An eccentric gas-proof and sand-proof submersible screw pump device

Abstract

The utility model relates to an eccentric gas and sand prevention submersible screw pump device belongs to oil extraction equipment technical field. Technical scheme is: screw pump (2) top and sand pipe (6) and oil pipe (7) are connected, and the sand pipe is arranged in the oil pipe inside, the eccentric flow guide cover (3) is equipped in the screw pump and oil pipe cover, the eccentric flow guide cover lower end is sleeved on the eccentric suction port (8) upper end, and the eccentric flow guide cover upper end is connected with the eccentric strip seam screen (13), the eccentric flow guide cover (3) and eccentric strip seam screen side are equipped with recess one (10) and recess two (15) respectively, and recess one and recess two are communicated, and the recess one and recess two are equipped with power cable (9). The utility model has the advantages of: avoid the power cable to knock and damage, reduce the projection area of unit, and the unit is more smooth to hoist, can carry out gas-liquid separation simultaneously, avoid the damage that sand particle and gas possibly bring to screw pump fully, and guarantee oil well operation efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to an eccentric type gas and sand prevention submersible screw pump device and belongs to the technical field of oil extraction equipment. BACKGROUND

[0002] The electric submersible screw pump oil extraction system directly drives the screw pump to lift liquid by using the downhole submersible motor, and the advantages of the rodless oil extraction system, downhole motor driving and screw pump are integrated. Compared with the rod pump, the energy saving can reach 30%-60%, and the pump depth can be broken through, and it can be applied to heavy oil wells, sand wells, gas wells, inclined wells and horizontal wells.

[0003] For coalbed methane wells, there is more downhole gas, and in the process of drainage and extraction, the gas-liquid mixture is lifted to the wellhead together. When passing through the screw pump, the dry grinding phenomenon occurs in the area where the gas exists without the lubrication of the well fluid. Long-term operation will accelerate the damage of the screw pump and affect the service life. Some wells have a large amount of sand, and the sand particles entering the pump or the sand accumulation in the pump will also accelerate the wear of the pump. In severe cases, the pump may be stuck, causing the unit to stop and affecting the yield.

[0004] The existing Chinese patent ZL 202223379551.2, entitled "Electric submersible screw pump device for preventing sand and gas", directly sleeves the annular screen pipe and the flow guide cover pipe on the screw pump and the oil pipe by adding the annular screen pipe and the flow guide cover pipe, to achieve the dual purposes of preventing sand through the annular screen pipe and supplying gas upward to escape to prevent gas, thereby protecting the screw pump and reducing the damage to the screw pump. The existing technology has the following problems: the power cable is attached to the outer wall of the flow guide cover pipe and is fixed by a cable clamp. Since the flow guide cover pipe increases the projected area of the unit, the power cable may be knocked during tripping, which increases the risk of the unit being stuck. In addition, the selection of the annular screen pipe is also important. The smallest sand particle (very fine sand) has a particle size of less than 0.15mm,

[0005] If small sand particles are to be prevented from entering the screw pump, an annular screen pipe with a smaller aperture needs to be selected, which will slow down the downward flow of well fluid and greatly reduce the efficiency of oil well operation. INVENTION CONTENTS

[0006] The utility model aims to provide an eccentric type gas and sand prevention submersible screw pump device, which not only achieves the purpose of reducing the projected area and protecting the power cable, but also can separate gas and liquid, prevent sand particles from damaging the screw pump, ensure the efficiency of oil well operation, and solve the problems in the background technology.

[0007] The technical scheme of the utility model is as follows:

[0008] The eccentric gas-proof and sand-proof submersible screw pump device comprises a screw pump, an eccentric fairing, a sand setting pipe, a tubing, an eccentric suction inlet and an eccentric slotted screen, the bottom end of the screw pump is connected with the eccentric suction inlet, the top end of the screw pump is connected with the sand setting pipe and the tubing, the sand setting pipe is arranged in the tubing, and an annular space one is arranged between the sand setting pipe and the tubing; the screw pump and the tubing are sleeved with the eccentric fairing, the lower end of the eccentric fairing is sleeved on the upper end of the eccentric suction inlet, the upper end of the eccentric fairing is connected with the eccentric slotted screen, the upper end of the tubing extends out of the eccentric slotted screen, and an annular space two is arranged between the tubing and the eccentric fairing; the side surface of the eccentric fairing and the side surface of the eccentric slotted screen are respectively provided with a groove one and a groove two, the groove one and the groove two are communicated, and a power cable is arranged in the groove one and the groove two.

[0009] The top of the screw pump is connected with the sand setting pipe and the tubing through a pump joint.

[0010] The upper end of the eccentric fairing is connected with the eccentric slotted screen through a fairing joint.

[0011] The top of the sand setting pipe is provided with a conical umbrella cap, the diameter of the conical umbrella cap is slightly larger than that of the sand setting pipe, and the length of the sand setting pipe is less than that of the tubing.

[0012] The upper end of the eccentric suction inlet is uniformly provided with a plurality of liquid inlets in the circumferential direction, and well fluid between the eccentric fairing and the screw pump enters the cavity of the screw pump through the liquid inlets.

[0013] The top end of the eccentric slotted screen is provided with a two-half-ring structure, and the eccentric slotted screen is fixed on the tubing through the two-half-ring structure.

[0014] The upper end of the tubing is provided with a centralizer, which can reduce the vibration caused by the operation of the unit and prolong the service life of the unit. The upper end of the centralizer is the tubing until the wellhead.

[0015] A plurality of long hole are uniformly arranged on the eccentric slotted screen, the aperture of the long hole is 0.3mm, and the long hole can block the sand and gravel with a diameter of more than 0.3mm from entering the unit.

[0016] The top of the sand setting pipe is provided with an opening around, and the well fluid in the sand setting pipe enters the annular space one between the sand setting pipe and the tubing through the opening.

[0017] The eccentric suction inlet is provided with a positioning stopper, the eccentric fairing is positioned by being installed at the positioning stopper, and the eccentric fairing is fixedly connected with the eccentric suction inlet through bolts.

[0018] The groove one and the groove two are both rectangular grooves, and both are provided with cover plates.

[0019] The lower end of the eccentric suction inlet is connected with the upper end of a universal shaft assembly, the lower end of the universal shaft assembly is connected with a motor and a protector, and the universal shaft assembly provides power for the operation of the unit.

[0020] The pump joint is a variable diameter joint.

[0021] The eccentric suction inlet, the eccentric flow guide cover and the eccentric slotted screen are all eccentric structures, and the side of the eccentric flow guide cover and the eccentric slotted screen is respectively provided with a rectangular groove inwardly, and the internal structure of the eccentric flow guide cover and the eccentric slotted screen except the rectangular groove is left-right symmetrical.

[0022] The length of the eccentric flow guide cover is different according to the gas content of the well, the number of the eccentric flow guide cover can be multiple, two adjacent eccentric flow guide covers are connected through the flow guide cover joint, and the uppermost eccentric flow guide cover is connected with the eccentric slotted screen through the flow guide cover joint, so that the gas-liquid separation can be fully realized.

[0023] The universal shaft assembly, the screw pump, the sand setting pipe, the oil pipe, the two half ring structures, the motor and the protector are all common devices in the field.

[0024] The well fluid enters the annulus two between the oil pipe and the eccentric flow guide cover through the eccentric slotted screen, the aperture of the long hole on the eccentric slotted screen is 0.3mm, which can prevent the sand with a diameter of more than 0.3mm from entering the unit; the well fluid realizes gas-liquid separation after entering the unit, the gas with small density goes upward, the well fluid goes downward along the annulus two until entering the screw pump cavity from the eccentric suction inlet; the well fluid is lifted upward by the screw pump rotating under the driving of the motor after the unit operates; the well fluid continues to go upward after coming out of the screw pump, passes through the sand setting pipe and continues to go upward along the opening at the top of the sand setting pipe, and the sand in the well fluid falls into the annulus one between the sand setting pipe and the oil pipe and deposits at the bottom due to the gravity, which avoids the sand from adhering and accumulating to the inner wall of the oil pipe when the well fluid is lifted upward, effectively reduces the running resistance and ensures the drainage efficiency. The conical umbrella cap at the top of the sand setting pipe is slightly larger in diameter than the sand setting pipe, which can avoid the sand in the well fluid from falling back into the sand setting pipe when the unit stops. The power cable comes out of the motor, passes through the protector and the universal shaft assembly, reaches the eccentric flow guide cover and the eccentric slotted screen, is placed into the grooves one and two inward of the eccentric flow guide cover and the eccentric slotted screen, and is buckled with the cover plate, which reduces the projection area of the unit and effectively reduces the damage to the power cable in the process of lowering and lifting the unit, saving the operation cost.

[0025] The beneficial effects of the utility model are that the damage of the power cable due to collision is avoided, the projection area of the unit is reduced, the unit is more smoothly lowered and lifted, the operation cost is saved, gas-liquid separation can be realized, the damage of the screw pump caused by the sand and gas is avoided, and the oil well operation efficiency is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a structural schematic view of the utility model;

[0027] Figure 2 It is eccentric guide cover structure schematic view of the utility model;

[0028] Figure 3 It is eccentric guide cover side view of the utility model;

[0029] Figure 4 It is eccentric suction inlet structure schematic view of the utility model;

[0030] Figure 5 It is Figure 4 B-B section view of the utility model;

[0031] Figure 6 It is eccentric strip slot screen structure schematic view of the utility model;

[0032] Figure 7 It is eccentric strip slot screen side view of the utility model;

[0033] In the drawing: universal shaft assembly 1, screw pump 2, eccentric guide cover 3, guide cover joint 4, pump joint 5, sand setting pipe 6, oil pipe 7, eccentric suction inlet 8, power cable 9, groove one 10, centralizer 11, conical umbrella cap 12, eccentric strip slot screen 13, two half ring structures 14, groove two 15, liquid inlet 16, opening 17, positioning stop 18, annulus one 19, annulus two 20. DETAILED DESCRIPTION

[0034] The utility model is further described below by examples in connection with the drawings.

[0035] An eccentric gas and sand prevention submersible screw pump device, containing screw pump 2, eccentric guide cover 3, sand setting pipe 6, oil pipe 7, eccentric suction inlet 8 and eccentric strip slot screen 13, the bottom end of screw pump 2 is connected with eccentric suction inlet 8, the top end of screw pump 2 is connected with sand setting pipe 6 and oil pipe 7, sand setting pipe 6 is arranged inside oil pipe 7, and annulus one 19 is arranged between sand setting pipe 6 and oil pipe 7;Screw pump 2 and oil pipe 7 are provided with eccentric guide cover 3, the lower end of eccentric guide cover 3 is sleeved on the upper end of eccentric suction inlet 8, the upper end of eccentric guide cover 3 is connected with eccentric strip slot screen 13, the upper end of oil pipe 7 extends out of eccentric strip slot screen 13, and annulus two 20 is arranged between oil pipe 7 and eccentric guide cover 3;The side of eccentric guide cover 3 and eccentric strip slot screen 13 is respectively provided with groove one 10 and groove two 15, groove one and groove two are communicated, and power cable 9 is arranged in groove one and groove two.

[0036] The top of screw pump 2 is connected with sand setting pipe 6 and oil pipe 7 through pump joint 5.

[0037] The upper end of eccentric guide cover 3 is connected with eccentric strip slot screen 13 through guide cover joint 4.

[0038] The top of the sand pipe 6 is provided with a conical umbrella 12, which has a diameter slightly larger than that of the sand pipe, so as to avoid the sand in the well fluid from falling into the sand pipe 6 when the unit is stopped; the length of the sand pipe 6 is less than that of the oil pipe 7, and the longer the sand pipe is, the larger the sand setting space is.

[0039] The upper end of the eccentric suction inlet 8 is uniformly provided with a plurality of liquid inlets 16 in the circumferential direction, and the well fluid between the eccentric flow guide cover 3 and the screw pump 2 enters the cavity of the screw pump 2 from the liquid inlet.

[0040] The top of the eccentric slotted screen 13 is provided with a two-half-ring structure 14, and the eccentric slotted screen 13 is fixed on the oil pipe 7 through the two-half-ring structure 14.

[0041] The upper end of the oil pipe 7 is provided with a centralizer 11, which can reduce the vibration caused by the operation of the unit and prolong the service life of the unit. The upper end of the centralizer 11 is the oil pipe until the wellhead.

[0042] The eccentric slotted screen 13 is uniformly provided with a plurality of long holes, and the aperture of the long hole is 0.3mm, which can block the sand with a diameter of more than 0.3mm from entering the unit.

[0043] The top of the sand pipe 6 is provided with an opening 17 around the periphery, and the well fluid in the sand pipe enters the annulus 19 between the sand pipe 6 and the oil pipe 7 through the opening.

[0044] The eccentric suction inlet 8 is provided with a positioning stop 18, the eccentric flow guide cover 3 is positioned by being installed to the positioning stop, and is fixedly connected with the eccentric suction inlet 8 through bolts.

[0045] The groove one 10 and the groove two 15 are both rectangular grooves, and both are provided with cover plates.

[0046] The lower end of the eccentric suction inlet 8 is connected with the upper end of the universal shaft assembly 1, the lower end of the universal shaft assembly 1 is connected with a motor and a protector, and provides power for the operation of the unit.

[0047] The pump joint 5 is a variable diameter joint.

[0048] The eccentric suction inlet 8, the eccentric flow guide cover 3 and the eccentric slotted screen 13 are all eccentric structures, and the side surfaces of the eccentric flow guide cover 3 and the eccentric slotted screen 13 are respectively provided with rectangular grooves inwardly, and due to the eccentric structure, the internal structures of the eccentric flow guide cover 3 and the eccentric slotted screen 13 except the rectangular grooves are left-right symmetrical.

[0049] According to the different gas content of the well, the length of the eccentric flow guide cover is also different, and the number of the eccentric flow guide covers can be multiple, and adjacent two eccentric flow guide covers are connected through a flow guide cover joint 4, and the uppermost eccentric flow guide cover is connected with the eccentric slotted screen 13 through the flow guide cover joint 4, so as to ensure that the gas-liquid separation can be fully performed.

[0050] In use, the well fluid enters the annulus two 20 between the eccentric slotted screen 13 and the eccentric flow guide 3, the eccentric slotted screen 13 is covered with long holes, the aperture is 0.3mm, which can prevent sand with a diameter of 0.3mm or more from entering the unit; the well fluid enters the unit to realize gas-liquid separation, the gas with small density goes up, and the well fluid goes down along the annulus two until it enters the screw pump 2 cavity from the liquid inlet of the eccentric suction port 8; according to the different gas content of the well, the length of the eccentric flow guide is also different, so as to ensure that the gas-liquid separation can be carried out fully; the lower end of the universal shaft assembly 1 is connected with the motor and the protector, which provides power for the operation of the unit; after the unit is operated, the motor drives the screw pump 2 to rotate and lift the well fluid upward; after the well fluid comes out of the screw pump 2, it continues to go upward through the sand settling pipe 6, the top of the sand settling pipe 6 has openings 17 around, and the well fluid continues to go upward along the openings at the top of the sand settling pipe, due to the action of gravity, the sand in the well fluid falls into the annulus one 19 between the sand settling pipe 6 and the oil pipe 7, and deposits at the bottom, avoiding the sand adhering and accumulating on the inner wall of the oil pipe when the well fluid is lifted upward, which can effectively reduce the running resistance and ensure the drainage efficiency. The top of the sand settling pipe 6 is provided with a conical umbrella cap 12, the diameter of the conical umbrella cap 12 is slightly larger than that of the sand settling pipe, which can avoid the sand in the well fluid falling back into the sand settling pipe 6 when the unit is stopped.

[0051] The eccentric suction port 8 is processed with a positioning stop 18, the eccentric flow guide 3 can be positioned and installed at the positioning stop, and fixed to the eccentric suction port 8 by bolts. The adjacent two eccentric flow guides 3 and the eccentric flow guide 3 and the eccentric slotted screen 13 are connected and fixed by the flow guide joint 4. The upper end of the eccentric slotted screen 13 is installed with a two-half ring structure 14 to fix the eccentric slotted screen. The upper end of the oil pipe 7 is provided with a centralizer 11, which can reduce the vibration caused by the operation of the unit and prolong the service life of the unit. The oil pipe is straight to the wellhead at the upper end of the centralizer 11.

[0052] The small flat cable (power cable) comes out of the motor, passes through the protector and the universal shaft assembly 1, reaches the eccentric flow guide 3 and the eccentric slotted screen 13, is placed into the groove one and the groove two inside the eccentric flow guide 3 and the eccentric slotted screen 13, and is buckled with the cover plate, which reduces the projection area of the unit and can effectively reduce the damage to the power cable during the process of lowering and lifting the well, saving the operation cost.

[0053] This invention, through optimization and improvement, employs an eccentric slotted screen and an eccentric flow guide. After the submersible screw pump operates, the negative pressure effect causes the well fluid to rise to the position of the eccentric slotted screen, then enters the area between the eccentric slotted screen and the thickened tubing (annular space 2), before flowing downwards. During this process, larger impurities in the well fluid are blocked by the eccentric slotted screen and do not enter the area between the screw pump and the eccentric slotted screen. For well fluid containing gas, the presence of the eccentric flow guide effectively extends the distance from the well fluid to the eccentric suction inlet at the lower end of the screw pump during downward movement. A dissipation channel for the gas in the well fluid is also formed between the eccentric flow guide and the tubing, allowing the lighter gas to gradually rise and dissipate. Well fluid enters the screw pump through the eccentric suction inlet, then flows through the reducing joint into the settling pipe. The fluid then enters the thickened tubing through the conical cap of the settling pipe. A temporary cavity (annular space 1) is formed between the settling pipe and the tubing to store impurities from the falling well fluid. The conical cap prevents impurities such as coal dust and gravel from entering the screw pump cavity after shutdown, thus preventing pump jamming. This significantly reduces the possibility of the fluid entering the eccentric suction inlet. The settling pipe's temporary storage of well fluid impurities provides further protection. In this way, sand and gas are effectively removed, minimizing potential damage to the screw pump and ensuring high well operating efficiency. This solves the technical problem in existing technologies where sand and gas entering the screw pump with the well fluid causes pump damage and reduced well operating efficiency.

[0054] This utility model is designed eccentrically, with a rectangular groove recessed inward at both the eccentric flow guide shroud 3 and the eccentric slotted screen 13 to hold a small flat cable (power cable). The small flat cable is covered with a protective cover, which reduces the projected area of ​​the unit, ensuring smooth tripping in and out of the well, and preventing damage to the power cable from impacts and scratches. Furthermore, a sand settling pipe is added to deposit sand from the well fluid into the annulus between the tubing and the sand settling pipe, effectively reducing pump jamming and extending the unit's service life.

[0055] This invention optimizes and improves existing gas and sand prevention devices through the rectangular grooves of the eccentric guide shroud 3 and the eccentric slotted screen 13, thereby reducing the projected area and protecting the power cable. Simultaneously, it enables gas-liquid separation, blocks large-diameter gravel from entering the unit, and allows gravel entering the unit to accumulate at designated locations, protecting the screw pump and reducing damage to it, thus ensuring oil well operation efficiency.

Claims

1. An eccentric gas and sand control ESP device, characterized in that: The utility model relates to a kind of eccentricity type slotted screen, including screw pump (2), eccentricity type fairing (3), sand pipe (6), oil pipe (7), eccentricity type suction inlet (8) and eccentricity type slotted screen (13), the bottom end of screw pump (2) is connected with eccentricity type suction inlet (8), the top end of screw pump (2) is connected with sand pipe (6) and oil pipe (7), sand pipe (6) is arranged in oil pipe (7) inside, annulus one (19) is equipped between sand pipe (6) and oil pipe (7);Screw pump (2) and oil pipe (7) are equipped with eccentricity type fairing (3) outside, the lower end of eccentricity type fairing (3) is sleeved on the upper end of eccentricity type suction inlet (8), the upper end of eccentricity type fairing (3) is connected with eccentricity type slotted screen (13), the upper end of oil pipe (7) is out of eccentricity type slotted screen (13), and annulus two (20) is equipped between oil pipe (7) and eccentricity type fairing (3);Eccentricity type fairing (3) and eccentricity type slotted screen (13) side are equipped with recess one (10) and recess two (15) respectively, recess one and recess two are communicated, and power cable (9) is arranged in recess one and recess two.

2. The eccentric gas and sand control ESP device of claim 1, wherein: The top of the screw pump (2) is connected with the sand pipe (6) and the oil pipe (7) through a pump joint (5).

3. The eccentric gas and sand proof ESP screw pump device according to claim 1 or 2, characterized in that: The upper end of the eccentricity type fairing (3) is connected with the eccentricity type slotted screen (13) through a fairing joint (4).

4. The eccentric gas and sand proof ESP screw pump device according to claim 1 or 2, characterized in that: The top of the sand pipe (6) is provided with a conical umbrella cap (12), the diameter of the conical umbrella cap (12) is larger than that of the sand pipe, and the length of the sand pipe (6) is less than that of the oil pipe (7).

5. The eccentric gas and sand proof ESP screw pump device according to claim 1 or 2, characterized in that: The upper end of the eccentricity type suction inlet (8) is uniformly provided with a plurality of liquid inlets (16) in the circumferential direction.

6. The eccentric gas and sand control ESP device of claim 1 or 2, wherein: The top of the eccentricity type slotted screen (13) is provided with a two-half-ring structure (14), and the eccentricity type slotted screen (13) is fixed on the oil pipe (7) through the two-half-ring structure (14).

7. The eccentric gas and sand control ESP device of claim 1 or 2, wherein: The upper end of the oil pipe (7) is provided with a centralizer (11).

8. The eccentric gas and sand control ESP device of claim 3, wherein: The eccentricity type slotted screen (13) is uniformly provided with a plurality of long holes, and the aperture of the long hole is 0.3 mm.

9. The eccentric gas and sand control ESP device of claim 1 or 2, wherein: The top of the sand pipe (6) is provided with an opening (17) around.

10. The eccentric gas and sand control ESP device of claim 1 or 2, wherein: The eccentricity type suction inlet (8) is provided with a positioning stop (18), the eccentricity type fairing (3) is positioned by being installed at the positioning stop, and is fixedly connected with the eccentricity type suction inlet (8) through bolts.

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