A well washing pipe string structure of an oil submersible screw pump without contaminating the formation

Abstract

The utility model relates to a kind of not to contaminate formation's submersible screw pump well washing pipe column structure of submersible screw pump technical field, including oil well casing, the inside middle end of oil well casing is equipped with fairing, the inside middle end of fairing is equipped with screw pump, the top of screw pump is connected with central tube suspension sealing structure, the bottom of screw pump is equipped with motor protector;The device injects water from water injection port, enters tubing and central tube annulus, water passes through water injection flow channel conversion hole and enters submersible screw pump and fairing annulus, and then enters screw pump suction inlet, fairing tail portion is equipped with check valve to prevent back injection water irrigation into formation, formation produced water can also pass through check valve and enter fairing, and then enter screw pump suction inlet, the design of this pipe column structure, establish not to depend on water injection pipe, water injection flow channel not to contaminate formation, there will not be due to the instability of water injection volume, back injection water irrigation into formation can occur, affect the situation of gas production occurs.

Description

Technical Field

[0001] This utility model relates to the field of submersible screw pump technology, and in particular to a submersible screw pump well washing tubing structure that does not contaminate the formation. Background Technology

[0002] Screw pump oil extraction is an oil extraction method that uses a surface or downhole drive unit to operate a screw pump, lifting crude oil from the well to the surface. This technology has been applied to crude oil extraction since the late 1970s, and is particularly suitable for oil wells with high viscosity (0-2000 mPa·s) and sand content below 5%. The maximum insertion depth is 1600 meters, and the ambient temperature range is below 120℃. According to the driving method, it can be divided into two categories: electric submersible screw pumps and surface-driven downhole screw pumps. The electric submersible type does not require the transmission of power by the sucker rod, while the surface-driven type drives the downhole pump through the rotation of the sucker rod.

[0003] When using submersible screw pumps in coalbed methane wells, a water return pipe is usually added to replenish water in the wellbore. Its main function is to increase the drainage capacity of the submersible screw pump to clean the pump inlet, pump body, and pump top tubing, and to discharge accumulated solid impurities (coal powder, mud and sand) to the surface. However, the traditional water return pipe is installed outside the tubing. During the water injection process, due to the instability of the water injection volume, water may be injected back into the formation, affecting gas production. Therefore, we propose a submersible screw pump well cleaning tubing structure that does not pollute the formation. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a submersible screw pump well washing tubing structure that does not contaminate the formation, offering the advantages of not relying on water injection pipes and not contaminating the formation.

[0005] The technical solution of this utility model is:

[0006] A formation-free submersible screw pump well-washing string structure includes a well casing, a first flow guide shroud installed at the middle of the inner side of the well casing, a screw pump installed at the middle of the inner side of the first flow guide shroud, a central tube suspension sealing structure connected to the top of the screw pump, and a motor installed at the bottom of the screw pump.

[0007] The protector has a submersible motor installed at its bottom, a single-flow valve at the bottom of the first flow guide, a water inlet installed at the top of one side of the oil pipe, a central pipe sealed to the top of the screw pump via a central pipe insertion sealing structure, an oil pipe installed outside the central pipe, and water inlet flow channel conversion holes opened at the bottom of both sides of the oil pipe.

[0008] In a further technical solution, a screw pump suction port is provided at the bottom end of the surface of the screw pump.

[0009] In a further technical solution, a submersible cable is installed on one side of the top of the submersible motor, and a cable sealing sleeve is installed at the connection between the submersible cable and the first guide shield.

[0010] In a further technical solution, a casing perforation section is formed on the bottom surface of the oil well casing.

[0011] In a further technical solution, the central tube insertion sealing structure includes a central tube connector mounted on the central tube. A sealing cylinder is installed at the bottom end of the central tube connector, and a sealing plunger is installed at the bottom end of the sealing cylinder. Multiple O-rings are installed on the surface of the sealing plunger, and a flow divider is installed on the surface of the sealing plunger. The top end of the flow divider is connected to the sealing cylinder through a set oil pipe coupling. A double-lock connector is installed at the bottom end of the flow divider. A second flow guide is installed on the outside of the double-lock connector. A cable sealing block is installed on the outside of the flow divider. The second flow guide is connected to the cable sealing block through an installed flow guide coupling. A cable sealing ring is installed on one side of the top end of the cable sealing block, and a sealing cap is installed on the top end of the cable sealing ring.

[0012] In a further technical solution, the central tube suspension sealing structure includes a suspension sealing head connected to the central tube. The surface of the suspension sealing head is provided with multiple O-rings. The surface of the suspension sealing head is sealed with a water injection short section through a pressure cap. A connecting hoop is installed at the bottom end of the suspension sealing head.

[0013] The beneficial effects of this utility model are:

[0014] The device injects water through the water inlet, which enters the annulus between the oil pipe and the central pipe. The water then flows through the water injection channel conversion hole into the annulus between the submersible screw pump and the guide shroud, and subsequently into the screw pump suction inlet. A one-way valve is installed at the tail of the guide shroud to prevent reinjected water from entering the formation. Formation-produced water can also enter the guide shroud through the one-way valve and then enter...

[0015] The design of this tubular structure at the screw pump inlet establishes a water injection channel that does not rely on water injection pipes and does not pollute the formation. This prevents the situation where back-injected water enters the formation due to unstable water injection volume, thus affecting gas production. Attached Figure Description

[0016] Figure 1 is a schematic diagram of the overall structure of an embodiment of this utility model;

[0017] Figure 2 is a schematic diagram of the cardiac tube insertion sealing structure in an embodiment of this utility model;

[0018] Figure 3 is a schematic diagram of the cardiac tube suspension sealing structure in an embodiment of this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Central tube; 2. Central tube suspension sealing structure; 3. Water injection port; 4. Oil tubing; 5. Central tube insertion sealing structure; 6. Submersible cable; 7. Oil well casing; 8. Cable sealing sleeve; 9. Water injection channel conversion hole; 10. Screw pump; 11. First guide shield; 12. Screw pump suction inlet; 13. Motor protector; 14. Submersible motor; 15. Check valve; 16. Casing perforation section;

[0021] 51. Center pipe joint; 52. Sealing cylinder; 53. Oil pipe coupling; 54. Sealing plunger; 55. O-ring; 56. Diverter joint; 57. Double-locking joint; 58. Sealing cap; 59. Cable sealing ring; 510. Cable sealing block; 511. Flow guide coupling; 512. Second flow guide;

[0022] 21. Suspension sealing head; 22. Pressure cap; 23. O-ring; 24. Connecting clamp; 25. Water injection short section. Detailed Implementation

[0023] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0024] Example:

[0025] As shown in Figure 1- Figure 3 As shown, a non-contaminating submersible screw pump well washing string structure includes a well casing 7, a first guide shield 11 installed at the middle of the inner end of the well casing 7, a screw pump 10 installed at the middle of the inner end of the first guide shield 11, a central tube suspension sealing structure 2 connected to the top of the screw pump 10, a motor protector 13 installed at the bottom of the screw pump 10, and a submersible motor 14 installed at the bottom of the motor protector 13.

[0026] A one-way valve 15 is provided at the bottom of the flow guide shroud 11. A water injection port 3 is installed at the top of one side of the oil pipe 4. The top of the screw pump 10 is sealed to the central pipe 1 through the central pipe insertion sealing structure 5. An oil pipe 4 is installed on the outside of the central pipe 1. Water injection flow channel conversion holes 9 are opened at the bottom of both sides of the oil pipe 4. A screw pump suction port 12 is opened at the bottom of the surface of the screw pump 10. A submersible cable 6 is installed on one side of the top of the submersible motor 14. A cable sealing sleeve 8 is installed at the connection between the submersible cable 6 and the first flow guide shroud 11. A casing perforation section 16 is opened on the bottom surface of the oil well casing 7.

[0027] The working principle of the above technical solution is as follows:

[0028] The entire structure, from bottom to top, consists of a check valve, a flow guide, a submersible screw pump (composed of a screw pump, motor protector, submersible motor), a central tube, a central tube suspension seal, and a central tube insertion seal. In operation, water is injected into the water inlet 3, entering the annulus between the oil pipe 4 and the central tube 1. The water then flows through the water inlet conversion hole 9 into the annulus between the submersible screw pump and the first flow guide 11, and then into the screw pump suction inlet 12. The check valve 15 at the tail of the first flow guide 11 effectively prevents reinjection water from entering the formation. Formation-produced water can also enter the first flow guide 11 through the check valve 15, and then into the screw pump suction inlet 12. The water produced by the screw pump 10 reaches the surface through the interior of the central tube 1, effectively preventing reinjection water from entering the formation.

[0029] In another embodiment, such as Figure 2 As shown, the central tube insertion sealing structure 5 includes a central tube connector 51 installed on the central tube 1. A sealing cylinder 52 is installed at the bottom end of the central tube connector 51, and a sealing plunger 54 is installed at the bottom end of the sealing cylinder 52. Multiple O-rings 55 are installed on the surface of the sealing plunger 54, and a flow divider 56 is installed on the surface of the sealing plunger 54. The top end of the flow divider 56 is connected to the sealing cylinder 52 through a set oil pipe coupling 53. A double-lock connector 57 is installed at the bottom end of the flow divider 56, and a second flow guide shroud 512 is installed on the outside of the double-lock connector 57. A cable sealing block 510 is installed on the outside of the flow divider 56. The second flow guide shroud 512 is connected to the cable sealing block 510 through an installed flow guide shroud coupling 511. The second flow guide shroud 512 and the cable sealing block 510 are connected in this way. Figure 1 The first guide shield 11 has the same structure, and a cable is installed on one side of the top of the cable sealing block 510.

[0030] The sealing ring 59 and the cable sealing ring 59 are equipped with a sealing cap 58 at the top. This sealing structure ensures effective sealing after insertion in a non-clean medium environment and under horizontal conditions. The bottom of the central pipe 1 is connected to the central pipe joint 1 and the sealing cylinder 2. The lower part of the oil well casing 7 is connected to the screw pump 10. The upper part of the oil well casing 7 is connected to the sealing plunger 4 and the flow divider 6. This effectively solves the connection and sealing problem between the central pipe and the screw pump, and at the same time ensures the annulus between the central pipe and the oil pipe, and the annulus between the flow guide and the screw pump, thereby further ensuring the sealing of the injected water and the water injection direction.

[0031] In another embodiment, such as Figure 3As shown, the central pipe suspension sealing structure 2 includes a suspension sealing head 21 connected to the central pipe 1. The surface of the suspension sealing head 21 is provided with multiple O-rings 23. The surface of the suspension sealing head 21 is sealed with a water injection short section 25 through a pressure cap 22. A connecting clamp 24 is installed at the bottom end of the suspension sealing head 21. This sealing structure includes a sealing connection between the water injection short section 25 and the suspension sealing head 21, thereby ensuring the sealing of the flow direction of the injected water, so that the injected water can circulate in the central pipe 1 and the oil pipe 4.

[0032] The above embodiments merely illustrate specific implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A formation-non-contaminated submersible screw pump well-washing tubing structure, comprising well casing (7), characterized in that: The well casing (7) is equipped with a first flow guide shroud (11) at the middle of its interior. A screw pump (10) is installed at the middle of the first flow guide shroud (11). A central pipe suspension sealing structure (2) is connected to the top of the screw pump (10). A motor protector (13) is installed at the bottom of the screw pump (10). A submersible motor (14) is installed at the bottom of the motor protector (13). A single-flow valve (15) is provided at the bottom of the first flow guide shroud (11). A water injection port (3) is installed at the top of one side of the tubing (4). A central pipe (1) is sealed to the top of the screw pump (10) through a central pipe insertion sealing structure (5). A tubing (4) is installed on the outside of the central pipe (1). Water injection flow channel conversion holes (9) are opened at the bottom of both sides of the tubing (4).

2. The formation-non-contaminated submersible screw pump well-washing tubing structure according to claim 1, characterized in that: The screw pump (10) has a screw pump inlet (12) at the bottom of its surface.

3. The formation-non-contaminated submersible screw pump well-washing tubing structure according to claim 1, characterized in that: A submersible cable (6) is installed on one side of the top of the submersible motor (14), and a cable sealing sleeve (8) is installed at the connection between the submersible cable (6) and the first guide shield (11).

4. The formation-non-contaminated submersible screw pump well-washing tubing structure according to claim 1, characterized in that: The bottom surface of the oil well casing (7) is provided with a casing perforation section (16).

5. The formation-non-contaminated submersible screw pump well-washing tubing structure according to claim 1, characterized in that: The central tube insertion sealing structure (5) includes a central tube connector (51) installed on the central tube (1). A sealing cylinder (52) is installed at the bottom end of the central tube connector (51). A sealing plunger (54) is installed at the bottom end of the sealing cylinder (52). Multiple O-rings (55) are installed on the surface of the sealing plunger (54). A flow divider (56) is installed on the surface of the sealing plunger (54). The top end of the flow divider (56) is connected to the sealing cylinder (52) through a set oil pipe coupling (53). A double-lock connector (57) is installed at the bottom of the diverter (56). A second flow guide (512) is installed on the outside of the double-lock connector (57). A cable sealing block (510) is installed on the outside of the diverter (56). The second flow guide (512) is connected to the cable sealing block (510) through the installed flow guide clamp (511). A cable sealing ring (59) is installed on one side of the top of the cable sealing block (510). A sealing cap (58) is installed on the top of the cable sealing ring (59).

6. The formation-non-contaminated submersible screw pump well-washing tubing structure according to claim 1, characterized in that: The central tube suspension sealing structure (2) includes a suspension sealing head (21) connected to the central tube (1). The surface of the suspension sealing head (21) is provided with multiple O-rings (23). The surface of the suspension sealing head (21) is sealed with a water injection short section (25) by a pressure cap (22). A connecting hoop (24) is installed at the bottom of the suspension sealing head (21).

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