Multistage high-speed centrifugal pump driven downhole sand control and plugging jetting mining system and use method

Abstract

The present application relates to oil and gas field and coal bed gas field exploitation and drainage engineering technical field, especially to a kind of multistage high-speed centrifugal pump drive downhole sand prevention and plugging jet drainage system and use method.The technical scheme is: the output end of horizontal centrifugal pump is connected to wellhead by pipeline, and sand prevention and plugging tubular jet pump is arranged in the downhole oil producing layer by tubing, and multiple sand settling support umbrellas are installed on small-diameter tubing in sections, and multiple sand settling support covers are installed on tubing in sections.The present application solves the problem that the length of pump shaft of multistage high-speed centrifugal pump is large, the rotating speed is high, and the pump is in axial fluctuation during starting and working, which makes it difficult for commonly used coupling force transmission and dynamic seal structure to adapt to high-speed working condition, resulting in high failure rate.In addition, the sand prevention and plugging tubular jet pump is improved, and its sand plugging resistance is enhanced, and its structure is novel and simple, safe and reliable, and multiple sand settling support umbrellas are installed on small-diameter tubing in sections, to avoid sand settling into pump cylinder and causing sand plugging of downhole pump and pipe string.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field and coalbed methane field exploitation and drainage engineering, and particularly relates to a multistage high-speed centrifugal pump driven downhole sand prevention and jetting drainage system and a use method thereof. BACKGROUND

[0002] The downhole jet pump has strong advantages in oil and gas well sand production, drainage gas recovery and coalbed methane well drainage gas recovery. The existing jetting drainage pump power fluid system is driven by a plunger pump due to high injection pressure. The plunger pump needs frequent maintenance and often needs to be stopped to replace the sealing element. For the well layer with high sand content and coal powder content, sand plugging often occurs when the pump is stopped, which causes the difficulty in opening the well. Sometimes, the pipe string is forced to be pulled out for unblocking and then the production is started, which brings great inconvenience to the production and increases the production cost. Secondly, when the plunger pump needs to be adjusted by a large amplitude, the plunger and the cylinder sleeve need to be replaced to achieve the adjustment, thereby further increasing the frequency of stopping the well. Thirdly, the plunger pump needs to be set indoors and be equipped with necessary insulation and heating facilities for use in cold regions in winter, which is difficult to realize the full-automatic unmanned management and control system, resulting in high management and maintenance cost. Fourthly, the plunger pump is limited in the vicinity of residential areas and offshore platform well areas due to high noise and large space occupation.

[0003] In addition, the existing ground commonly used centrifugal pump is limited in pump pressure due to few stages and low rotation speed (less than 1500 revolutions per minute). The existing downhole multistage high-pressure high-speed (more than 2700 revolutions per minute) submersible centrifugal electric pump has a long pump shaft, high rotation speed and is in axial fluctuation during pump starting and working process, which makes the commonly used coupling transmission force and dynamic sealing structure difficult to adapt to high rotation speed working condition and high temperature, resulting in high failure rate and easy leakage at the dynamic sealing position. Therefore, the high-speed high-pressure multistage centrifugal pump is still in the research and development stage in China.

[0004] Furthermore, the existing downhole jet pump sand production system has complex and circuitous inner flow channel. The centrifugal force, impact and shear force of sand particles during turning flow and the great difference between the liquid flow result in serious wear and erosion, which is difficult to maintain long working life. When power failure occurs or the pump core needs to be replaced, the sand in the wellbore liquid will be deposited and plugged, which easily causes sand jamming of the pump core or sand plugging of the flow channel. Therefore, a new type of jetting drainage system with wear resistance and sand plugging resistance needs to be invented. SUMMARY

[0005] The present application aims at the above-mentioned defects in the prior art, and provides a multistage high-speed centrifugal pump driven downhole sand prevention and plugging jet flow drainage system and a use method, which solves the problem of high failure rate caused by the difficulty of common coupling transmission force and dynamic sealing structure in adapting to high-speed working condition due to the large pump shaft length, high rotating speed and axial fluctuation of the multistage high-speed centrifugal pump during pump starting and working process; in addition, the sand prevention and plugging pipe type jet flow pump is improved, and the sand prevention and plugging performance is enhanced, the structure is novel and simple, safe and reliable, and a plurality of sand setting support umbrellas are installed on the small-diameter oil pipe in sections, so that the sand setting into the pump cylinder is avoided, and the sand plugging of the downhole pump and the pipe string is avoided.

[0006] The multistage high-speed centrifugal pump driven downhole sand prevention and plugging jet flow drainage system provided by the present application has the technical scheme that: the system comprises a wellhead and a water tank, the water tank is arranged on one side of the wellhead, further comprises a horizontal centrifugal pump, a sand setting support umbrella and a sand prevention and plugging pipe type jet flow pump, the horizontal centrifugal pump is installed beside the water tank on the ground, the output end of the horizontal centrifugal pump is connected to the wellhead through a pipeline, the sand prevention and plugging pipe type jet flow pump is arranged in the oil production layer downhole through the oil pipe, a small-diameter oil pipe is installed in the oil pipe, the lower end of the small-diameter oil pipe is connected to the upper end of the sand prevention and plugging pipe type jet flow pump, a plurality of sand setting support umbrellas are installed on the small-diameter oil pipe in sections, a plurality of sand setting support covers are installed on the oil pipe in sections, each sand setting support umbrella is located in the inner cavity of the sand setting support cover, an annulus is formed between the upper outer wall of the sand setting support umbrella and the inner wall of the sand setting support cover, sand is received by the sand setting support umbrella, and the sand in the sand setting support umbrella is discharged to the ground when liquid goes up through the annulus.

[0007] Preferably, the horizontal centrifugal pump comprises a driving motor, a shaft coupling, a liquid outlet pipe, a high-speed damping sealing protector, a pump body, a foundation support, a one-way valve, the lower part of the pump body and the high-speed damping sealing protector is installed with the foundation support, the output end of the driving motor is connected to the high-speed damping sealing protector through the shaft coupling, the output end of the high-speed damping sealing protector is connected to one end of the pump body, the other end of the pump body is arranged with the one-way valve and the liquid outlet pipe, and a plurality of impellers are installed in the pump body.

[0008] Preferably, the high-speed damping sealing protector comprises a protector main body, a lubricating cavity shell, a righting bearing, a first dynamic sealing device, a centrifugal pump shaft coupling, a water injection port, a lubricating oil injector, an oil injection through-hole, a gland, a second dynamic sealing device and a water passing hole, the inner cavity center of the protector main body is installed with the lubricating cavity shell, the annulus formed between the lubricating cavity shell and the protector main body is a water cooling cavity, the right side of the transmission shaft is installed in the inside of the lubricating cavity shell, a plurality of righting bearings are installed on the transmission shaft, the transmission shaft and the left end of the protector main body are connected through the first dynamic sealing device, the second dynamic sealing device is installed on the right end of the protector main body, the oil injection through-hole is arranged in the right end of the protector main body, the lubricating oil injector is installed on the upper part of the oil injection through-hole, the water injection port is arranged on the right side of the protector main body, and the centrifugal pump shaft coupling is installed on the outside of the left end of the protector main body and connected to the inlet end of the pump body.

[0009] Preferably, a plurality of water passing holes are arranged at the left end of the protector body to connect the water cooling cavity with the inner cavity of the centrifugal pump coupling, and the water is connected to the inlet end of the pump body through the annular space formed between the transmission shaft and the inner wall of the centrifugal pump coupling.

[0010] Preferably, the sand blocking prevention pipe type jet pump comprises a pump cylinder, a pump core, an accelerating ring gap, a flow switching hole, a mixing cavity, a decelerating cavity, a mixed liquid flow switching hole, a ball valve and a fishing head, the pump cylinder adopts a double-layer structure, the bottom of the inner cylinder and the outer cylinder is provided with the mixed liquid flow switching hole, the top of the inner cylinder is connected with a small-diameter oil pipe, the top of the outer cylinder is connected with an oil pipe, the pump core is installed in the inner cavity of the inner cylinder, the middle part of the pump core is a cavity structure, the lower end of the pump core is communicated with the lower joint of the pump cylinder, the ball valve is installed in the lower joint, and the upper end of the pump core is provided with the fishing head; the accelerating ring gap formed between the pump core and the inner wall of the inner cylinder serves as a nozzle, the flow switching hole is arranged below the accelerating ring gap, the mixing cavity and the decelerating cavity are arranged below the flow switching hole, the power liquid is sprayed downward along the accelerating ring gap to drive the formation liquid to enter the flow switching hole along the ball valve, the inner cavity of the pump core and the liquid outlet hole, and then enter the outer cylinder through the mixing cavity, the decelerating cavity and the mixed liquid flow switching hole, and then continue to flow upward along the annular space between the oil pipe and the small-diameter oil pipe.

[0011] Preferably, the pump skin bowl is installed at the upper part of the pump core, the pressure cap is installed at the upper part of the pump skin bowl, the outer diameter of the lower part of the pump skin bowl is greater than the outer diameter of the pump core, and the lower end of the pump core is arranged at the upper center of the lower joint.

[0012] Preferably, the sand setting support umbrella comprises a central pipe, a support umbrella body, an upper joint and a lower joint, the upper end of the central pipe is connected with the upper joint, the lower end of the central pipe is connected with the lower joint, and the central pipe is connected with the small-diameter oil pipe through the upper joint and the lower joint, the outer wall of the central pipe is provided with the umbrella-shaped support umbrella body, and the opening of the umbrella-shaped support umbrella body faces upward.

[0013] Preferably, the sand setting support umbrella comprises a central pipe, a support umbrella body, an upper joint and a lower joint, the upper end of the central pipe is connected with the upper joint, the lower end of the central pipe is connected with the lower joint, and the central pipe is connected with the small-diameter oil pipe through the upper joint and the lower joint, the outer wall of the central pipe is provided with the umbrella-shaped support umbrella body, and the opening of the umbrella-shaped support umbrella body faces upward.

[0014] The use method of the multi-stage high-speed centrifugal pump driving downhole sand blocking prevention jet flow drainage system mentioned in the application comprises the following processes:

[0015] I. Start the driving motor of the horizontal centrifugal pump, the driving motor drives the transmission shaft to rotate through the shaft coupling, the right side of the transmission shaft is installed in the high-speed damping sealing protector, the circulating water in the water tank is sent to the water injection port of the high-speed damping sealing protector, the circulating water is cooled and cooled through the flow in the water cooling cavity, in addition, the axial fluctuation of the transmission shaft is reduced through the first dynamic seal and the second dynamic seal; then, the circulating water enters the pump body and is pressurized step by step under the action of centrifugal force through the multistage impeller, and then enters the small-diameter oil pipe as power fluid through the one-way valve, the liquid outlet pipe and the wellhead; the power fluid drives the downhole sand blocking pipe type jet pump to carry out the production;

[0016] II. The power fluid enters the accelerating ring gap through the annulus between the inner cylinder of the sand blocking pipe type jet pump and the outer wall of the pump core, the sprayed power fluid drives the formation fluid in the pump core cavity to enter the flow hole, and then the mixed fluid enters the annulus between the outer cylinder and the inner cylinder through the mixing cavity and the power fluid, and then continues to flow upward along the annulus between the oil pipe and the small-diameter oil pipe, and finally is discharged to the wellhead;

[0017] III. When the driving motor is powered off or the well needs to be shut down, the mixed fluid containing sand in the annulus between the oil pipe and the small-diameter oil pipe stops flowing upward, the sand particles in the mixed fluid sink, and 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, so that the sand in the annulus is collected in sections, avoiding the sand sinking into the pump cylinder to cause sand blocking of the downhole pump and the pipe string; when the well is opened for production again, the upward flowing mixed fluid sprays upward through the annulus between the support cover body and the support umbrella body, and drives the sand in the sand sinking support umbrella to flow upward with the fluid, thereby realizing the sand blocking function.

[0018] IV. When the pump core needs to be pulled up, the power fluid is injected into the annulus between the oil pipe and the small-diameter oil pipe at the wellhead on the ground, the power fluid flows downward along the annulus between the oil pipe and the small-diameter oil pipe to the mixed fluid flow hole of the sand blocking pipe type jet pump, enters the annulus between the inner cylinder of the pump cylinder and the pump core, and then passes through the deceleration cavity, the mixing cavity and the accelerating ring gap in turn, the power fluid pushes up the pump skin bowl, and then drives the pump core to flow upward along the small-diameter oil pipe to the wellhead on the ground.

[0019] Compared with the prior art, the beneficial effects of the present application are as follows:

[0020] 1. The horizontal centrifugal pump adopted in the present application has the advantages of low noise, simple and easy-to-control pressure and displacement parameters, no need for additional heating and anti-freezing facilities in cold regions, no need for more daily maintenance, long service life of the equipment, saved production cost, and outstanding advantages over the currently used plunger pump; wherein the high-speed damping sealing protector has the functions of transmitting high-speed torque, balancing axial thrust, lubricating and protecting high-speed rotating dynamic sealing components, preventing overheating and shaft seizure, preventing thermal expansion and cracking of the rigid sealing ring, and preventing vibration. 2. The sand blocking pipe type jet pump adopted in the present application has the advantages of simple structure, convenient operation, low cost, no need for additional heating and anti-freezing facilities in cold regions, no need for more daily maintenance, long service life of the equipment, saved production cost, and outstanding advantages over the currently used plunger pump; wherein the high-speed damping sealing protector has the functions of transmitting high-speed torque, balancing axial thrust, lubricating and protecting high-speed rotating dynamic sealing components, preventing overheating and shaft seizure, preventing thermal expansion and cracking of the rigid sealing ring, and preventing vibration.

[0021] 2、When sudden power failure or well shut-in is encountered, the mixed fluid containing sand in the annulus between the tubing and the small-diameter tubing stops ascending, the sand particles in the mixed fluid sink, and when passing through each sand sink supporting umbrella and sand sink supporting cover, the sand particles sink to the bottom of the sand sink supporting umbrella and are collected, so that the collected sand in the annulus is segmented, avoiding the sand sinking into the pump barrel and causing sand blockage of the downhole pump and the pipe string; when the well is opened for production again, the ascending mixed fluid flows through the annulus between the supporting cover body and the supporting umbrella body and is sprayed upward, and the sand in the sand sink supporting umbrella is carried upward with the fluid flow, thereby realizing the sand blocking prevention function;

[0022] 3、The inner fluid flow channel of the sand blocking prevention pipe type jet pump is a longitudinal parallel straight line type annular and columnar flow channel, and there is no sand sink residence space in the straight line type flow channel, so that the sand particles in the formation fluid and the mixed fluid are not easy to reside and deposit, the wear on the inner flow channel of the sand blocking prevention pipe type jet pump is reduced, the sand blocking resistance is enhanced, the structure is novel and simple, safe and reliable; the sand blocking prevention pipe type jet pump can safely and reliably pump the formation fluid with sand content of 1%-12% to the ground, without the phenomenon of sand blockage and difficulty in opening the well after pump stop, and is more suitable for high-sand formation, oil and gas well layer with unstable sand production intensity and coalbed methane well with high coal powder content. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the overall structure schematic diagram of the present application;

[0024] Figure 2 is the structure schematic diagram of the horizontal centrifugal pump of the present application;

[0025] Figure 3 is the structure schematic diagram of the high-speed damping sealing protector;

[0026] Figure 4 is the structure schematic diagram of the sand blocking prevention pipe type jet pump;

[0027] Figure 5 is the structure schematic diagram of the sand sink supporting umbrella;

[0028] Figure 6 is the structure schematic diagram of the sand sink supporting cover;

[0029] In the figure: wellhead 1, horizontal centrifugal pump 2, water tank 3, casing 4, oil pipe 5, small-diameter oil pipe 6, sand bearing umbrella 7, sand blocking pipe type jet pump 8, oil producing layer 9, sand bearing umbrella cover 10, driving motor 2.1, shaft coupling 2.2, liquid outlet pipe 2.3, high-speed shock-absorbing sealing protector 2.4, pump body 2.5, base support 2.6, check valve 2.7, protector main body 2.4.1, lubricating cavity shell 2.4.2, centralizing bearing 2.4.3, first dynamic seal 2.4.4, centrifugal pump shaft coupling 2.4.5, water injection port 2.4.6, lubricating oil injector 2.4.7, oil injection through hole 2.4.8, gland 2.4.9, second dynamic seal 2.4.10, transmission shaft 2.4.11, water passage hole 2.4.12, thrust bearing 2.4.13, central pipe 7.1, bearing umbrella body 7.2, upper coupling 7.3, lower coupling 7.4, pump barrel 8.1, pump core 8.2, pump skin bowl 8.3, pressure cap 8.4, accelerating ring gap 8.5, flow turning hole 8.6, mixing cavity 8.7, deceleration cavity 8.8, mixed liquid flow turning hole 8.9, ball valve 8.10, fishing head 8.11, lower joint 8.12, liquid outlet hole 8.13, bearing cover body 10.1, upper joint 10.2, lower joint 10.3. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, which should be understood to be for illustration only and not for limiting the present application.

[0031] Embodiment 1, refer to Figures 1-6 The present application refers to a multi-stage high-speed centrifugal pump driven downhole sand blocking jetting production system, which comprises a wellhead 1, a water tank 3, a horizontal centrifugal pump 2, a sand bearing umbrella 7, and a sand blocking pipe type jet pump 8. The horizontal centrifugal pump 2 is installed beside the water tank 3 on the ground, and the output end of the horizontal centrifugal pump 2 is connected to the wellhead 1 through a pipeline. The sand blocking pipe type jet pump 8 is installed in the oil producing layer 9 under the casing 4 through the oil pipe 5. A small-diameter oil pipe 6 is installed in the oil pipe 5, and the lower end of the small-diameter oil pipe 6 is connected to the upper end of the sand blocking pipe type jet pump 8. A plurality of sand bearing umbrellas 7 are installed on the small-diameter oil pipe 6 in sections, and a plurality of sand bearing umbrella covers 10 are installed on the oil pipe 5 in sections. Each sand bearing umbrella 7 is located in the inner cavity of the sand bearing umbrella cover 10, and an annulus is formed between the upper outer wall of the sand bearing umbrella 7 and the inner wall of the sand bearing umbrella cover 10. Sand is carried by the sand bearing umbrella 7, and liquid carries the sand in the sand bearing umbrella 7 up to the ground through the annulus.

[0032] Refer to Figure 2The horizontal centrifugal pump 2 comprises a driving motor 2.1, a shaft coupling 2.2, a liquid outlet pipe 2.3, a high-speed damping sealing protector 2.4, a pump body 2.5, a foundation support 2.6, and a single-way valve 2.7, wherein the lower part of the pump body 2.5 and the high-speed damping sealing protector 2.4 are installed with the foundation support 2.6, the output end of the driving motor 2.1 is connected with the high-speed damping sealing protector 2.4 through the shaft coupling 2.2, the output end of the high-speed damping sealing protector 2.4 is connected with one end of the pump body 2.5, the other end of the pump body 2.5 is provided with the single-way valve 2.7 and the liquid outlet pipe 2.3, and a plurality of multi-stage impellers are installed in the pump body 2.5.

[0033] Referring to Figure 3 The high-speed damping sealing protector 2.4 comprises a protector main body 2.4.1, a lubricating cavity shell 2.4.2, a righting bearing 2.4.3, a first dynamic sealing device 2.4.4, a centrifugal pump shaft coupling 2.4.5, a water injection port 2.4.6, a lubricating oil injector 2.4.7, an oil injection through hole 2.4.8, a gland 2.4.9, a second dynamic sealing device 2.4.10, and a water passing hole 2.4.12, wherein the inner cavity center of the protector main body 2.4.1 is installed with the lubricating cavity shell 2.4.2, the annular space formed between the lubricating cavity shell 2.4.2 and the protector main body 2.4.1 is a water cooling cavity, the right side of a transmission shaft 2.4.11 is installed in the inner part of the lubricating cavity shell 2.4.2, and a plurality of righting bearings 2.4.3 are installed on the transmission shaft 2.4.11, the left end part of the protector main body 2.4.1 is connected with the transmission shaft 2.4.11 through the first dynamic sealing device 2.4.4, the right end part of the protector main body 2.4.1 is installed with the second dynamic sealing device 2.4.10, the oil injection through hole 2.4.8 is arranged in the right end part of the protector main body 2.4.1, the lubricating oil injector 2.4.7 is installed on the upper part of the oil injection through hole 2.4.8, the water injection port 2.4.6 is arranged on the right upper part of the protector main body 2.4.1, the glands 2.4.9 are respectively installed on the outer sides of the two ends of the protector main body 2.4.1, and the centrifugal pump shaft coupling 2.4.5 is installed on the outer side of the left end part of the protector main body 2.4.1 to be connected with the inlet end of the pump body 2.5.

[0034] In addition, a plurality of water passing holes 2.4.12 are arranged on the left end part of the protector main body 2.4.1 to connect the water cooling cavity with the inner cavity of the centrifugal pump shaft coupling 2.4.5, and the water is connected to the inlet end of the pump body 2.5 through the annular space formed between the transmission shaft 2.4.11 and the inner wall of the centrifugal pump shaft coupling 2.4.5.

[0035] In addition, the transmission shaft 2.4.11 of the inner end of the first dynamic sealing device 2.4.4 and the second dynamic sealing device 2.4.10 is respectively installed with a thrust bearing 2.4.13.

[0036] Referring to Figure 4The anti-sand blocking tubular jet pump 8 mentioned in the present application comprises a pump barrel 8.1, a pump core 8.2, an accelerating ring gap 8.5, a flow diversion hole 8.6, a mixing cavity 8.7, a deceleration cavity 8.8, a mixed liquid flow diversion hole 8.9, a ball valve 8.10 and a fishing head 8.11. The pump barrel 8.1 adopts a double-layer structure, the bottom of the inner barrel and the outer barrel is provided with the mixed liquid flow diversion hole 8.9, the top of the inner barrel is connected with the small-diameter oil pipe 6, the top of the outer barrel is connected with the oil pipe 5, the inner cavity of the inner barrel is installed with the pump core 8.2, the middle part of the pump core 8.2 is a hollow structure, the lower end of the pump core 8.2 is communicated with the lower joint 8.12 of the pump barrel 8.1, the ball valve 8.10 is installed in the lower joint 8.12, and the upper end of the pump core 8.2 is provided with the fishing head 8.11. The accelerating ring gap 8.5 formed between the pump core 8.2 and the inner wall of the inner barrel is used as a nozzle, the lower part of the accelerating ring gap 8.5 is provided with the flow diversion hole 8.6, the lower part of the flow diversion hole 8.6 is provided with the mixing cavity 8.7 and the deceleration cavity 8.8, the power liquid is sprayed downward along the accelerating ring gap 8.5, the formation liquid is driven to enter the flow diversion hole 8.6 along the ball valve 8.10, the inner cavity of the pump core 8.2 and the liquid outlet hole 8.13, then enters the annular space between the outer barrel and the inner barrel through the mixing cavity 8.7, the deceleration cavity 8.8 and the mixed liquid flow diversion hole 8.9, and then continues to flow upward along the annular space between the oil pipe 5 and the small-diameter oil pipe 6.

[0037] The upper part of the pump core 8.2 is installed with a pump skin bowl 8.3, the upper part of the pump skin bowl 8.3 is installed with a pressure cap 8.4, the lower part of the pump skin bowl 8.3 has an outer diameter larger than that of the pump core 8.2, and the lower end of the pump core 8.2 is seated at the upper central part of the lower joint 8.12.

[0038] Referring to Figure 5 The sand setting support umbrella 7 mentioned in the present application comprises a central pipe 7.1, a support umbrella body 7.2, an upper joint 7.3 and a lower joint 7.4. The upper end of the central pipe 7.1 is connected with the upper joint 7.3, the lower end of the central pipe 7.1 is connected with the lower joint 7.4, the upper joint 7.3 and the lower joint 7.4 are connected with the small-diameter oil pipe 6, the outer wall of the central pipe 7.1 is installed with the umbrella-shaped support umbrella body 7.2, and the opening is upward.

[0039] Referring to Figure 6 The sand setting support umbrella 7 mentioned in the present application comprises a central pipe 7.1, a support umbrella body 7.2, an upper joint 7.3 and a lower joint 7.4. The upper end of the central pipe 7.1 is connected with the upper joint 7.3, the lower end of the central pipe 7.1 is connected with the lower joint 7.4, the upper joint 7.3 and the lower joint 7.4 are connected with the small-diameter oil pipe 6, the outer wall of the central pipe 7.1 is installed with the umbrella-shaped support umbrella body 7.2, and the opening is upward.

[0040] The use method of the multi-stage high-speed centrifugal pump driving downhole sand prevention and blocking jetting and production system mentioned in the present application comprises the following processes:

[0041] I. 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 shaft coupling 2.2, the right side of the transmission shaft 2.4.11 is installed in the high-speed damping sealing protector 2.4, the circulating water in the water tank 3 is sent to the water inlet 2.4.6 of the high-speed damping sealing protector 2.4, the circulating water realizes the cooling of the lubricating cavity shell 2.4.2 through the flow in the water cooling cavity, 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 the multi-stage impeller is gradually pressurized under the action of centrifugal force, and then the single-flow valve 2.7, the liquid outlet pipe 2.3 and the wellhead 1 enter the small-diameter oil pipe 6 as power fluid, drive the sand blocking pipe type jet pump 8 in the downhole to carry out the production;

[0042] II. The power fluid enters the accelerating ring gap 8.5 through the annulus between the inner cylinder of the sand blocking pipe type jet pump 8 and the outer wall of the pump core 8.2, the sprayed power fluid drives the formation fluid in the inner cavity of the pump core 8.2 to enter the flow diversion hole 8.13, and then the mixed fluid enters the annulus between the outer cylinder and the inner cylinder through the mixing cavity 8.7 and the power fluid, and then continues to flow upward along the annulus between the oil pipe 5 and the small-diameter oil pipe 6, and is finally discharged to the wellhead 1.

[0043] III. When the drive motor 2.1 is powered off or needs to be shut down, the mixed fluid containing sand in the annulus between the oil pipe 5 and the small-diameter oil pipe 6 stops flowing upward, the sand particles in the mixed fluid sink, and then pass through each sand sink support umbrella 7 and sand sink support cover 10, the sand particles sink to the bottom of the sand sink support umbrella 7 and are collected, so that the sand in the annulus is collected in sections, avoiding the sand from sinking into the pump cylinder 8.1 and causing sand blocking of the downhole pump and the pipe string; when the well is opened for production again, the upward flowing mixed fluid sprays upward through the annulus between the support cover body 10.1 and the support umbrella body 7.2, and drives the sand in the sand sink support umbrella 7 to flow upward with the fluid, thereby realizing the sand blocking function.

[0044] IV. When the pump core 8.2 needs to be pulled up, the power fluid is injected into the annulus between the oil pipe 5 and the small-diameter oil pipe 6 at the wellhead 1 on the ground, the power fluid flows downward along the annulus between the oil pipe 5 and the small-diameter oil pipe 6 to the mixed fluid flow diversion hole 8.9 of the sand blocking pipe type jet pump 8, enters the annulus between the inner cylinder of the pump cylinder 8.1 and the pump core 8.2, and then passes through the deceleration cavity 8.8, the mixing cavity 8.7 and the accelerating ring gap 8.5 in turn, the power fluid pushes the pump skin bowl 8.3, and then drives the pump core 8.2 to flow upward along the small-diameter oil pipe 6 to the wellhead 1 on the ground.

[0045] Embodiment 2, the application refers to a multi-stage high-speed centrifugal pump driven downhole sand prevention and plugging jet flow drainage system, comprising a wellhead 1, a water tank 3, a horizontal centrifugal pump 2, a sand bearing umbrella 7, and a sand prevention and plugging tubular jet pump 8, the horizontal centrifugal pump 2 is installed beside 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 prevention and plugging tubular jet pump 8 is installed in the oil production layer 9 downhole through the oil pipe 5, a small-diameter oil pipe 6 is installed in the oil pipe 5, and the lower end of the small-diameter oil pipe 6 is connected to the upper end of the sand prevention and plugging tubular jet pump 8, a plurality of sand bearing umbrellas 7 are installed on the small-diameter oil pipe 6 in sections, a plurality of sand bearing umbrella covers 10 are installed on the oil pipe 5 in sections, each sand bearing umbrella 7 is located in the inner cavity of the sand bearing umbrella cover 10, and an annulus is formed between the upper outer wall of the sand bearing umbrella 7 and the inner wall of the sand bearing umbrella cover 10, sand is collected by the sand bearing umbrella 7, and the sand in the sand bearing umbrella 7 is carried out of the ground by the liquid flowing upward through the annulus.

[0046] The difference between this embodiment and embodiment 1 is that:

[0047] The outer wall of the central pipe 7.1 of the sand bearing umbrella 7 in this embodiment is provided with a plurality of groups of umbrella bodies 7.2, and the openings are upward, which can better achieve the collection of sand.

[0048] The above is only part of the preferred embodiments of the application, and any skilled person in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, the corresponding simple modifications or equivalent transformations according to the technical solutions of the application are within the scope of protection claimed by the application.

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. 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). 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).

2. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 1, 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).

3. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 2, 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).

4. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 3, 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).

5. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 4, 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.

6. The multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 5, 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).

7. The method of using the multi-stage high-speed centrifugal pump driven downhole sand control and jet drainage system according to claim 6, 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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