Inverted gas-proof and sand-proof submersible screw pump device
The inverted gas and sand-proof submersible screw pump unit achieves gas-liquid separation and sand and gravel deposition by placing the guide shroud and filter screen at the lower end of the unit. This solves the problems of blockage and pump jamming during coalbed methane well drainage, protects the power cable, and improves the efficiency of oil well operations and the life of the unit.
Patent Information
- Application Number
- CN202521189389.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2035-06-11
AI Technical Summary
During the drainage process, coalbed methane wells face problems such as increased gas volume after the high water cut period, coal dust blockage, and difficulty in sand control, which can lead to pump jamming, a sharp drop in production, and easy blockage of conventional submersible screw pump gas and sand prevention devices and damage to power cables, affecting the service life and efficiency of the unit.
The submersible screw pump device with inverted anti-gas and anti-sand features a flow guide and filter screen at the bottom of the unit, which realizes gas-liquid separation and sand deposition, reduces the projected area, protects the power cable, and prevents sand from entering through a one-way valve body. It also uses gravity and pressure difference to flush out blockages and ensure smooth liquid intake.
It effectively prevents air lock and blockage, protects power cables, improves oil well operation efficiency, extends unit service life, reduces pump jamming, and ensures normal unit operation.
Smart Images
Figure CN223908378U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of inverted air and sand prevention submersible screw pump devices, belong to oil production equipment technical field. BACKGROUND
[0002] Coalbed gas well exploitation is developing rapidly, and the national coalbed gas production in 2023 is about 10 billion cubic meters. However, the drainage technology of coalbed gas well has the following difficulties: 1. High water content in the early stage of drainage, but gas increases after the water production decreases in the later stage, which is prone to gas lock; 2. Coal dust blockage is relatively serious, and coal dust with a particle size of less than 50 μm is easy to accumulate in the pump, screen pipe or crack, causing pump jamming and sudden yield drop; 3. It is difficult to prevent sand, and fine sand is easy to accumulate in the pump, causing pump jamming.
[0003] Submersible direct-drive screw pump technology can adapt to gas and sand-containing well conditions, but for coalbed gas wells with high gas and sand content, an air and sand prevention device is still needed to ensure normal operation of the unit, prolong its service life and improve drainage efficiency.
[0004] Conventional air and sand prevention for submersible screw pumps involves placing a flow guide cover on the outside of the pump and extending it upwards, with a slotted screen at the top. The screen has slits through which well fluid enters the annulus between the flow guide cover and the pump, flowing downward to the pump's suction inlet and eventually being lifted to the surface. Since the pump's suction inlet is at the very bottom of the flow guide cover, sand, coal dust and oil sludge present in the well fluid entering the annulus tend to accumulate at the bottom of the annulus, causing blockage of the screw pump's suction inlet, resulting in failure to draw fluid and dry grinding of the pump, greatly reducing pump efficiency. In addition, the power cable is fixed on the outside of the flow guide cover, increasing the projected area of the entire unit and making it more prone to collision with the power cable during downhole operations, increasing the risk of damage to the power cable. SUMMARY
[0005] The utility model aims to provide an inverted air and sand prevention submersible screw pump device, placing the flow guide cover and filter screen at the lower end of the unit, which not only better separates gas and liquid, prevents gas lock and suction inlet blockage, but also reduces the projected area, protects the power cable, reduces sand accumulation, ensures oil well operation efficiency, prolongs the service life of the unit, and solves the problems in the background technology.
[0006] The technical solution of the utility model is:
[0007] The device comprises a screw pump, a suction assembly, a protector, a power cable, a submersible permanent magnet motor, a downhole sensor, a flow guide cover, a tubing, a filter screen one, a seamless pipe, a filter screen two, a perforated tubing and a sand pipe, the screw pump, the suction assembly, the protector, the submersible permanent magnet motor and the downhole sensor are sequentially connected from top to bottom, the suction assembly, the protector, the submersible permanent magnet motor and the downhole sensor are arranged in the flow guide cover and an annulus one is arranged between the flow guide cover and the inner wall of the flow guide cover, the screw pump is connected with the suction assembly through a pump joint, the pump joint is provided with a flat hole, one end of the power cable is connected with a junction box on the well, the power cable passes through the flat hole of the pump joint, the other end of the power cable is connected with the submersible permanent magnet motor, the upper end of the flow guide cover is fixedly connected with the pump joint, the lower end of the flow guide cover is connected with the plurality of tubings, the power cable between the pump joint and the submersible permanent magnet motor is arranged in the flow guide cover, the outer side of the tubing is provided with the filter screen one, a plurality of long holes are uniformly arranged on the filter screen one in the circumferential direction, the upper end of the filter screen one is a conical structure, the lower end of the filter screen one is connected with the seamless pipe, the tubing is arranged in the seamless pipe, an annulus two is arranged between the seamless pipe and the tubing, the seamless pipe is connected with the sand pipe through a sand pipe joint, the lowermost tubing is the perforated tubing, the perforated tubing is wrapped with the filter screen two outside the hole, the lower end of the perforated tubing is provided with a one-way valve body, the lower end of the one-way valve body is connected with the sand pipe joint and communicates with the sand pipe, the bottom of the sand pipe is closed.
[0008] The lower end of the flow guide cover is connected with the plurality of tubings through the flow guide cover joint and the tubing joint.
[0009] The seamless pipe comprises a seamless pipe one and a seamless pipe two, the filter screen one is connected with the upper end of the seamless pipe one through the filter screen connecting head and the seamless pipe one joint, the lower end of the seamless pipe one is connected with the upper end of the seamless pipe two, the lower end of the seamless pipe two is connected with the sand pipe joint through the seamless pipe two joint.
[0010] The outer side of the tubing is welded with a righting block, the righting block is attached to the inner wall of the seamless pipe one joint, so as to ensure the relative stability of the tubing.
[0011] The plurality of tubings are connected through tubing couplings.
[0012] The one-way valve body is provided with a spring and a ball, and the liquid can only flow from bottom to top.
[0013] The width of the long hole is 0.3mm, which can block the particles with a diameter greater than 0.3mm.
[0014] The screw pump, the suction assembly, the protector, the power cable, the submersible permanent magnet motor and the downhole sensor are all commonly used devices in the field.
[0015] The screw pump, the suction assembly, the protector, the submersible permanent magnet motor and the downhole sensor are sequentially connected from top to bottom to form a unit.
[0016] In use, the well fluid enters the annular space two from the long hole of the filter screen one, and the taper of the conical structure at the upper end of the filter screen one can ensure that the well fluid enters smoothly and sufficiently; the well fluid flows downward, and the gas in the well fluid goes upward and floats out from the long hole; the well fluid fills the annular space two downward and enters and fills the sand settling pipe along the valve hole of the one-way valve body; due to the gravity, the sand in the well fluid goes downward and continuously accumulates in the sand settling pipe; the well fluid enters the oil pipe from the filter screen two and the perforated oil pipe, continuously goes upward along the oil pipe, enters the annular space one, and enters the screw pump from the liquid inlet hole of the suction assembly, and is lifted to the ground by the screw pump.
[0017] The one-way valve body has two functions: one is that the well fluid and sand in the sand settling pipe cannot enter the oil pipe under normal circumstances; and the other is that if the filter screen two and the perforated oil pipe are blocked, the well fluid cannot enter the oil pipe smoothly, and the well fluid flows to the sand settling pipe along the valve hole of the one-way valve body, so that the pressure of the sand settling pipe is increased; due to the upward lifting of the screw pump, the liquid in the oil pipe is reduced, and the external liquid cannot be supplemented, so that negative pressure is formed, and when the pressure difference between the two sides of the one-way valve body reaches a certain value, the liquid in the sand settling pipe impacts the ball and the compression spring upward, and the liquid enters the oil pipe from the lower end of the valve body along the gap, and due to the pressure difference, the liquid has a certain impact force, which can flush away the sand and sludge blocked in the liquid inlet, so that the liquid inlet of the unit is smooth.
[0018] The beneficial effects of the utility model are: the power cable is prevented from being damaged by collision, the double-layer filter screen plays the role of double filtration and protection, gas-liquid separation is more sufficient, gas entering the pump is effectively reduced, air lock and dry grinding of the screw pump are avoided, damage of the screw pump caused by sand and gas is avoided, the efficiency of oil well operation is ensured, and the service life of the unit is prolonged. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a whole structure schematic view of the utility model;
[0020] Figure 2 It is a unit structure schematic view of the utility model;
[0021] Figure 3 It is an inverted type flow guide cover structure schematic view of the utility model;
[0022] In the figure: screw pump 1, pump joint 2, suction assembly 3, protector 4, power cable 5, submersible permanent magnet motor 6, downhole sensor 7, flow guide cover 8, flow guide cover joint 9, tubing joint 10, oil pipe 11, filter screen one 12, filter screen joint 13, centralizer 14, seamless round pipe one joint 15, seamless round pipe one 16, oil pipe joint 17, seamless round pipe two 18, filter screen two 19, perforated oil pipe 20, one-way valve body 21, seamless round pipe two joint 22, sand trap joint 23, sand trap 24, annulus one 25, annulus two 26. DETAILED DESCRIPTION
[0023] The utility model is further described by examples in connection with the drawings.
[0024] A downhole screw pump device with inverted gas and sand prevention comprises a screw pump 1, a suction assembly 3, a protector 4, a power cable 5, a submersible permanent magnet motor 6, a downhole sensor 7, a flow guide cover 8, an oil pipe 11, a filter screen one 12, a seamless round pipe, a filter screen two 19, a perforated oil pipe 20, and a sand trap 24. The screw pump 1, the suction assembly 3, the protector 4, the submersible permanent magnet motor 6, and the downhole sensor 7 are sequentially connected from top to bottom. The suction assembly 3, the protector 4, the submersible permanent magnet motor 6, and the downhole sensor 7 are arranged in the flow guide cover 8 and are provided with an annulus one 25 between the inner wall of the flow guide cover 8. The screw pump 1 is connected with the suction assembly 3 through a pump joint 2. The pump joint 2 is provided with a flat hole. One end of the power cable 5 is connected with a terminal box on the well, the power cable 5 passes through the flat hole of the pump joint 2, and the other end of the power cable 5 is connected with the submersible permanent magnet motor 6. The upper end of the flow guide cover 8 is fixedly connected with the pump joint 2, and the lower end of the flow guide cover 8 is connected with a plurality of oil pipes 11. The power cable 5 between the pump joint 2 and the submersible permanent magnet motor 6 is arranged in the flow guide cover 8. The filter screen one 12 is mounted on the outer side of the oil pipe 11. A plurality of long holes are uniformly arranged on the filter screen one 12 in the circumferential direction. The upper end of the filter screen one 12 is a conical structure, and the lower end of the filter screen one 12 is connected with a seamless round pipe. The oil pipe 11 is arranged in the seamless round pipe. The annulus two 26 is arranged between the seamless round pipe and the oil pipe 11. The seamless round pipe is connected with the sand trap 24 through the sand trap joint 23. The lowermost oil pipe 11 is a perforated oil pipe 20. The perforated oil pipe 20 is wrapped with the filter screen two 19 outside the hole. The perforated oil pipe 20 is provided with a one-way valve body 21 at the lower end. The lower end of the one-way valve body 21 is connected with the sand trap joint 23 and is in communication with the sand trap 24. The bottom of the sand trap 24 is closed.
[0025] The lower end of the flow guide cover 8 is connected with a plurality of oil pipes 11 through the flow guide cover joint 9 and the tubing joint 10.
[0026] The seamless circular pipe comprises a seamless circular pipe one 16 and a seamless circular pipe two 18, the filter screen one 12 is connected with the upper end of the seamless circular pipe one 16 through the filter screen connecting head 13 and the seamless circular pipe one connecting head 15, the lower end of the seamless circular pipe one 16 is connected with the upper end of the seamless circular pipe two 18, and the lower end of the seamless circular pipe two 18 is connected with the sand pipe connecting head 23 through the seamless circular pipe two connecting head 22.
[0027] The oil pipe 11 is welded with the righting block 14 outside, the righting block 14 is attached to the inner wall of the seamless circular pipe one connecting head 15, and the relative stability of the oil pipe is ensured.
[0028] The oil pipes 11 are connected through the oil pipe coupling 17.
[0029] The one-way valve body 21 is provided with a spring and a ball, and the liquid can only flow from bottom to top.
[0030] The width of the long hole is 0.3 mm, and the particle with the diameter greater than 0.3 mm can be blocked.
[0031] The screw pump 1, the suction assembly 3, the protector 4, the power cable 5, the submersible permanent magnet motor 6 and the downhole sensor 7 are all devices known in the art.
[0032] The screw pump 1, the suction assembly 3, the protector 4, the submersible permanent magnet motor 6 and the downhole sensor 7 are sequentially connected from top to bottom to form a unit; the upper part of the screw pump is provided with a plurality of oil pipes, and the oil pipes provide a channel for the liquid lifted to the wellhead; the power cable 5 is connected to the submersible permanent magnet motor 6 and fixed on the unit and connected to the junction box on the wellhead; the downhole sensor 7, the submersible permanent magnet motor 6, the protector 4, the suction assembly 3 and the power cable 5 in the region are all covered by the flow guide cover 8, and the flow guide cover 8 is fixed on the pump connecting head; a flat hole is formed in the pump connecting head 2, and the flat hole is sealed; the power cable 5 can pass through the flat hole; the inner wall of the flow guide cover 8 and the outer wall of the unit are provided with an annular space 25.
[0033] The lower end of the flow guide cover 8 is connected with a plurality of oil pipes 11 at the lower end through a flow guide cover joint 9 and an oil pipe joint 10, and adjacent oil pipes are connected through an oil pipe coupling 17. A filter screen 1 2 is installed outside the oil pipes, a plurality of long slot holes with a width of 0.3 mm are formed in the filter screen 1 2, well fluid enters the unit from the long slot holes, and the long slot holes can block particles with a diameter greater than 0.3 mm. The filter screen 1 2 is connected with the upper end of a seamless circular pipe 1 6 through a filter screen connecting joint 1 3 and a seamless circular pipe 1 joint 1 5, and the lower end of the seamless circular pipe 1 6 is connected with the upper end of a seamless circular pipe 2 1 8. A righting block 1 4 is welded around the outside of the oil pipe 1 1, which is in close contact with the inner wall of the seamless circular pipe 1 joint 1 5, thereby ensuring the relative stability of the oil pipe. The lowermost oil pipe is a perforated oil pipe 20, well fluid enters the oil pipe from the hole, and a filter screen 2 1 9 is wrapped around the outside of the hole, and the filter screen 2 1 9 and the filter screen 1 2 have a double filtering and protection effect. The lower end of the oil pipe is a one-way valve body 2 1, and the one-way valve body 2 1 has a spring and a ball inside, and liquid can only flow from bottom to top. The lower end of the one-way valve body is connected with a sand setting pipe joint 2 3 and communicates with a sand setting pipe 2 4. The seamless circular pipe 2 1 8 is connected with a plurality of sand setting pipes through a seamless circular pipe 2 joint 2 2 and the sand setting pipe joint 2 3, and the bottom of the sand setting pipe is sealed, and the pipe is used to store sand and gravel settled in the well fluid.
[0034] Well fluid enters the annular space 2 6 from the long slot holes (well fluid inlet) of the filter screen 1 2, and the taper of the conical structure at the upper end of the filter screen 1 2 can ensure that the well fluid enters smoothly and fully. The well fluid flows downward, and the gas in the well fluid flows upward and floats out from the long slot holes. The well fluid fills the annular space 2 and enters and fills the sand setting pipe along the valve hole of the one-way valve body 2 1. Due to the action of gravity, the sand and gravel in the well fluid will flow downward and continuously accumulate in the sand setting pipe. The well fluid enters the oil pipe 1 1 from the filter screen 2 1 9 and the perforated oil pipe 20, and continuously flows upward along the oil pipe, enters the annular space 1 5 between the flow guide cover 8 and the unit, and enters the screw pump from the liquid inlet hole (screw pump liquid inlet) of the suction assembly 3, and is lifted to the ground by the screw pump.
[0035] The one-way valve body 2 1 has two functions: first, under normal circumstances, the well fluid and sand and gravel in the sand setting pipe will not enter the oil pipe; second, if the hole of the filter screen 2 1 9 and the perforated oil pipe 20 is blocked, the well fluid cannot enter the oil pipe smoothly, and the well fluid will flow into the sand setting pipe along the valve hole on the side of the one-way valve body 2 1, causing the pressure in the sand setting pipe to rise. Because the screw pump is always lifted upward, the liquid in the oil pipe decreases, and the external liquid does not supplement, forming a negative pressure. When the pressure difference between the two sides of the one-way valve body 2 1 reaches a certain value, the liquid in the sand setting pipe will impact the ball and compress the spring upward, and the liquid will enter the oil pipe from the lower end of the valve body along the gap. Due to the pressure difference, the liquid has a certain impact force, which can flush away the sand and mud blocked in the liquid inlet, ensuring smooth liquid inlet of the unit.
[0036] The utility model discloses a filter screen is placed to the lower extreme of unit with fairing, and power cable is wrapped in fairing, avoids the power cable to have the knock damage. The whole sand setting system is at the bottom, and the sand and gravel will sink to the sand setting pipe of the lower extreme after entering unit, and the sand setting pipe upper end is equipped with the check valve body, can effectively reduce the sand and gravel into the pump, causes the situation of pump jamming and pump blocking. When the liquid inlet is blocked, can also flush and clean according to the structure of itself, avoid the dry grinding of pump to cause the damage of pump, improve the drainage efficiency simultaneously. The gas-liquid separation section is longer, and the gas-liquid separation is more sufficient, effectively reduces the gas into the pump, avoids causing the gas lock and dry grinding of screw pump, improves the pump efficiency. The utility model can fully avoid the damage that sand particle and gas possibly bring to screw pump, guarantees the oil well operation efficiency, prolongs the service life of unit.
Claims
1. An inverted gas and sand control ESP device, characterized in that: The utility model provides a kind of screw pump (1), suction assembly (3), protector (4), power cable (5), submersible permanent magnet motor (6), downhole sensor (7), flow guide cover (8), oil pipe (11), filter screen one (12), seamless circular tube, filter screen two (19), perforated oil pipe (20) and sand pipe (24), the screw pump (1), suction assembly (3), protector (4), submersible permanent magnet motor (6) and downhole sensor (7) are sequentially connected from top to bottom, suction assembly (3), protector (4), submersible permanent magnet motor (6) and downhole sensor (7) are arranged in flow guide cover (8), and annulus one (25) is equipped between with flow guide cover (8) inner wall;The screw pump (1) is connected with suction assembly (3) by pump connector (2), and pump connector (2) is equipped with flat hole;Power cable (5) one end is connected with the terminal box on well, and power cable (5) passes through the flat hole of pump connector (2), and the other end is connected with submersible permanent magnet motor (6);The upper end of flow guide cover (8) is fixedly connected with pump connector (2), and the lower end is connected with multiple oil pipes (11), and power cable (5) between pump connector (2) and submersible permanent magnet motor (6) is arranged in flow guide cover (8);Filter screen one (12) is installed on the outside of oil pipe (11), and multiple long slot holes are evenly arranged on filter screen one (12) in circumferential direction, the upper end of filter screen one (12) is conical structure, the lower end is connected with seamless circular tube, and oil pipe (11) is arranged in seamless circular tube, and annulus two (26) is equipped between seamless circular tube and oil pipe (11), and seamless circular tube is connected with sand pipe (24) by sand pipe connector (23);The lowermost oil pipe (11) is perforated oil pipe (20), and the hole of perforated oil pipe (20) is wrapped with filter screen two (19) outside;Perforated oil pipe (20) lower end is equipped with one-way valve body (21), and one-way valve body (21) lower end is connected with sand pipe connector (23), and is communicated with sand pipe (24), and the bottom of sand pipe (24) is closed.
2. The inverted gas and sand control ESP device of claim 1, wherein: The lower end of flow guide cover (8) is connected with multiple oil pipes (11) by flow guide cover connector (9) and oil pipe connector (10).
3. The inverted gas and sand control ESP device of claim 1 or 2, wherein: The seamless circular tube includes seamless circular tube one (16) and seamless circular tube two (18), the upper end of seamless circular tube one (16) is connected with filter screen one (12) by filter screen connector (13) and seamless circular tube one connector (15), the lower end of seamless circular tube one (16) is connected with the upper end of seamless circular tube two (18), and the lower end of seamless circular tube two (18) is connected with sand pipe connector (23) by seamless circular tube two connector (22).
4. The inverted gas and sand control ESP device of claim 3, wherein: The outside of oil pipe (11) is welded with righting block (14), and the righting block (14) is attached to the inner wall of seamless circular tube one connector (15).
5. The inverted gas and sand control ESP device of claim 1 or 2, wherein: Multiple oil pipes (11) are connected by oil pipe clamp (17).
6. The inverted gas and sand control ESP device of claim 1 or 2, wherein: The one-way valve body (21) is equipped with spring and ball inside.
7. The inverted gas and sand control ESP device of claim 1 or 2, wherein: The width of long slot hole is 0.3mm.