umbrellas (7) are installed in sections on the small-diameter oil pipe (6), and multiple sand-supporting covers (10) are installed in sections on the oil pipe (5). Each sand-supporting umbrella (7) is located in the inner cavity of the sand-supporting cover (10), and an annular space is formed between the upper outer wall of the sand-supporting umbrella (7) and the inner wall of the sand-supporting cover (10). The sand is received by the sand-supporting umbrella (7), and when the liquid rises through the annular space, it drives the sand in the sand-supporting umbrella (7) to be discharged to the ground.

2. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 1, characterized in that: The horizontal centrifugal pump (2) includes a drive motor (2.1), a coupling (2.2), a discharge pipe (2.3), a high-speed vibration damping seal protector (2.4), a pump body (2.5), a foundation support (2.6), and a check valve (2.7). The foundation support (2.6) is installed on the lower part of the pump body (2.5) and the high-speed vibration damping seal protector (2.4). The output end of the drive motor (2.1) is connected to the high-speed vibration damping seal protector (2.4) through the coupling (2.2). The output end of the high-speed vibration damping seal protector (2.4) is connected to one end of the pump body (2.5). The other end of the pump body (2.5) is equipped with a check valve (2.7) and a discharge pipe (2.3). A multi-stage impeller is installed inside the pump body (2.5).

3. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 2, characterized in that: The high-speed shock-absorbing sealing protector (2.4) includes a protector body (2.4.1), a lubrication chamber housing (2.4.2), a centering bearing (2.4.3), a first dynamic seal (2.4.4), a centrifugal pump coupling (2.4.5), a water inlet (2.4.6), a lubrication injector (2.4.7), an oil injection through hole (2.4.8), a gland (2.4.9), a second dynamic seal (2.4.10), and a water passage hole (2.4.12). The lubrication chamber housing (2.4.2) is installed in the center of the inner cavity of the protector body (2.4.1). The annular space formed between the lubrication chamber housing (2.4.2) and the protector body (2.4.1) is a water-cooled cavity. The right side of the drive shaft (2.4.11) is installed in the lubrication chamber housing (2.4.2). Inside the device, and a set of more than one set of centering bearings (2.4.3) are installed on the drive shaft (2.4.11). The drive shaft (2.4.11) is connected to the left end of the protector body (2.4.1) through the first dynamic seal (2.4.4). The right end of the protector body (2.4.1) is equipped with a second dynamic seal (2.4.10). An oil injection hole (2.4.8) is provided inside the right end of the protector body (2.4.1). A lubricating oil injector (2.4.7) is installed on the upper part of the oil injection hole (2.4.8). A water injection port (2.4.6) is provided on the upper right side of the protector body (2.4.1). The left side of the protector body (2.4.1) is connected to the inlet end of the pump body (2.5) through a centrifugal pump coupling (2.4.5).

4. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 3, characterized in that: Multiple water passage holes (2.4.12) are provided at the left end of the protector body (2.4.1) to connect the water-cooled cavity with the inner cavity of the centrifugal pump coupling (2.4.5). Water is connected to the inlet end of the pump body (2.5) through the annular space formed between the drive shaft (2.4.11) and the inner wall of the centrifugal pump coupling (2.4.5).

5. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 4, characterized in that: The sand-proof plugging jet pump (8) includes a pump barrel (8.1), a pump core (8.2), an accelerating annular seam (8.5), a flow conversion hole (8.6), a mixing chamber (8.7), a deceleration chamber (8.8), a mixed liquid flow conversion hole (8.9), a ball valve (8.10), and a retrieval head (8.11). The pump barrel (8.1) adopts a double-layer structure. The bottom of the inner and outer cylinders are provided with mixed liquid flow conversion holes (8.9). A small-diameter oil pipe (6) is connected to the top of the inner cylinder, and an oil pipe (5) is connected to the top of the outer cylinder. The pump core (8.2) is installed in the inner cavity of the inner cylinder, and the middle part of the pump core (8.2) is a hollow structure. The lower end of the pump core (8.2) is connected to the lower connector (8.12) of the pump barrel (8.1). A ball valve (8.10) is installed in the lower connector (8.12). 0), the upper end of the pump core (8.2) is provided with a retrieval head (8.11); the pump core (8.2) and the inner wall of the inner cylinder form an acceleration annular gap (8.5) as a nozzle, and a flow conversion hole (8.6) is provided below the acceleration annular gap (8.5). A mixing chamber (8.7) and a deceleration chamber (8.8) are provided below the flow conversion hole (8.6). The power fluid is sprayed downward along the acceleration annular gap (8.5), which drives the formation fluid to enter the flow conversion hole (8.6) along the ball valve (8.10), the inner cavity of the pump core (8.2) and the outlet hole (8.13). Then, it enters the annulus between the outer cylinder and the inner cylinder through the mixing chamber (8.7), the deceleration chamber (8.8) and the mixed fluid flow conversion hole (8.9), and continues to rise along the annulus between the oil pipe (5) and the small diameter oil pipe (6).

6. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 5, characterized in that: The upper part of the pump core (8.2) is equipped with a pump lifting cup (8.3), and the upper part of the pump lifting cup (8.3) is equipped with a pressure cap (8.4). The lower outer diameter of the pump lifting cup (8.3) is larger than the outer diameter of the pump core (8.2). The lower end of the pump core (8.2) sits at the upper center of the lower connector (8.12).

7. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 6, characterized in that: The sediment support umbrella (7) includes a central tube (7.1), a support umbrella body (7.2), an upper coupling (7.3), and a lower coupling (7.4). The upper end of the central tube (7.1) is connected to the upper coupling (7.3), and the lower end of the central tube (7.1) is connected to the lower coupling (7.4). The central tube (7.1) is connected to the small-diameter oil pipe (6) through the upper coupling (7.3) and the lower coupling (7.4). The umbrella-shaped support umbrella body (7.2) is installed on the outer wall of the central tube (7.1), and the opening faces upward.

8. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 7, characterized in that: The sediment support cover (10) includes a support cover body (10.1), an upper connector (10.2), and a lower connector (10.3). The upper end of the support cover body (10.1) is connected to the upper connector (10.2), and the lower end of the support cover body (10.1) is connected to the lower connector (10.3). The support cover body (10.1) adopts a conical cover structure, and the inner diameter of the support cover body (10.1) is larger than the outer diameter of the support umbrella body (7.2).

9. The method of using the multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 8, characterized in that: Includes the following processes:

1. Turn on the drive motor (2.1) of the horizontal centrifugal pump (2). The drive motor (2.1) drives the transmission shaft (2.4.11) to rotate through the coupling (2.2). The transmission shaft (2.4.11) is installed in the high-speed shock-absorbing seal protector (2.4) on the right side. The circulating water in the water tank (3) is sent to the water inlet (2.4.6) of the high-speed shock-absorbing seal protector (2.4). The circulation of the circulating water in the water-cooled cavity realizes the lubrication of the housing (2). 4.2) cooling and temperature reduction, in addition, the axial fluctuation of the drive shaft (2.4.11) is reduced by the first dynamic seal (2.4.4) and the second dynamic seal (2.4.10); then, the circulating water enters the pump body (2.5) and is gradually pressurized by the multi-stage impeller under the action of centrifugal force, and then enters the small diameter oil pipe (6) through the single flow valve (2.7), the liquid outlet pipe (2.3) and the wellhead (1) as the power fluid to drive the sand-proof plugging jet pump (8) downhole for drainage work; 2. The power fluid enters the acceleration annular gap (8.5) through the annular space between the inner cylinder of the sand-proof plugging jet pump (8) and the outer wall of the pump core (8.2). The ejected power fluid drives the formation fluid in the inner cavity of the pump core (8.2) to enter the transfer hole (8.6) along the outlet hole (8.13). After being mixed with the power fluid in the mixing chamber (8.7), it enters the annular space between the outer cylinder and the inner cylinder through the deceleration chamber (8.8) and the mixed fluid transfer hole (8.9). It then continues to rise along the annular space between the oil pipe (5) and the small diameter oil pipe (6) until it is discharged to the wellhead (1).

3. When the drive motor (2.1) is powered off or the well needs to be shut down, the sand-containing mixture in the annulus between the tubing (5) and the small-diameter tubing (6) stops rising, and the sand particles in the mixture will sink. When passing through each sand-sinking support umbrella (7) and sand-sinking support cover (10), the sand particles sink to the bottom of the sand-sinking support umbrella (7) and are collected. In this way, the sand in the annulus is collected in sections, avoiding the sand from sinking into the pump barrel (8.1) and causing sand blockage of the downhole pump and tubing. When the well is reopened for production, the upward flow of the mixed liquid passes through the annulus between the support cover body (10.1) and the support umbrella body (7.2) and sprays upward, and drives the sand in the sand-settling support umbrella (7) to rise with the liquid flow, thereby achieving the function of preventing sand particles from clogging.

4. When it is necessary to lift the pump core (8.2), the power fluid is injected into the annulus between the tubing (5) and the small-diameter tubing (6) at the wellhead (1) on the ground. The power fluid flows down along the annulus between the tubing (5) and the small-diameter tubing (6) to the mixing fluid transfer hole (8.9) of the sand-blocking jet pump (8), enters the annulus between the inner cylinder of the pump barrel (8.1) and the pump core (8.2), and then passes through the deceleration chamber (8.8), the mixing chamber (8.7) and the acceleration annulus (8.5) in sequence. The power fluid pushes the pump cup (8.3), which in turn drives the pump core (8.2) to move upward, and moves upward along the small-diameter tubing (6) to the wellhead (1) on the ground for removal.

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