Plug-in sealing structure of a submersible screw pump well washing pipe string

Abstract

This utility model relates to a plug-in sealing structure for a submersible screw pump well-washing tubing string in the field of submersible screw pump technology. It includes a flow guide shroud, inside which a submersible screw pump is installed. A central tube is plugged into the top of the submersible screw pump via a plug-in sealing structure, and an oil pipe is installed outside the central tube. This sealing structure ensures the sealing effectiveness of the central tube after plugging in, even in a non-clean medium environment and under horizontal conditions. It allows for an effective seal between the central tube and the screw pump, while also ensuring annular space between the central tube and the oil pipe, and between the flow guide shroud and the screw pump. This further ensures the sealing of the injected water and the direction of water flow. Multiple O-ring seals are used, providing a high pressure rating and maintaining effective sealing even after multiple pluggings. The sealing cylinder and sealing plunger surfaces are chrome-plated, solving the corrosion problem of the sealing ring surface and improving the practicality of the device.

Description

Technical Field

[0001] This utility model relates to the field of submersible screw pump technology, and in particular to a plug-in sealing structure for a submersible screw pump well washing tubing string. Background Technology

[0002] Screw pump oil extraction is a method of oil extraction 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] To address the issue of unstable water injection volume in submersible screw pumps leading to reinjected water entering the formation, we designed a well-washing tubing structure. This well-washing tubing structure needs to ensure the sealing of the interface between the central tube and the screw pump, as well as the annulus between the central tube and the tubing, and the annulus between the flow guide and the screw pump. This prevents the injected water from not flowing into the required channel due to poor sealing. Therefore, we propose an insertion sealing structure for the well-washing tubing of a submersible screw pump. Utility Model Content

[0004] To address the aforementioned issues, this invention provides an insertion sealing structure for a submersible screw pump well-washing tubing string, ensuring a sealing effect after the central tube is inserted.

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

[0006] A plug-in sealing structure for a submersible screw pump well washing string includes a flow guide shroud. A submersible screw pump is installed inside the flow guide shroud. A central tube is plugged into the top of the submersible screw pump via the plug-in sealing structure. An oil pipe is installed outside the central tube. The plug-in sealing structure includes a sealing cylinder. A central tube connector for connecting to the central tube is installed at the top of the sealing cylinder. A flow divider connector connected via an oil pipe coupling is installed outside the sealing cylinder. A sealing plunger is installed at the bottom of the sealing cylinder. Multiple O-rings are arranged outside the sealing plunger and inside the sealing cylinder. A double-lock connector is installed at the bottom of the sealing plunger.

[0007] In a further technical solution, the bottom end of the sealing plunger is inserted into the middle end of the double-lock connector, the bottom end of the diverter is inserted into the top end of the double-lock connector, and diverter ports are also provided on both sides of the diverter.

[0008] In a further technical solution, a cable sealing block is installed on the outside of the shunt connector, and a flow guide clamp is installed on the bottom of the cable sealing block. The cable sealing block is connected to the flow guide clamp.

[0009] In a further technical solution, a cable through hole is provided on one side of the inside of the cable sealing block, a cable sealing ring is installed at the top of the cable through hole, and a sealing cap is installed at the top of the cable sealing ring.

[0010] In a further technical solution, the sealing cap has a through hole at its middle end for cable penetration.

[0011] In a further technical solution, both the sealing cylinder and the sealing plunger are coated with a chrome plating layer.

[0012] The beneficial effects of this utility model are:

[0013] This sealing structure ensures the sealing effectiveness of the central tube after insertion in a non-clean medium environment and under horizontal conditions. It enables an effective seal between the central tube and the screw pump, while also ensuring the annulus between the central tube and the tubing, and between the flow guide and the screw pump. This further guarantees the sealing of the injected water and the direction of water injection. It uses multiple O-ring seals with high pressure ratings and maintains effective sealing even after multiple insertions. The sealing cylinder and sealing plunger surfaces are chrome-plated, solving the corrosion problem of the sealing ring surface and improving the practicality of the device. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0015] Figure 2 This is a schematic diagram of the plug-in sealing structure of an embodiment of this utility model.

[0016] Explanation of reference numerals in the attached figures:

[0017] 1. Central tube; 2. Oil pipe; 3. Insert sealing structure; 4. Submersible screw pump; 5. Flow guide; 31. Central tube joint; 32. Sealing cylinder; 33. Oil pipe coupling; 34. Sealing plunger; 35. O-ring; 36. Diverter joint; 37. Double-lock joint; 38. Sealing cap; 39. Cable sealing ring; 310. Cable sealing block; 311. Flow guide coupling. Detailed Implementation

[0018] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0019] Example:

[0020] like Figures 1-2As shown, a plug-in sealing structure for a submersible screw pump well cleaning string includes a flow guide shroud 5. A submersible screw pump 4 is installed inside the flow guide shroud 5. A central tube 1 is plugged into the top of the submersible screw pump 4 via a plug-in sealing structure 3. An oil pipe 2 is installed outside the central tube 1. The plug-in sealing structure 3 includes a sealing cylinder 32. A central tube connector 31 for connecting to the central tube 1 is installed at the top of the sealing cylinder 32. A diverter connector 36 connected via an oil pipe coupling 33 is installed outside the sealing cylinder 32. A sealing plunger 34 is installed at the bottom inside the sealing cylinder 32. Multiple O-rings 35 are arranged outside the sealing plunger 34 and inside the sealing cylinder 32. A double-lock connector 37 is installed at the bottom of the sealing plunger 34. The bottom end of plug 34 is inserted into the middle end of double-lock connector 37, and the bottom end of diverter 36 is inserted into the top end of double-lock connector 37. Diverter 36 also has diverter ports on both sides. A cable sealing block 310 is installed on the outside of diverter 36. A flow guide clamp 311 is installed on the bottom of the cable sealing block 310. The cable sealing block 310 is connected to the flow guide 5 through the flow guide clamp 311. A cable through hole is opened on one side of the inside of the cable sealing block 310. A cable sealing ring 39 is installed on the top of the cable through hole. A sealing cap 38 is installed on the top of the cable sealing ring 39. A through hole for cable penetration is opened in the middle of the sealing cap 38. The surfaces of sealing cylinder 32 and sealing plunger 34 are coated with chrome plating.

[0021] The working principle of the above technical solution is as follows:

[0022] By connecting the bottom of the central tube 1 to the central tube 1 and the tubing 2, with the lower part of 7 connected to the submersible screw pump 4 and the upper part of 7 connected to the sealing plunger 34 and the diverter 36, the bottom end of the guide sleeve coupling 311 connected to the guide sleeve 5, and the bottom of the tubing 2 connected to the tubing coupling 33 and the diverter 36, the well washing tubing structure can ensure effective sealing after insertion in a non-clean medium environment and in a horizontal state. It also adopts multiple O-ring seals, has a high pressure rating, and can still maintain effective sealing even after multiple insertions. The surfaces of the sealing cylinder 32 and the sealing plunger 34 are chrome-plated, which solves the corrosion problem of the sealing ring surface and ensures that the insertion seal can be used multiple times in a corrosive environment.

[0023] 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 plug-in sealing structure for a submersible screw pump well washing string, comprising a flow guide (5), characterized in that: The flow guide (5) is equipped with a submersible screw pump (4). The top of the submersible screw pump (4) is sealed with a central tube (1) through a set plug-in sealing structure (3). An oil pipe (2) is installed on the outside of the central tube (1). The plug-in sealing structure (3) includes a sealing cylinder (32). The top of the sealing cylinder (32) is equipped with a central tube connector (31) for connecting with the central tube (1). The outside of the sealing cylinder (32) is equipped with a diverter connector (36) connected by an oil pipe coupling (33). The bottom of the sealing cylinder (32) is equipped with a sealing plunger (34). Multiple O-rings (35) are set on the outside of the sealing plunger (34) and inside the sealing cylinder (32). The bottom of the sealing plunger (34) is equipped with a double-lock connector (37).

2. The plug-in sealing structure for a submersible screw pump well-washing string according to claim 1, characterized in that: The bottom end of the sealing plunger (34) is inserted into the middle end of the double-lock connector (37), the bottom end of the diverter (36) is inserted into the top end of the double-lock connector (37), and diverter ports are also provided on both sides of the diverter (36).

3. The plug-in sealing structure for a submersible screw pump well-washing tubing string according to claim 1, characterized in that: The outside of the diverter (36) is equipped with a cable sealing block (310), and the bottom of the cable sealing block (310) is equipped with a flow guide clamp (311). The cable sealing block (310) is connected to the flow guide (5) through the flow guide clamp (311).

4. The plug-in sealing structure for a submersible screw pump well-washing tubing string according to claim 3, characterized in that: The cable sealing block (310) has a cable through hole on one side inside. A cable sealing ring (39) is installed at the top of the cable through hole, and a sealing cap (38) is installed at the top of the cable sealing ring (39).

5. The plug-in sealing structure for a submersible screw pump well-washing string according to claim 4, characterized in that: The sealing cap (38) has a through hole at the middle end for cable penetration.

6. The plug-in sealing structure for a submersible screw pump well-washing string according to claim 1, characterized in that: The surfaces of the sealing cylinder (32) and the sealing plunger (34) are both coated with a chrome plating layer.

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