Shale oil underground multi-stage rotating disc type gas-liquid separation device

Abstract

The invention relates to the technical field of oil field underground gas-liquid separation, in particular to a shale oil underground multi-stage rotating disc type gas-liquid separation device which is characterized in that one end of a shell is connected with a liquid inlet connector, and the other end of the shell is connected with a flow dividing connector; a rotating shaft is arranged in the shell and the liquid inlet connector, and the outer wall of the rotating shaft is sleeved with a plurality of stages of disc type separation wheels along the axis. A pressurizing mechanism which is used for enabling the gas-liquid mixed liquid to move towards the shunting joint and enabling the gas-liquid mixed liquid to rotate around the rotating shaft is arranged in the liquid inlet joint; a body of the disc-type separation wheel is in a circular truncated cone shape, the large-diameter end of the disc-type separation wheel faces upwards, a top gas-phase flow guide opening is formed in the top end of the disc-type separation wheel, a bottom gas-phase flow guide opening is formed in the side wall of the disc-type separation wheel, the top gas-phase flow guide opening is close to the rotating shaft, and the bottom gas-phase flow guide opening is close to the bottom end of the disc-type separation wheel. The problem that the working performance of an electric submersible pump is affected due to the fact that the efficiency of an existing separator is sharply reduced due to the fact that the volume content of gas is too high during gas-liquid separation in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the field of gas-liquid separation in oil wells, in particular to a shale oil well multi-stage rotary disc type gas-liquid separation device. Background Art

[0002] In recent years, shale oil reservoirs have been developed on a certain scale, and submersible electric pumps have been used on a large scale in the field of artificial lifting. With the gradual decrease in production and bottom hole pressure, shale oil begins to degas in large quantities. After the well fluid enters the submersible electric pump with gas, gas lock often occurs, causing high temperature alarm shutdown. The existing downhole gas-liquid separator can handle well fluid with gas volume accounting for 30% of the total volume of oil, gas and water, and the separation efficiency can reach more than 90%, improving the efficiency of the submersible electric pump unit and extending the service life of the submersible electric pump unit. Once the gas volume fraction in the well fluid at the suction port of the submersible electric pump exceeds 30%, the separation efficiency of the separator will drop sharply with the increase of gas content in the well fluid, which directly affects the working performance of the entire submersible electric pump. Therefore, how to improve the separation efficiency of the gas-liquid separator in high gas content well fluid, effectively avoid the occurrence of gas lock, and improve the stability of the entire unit during operation is a difficult problem that needs to be solved in the field of rodless pump lifting in shale oil reservoirs. Summary of the invention

[0003] In view of this, the present invention provides a shale oil downhole multi-stage rotating disc type gas-liquid separation device to solve the problem that the efficiency of the existing separator drops sharply due to the excessive gas volume content during gas-liquid separation, thereby affecting the working performance of the submersible electric pump.

[0004] The present invention provides a shale oil downhole multi-stage rotating disc type gas-liquid separation device, comprising: a shell; One end of the shell is connected to the liquid inlet joint, and the other end is connected to the diverter joint; A rotating shaft is arranged inside the housing and the liquid inlet joint, and a plurality of disc-type separation wheels are sleeved on the outer wall of the rotating shaft along the axis line; The interior of the liquid inlet joint is in communication with the interior of the shell, and a pressurizing mechanism is provided inside the liquid inlet joint for moving the gas-liquid mixture toward the diverter joint and rotating the gas-liquid mixture around the rotating shaft; The body of the disc-type separation wheel is in the shape of a truncated cone, is hollow inside, and has the end with a larger diameter facing upward. A top gas-phase guide port is provided at the top of the disc-type separation wheel, and a bottom gas-phase guide port is provided on the side wall. The top gas-phase guide port is located close to the rotating shaft, and the bottom gas-phase guide port is located close to the bottom end of the disc-type separation wheel.

[0005] Preferably, the top diameter of the disc-type separation wheel is 0.85 to 0.9 times the diameter of the inner cavity of the shell; The angle formed by the two opposite oblique sides on the cross section of the disc-type separation wheel along the axis is 60°~61°; The axial length of the disc-type separation wheel is 40 mm to 42 mm; The wall thickness of the disc-type separation wheel is 2.5 mm to 3 mm.

[0006] Preferably, the top gas phase flow guide port is symmetrically arranged with the rotation axis as the center on the top end surface of the disc-type separation wheel. The top gas phase flow guide port is in the shape of a fan ring, and the outer diameter of the circle formed by the two fan rings is 0.6 to 0.65 times the diameter of the top end of the disc-type separation wheel; The central angle of the fan-shaped shape of the top gas phase guide port is 75° to 80°.

[0007] Preferably, the supercharging mechanism comprises: a plurality of inducers; The inducer comprises: an inducer hub and guide vanes; The inducer wheel hub is sleeved on the outside of the rotating shaft, and the guide blade is arranged on the outside of the inducer wheel hub, and the guide blade is spiral-shaped; The number of the guide blades is 2, and the two guide blades are symmetrically arranged on the outer circumference of the inducer hub, and the two guide blades have the same rotation direction.

[0008] Preferably, the shape of the outer contour line of the guide vane is determined by formulas (1) and (2); X(t)=(P / 2)*t / π (1); Y(t)=(D / 2)*sin(t) (2); Where: P is the outer profile pitch, D is the outer diameter of the guide vane along the projection direction of the rotation axis, and t is the parameter value; The shape of the inner contour line of the guide vane is determined by formulas (3) and (4); x(t)=(p / 2)*t / π (3); y(t)=(d / 2)*sin(t) (4); Wherein: p is the pitch of the inner contour, d is the outer diameter of the inner contour line along the projection direction of the rotation axis, and t is the parameter value.

[0009] Preferably, it also includes: a turbine; The turbine comprises: a turbine hub and rotating blades; The turbine hub is sleeved on the outside of the rotating shaft and is located below the disc-type separation wheel; The rotating blades are arranged outside the turbine hub, and the rotating blades are spiral-shaped; The number of the rotating blades is 3, and the 3 rotating blades are evenly distributed outside the turbine hub.

[0010] Preferably, the interior of the flow splitter joint is in communication with the interior of the shell, and the flow splitter joint has a gas phase channel and a liquid phase channel; There is a certain distance between the outer wall of one end of the flow dividing joint located inside the shell and the inner wall of the shell; The top opening of the gas phase channel is connected to the outside of the shell, and the bottom opening of the gas phase channel is connected to the inside of the diverter joint; The top opening of the liquid phase channel is connected to the interior of the diverter joint, and the bottom opening of the liquid phase channel is located on the side wall of the diverter joint and is connected to the interior of the shell.

[0011] Preferably, the angle between the axis of the gas phase channel and the liquid phase channel and the axis of the diverter joint is 10° to 11°; The diameter of the gas phase channel is smaller than the diameter of the liquid phase channel.

[0012] Preferably, a plurality of liquid inlets are provided on the side wall of the liquid inlet joint, and the plurality of liquid inlets are evenly distributed along the circumference of the liquid inlet joint; A filter screen is arranged outside the liquid inlet.

[0013] Preferably, a liner is provided on the inner wall of the shell; The number of the disc-type separation wheels is at least: 13; The number of the induction wheels is at least 2. The present invention has at least the following beneficial effects:

[0014] The present invention provides a multi-stage rotating disc-type gas-liquid separation device for shale oil wells. By arranging a multi-stage disc-type separation wheel and a pressurizing mechanism, efficient gas-liquid separation can be achieved, and the phenomenon of gas lock and high-temperature shutdown of the submersible electric pump during oil production can be effectively avoided, thereby improving the operating rate of the unit and ensuring continuous production of the oil well. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which: Figure 1 This is a schematic structural diagram of a shale oil downhole multi-stage rotating disc type gas-liquid separation device according to an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of an inducer in an embodiment of the present invention; Figure 3 is a top view of a turbine in an embodiment of the present invention; Figure 4 is a front view of a turbine in an embodiment of the present invention; Figure 5 is a top view of a disc-type separation wheel in an embodiment of the present invention; Figure 6 is a cross-sectional view of a disc-type separation wheel in an embodiment of the present invention; Figure 7 Schematic diagram of the structure of the flow splitter joint in an embodiment of the present invention.

[0016] In the figure, 1-liquid inlet connector, 2-inducer, 3-turbine, 4-rotating shaft, 5-gas-liquid separation chamber, 6-disc separation wheel, 7-liner, 8-shell, 9-diverter connector, 10-gas phase chamber, 11-liquid inlet, 12-gas-liquid suction chamber, 13-filter screen, 14-liquid phase chamber, 21-first guide blade, 22-second guide blade, 23-inducer hub, 24-outer contour line, 25-inner contour line, 31-turbine hub, 32-rotating blade, 61-disc separation wheel hub, 62-guide shell, 63-top gas phase guide port, 64-bottom gas phase guide port, 91-liquid phase channel, 92-gas phase channel. Implementation

[0017] The present invention is described below based on embodiment, but it is worth noting that the present invention is not limited to these embodiments. In the detailed description of the present invention below, some specific details are described in detail. However, for the part not described in detail, those skilled in the art can also fully understand the present invention.

[0018] In addition, those skilled in the art should understand that the drawings are only provided to illustrate the purpose, features and advantages of the present invention, and the drawings are not actually drawn to scale.

[0019] At the same time, unless the context clearly requires otherwise, the words "include", "comprises" and similar words throughout the specification and claims should be interpreted as inclusive rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0020] Figure 1 This is a schematic structural diagram of a shale oil downhole multi-stage rotating disc type gas-liquid separation device according to an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of an inducer in an embodiment of the present invention; Figure 3 is a top view of a turbine in an embodiment of the present invention; Figure 4 is a front view of a turbine in an embodiment of the present invention; Figure 5 is a top view of a disc-type separation wheel in an embodiment of the present invention; Figure 6 is a cross-sectional view of a disc-type separation wheel in an embodiment of the present invention; Figure 7 Schematic diagram of the structure of the flow divider in the embodiment of the present invention. Figure 1-7 As shown, a multi-stage rotating disc-type gas-liquid separation device for shale oil wells comprises: a shell 8; one end of the shell 8 is connected to a liquid inlet joint 1, and the other end is connected to a diverter joint 9; a rotating shaft 4 is arranged inside the shell 8 and the liquid inlet joint 1, and a plurality of disc-type separation wheels 6 are sleeved on the outer wall of the rotating shaft 4 along the axis; the interior of the liquid inlet joint 1 is communicated with the interior of the shell 8, and a booster mechanism is arranged inside the liquid inlet joint 1 for moving the gas-liquid mixture toward the diverter joint 9 and rotating the gas-liquid mixture around the rotating shaft 4; the body of the disc-type separation wheel 6 is truncated cone-shaped, hollow inside, and the end with a larger diameter faces upward, a top gas phase guide port 63 is arranged at the top of the disc-type separation wheel 6, and a bottom gas phase guide port 64 is arranged on the side wall, the top gas phase guide port 63 is located close to the rotating shaft 4, and the bottom gas phase guide port 64 is located close to the bottom end of the disc-type separation wheel 6.

[0021] In the embodiment of the present invention, the housing 8 has a gas-liquid separation chamber 5 inside, and the central shaft and the disc-type separation wheel 6 are inside the gas-liquid separation chamber 5. When the gas-liquid separation is performed, the mixed liquid enters the gas-liquid separation chamber 5 of the housing 8 through the liquid inlet joint 1; the rotating shaft 4 is connected to the submersible motor, and the submersible motor starts to drive the rotating shaft 4 to rotate along the axis; the boosting mechanism is connected to the rotating shaft 4, and the rotating shaft 4 drives the boosting mechanism to move when it rotates. After the boosting mechanism boosts the mixed liquid, the mixed liquid obtains a certain speed and moves upward to the disc-type separation wheel 6 at the bottom. The submersible motor drives the disc-type separation wheel 6 to rotate through the rotating shaft 4. When the mixed liquid reaches the disc-type separation wheel 6, the disc-type separation wheel 6 rotates, stirring the mixed liquid to rotate around it and accelerate the flow; because the gas phase density in the mixed liquid is relatively small, it will converge toward the center of the rotating shaft 4 when it rotates faster, and when it contacts the disc-type separation wheel 6 fixed on the rotating shaft 4, it will enter from the bottom gas phase guide port 64 on the side wall thereof, and after flowing through the inside of the disc-type separation wheel 6, it will flow out from the top gas phase guide port 63 at its top, and continue to move upward, along the side wall of the rotating shaft 4, to reach the disc-type separation wheel 6 of the next upper level, and from the disc-type separation wheel 6 of the upper level The gas enters the bottom gas phase guide port 64 of the separation wheel 6, and then flows out from the top gas phase guide port 63 of the upper disc separation wheel 6, and so on, after passing through all levels of disc separation wheels 6 upward, it reaches the top diversion joint 9, and flows out from the gas phase channel 92 of the diversion joint 9 to the casing annulus outside the shell 8; when the disc separation wheel 6 rotates, the liquid phase fluid with relatively large density in the mixed liquid will gather at the inner wall of the shell 8 away from the rotating shaft 4, and after reaching the diversion joint 9 along the inner wall of the gas-liquid separation chamber 5 of the shell 8 upward, it flows from the liquid phase channel 91 of the diversion joint 9 to the submersible electric pump connected to it, thereby completing gas-liquid separation. When the disc separation wheel 6 rotates, it can also break up large bubbles in the mixed liquid to prevent them from getting stuck at the gas phase guide port and unable to enter.

[0022] In the present invention, the top diameter of the disc-type separation wheel 6 is 0.85 to 0.9 times the diameter of the internal cavity of the shell 8; the angle formed between the opposite two side hypotenuses on the cross section of the disc-type separation wheel 6 along the axis is 60° to 61°; the axial length of the disc-type separation wheel 6 is 40mm to 42mm; the wall thickness of the disc-type separation wheel 6 is 2.5mm to 3mm.

[0023] In the embodiments of the present invention and Figure 6 In the figure, the disc-type separation wheel 6 includes a disc-type separation wheel hub 61 and a guide shell 62. The guide shell 62 is in a truncated cone shape and is hollow inside. A bottom gas-phase guide port 64 is arranged on the side wall of the guide shell 62 near the bottom end, and a top gas-phase guide port 63 is arranged on the top near the disc-type separation wheel hub 61. The guide shell 62 is sleeved on the outside of the disc-type separation wheel hub 61, and the disc-type separation wheel hub 61 is sleeved on the rotating shaft 4.

[0024] The top diameter D2 of the guide shell 62 of the disc-type separation wheel 6 is 0.85~0.9 times the inner diameter of the gas-liquid separation chamber 5; the angle θ1 between the two oblique sides of the guide shell 62 of the disc-type separation wheel 6 is 60°~61°, preferably 60°; the height L1 of the guide shell 62 along the axis is 40mm~42mm, preferably 40mm; the wall thickness δ2 of the guide shell 62 is 2.5mm~3mm, preferably 2.5mm; the diameter of the smaller end of the guide shell 62, that is, the bottom end, matches the diameter of the rotating shaft 4.

[0025] In the present invention, the top gas-phase guide port 63 is centered on the rotating shaft 4, and two are symmetrically arranged on the top end face of the disc-type separation wheel 6; the top gas-phase guide port 63 is in the shape of a fan ring, and the outer diameter of the circle formed by the two fan rings is 0.6~0.65 times the diameter of the top end of the disc-type separation wheel 6; the central angle of the fan ring of the top gas-phase guide port 63 is 75°~80°.

[0026] In the embodiment of the present invention, there are two top gas phase guide ports 63 and two bottom gas phase guide ports 64. When observed along the axial direction of the disc-type separation wheel hub 61, the top gas phase guide ports 63 and the bottom gas phase guide ports 64 are evenly distributed on the disc-type separation wheel 6, that is, they are relatively arranged with the disc-type separation wheel hub 61 as the center.

[0027] In the circular ring formed by the two top gas-phase guide ports 63, the diameter d2 of the outer circle is 0.6 to 0.65 times of D2, preferably 0.6 times; the central angle θ2 corresponding to the fan ring of the top gas-phase guide port 63 is 75° to 80°, preferably 80°; the edges of the top gas-phase guide port 63 and the bottom gas-phase guide port 64 are a smooth transition structure. The disc-type separation wheel 6 is fixedly connected to the rotating shaft 4 by a square key.

[0028] In the present invention, the supercharging mechanism includes: a plurality of inducers 2; the inducer 2 includes: an inducer hub 23 and guide vanes; the inducer hub 23 is sleeved on the outside of the rotating shaft 4, the guide vanes are arranged on the outside of the inducer hub 23, and the guide vanes are spiral-shaped; the number of the guide vanes is 2, the two guide vanes are symmetrically arranged on the outer circumference of the inducer hub 23, and the two guide vanes have the same rotation direction.

[0029] In the embodiment of the present invention, the liquid inlet joint 1 has a gas-liquid suction chamber 12 inside, the rotating shaft 4 is inserted into the liquid inlet joint 1, and a plurality of inducers 2 are sleeved on the rotating shaft 4 in the liquid inlet joint 1. When the rotating shaft 4 rotates, the inducer 2 is driven to rotate, thereby pressurizing the mixed liquid entering the liquid inlet joint 1, causing it to move upward, that is, toward the diversion joint 9, and at the same time, the mixed liquid obtains a certain rotation speed.

[0030] The two guide blades are the first guide blade 21 and the second guide blade 22. When observed along the axial direction of the inducer hub 23, the first guide blade 21 and the second guide blade 22 are evenly distributed on the outer surface of the inducer hub 23. The length of the first guide blade 21 and the second guide blade 22 each occupies half the circumference of the inducer hub 23. Both side edges of the first guide blade 21 and the second guide blade 22 are S-shaped. The inducer 2 is fixedly connected to the rotating shaft 4 by a square key.

[0031] The thickness δ1 of the first guide vane 21 and the second guide vane 22 is 1.5-2 mm, preferably 1 mm.

[0032] In the present invention, the shape and length of the outer contour line of the guide vane are determined by formulas (1) and (2); X(t)=(P / 2)*t / π (1); Y(t)=(D / 2)*sin(t) (2); Wherein: X(t) is the lateral analytical expression of the outer contour line of the guide blade in the two-dimensional plane, Y(t) is the longitudinal analytical expression of the outer contour line of the guide blade in the two-dimensional plane, P is the outer contour pitch, D is the outer diameter of the guide blade along the projection direction of the rotating axis 4, and t is the parameter value; The shape and length of the inner contour line of the guide vane are determined by formulas (3) and (4); x(t)=(p / 2)*t / π (3); y(t)=(d / 2)*sin(t) (4); Wherein: x(t) is the lateral analytical expression of the inner contour line of the guide vane in the two-dimensional plane, y(t) is the longitudinal analytical expression of the inner contour line of the guide vane in the two-dimensional plane, p is the inner contour pitch, d is the outer diameter of the inner contour line along the projection direction of the rotating axis 4, and t is the parameter value; In the embodiment of the present invention, the shape and length of the edge line (outer contour line 24) of the guide vane away from the inducer hub 23, that is, the structure of the outer helix, are calculated by formulas (1) and (2), wherein the outer contour pitch P of the two guide vanes is less than or equal to 52 mm, preferably 52 mm, the outer diameter D in the projection direction of the rotating shaft 4 is less than or equal to 54 mm, preferably 54 mm, and the parameter t is π.

[0033] The shape and length of the edge line (inner contour line 25) of the guide vane on the side close to the inducer hub 23, that is, the structure of the inner helix, are calculated by formulas (3) and (4), wherein the inner contour pitch p of the two guide vanes is less than or equal to 52 mm, preferably 52 mm, the outer diameter d in the projection direction of the rotating shaft 4 is the outer diameter of the inducer hub 23, that is, 27 to 28 mm, and the parameter t is π this time.

[0034] In order to improve the lifting (supercharging) effect of the mixed liquid, the values ​​of the outer contour pitch P, the outer diameter D in the projection direction of the rotating shaft 4 and the parameter value t in the inner and outer contour shape formulas of the guide vanes of the inducer 2 can be adjusted. When the values ​​of P, D and t increase, the supercharging effect of the inducer 2 can be improved, but the overall length and manufacturing cost of the inducer 2 will increase, which is specifically adjusted according to the use requirements, that is, the maximum length allowed for installation.

[0035] In the present invention, it also includes: a turbine 3; the turbine 3 includes: a turbine hub 31 and rotating blades 32; the turbine hub 31 is sleeved on the outside of the rotating shaft 4 and is located below the disc-type separation wheel 6; the rotating blades 32 are arranged on the outside of the turbine hub 31, and the rotating blades 32 are spiral-shaped; the number of the rotating blades 32 is 3, and the 3 rotating blades 32 are evenly distributed outside the turbine hub 31.

[0036] In the embodiment of the present invention, the turbine 3 is close to the liquid inlet joint 1. When the rotating shaft 4 rotates, the turbine 3 is driven to rotate. When the mixed liquid in the liquid inlet joint 1 is pressurized by the induction wheel 2 and enters the gas-liquid separation chamber 5 upward and reaches the turbine 3, the mixed liquid is pressurized again by the rotation of the turbine 3 and obtains a rotation speed, so that it moves upward, that is, toward the direction close to the diversion joint 9.

[0037] The profile of the rotating blades 32 is a cylindrical spiral line. When viewed along the axial direction of the turbine hub 31, the three rotating blades 32 are evenly distributed on the circumference of the turbine hub 31. The diameter d of the turbine hub 31 is 12The diameter D1 of the circle formed by the contour (edge ​​line) of the three rotating blades 32 away from the rotating shaft 4 is 1.6 to 1.7 times, preferably 1.6 times, of the diameter d1 of the rotating shaft 4; the diameter D1 of the circle formed by the contour (edge ​​line) of the three rotating blades 32 away from the rotating shaft 4 is 0.85 to 0.9 times, preferably 0.9 times, of the diameter of the gas-liquid separation chamber 5 inside the shell 8. The distance between each rotating blade 32 is greater than or equal to 400 mm, preferably 400 mm.

[0038] The edge of each rotating blade 32 is smoothly transitioned through an arc surface, and the turbine hub 31 is fixedly connected to the rotating shaft 4 by a square key.

[0039] In the present invention, the interior of the diverter joint 9 is connected to the interior of the shell 8, and the diverter joint 9 has a gas phase channel 92 and a liquid phase channel 91; the outer wall of one end of the diverter joint 9 located inside the shell 8 has a certain distance from the inner wall of the shell 8; the top opening of the gas phase channel 92 is connected to the outside of the shell 8, and the bottom opening of the gas phase channel 92 is connected to the interior of the diverter joint 9; the top opening of the liquid phase channel 91 is connected to the interior of the diverter joint 9, and the bottom opening of the liquid phase channel 91 is on the side wall of the diverter joint 9 and connected to the interior of the shell 8.

[0040] In the embodiment of the present invention, the part of the diverter joint 9 inside the shell 8 is shaped like a frustum, with its narrower end facing downward, that is, toward the disc-type separation wheel 6; there is a certain distance between the outer wall of the diverter joint 9 and the inner wall of the shell 8.

[0041] The interior of the diverter joint 9 is hollow, the top end is connected to the submersible electric pump, and the bottom end in the shell 8 is open; the top end of the rotating shaft 4 is inserted into the hollow interior of the diverter joint 9, and the side wall of the rotating shaft 4 is fixed inside the diverter joint 9 through a bearing, and the bearing divides the hollow interior of the diverter joint 9 into two upper and lower chambers, wherein the upper chamber is a liquid phase chamber 14, and the lower chamber is a gas phase chamber 10, wherein the gas phase chamber 10 is shaped like a trumpet, and the opening of the trumpet faces downward, that is, toward the disc-type separation wheel 6.

[0042] The top opening of the gas phase channel 92 is located on the side wall of the flow dividing joint 9 outside the shell 8, so as to communicate with the casing annulus; the bottom opening of the gas phase channel 92 is located on the side wall of the gas phase chamber 10, so as to communicate with the gas phase chamber 10. The top opening of the liquid phase channel 91 is located on the side wall of the liquid phase chamber 14, so as to communicate with the liquid phase chamber 14; the bottom opening of the liquid phase channel 91 is located on the side wall of the flow dividing joint 9 inside the shell 8, so as to communicate with the gas-liquid separation chamber 5 inside the shell 8.

[0043] When the gas phase in the mixed liquid separated by the disc-type separation wheel 6 moves upward along the rotating shaft 4 to the diverter joint 9, it enters the interior of the gas phase chamber 10 from the bottom opening, then enters the gas phase flow channel with the bottom opening on the side wall of the gas phase chamber 10, and finally is discharged into the casing annulus. When the liquid phase in the mixed liquid separated by the disc-type separation wheel 6 moves upward along the inner wall of the shell 8 in the gas-liquid separation chamber 5 to the diverter joint 9, it will enter the annular space formed between the outer wall of the diverter joint 9 and the inner wall of the shell 8, then enter the liquid phase channel 91 with the bottom opening on the side wall of the diverter joint 9, and finally enter the submersible electric pump through the liquid phase chamber 14.

[0044] By setting a trumpet-shaped gas phase chamber 10 at the bottom end of the diverter joint 9, the gas phase moving close to the rotating shaft 4 can smoothly enter the gas phase flow channel, preventing it from diffusing to the liquid phase flow channel due to the small opening of the gas phase flow channel. The gas phase chamber 10 provides a certain buffer space for the gas phase moving to the diverter joint 9, and the trumpet shape can better gather the gas phase separation.

[0045] By designing the flow dividing joint 9 as a frustum, and having a certain distance between its outer wall and the inner wall of the shell 8, the liquid phase moving close to the inner wall of the shell 8 can enter the annulus formed by the flow dividing joint 9 and the shell 8, and thus smoothly enter the liquid phase channel 91 on the side wall of the flow dividing joint 9, preventing it from diffusing to the middle to the gas phase chamber 10. The gas-liquid separation effect can be better improved by designing the positions and angles of the two ends of the gas phase flow channel and the liquid phase flow channel.

[0046] In the present invention, the angle between the axes of the gas phase channel 92 and the liquid phase channel 91 and the axis of the diversion joint 9 is 10°-11°; the diameter of the gas phase channel 92 is smaller than the diameter of the liquid phase channel 91.

[0047] In an embodiment of the present invention, the angle θ4 formed between the axis of the gas phase channel 92 and the axis of the central axis is 10°~11°, preferably 10°; the angle θ3 formed between the axis of the liquid phase channel 91 and the axis of the central axis is 10°~11°; the diameter d4 of the gas phase channel 92 is smaller than the diameter d3 of the liquid phase channel 91.

[0048] In the present invention, a plurality of liquid inlets 11 are arranged on the side wall of the liquid inlet joint 1 , and the plurality of liquid inlets 11 are evenly distributed along the circumference of the liquid inlet joint 1 ; a filter screen 13 is arranged outside the liquid inlet 11 .

[0049] In the embodiment of the present invention, the top of the liquid inlet joint 1 is sealedly connected to the housing 8 through a thread, and the bottom is connected to the protector through a flange. There are three liquid inlets 11, which are evenly distributed along the circumference of the liquid inlet joint 1. The size and shape of the liquid inlet 11 can be determined according to the rated displacement per hour of the oil well submersible electric pump; the edge of the liquid inlet 11 is smoothly transitioned. The filter screen 13 is wrapped around the outside of the liquid inlet joint 1 to filter impurities in the mixed liquid to prevent clogging of the inside of the separation device.

[0050] In the present invention, a liner 7 is provided on the inner wall of the shell 8; the number of the disc-type separation wheels 6 is at least 13; the number of the inducer wheels 2 is at least 2.

[0051] In the embodiment of the present invention, the bottom end of the rotating shaft 4 is inserted into the liquid inlet joint 1, and the top end is inserted into the flow diversion joint 9. Both ends of the rotating shaft 4 are fixed and supported by hard alloy bearings. When performing gas-liquid separation, the rotating shaft 4 rotates at a speed of 2500-2850 rpm.

[0052] The liner 7 is used to protect the inner wall of the shell 8, and the middle part of the liner 7 forms a gas-liquid separation chamber 5.

[0053] Under the existing allowable length requirement of the gas-liquid separation device, the provision of a 13-stage disc-type separation wheel 6 can achieve a better separation effect and meet the construction requirements.

[0054] In an embodiment of the present invention, the mixed liquid enters the liquid inlet joint 1 through the filter screen 13 and the liquid inlet 11, the rotating shaft 4 rotates under the drive of the submersible motor, the inducer 2 rotates to accelerate the mixed liquid into the gas-liquid separation chamber 5, the mixed liquid rises vertically, and obtains a certain rotation speed, and is accelerated again by the high-speed rotation of the turbine 3 to reach the disc-type separation wheel 6 in the gas-liquid separation chamber 5, and then passes through the thirteen-stage disc-type separation wheel 6, and the gas phase is gathered to the vicinity of the rotating shaft 4 through the gas phase diversion port, and the liquid phase is gathered to the inner wall of the liner 7 away from the rotating shaft 4, through the cross-diversion channel of the diversion joint 9, that is, the liquid phase flow channel and the gas phase flow channel, the gas enters the submersible electric pump and the casing annulus, and the liquid enters the submersible electric pump, thereby realizing efficient gas-liquid separation.

[0055] The shale oil downhole multi-stage rotating disc gas-liquid separation device of the present invention adopts a multi-stage design, increases the gas-liquid flow area, enhances the separation efficiency of the gas-liquid mixed medium under high gas content conditions, broadens the application range of conventional downhole gas-liquid separators, and can prevent the submersible electric pump unit from gas lock and high-temperature shutdown.

[0056] The above-mentioned embodiments are only embodiments of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, without departing from the concept of the present invention, several variations, equivalent substitutions, improvements, etc. can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A shale oil downhole multi-stage rotating disc type gas-liquid separation device, characterized in that: include: Housing (8); One end of the housing (8) is connected to the liquid inlet connector (1), and the other end is connected to the flow diversion connector (9); A rotating shaft (4) is arranged inside the housing (8) and the liquid inlet joint (1), and a plurality of disc-type separation wheels (6) are sleeved on the outer wall of the rotating shaft (4) along the axis line; The interior of the liquid inlet joint (1) is in communication with the interior of the housing (8), and a pressurizing mechanism is provided inside the liquid inlet joint (1) for causing the gas-liquid mixture to move in the direction of the diverter joint (9) and causing the gas-liquid mixture to rotate around the rotating shaft (4); The body of the disc-type separation wheel (6) is in the shape of a truncated cone and is hollow inside, with the end with a larger diameter facing upwards. A top gas-phase guide port (63) is provided at the top of the disc-type separation wheel (6), and a bottom gas-phase guide port (64) is provided on the side wall. The top gas-phase guide port (63) is located close to the rotating shaft (4), and the bottom gas-phase guide port (64) is located close to the bottom end of the disc-type separation wheel (6).

2. The shale oil downhole multi-stage rotating disc type gas-liquid separation device according to claim 1 is characterized in that: The top diameter of the disc-type separation wheel (6) is 0.85 to 0.9 times the diameter of the internal cavity of the shell (8); The angle formed between the two opposite oblique sides of the disc-type separation wheel (6) along the axis is 60° to 61°; The axial length of the disc-type separation wheel (6) is 40 mm to 42 mm; The wall thickness of the disc-type separation wheel (6) is 2.5 mm to 3 mm.

3. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 1 is characterized in that: The top gas phase flow guide ports (63) are symmetrically arranged with the rotation axis (4) as the center on the top end surface of the disc-type separation wheel (6); The top gas phase flow guide port (63) is in the shape of a fan ring, and the outer diameter of the circle formed by the two fan rings is 0.6 to 0.65 times the diameter of the top end of the disc-type separation wheel (6); The central angle of the fan-shaped shape of the top gas phase flow guide port (63) is 75° to 80°.

4. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 1 is characterized in that: The supercharging mechanism comprises: a plurality of induction wheels (2); The inducer (2) comprises: an inducer hub (23) and guide vanes; The inducer wheel hub (23) is sleeved on the outside of the rotating shaft (4), and the guide blade is arranged on the outside of the inducer wheel hub (23), and the guide blade is spiral-shaped; The number of the guide blades is two, and the two guide blades are symmetrically arranged on the outer circumferential surface of the inducer hub (23), and the two guide blades have the same rotation direction.

5. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 4 is characterized in that: The shape of the outer contour line of the guide vane is determined by formulas (1) and (2); X(t)=(P / 2)*t / π (1); Y(t)=(D / 2)*sin(t) (2); Wherein: P is the outer profile pitch, D is the outer diameter of the guide blade along the projection direction of the rotation axis (4), and t is the parameter value; The shape of the inner contour line of the guide vane is determined by formulas (3) and (4); x(t)=(p / 2)*t / π (3); y(t)=(d / 2)*sin(t) (4); Wherein: p is the pitch of the inner contour, d is the outer diameter of the inner contour line along the projection direction of the rotation axis (4), and t is the parameter value.

6. The shale oil downhole multi-stage rotating disc type gas-liquid separation device according to claim 1 is characterized in that: Also includes: Turbine (3); The turbine (3) comprises: a turbine hub (31) and rotating blades (32); The turbine hub (31) is sleeved on the outside of the rotating shaft (4) and is located below the disc-type separation wheel (6); The rotating blades (32) are arranged outside the turbine hub (31), and the rotating blades (32) are spiral-shaped; The number of the rotating blades (32) is three, and the three rotating blades (32) are evenly distributed outside the turbine hub (31).

7. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 1 is characterized in that: The interior of the flow dividing joint (9) is in communication with the interior of the shell (8), and the flow dividing joint (9) is provided with a gas phase channel (92) and a liquid phase channel (91); There is a certain distance between the outer wall of one end of the flow dividing joint (9) located inside the shell (8) and the inner wall of the shell (8); The top opening of the gas phase channel (92) is connected to the outside of the shell (8), and the bottom opening of the gas phase channel (92) is connected to the inside of the flow diversion joint (9); The top opening of the liquid phase channel (91) is connected to the interior of the flow diversion joint (9), and the bottom opening of the liquid phase channel (91) is located on the side wall of the flow diversion joint (9) and is connected to the interior of the shell (8).

8. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 7 is characterized in that: The angle between the axes of the gas phase channel (92) and the liquid phase channel (91) and the axis of the flow dividing joint (9) is 10° to 11°; The diameter of the gas phase channel (92) is smaller than the diameter of the liquid phase channel (91).

9. The multi-stage rotary disc type gas-liquid separation device for shale oil wells according to claim 1 is characterized by: A plurality of liquid inlets (11) are arranged on the side wall of the liquid inlet joint (1), and the plurality of liquid inlets (11) are evenly distributed along the circumference of the liquid inlet joint (1); A filter screen (13) is provided outside the liquid inlet (11).

10. The shale oil downhole multi-stage rotating disc type gas-liquid separation device according to any one of claims 1 to 9, characterized in that: A liner (7) is provided on the inner wall of the shell (8); The number of the disc-type separation wheels (6) is at least: 13; The number of the induction wheels (2) is at least 2.

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