A gas-liquid separator for oil fields

Abstract

The invention discloses a gas-liquid separator for oil fields, comprising an oil well casing, a flow guide cover placed in the oil well casing, and a screw pump arranged in the flow guide cover, wherein the lower end of the flow guide cover is a sealed end and the upper end is an open end, and the discharge port at the upper end of the screw pump is connected with an oil outlet pipe extending upward; a lower mounting ring is arranged at the upper end of the flow guide cover, an upper mounting ring directly above the lower mounting ring is fixed to the outside of the oil outlet pipe through a bracket, a plurality of stirring shafts are rotatably mounted between the lower mounting ring and the upper mounting ring, each stirring shaft is circumferentially distributed between the oil well casing and the oil outlet pipe, and a pinion is coaxially arranged at the lower end of each stirring shaft; a driving impeller is arranged between the lower mounting ring and the oil outlet pipe, the driving impeller comprises an inner ring, an outer gear ring coaxially arranged outside the inner ring, and a plurality of blades arranged between the inner ring and the outer gear ring, the inner ring is rotatably mounted on the oil outlet pipe, and the outer gear ring is respectively meshed with each pinion. The invention can improve the effect of gas-liquid separation in the process of oil production.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield equipment, and in particular to a gas-liquid separator for oilfields. Background Art

[0002] At present, most of the oil well pumps use screw pumps. In addition to producing crude oil, the oil layer also produces a large amount of associated natural gas, and a part of this associated natural gas will inevitably enter the pump barrel of the screw pump. This part of the gas will occupy the volume of the pump barrel, thereby greatly reducing the liquid capacity of the pump barrel. Therefore, a gas-liquid separator is generally required at the input end of the screw pump to separate the gas from the crude oil.

[0003] Chinese invention patent CN210461052U discloses an inverted guide cover type electric submersible screw pump oil production device, including casing, guide cover, screw pump and submersible motor. When working, the gas-liquid mixed fluid enters the casing from the oil and gas inlet, and then flows upward along the annulus between the casing and the guide cover. When the gas-liquid mixed fluid flows to the top of the guide cover, the gas with lighter specific gravity will separate from the liquid, continue to flow upward, and be discharged out of the well, while the liquid with larger specific gravity will flow downward due to the suction action of the screw pump, flow into the annulus between the screw pump and the guide cover, and continue to flow downward into the liquid inlet of the screw pump, and then be discharged out of the well through the screw pump.

[0004] However, when the gas-liquid mixed fluid flows to the top of the guide cover, it is difficult to separate the gas completely. A part of the gas is still trapped in the liquid and cannot be discharged. The gas is carried downward by the liquid into the space between the screw pump and the guide cover and enters the screw pump. Therefore, there is a problem of poor gas-liquid separation effect. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a gas-liquid separator for oil fields to improve the effect of gas-liquid separation during oil production.

[0006] The present invention provides a gas-liquid separator for oil fields, comprising an oil well casing, a flow guide cover placed in the oil well casing, and a screw pump arranged in the flow guide cover, wherein the lower end of the flow guide cover is a sealed end and the upper end is an open end, the lower end of the screw pump is provided with a liquid inlet, the upper end is provided with a liquid discharge port, and the liquid discharge port at the upper end of the screw pump is connected to an oil outlet pipe extending upward;

[0007] A lower mounting ring is arranged at the upper end of the deflector, an upper mounting ring facing the lower mounting ring is fixed to the outside of the oil outlet pipe through a bracket, a plurality of stirring shafts are rotatably mounted between the lower mounting ring and the upper mounting ring, each stirring shaft is distributed around the oil well casing and the oil outlet pipe, and a pinion is coaxially arranged at the lower end of each stirring shaft;

[0008] A driving impeller is arranged between the lower mounting ring and the oil outlet pipe, and the driving impeller includes an inner ring, an outer gear ring coaxially arranged outside the inner ring, and a plurality of blades arranged between the inner ring and the outer gear ring. The inner ring is rotatably mounted on the oil outlet pipe, and the outer gear ring is respectively meshed with each of the pinions.

[0009] Furthermore, the lower mounting ring includes a lower ring body, an outer ring body, an upper ring body and an inner ring body, the lower ring body is arranged at the upper end of the fairing, the outer ring body extends upward from the outer periphery of the lower ring body, the outer periphery of the upper ring body is connected to the upper edge of the outer ring body, the inner ring body extends downward from the inner periphery of the upper ring body, an annular opening is formed between the lower periphery of the inner ring body and the inner periphery of the lower ring body, the outer gear ring is arranged in the annular opening, and each pinion is arranged between the lower ring body and the upper ring body.

[0010] Furthermore, the inner periphery of the lower ring body is connected to the upper end of the air guide cover, and a supporting air guide ring is connected between the outer periphery of the lower ring body and the outer periphery of the air guide cover.

[0011] Furthermore, the inner ring is installed outside the oil outlet pipe through a bearing.

[0012] Furthermore, an upper convex ring opposite to the inner ring body is provided outside the oil outlet pipe, and the inner ring and the bearing are arranged below the upper convex ring.

[0013] Furthermore, a lower convex ring located below the inner ring is also provided outside the oil outlet pipe.

[0014] Furthermore, a plurality of vertical flow guide support plates are arranged between the inner ring body and the upper convex ring.

[0015] Furthermore, an upper stabilizing ring is connected to the periphery of the upper mounting ring via a bracket, a middle stabilizing ring is connected to the periphery of the lower mounting ring via a bracket, and a lower stabilizing ring is connected to the periphery of the lower end of the fairing via a bracket.

[0016] Furthermore, a connecting flange for connecting to an oil extraction pipe is provided at the upper end of the oil outlet pipe.

[0017] Furthermore, a submersible motor is provided at the lower end of the deflector, and the submersible motor is connected to the rotor of the screw pump through a protector.

[0018] The beneficial effects of the present invention are embodied in:

[0019] When working, start the screw pump, and the fluid in the oil well casing flows upward through the space between the oil well casing and the guide cover, and then enters the guide cover from the opening at the upper end of the guide cover, and finally the oil is pumped out of the well through the screw pump. When the fluid flows through the driving impeller, it will drive the driving impeller to rotate. The rotation of the driving impeller will drive the small gears to rotate through the outer gear ring on its outer periphery, and then drive the stirring shafts to rotate, thereby stirring and exhausting the fluid flowing through the upper end of the guide cover. Therefore, compared with the natural exhaust method in the prior art, the present application uses the flow of fluid as power to drive each stirring shaft to stir and exhaust the fluid flowing through the upper end of the guide cover, without increasing too much cost, it can greatly improve the exhaust effect, thereby improving the gas-liquid separation effect during oil production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0021] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A partial enlarged view of

[0023] Figure 3 for Figure 1 AA section view;

[0024] Figure 4 for Figure 1 BB cross-sectional view;

[0025] Figure 5 for Figure 1 CC section view;

[0026] Figure 6 for Figure 1 DD cross-sectional view;

[0027] Figure 7 FIG. 2 is a schematic diagram of the working example of the present invention.

[0028] In the attached drawings, 100-oil well casing; 200-flow guide cover; 210-lower stabilizing ring; 300-screw pump; 310-liquid inlet; 320-liquid discharge port; 330-submersible motor; 340-protector; 400-oil outlet pipe; 410-connecting flange; 420-upper convex ring; 430-lower convex ring; 500-lower mounting ring; 510-lower ring body; 520-outer ring body; 530-upper ring body; 540-inner ring body; 541-vertical flow guide support plate; 550-annular opening; 560-support guide ring; 570-middle stabilizing ring; 600-upper mounting ring; 610-upper stabilizing ring; 700-agitation shaft; 710-pinion; 800-driving impeller; 810-inner ring; 820-outer gear ring; 830-blade; 840-bearing. DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0030] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0031] like Figure 1-Figure 7 As shown, an embodiment of the present invention provides a gas-liquid separator for oil fields, including an oil well casing 100, a flow guide hood 200 placed in the oil well casing 100, and a screw pump 300 arranged in the flow guide hood 200, the lower end of the flow guide hood 200 is a sealed end, and the upper end is an open end, the lower end of the screw pump 300 is provided with a liquid inlet 310, and the upper end is provided with a liquid discharge port 320, and the liquid discharge port 320 at the upper end of the screw pump 300 is connected to an oil outlet pipe 400 extending upward.

[0032] In order to facilitate fixing the upper end of the oil outlet pipe 400 under the oil extraction pipe, a connecting flange 410 for connecting with the oil extraction pipe is provided at the upper end of the oil outlet pipe 400 .

[0033] In order to drive the screw pump 300 , a submersible motor 330 is provided at the lower end of the guide cover 200 , and the submersible motor 330 is connected to the rotor of the screw pump 300 through a protector 340 .

[0034] Reference Figure 1 , Figure 2 and Figure 3A lower mounting ring 500 is provided at the upper end of the guide cover 200, and an upper mounting ring 600 is fixed to the outside of the oil outlet pipe 400 through a bracket, which is directly opposite to the lower mounting ring 500. A plurality of stirring shafts 700 are rotatably installed between the lower mounting ring 500 and the upper mounting ring 600, and each stirring shaft 700 is distributed around and between the oil well casing 100 and the oil outlet pipe 400, and a pinion 710 is coaxially provided at the lower end of each stirring shaft 700.

[0035] A driving impeller 800 is arranged between the lower mounting ring 500 and the oil outlet pipe 400. The driving impeller 800 includes an inner ring 810, an outer gear ring 820 coaxially arranged outside the inner ring 810, and a plurality of blades 830 arranged between the inner ring 810 and the outer gear ring 820. The inner ring 810 is rotatably mounted on the oil outlet pipe 400. Specifically, the inner ring 810 can be mounted outside the oil outlet pipe 400 via a bearing 840. The outer gear ring 820 is respectively meshed with each of the pinions 710.

[0036] Figure 7 The solid arrows shown represent the direction of liquid flow, and the hollow arrows represent the direction of gas flow. Figure 7 As shown, when working, the screw pump 300 is started, and the fluid in the oil well casing 100 flows upward through the space between the oil well casing 100 and the guide cover 200, and then enters the guide cover 200 from the opening at the upper end of the guide cover 200, and finally the oil is pumped out of the well through the screw pump 300. When the fluid flows through the driving impeller 800, it will drive the driving impeller 800 to rotate. The rotation of the driving impeller 800 will drive the pinions 710 to rotate through the outer gear ring 820 on its outer periphery, and then drive the stirring shafts 700 to rotate, thereby stirring and exhausting the fluid flowing through the upper end of the guide cover 200. Therefore, compared with the natural exhaust method in the prior art, the present application uses the flow of fluid as a power to drive each stirring shaft 700 to stir and exhaust the fluid flowing through the upper end of the guide cover 200, without increasing too much cost, and can greatly improve the exhaust effect, thereby improving the gas-liquid separation effect during oil production.

[0037] In a preferred embodiment, referring to Figure 1-Figure 4 The lower mounting ring 500 includes a lower ring body 510, an outer ring body 520, an upper ring body 530 and an inner ring body 540. The lower ring body 510 is arranged at the upper end of the shroud 200. The outer ring body 520 extends upward from the outer periphery of the lower ring body 510. The outer periphery of the upper ring body 530 is connected to the upper periphery of the outer ring body 520. The inner ring body 540 extends downward from the inner periphery of the upper ring body 530. An annular opening 550 is formed between the lower periphery of the inner ring body 540 and the inner periphery of the lower ring body 510. The outer gear ring 820 is arranged in the annular opening 550, and each pinion 710 is arranged between the lower ring body 510 and the upper ring body 530.

[0038] By adopting the above-mentioned lower mounting ring 500 structure, the upper ring body 530 can support and install the stirring shaft 700, and the outer ring body 520 can guide the fluid outside the guide cover 200 to the top of the upper ring body 530, and the fluid then flows into the inner ring body 540. The inner ring body 540 can guide and stabilize the fluid, ensuring that the fluid passing through the inner ring body 540 can rush directly toward the driving impeller 800, thereby improving the effect of the fluid impact driving the impeller 800 to rotate. The outer gear ring 820 of the driving impeller 800 extends into the annular opening 550, which can not only meet the meshing transmission between the outer gear ring 820 and the small gear 710 in the annular opening 550, but also can limit the outer gear ring 820 in the upper and lower directions, thereby playing a role in stabilizing the driving impeller 800.

[0039] More preferably, the inner periphery of the lower ring body 510 is connected to the upper end of the air duct 200, and the inner ring body 540 is aligned with the air duct 200, so that the fluid entering from the inner ring body 540 can flow smoothly into the air duct 200, reducing the flow resistance of the fluid inflow, and a supporting guide ring 560 is connected between the outer periphery of the lower ring body 510 and the outer periphery of the air duct 200. The supporting guide ring 560 not only supports and stabilizes the lower mounting ring 500, but also guides and reduces the flow resistance when the fluid flows from the outside of the air duct 200 to the lower mounting ring 500.

[0040] In this embodiment, refer to Figure 1 and Figure 2 The oil outlet pipe 400 is provided with an upper convex ring 420 opposite to the inner ring body 540, the inner ring 810 and the bearing 840 are arranged below the upper convex ring 420, and the oil outlet pipe 400 is also provided with a lower convex ring 430 located below the inner ring 810. By placing the inner ring 810 and the bearing 840 between the upper convex ring 420 and the lower convex ring 430, the fluid can be prevented from directly rushing to the bearing 840, thereby improving the service life of the bearing 840.

[0041] In this embodiment, refer to Figure 1 , Figure 2 and Figure 4 A plurality of vertical flow guide support plates 541 are arranged between the inner ring body 540 and the upper convex ring 420. The vertical flow guide support plates 541 can support and connect the guide cover 200 and the oil outlet pipe 400, thereby improving the stability of the structure and further stabilizing the flow of the fluid rushing toward the driving impeller 800, thereby further ensuring that the fluid can rush vertically toward the driving impeller 800.

[0042] In addition, if Figure 1 , Figure 4 , Figure 5 and Figure 6As shown, the upper mounting ring 600 is connected to an upper stabilizing ring 610 via a bracket, the lower mounting ring 500 is connected to a middle stabilizing ring 570 via a bracket, and the lower end of the guide cover 200 is connected to a lower stabilizing ring 210 via a bracket. When the gas-liquid separator is placed in the oil well casing 100, it can be positioned in the oil well casing 100 through the upper stabilizing ring 610, the middle stabilizing ring 570 and the lower stabilizing ring 210.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A gas-liquid separator for oil fields, comprising an oil well casing, a flow guide cover placed in the oil well casing, and a screw pump arranged in the flow guide cover, wherein the lower end of the flow guide cover is a sealed end and the upper end is an open end, the lower end of the screw pump is provided with a liquid inlet, and the upper end is provided with a liquid discharge port, and the liquid discharge port at the upper end of the screw pump is connected to an oil outlet pipe extending upward, characterized in that: A lower mounting ring is arranged at the upper end of the deflector, an upper mounting ring facing the lower mounting ring is fixed to the outside of the oil outlet pipe through a bracket, a plurality of stirring shafts are rotatably mounted between the lower mounting ring and the upper mounting ring, each stirring shaft is distributed around the oil well casing and the oil outlet pipe, and a pinion is coaxially arranged at the lower end of each stirring shaft; A driving impeller is arranged between the lower mounting ring and the oil outlet pipe, and the driving impeller includes an inner ring, an outer gear ring coaxially arranged outside the inner ring, and a plurality of blades arranged between the inner ring and the outer gear ring. The inner ring is rotatably mounted on the oil outlet pipe, and the outer gear ring is respectively meshed with each of the pinions.

2. The gas-liquid separator for oil field according to claim 1, characterized in that: The lower mounting ring includes a lower ring body, an outer ring body, an upper ring body and an inner ring body. The lower ring body is arranged at the upper end of the fairing, the outer ring body extends upward from the outer periphery of the lower ring body, the outer periphery of the upper ring body is connected to the upper edge of the outer ring body, the inner ring body extends downward from the inner periphery of the upper ring body, and an annular opening is formed between the lower periphery of the inner ring body and the inner periphery of the lower ring body, the outer gear ring is arranged in the annular opening, and each pinion is arranged between the lower ring body and the upper ring body.

3. The gas-liquid separator for oil field according to claim 2, characterized in that: The inner periphery of the lower ring body is connected to the upper end of the air guide cover, and a supporting air guide ring is connected between the outer periphery of the lower ring body and the outer periphery of the air guide cover.

4. The gas-liquid separator for oil field according to claim 2, characterized in that: The inner ring is installed outside the oil outlet pipe through a bearing.

5. The gas-liquid separator for oil field according to claim 4, characterized in that: An upper convex ring opposite to the inner ring body is arranged outside the oil outlet pipe, and the inner ring and the bearing are arranged below the upper convex ring.

6. The gas-liquid separator for oil field according to claim 5, characterized in that: A lower convex ring located below the inner ring is also provided outside the oil outlet pipe.

7. The gas-liquid separator for oil field according to claim 5, characterized in that: A plurality of vertical flow guide support plates are arranged between the inner ring body and the upper convex ring.

8. The gas-liquid separator for oil field according to claim 1, characterized in that: The upper mounting ring is connected to an upper stabilizing ring via a bracket, the lower mounting ring is connected to a middle stabilizing ring via a bracket, and the lower end of the fairing is connected to a lower stabilizing ring via a bracket.

9. The gas-liquid separator for oil field according to claim 1, characterized in that: The upper end of the oil outlet pipe is provided with a connecting flange for connecting with the oil pumping pipe.

10. The gas-liquid separator for oil field according to claim 1, characterized in that: A submersible motor is provided at the lower end of the deflector, and the submersible motor is connected to the rotor of the screw pump through a protector.

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