KR880000779B1 - Liquid-gas separator apparatus - Google Patents

Abstract

Liquid-gas separator to separate the gas from the oil, consists of an elongaged hub which is coupled to a rotatable shaft. A first part of the hub is fitted with screw turns to act as a worm conveyor. A second part with axial blades represents a centrifugal separator and the blades of the latter are joined to the turns of the former by smooth transition segments. This separates the gas and oil effectively even at a high volumetric gas-to-oil ratio. It is a compact design which can be produced at lower cost.

Description

Liquid-Gas Separator

1 is a longitudinal cross-sectional view of a liquid-gas separation device according to the present invention.

2 is a perspective view of the separator unit of the FIG. 1 apparatus.

3 is a plan view of FIG.

4 is a rear view of FIG.

5 is a graph showing the performance of a conventional reversible flow separator at different volume ratios.

6 is a graph showing the performance of a liquid-gas separation device according to the present invention at different volume ratios.

* Explanation of symbols for main parts of the drawings

10 fluid-gas separator 12 tubular housing

14 discharge head 16 submersible pump

18: suction head 20: electric motor

22: drive shaft 24, 28, 40, 82: sleeve

26: bearing assembly 28: separator unit

30 hub 32 axial hole

34: keyway 36: bushing

42: snap ring 44: circumferential groove

46: fluid separator 48: spiral induction

50: centrifuge 52: transition region

54: transition region 54: suction port

60, 62, 70, 72: day 64, 66, 74, 76: guide corner

60 ', 62', 70 ', 72': feather 60 ", 62", 70 ", 72": blade segment

80: channel 84: upper chamber

86 passage 88 lower chamber

90: gas discharge path 92: cylindrical member

94: spoke 96: hole

100: groove member

The present invention relates to a separator, in particular a downhole liquid-gas separator in connection with a submersible pump.

Liquid-gas separators are used in downholes in oil wells to separate gas from crude oil before oil enters the downhole pumps. In the oil supplied to the pump, there is a gas which reduces the volumetric efficiency of the pump. If excess gas is present in the oil, a "rock" phenomenon can occur that completely blocks the flow of oil from the pump. When the "gaslock" phenomenon occurs, the pump must be turned off to restart later. Effective liquid-gas separators reduce the incidence of "gas locks" and allow pumps to continue to pump more oil continuously and effectively.

The prior art of liquid-gas separators for use in downhaul is U.S. Patent No. 3887342, issued to Bunnell on June 3, 1975, and U.S. Pat. 4088459 shows a centrifugal liquid gas separator. A reversible flow liquid-gas separator is shown in US Patent No. 2969742, issued to Arutunoff on January 31, 1961, assigned to the same assignee of the present invention. Also shown in US Pat. No. 4,231,767 to Acker on November 4, 1980, assigned to the same assignee of the present invention, is a screen-type liquid-gas separator.

Conventional centrifuges can be safely used at low flow rates, but they do not work well at high flow rates, especially when the gas volume to liquid ratio is increased, and most high capacity submersible pumps can dry out and reduce output. Not suitable when needed Reversible flow type separators also have the same disadvantage. Screened separators work well at high flow ratios. However, over time, the screen may become clogged, reducing the capacity of the separator.

It was therefore necessary to provide a liquid-gas separator to overcome these and other disadvantages of conventional separators, and for this reason the present invention has emerged.

The present invention provides a liquid-gas separator that can operate at a high flow ratio even though it has a relatively large volume ratio of gas to liquid and is also expected to effectively separate the downhaul oil from the fluid and gas components. The separator is also smaller, less complex and cheaper to manufacture than conventional separators.

According to the present invention, a liquid-gas separation device is connected to a blade device and a blade device, and a blade device forming a long hub having a device for connecting to a rotating shaft, a centrifuge installed on the first longitudinal part of the hub, and between the blade device and the blade device. It consists of a bent edge formed to provide a gently bent transition portion.

According to FIG. 1, there is shown a liquid-gas separation device according to the present invention, which is spaced apart from an oil well casing (not shown) and has a tubular shape (cylindrically longer) extending longitudinally therein (housing). There is a 12. The upper end of the housing is engaged by the discharge head and the screw, which is connected to the housing of the submersible pump 16 (shown schematically) and the lower end of the housing is engaged with the suction head 18, which is also ( Connected to the housing of the electric vibrator 20. The pump 16 and the motor 20 are conventional submersible pumps and drive motors suitable for other hole operations in wells. The shaft 22 extends from the electric motor to the pump in the axial direction of the housing through the discharge head and the bearing assembly also installed in the suction head by means of a sleeve 24 installed in the discharge head and the suction head. By 26 and is supported in the housing.

The present invention uses a separator unit 28 located in a housing between the suction head 18 and the discharge head 14 (described in detail in FIGS. 2-4). The separator unit 28 has an elongated tubular hub 30 which is installed coaxially with the shaft 22 and has an axial bore 32 so that the hub can rotate with it. The hub is connected to the axle by a key (not shown) that is received in a corresponding keyway (not shown) on the axis and the ear groove 34 in FIGS. 2 and 4 in the hole 32. As in FIG. 1, the hub is on the shaft by means of a bushing 36 at the opposite end of the hub and sleeves 38, 40 provided on the shaft by snap rings 42 received in the circumferential groove 44 of the shaft. It will be located axially. The sleeve 40 at the top of the hub is the inner sleeve portion of the fluid separator 46 which will be described later.

The inductor 48 of the separator unit 28 consists of a pair of helical blades 60, 62 installed symmetrically with respect to the bottom of the hub 30 to form a double helix threaded inductor. Each blade has radially extending guide edges 64, 66 located near the bottom of the hub adjacent to the suction head, respectively. As in FIG. 2, the blades 60, 62 are inclined toward their guide edges (circumferentially) so that the guide edges are formed with sharp cutting blades. This reduces turbulence and cavitation in the fluid mixture entering the guide. In FIG. 4, the guide edges 64, 66 are symmetrically mounted 180 degrees away from the opposite side of the hub and they lie on a plane extending axially by a line.

As in FIG. 1 and FIG. 2, a plurality of feathers and blades having different shapes are provided at different longitudinal positions of the periphery of the hub 30. As shown in FIG. The blades and feathers are shaped to perform different functions, which drive the separator unit into three distinct areas or stages. As will be described in detail later, the lower part of the separator unit consists of a screw-type inductor 48, the upper part of the separator unit consists of a centrifuge 50, and the part between the induction part and the centrifuge part consists of a transition region 52. . The inducer pressurizes the liquid-gas fluid mixture that is sucked in the suction portion 54 of the suction head 18 to sufficiently push the fluid mixture through the separator. The centrifuge 50 communicates with the induction machine through the transition region 52 and causes rotational or circulating motion to the fluid mixture by centrifugal action. The transition region 52 provides a gentle transition between the induction machine and the centrifuge and is shaped to minimize losses.

인 함수에서 반경(γ)의 함수에 의한다. (허브에서의) 날의 내부반경에서 날각은 대략 29.6이다. 주어진 반경에서 각 날(60, 62)의 날각은 날이 허브에 대하여 나선형으로 상향으로 연장될때 일정한다.The blades 60, 62 from their respective guide edges extend upward spirally with respect to the hub 30 at a hub length of about 1/3. Each blade has a relatively small blade Q relative to the vertical plane of the hub axis and is approximately two revolutions (720 degrees) relative to the hub. In an advanced form, the blade has a pitch of 2 inches and for example it moves 2 inches of shaft length when rotated 360 degrees. The blade angle (Q) is 2 inches in the above example, when P = pitch

Is a function of the radius γ in the function of. In the inner radius of the blade (in the hub), the blade is approximately 29.6. The blade angle of each blade 60, 62 at a given radius is constant when the blade extends upwardly helically with respect to the hub.

The blade angle of each blade 60, 62 in the transition zone 52 is from a constant blade angle in the bottom of the hub (a quarter turn relative to the hub) from a circumferential distance of approximately 90 ° to a vertical blade angle of 90 °. First-order function of shaft length. The blade thus extends vertically upwards from the remaining length of the hub (in the centrifuge portion) that is erected at right angles radially to form axially extending (60 ', 62').

As can be seen in FIG. 3, the blades 60 ', 62' are symmetrically mounted 180 ° away from the hub 30 and on an axially extending plane indicated by the line BB perpendicular to the axis plane AA. . The quarter turn blades 60 "and 62" in the transition region 52 have a smoothly curved change between the spiral blades 60 and 62 and their corresponding axial feathers 60 'and 62', respectively. For example, the flow transition region in the pump is shaped as in the prior art rather than by providing a change in the blade angle, which is the first function of the distance, in order to obtain a flow rate change that is the first function of the distance as in the present invention. As a result of designing the transition region 52 in a conventional manner, a sharp change in the blade causes unnecessary loss.)

For a more even distribution of the fluid mixture in the centrifuge part of the device, the centrifuge 50 extends axially symmetrically installed 180 ° away from the opposite side of the hub 50 and with respect to the vanes 60 ', 62'. It has another pair of feathers 70 'and 72' located at right angles.

As in FIG. 3, the feathers 70, 72 'are located in the A-A axis plane. Each feather 70 ', 72' is connected to a spiral blade 70, 72 coupled by a gently curved blade portion 70 ", 72" coupled in the transition region 52, respectively. The blades 70 "and 72" have the same shape as the blades 60 "and 62" and have the same function in the same way as to provide a gentle change between the feathers 70 'and 72'.

However, unlike blades 60, 62, blades 70, 72 do not extend to the bottom of hub 30. Furthermore, as in FIGS. 1 and 2, the blades 70 and 72 end at tapered guide edges 74 and 76, respectively, directly below the transition region 52. As shown in FIG. As shown in FIG. 1, each joining blade, blade and feather (70-70 "-70 ', 72-72" -72') rotate approximately 180 ° (1/2 revolutions) with respect to hub 30. The guide edges 74 and 76 are thus placed in the axial plane AA. Each blade 70 ", 72 " rotates quarterly with respect to the hub and its engagement blades 70, 72 are again quarter-turned. Guide edges 74 and 76 of blades 70 and 72 are located in the middle of adjacent blades 60 and 62, respectively. The blades 70 and 72 operate to divide the fluid mixture flowing between the blades 60 and 62 into two different passages to distribute the fluid mixture evenly between adjacent blades of the centrifuge. The blades 70 and 72 do not extend to the bottom of the hub 30 and this will severely limit suction to the induction machine.

As shown in FIGS. 1-4, both the collar, the blade and the blade arc have the same radius and extend slightly to the inner surface of the tubular hub 12. The approximate dimensions of the separator unit are 3.4 inches in external diameter, 11 inches in length, 3.75 inches in centrifuge, and 3.35 inches in transition area.

As mentioned above, the inducer 48 pressurizes the fluid to sufficiently push the fluid mixture through the separator 10. Centrifugation 50 centrifugates the gas and liquid components of the fluid mixture. Centrifuges are designed to exert maximum tangential velocities for liquid-gas mixtures. Due to the large density of the liquid, the fluid is pushed by the centrifugal force from the shaft 22 by the rotational motion applied to the fluid mixture by the vane of the centrifuge, and the gas of low density is collected near the shaft. The discharge head 14 is symmetrically installed at its periphery (although there is only one narrow passage in FIG. 1) and a plurality of fluidic paths formed together with the tubular sleeve 82 fitted to the inner surface of the housing 12. Has a narrow road 80. Each narrow passage is connected by an upwardly inclined passageway 86 with an upper chamber 84 in the discharge head in communication with an impeller inlet. The discharge head 14 also has a lower chamber 88 formed around an axis 22 for receiving gas (although only one gas outlet is shown in FIG. 1) in communication with the chamber 88. It has a plurality of gas discharge passages 90 installed symmetrically with respect to the discharge head.

The fluid separator 46 of the illustrated type with a spider assembly connected to the shaft 22 to rotate with the shaft directs the separated liquid into the narrowway 80 and guides the separated gas into the chamber 88. To help. As shown, the fluid separator 46 has an outer sleeve 40 and an outer concentric cylindrical member connected to the sleeve 40 by means of the spokes 94 and the inner sleeve 40 through which the shaft 22 passes. 92). A hole 96 between the cylindrical member 92 and the sleeve 40 provides a passage to the chamber 88 for gas and collects the gas leaving the centrifuge by tapering the lower inner surface of the cylindrical member 92. To help. The fluid separator provides a processing time for the fluid leaving the centrifuge slightly away from the centrifuge. This allows for better separation of liquids and gases. Although shown, the fluid separator is a separate member connected to the shaft 22 and rotating with the shaft, but if desired, the bottom of the discharge head 14 may be shaped to perform the fluid separator.

In operation, pump 16, separator 10 and electric motor 20 submerge into down holes in the fluid mixture of the liquid-gas well. The fluid gas mixture enters the suction portion 54 of the suction head 18 through the groove member 100 supported by the platen in which the fluid mixture is accumulated. From the suction port the fluid mixture enters the inducer 48 to pressurize the fluid mixture and enters the centrifuge 50 through the transition zone 52. As mentioned earlier, the centrifuge separates the liquid from the gas and separates the liquid from the intake of the pump. The separated gas is discharged through the gas outlet into the space between the well casing (not shown) and the discharge head and the outer surface of the pump housing.

Helical inductors have a smaller cross section than standard pump vanes and do not have the same high output as pumps, but helical inductors have many advantages. It is necessary to gradually increase the pressure of the fluid mixture entering the inductor in order to prevent cavitation of the pump and possible "gas lock". This can be accomplished by keeping the spiral blades relatively small, as shown earlier. The inclined guide edges of the blades can also reduce turbulence in the fluid mixture and provide a gentle flow of the guide period. The gently curved transition region between the induction machine and the centrifuge also contributes to the gentle fluid flow of the device and reduces unnecessary losses. The flow rate through the separator is first a function of the blade angle and the length of the induction machine. Although it is necessary to maintain a relatively small blade to prevent pump cavitation, the length of the inductor should be appropriately selected to provide the required output flow and pressure.

5 and 6 compare the performance of the liquid-gas separator according to the present invention (FIG. 6) with that of the conventional reversible flow liquid-gas separator (FIG. 5). According to FIG. 5, the flow ratio of the reversible flow separator decreases dramatically as the volume ratio of vapor (gas) to liquid increases. For example, the flow ratio at V / L = 0.20 is about half the flow ratio at V / L = 0. In contrast, the curve of FIG. 6 derived from the experiment in which the liquid-gas separation device according to the present invention was performed shows very little change even if the volume ratio is changed. That is, even when the relatively large volume ratio V / L = 0.60, the flow ratio was not significantly different from the flow ratio when V / L = 0. The curve of FIG. 6 shows that the liquid-singular separation device according to the present invention can maintain a relatively constant flow ratio over a wide range of volume ratios, thereby eventually allowing the submersible pump to operate at maximum efficiency. In particular, the present invention achieves such advanced results with a relatively simple and inexpensive structure.

While the preferred embodiments of the invention have already been described and illustrated, it will be apparent to those skilled in the art that these embodiments may be modified without departing from the spirit and spirit of the invention and that such areas are limited to the claims claimed. will be.

Claims (25)

An elongated hub having means for connecting the hub to the rotating shaft, spiral blade means for forming a screw-shaped inductor provided on the first longitudinal portion of the hub, quill means for forming a centrifuge provided on the second longitudinal portion of the hub; And a curved blade means connected between the blade means and the blade means and shaped to have a gently curved transition portion therebetween. 2. A liquid-gas separation device according to claim 1, wherein the blade means consists of a pair of symmetrically installed blades extending spirally with respect to the hub and longitudinally towards the second portion from the first end region of the hub. 3. A liquid-gas separation device according to claim 2, wherein each blade has about two revolutions with respect to the hub and has a substantially constant blade angle with respect to the hub axis at a given radius. 4. The liquid-gas separation device of claim 3, wherein the blade angle with respect to the vertical plane of the hub axis varies from about 30 degrees at the hub to about 10 degrees at the outer radius of the blade. 3. A liquid-gas separation device according to claim 2, wherein each blade has a radial guide edge located in the first end region and tapered towards the guide edge. 3. A liquid-gas separation device according to claim 2, wherein the feather means consists of a pair of substantially perpendicular radial symmetrical feathers extending axially from the second end region of the hub to the first portion. 7. A liquid-gas separation device according to claim 6, wherein the blade arc means comprises a pair of curved blades which connect each feather to the joining blade. 8. A liquid-gas separation apparatus according to claim 7, wherein the blade angle between the blade hob and the hub shaft is changed by the first function of the shaft distance. 7. A blade according to claim 6, characterized in that the collar means consists of a pair of substantially right angled radial vanes extending symmetrically to the second part of the hub and extending axially from the second end region towards the first part of the hub. Liquid-gas separators. 10. The blade of claim 9, wherein the blade arcing means consists of another pair of curved blades connected to the other pair of blades, the other pair of blades being symmetrically installed on the opposite side of the hub and positioned between the pair of blades mentioned above. Liquid-gas separation apparatus, characterized in that. 11. A blade according to claim 10, wherein the blade means consists of another pair of blades installed symmetrically with respect to the hub and connected to another pair of blade portions, each blade of the other pair rotating about one quarter about the hub and in the first portion. A liquid-gas separation device, characterized in that it is terminated at a guide edge located between the first pair of blades. 12. The liquid-gas separation device of claim 11, wherein each blade extends about a quarter of a turn relative to the hub. 12. The liquid-gas separation device of claim 11, wherein the guide edges of the other pair of blades are tapered. The liquid-gas separation device according to claim 1, wherein the long hub has an axial hole for receiving the shaft. A liquid-gas separation apparatus using a submersible pump connected to an electric motor by a shaft, comprising: a housing having first and second discharge means for liquid and gas, respectively, separated from the suction means of a liquid-gas fluid mixture; A spiral inducer having a shaft passing longitudinally through the shaft, and a spiral blade means connected to the shaft in the housing and installed about the shaft to pressurize the fluid mixture entering the housing, the pressurized fluid from the inductor receiving liquid from the gas Each discharge means consisting of a blade means connected to the blade means by means of a blade means shaped to provide a smooth transition between the longitudinally extending feather means connected to the shaft and the blade means for giving a rotational motion to the fluid mixture to separate the Means for inducing liquids and gases separated by Body-gas separation system. 16. The liquid-gas separation device according to claim 15, wherein the blade means, the feather means, and the blade means are formed in a single assembly coaxially with the shaft and positioned on the elongate hub. 17. The liquid-gas separation device of claim 16, comprising a device connecting the hub to the shaft. 16. The blade of claim 15 wherein the blade means comprises a pair of helical blades installed symmetrically with respect to the first portion of the hub, the blade means consisting of a pair of substantially vertical feathers installed symmetrically with respect to the second portion of the hub, Liquid-gas separation device, characterized in that the blade means consists of a pair of curved blades connecting each feather to the coupling blade. 19. A liquid-gas separation device according to claim 18, wherein each blade means is at least one revolution relative to the hub and has guide edges near the absorbing means. 20. A blade according to claim 19, wherein the collar means consists of another pair of nearly vertical feathers symmetrically installed in the second portion of the hub, and the blade means consists of another pair of curved blades connected to the other pair of feathers. Liquid-gas separators. 21. The blade of claim 20 wherein the blade means consists of another pair of blades symmetrically installed with respect to the hub and connected to another pair of blades, wherein the other pair of blades are located in the axial direction between the pair of blades mentioned first Liquid-gas separation device characterized in that it terminates in the guide edge moved in the axial direction from the guide edge of the pair of blades. 16. The device of claim 15, wherein the first and second discharge means are located in one end of the housing, the discharge head forming a seal adjacent the axis and a plurality of narrows radially and circumferentially relative to the seal, The first discharge means of the liquid is composed of a hole connecting the vane suction portion of the pump and the narrow passage, the second discharge means of gas is characterized by consisting of a plurality of holes connecting the outside of the discharge head and the seal, etc. Liquid-gas separator. 23. The liquid-gas separation device of claim 22, wherein the induction device comprises a fluid separator connected to an axis axially away from the centrifuge for guiding gas into the room and for introducing liquid into the plurality of narrow passages. 24. The fluid separator of claim 23, wherein the fluid separator is a sleeve coaxial with the shaft and concentrically spaced from the sleeve and connected to the sleeve by spokes to form a plurality of holes therein surrounding the shaft and in communication with the seal. Liquid-gas separation device, characterized in that consisting of a cylindrical member and the like. 25. A liquid according to claim 24, wherein the cylindrical member is shaped to induce a separated gas into the hole surrounding the shaft and to induce a separated liquid into the space between the outer surface of the cylindrical member and the inner surface of the housing. Gas separator.

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