An oil-gas mixed transportation skid-mounted unit dedicated for oilfields

Abstract

The present invention belongs to the field of oilfield transportation equipment, and particularly relates to a special oil-gas mixed transportation skid-mounted unit for oilfields. The specific technical solution is as follows: a screw rotor, the end face tooth profile line of the screw rotor is a cycloid ab, an arc line bc, and an involute cf connected in sequence. The tooth profile line is simple and smooth, reducing the friction area between the screw and the hole, and at the same time adding the function of forming an oil wedge after applying glue.

Description

Technical Field

[0001] The present invention belongs to the field of oilfield transportation equipment, and particularly relates to a special oil-gas mixed transportation skid-mounted unit for oilfields. Background Art

[0002] The twin-screw pump belongs to the positive-displacement pump. It consists of a pair of left and right screws with opposite helix directions that cooperate with the inner wall of the sealing bushing. During the rotation of the screws, a sealing cavity is gradually established, and as the screws rotate, the sealing cavity continuously moves axially from the suction end of the pump to the discharge end. The medium sealed in the sealing cavity is continuously discharged. The screw pump has many advantages such as stable transportation of the medium, low turbulence of the discharged medium, weak pressure pulsation, small mechanical vibration, and low noise.

[0003] The existing twin-screw pumps have the following defects during use:

[0004] 1. After the screws are meshed, the adjacent tooth grooves communicate with each other due to the leakage triangle defect of the tooth profile itself, reducing the volumetric efficiency of the pump.

[0005] 2. After the screws are mated, the large gap results in poor self-priming performance and it is not easy to form high pressure.

[0006] 3. The phenomenon of pump jamming is likely to occur. Summary of the Invention

[0007] To solve the above technical problems, the object of the present invention is to provide a special oil-gas mixed transportation skid-mounted unit for oilfields.

[0008] To achieve the above invention object, the technical solution adopted by the present invention is: a screw rotor, the end face tooth profile line of the screw rotor is a line segment ab, a line segment bc, and a line segment cf connected in sequence, the line segment ab is a cycloid, the line segment bc is an arc line, and the line segment cf is an involute;

[0009] The curve equation of the cycloid ab is as follows:

[0010] x = [cos(λ - θ) - k cos(λ - 2θ)]d j ;

[0011] y = [sin(λ - θ) - k sin(λ - 2θ)]d j ;

[0012] The curve equation of the involute cf is as follows:

[0013] x = [cosθ + θsinθ]d j ·k / 2;

[0014] y = [sinθ - θcosθ]dj·k / 2;

[0015] Wherein, k takes a value of 0.65, λ takes a value of 81°56′22″, and d j is the pitch diameter of the screw rotor.

[0016] Preferably: There is rubber coating provided on the outer side of the screw rotor axially, and the rubber coating material is one or more of nitrile rubber, fluororubber, hydrogenated nitrile rubber, natural rubber, styrene-butadiene rubber, food-grade nitrile rubber, ethylene-propylene rubber, chlorosulfonated polyethylene rubber.

[0017] Preferably: D = 1.3d j , d = 0.7d j ; D is the addendum circle diameter of the screw rotor, d is the dedendum circle diameter of the screw rotor, and d j is the pitch diameter of the screw rotor.

[0018] Correspondingly: An oil and gas metering and mixing transportation pump includes a set of meshing driving screw rotors and driven screw rotors. The driving screw rotor is connected to a driving gear through a driving shaft, the driven screw rotor is connected to a driven gear through a driven shaft, and the driving gear meshes with the driven gear.

[0019] Preferably: There is a cartridge mechanical seal provided between the driving screw rotor and the driving gear and between the driven screw rotor and the driven gear.

[0020] Preferably: There is a cylindrical roller bearing provided on one side of the driving gear and the driven gear, close to the cartridge mechanical seal;

[0021] and / or, there is a double-row angular contact bearing provided on one side of the driving gear and the driven gear, away from the cartridge mechanical seal.

[0022] Preferably: It includes a housing, and a first cover plate and a second cover plate provided on both sides of the housing along the conveying direction of the screw rotor. The first cover plate and the second cover plate are detachably connected to the housing.

[0023] Correspondingly: An oilfield-specific oil and gas mixing transportation skid-mounted unit includes a metering module, a flow regulation module, a filtration module, and a boosting module arranged in sequence. The boosting module includes a mixing transportation pump, and the metering module, the flow regulation module, the filtration module, and the boosting module are controlled by an electrical control module.

[0024] Preferably: The metering module includes a gas flowmeter and a liquid flowmeter, the flow regulation module includes an inlet control valve, the filtration module includes an inlet filter, and the inlet filter includes a basket filter or a tube filter.

[0025] Preferably, an inlet header is provided downstream of the gas flowmeter and the liquid flowmeter. Downstream of the inlet header, the inlet control valve is sequentially provided. Downstream of the inlet control valve, the inlet filter and the multiphase pump are provided. Downstream of the multiphase pump, the outlet control valve and the outlet header are sequentially provided.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The end face tooth profile line of the screw rotor adopts a cycloid, an arc line and an involute connected in sequence. The tooth profile line is simple and smooth, reducing the friction area between the screw and the hole. At the same time, after applying glue, the function of forming an oil wedge is added.

[0028] 2. The twin-screw pump can transport low-viscosity media, has strong self-priming ability and strong solid particle passing ability. Glue is applied on the surfaces of the two screw rotors. The working surface of the screw is more wear-resistant than that of a metal screw, and suitable glue materials are selected according to the needs of different media. Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the end face shape of the screw rotor of the present invention;

[0030] Figure 2 It is a schematic diagram of the end face tooth profile line of the screw rotor of the present invention;

[0031] Figure 3 It is a schematic diagram of the meshing state of the two screw rotors of the present invention;

[0032] Figure 4 It is a schematic top sectional view of the multiphase pump of the present invention;

[0033] Figure 5 It is a schematic front sectional view of the multiphase pump of the present invention;

[0034] Figure 6 It is a schematic left view of the multiphase pump of the present invention;

[0035] Figure 7 It is a schematic top view of the oil-gas multiphase pumping skid of the present invention;

[0036] Figure 8 It is a schematic front view of the oil-gas multiphase pumping skid of the present invention.

[0037] In the figure: base 1, housing 2, first cover plate 3, second cover plate 4, applied glue 5, driving screw rotor 6, driven screw rotor 7, driving shaft 8, driven shaft 9, driving gear 10, driven gear 11, first bearing 12, second bearing 13, assembled mechanical seal 14, logistics inlet 15, logistics outlet 16, bearing seat 17, skid base 18, electrical control cabinet 19, gas flowmeter 20, inlet manifold 21, inlet control valve 22, inlet filter 23, multiphase pump 24, outlet control valve 25, outlet manifold 26, liquid flowmeter 27. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0039] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0040] The present invention discloses a screw rotor, as Figure 1 shown, the end face tooth profile line of the screw rotor is a line segment ab, a line segment bc, and a line segment cf connected in sequence. The line segment ab is a cycloid, the line segment bc is an arc line, and the line segment cf is an involute. By using a cycloid, an arc line, and an involute connected in sequence, the tooth profile line is simple and smooth, reducing the friction area between the screw and the hole.

[0041] Furthermore, it includes two screw rotors that mesh with each other and have the same end face tooth profile line. The meshing state is as Figure 3 shown. The line segment ab is the force transmission side in the meshing state, and the line segment cf is the sealing side in the meshing state. It is not difficult to understand that the pitch diameter of the screw rotor is D, the root diameter of the screw rotor is d, and the pitch diameter of the screw rotor is d j .

[0042] The curve equation of the cycloid ab is as follows:

[0043] x = [cos(λ - θ) - k cos(λ - 2θ)]d j ;

[0044] y = [sin(λ - θ) - k sin(λ - 2θ)]d j ;

[0045] The curve equation of the involute cf is as follows:

[0046] x = [cosθ + θsinθ]d j ·k / 2;

[0047] y = [sinθ - θcosθ]dj·k / 2;

[0048] R 2 = (0.35d j ) 2 ·(1 + θ 2 ).

[0049] Among them, the value range of θ of the cycloid ab is 0 - 39°42′54″, the value of k is 0.65, and the value of λ is 81°56′22″. Among them, the value range of θ of the involute cf is 0 - 89°39′48″, R is the addendum circle radius, R = 2D, and the value range is 0.35d j - 0.65d j .

[0050] Preferably, the technical solution is that D = 1.3d j , d = 0.7d j .

[0051] Furthermore, as Figure 1-3 shown, the spiral teeth of the screw rotor are provided with the rubber coating 5 corresponding to its line type. That is, after the rubber coating 5 is set, the line segment ab is still a cycloid, the line segment bc is still an arc line, and the line segment cf is still an involute. It should be noted that the arc line in this application refers to the arc corresponding to an ordinary circle. The material of the rubber coating 5 can be one or more of nitrile rubber, fluororubber, hydrogenated nitrile rubber, natural rubber, styrene-butadiene rubber, food nitrile rubber, ethylene-propylene rubber, chlorosulfonated polyethylene rubber, etc. By setting the rubber coating on the surfaces of the two screw rotors, the working surface of the screw is more wear-resistant than that of a metal screw, and the appropriate rubber coating material can be selected according to the needs of different media.

[0052] The present invention also discloses an oil and gas metering and mixing pump, as Figure 4-6As shown in the figure, it includes a base 1 and a pump body arranged on the base 1. A set of driving screw rotors 6 and driven screw rotors 7 which are meshed with each other and have the same end face tooth profile are arranged in the pump body. One end of the driving screw rotor 6 is connected to a driving gear 10 driven by a motor, and the driving gear 10 meshes with a driven gear 11 connected to the driven screw rotor 7. A material inlet 15 and a material outlet 16 are arranged on the pump body. Sealing bushings are arranged around the driving screw rotor 6 and the driven screw rotor 7, enabling the two screw rotors to rotate within the sealing bushings, and a sealing cavity is formed between the two screw rotors and the inner wall of the sealing bushings. During operation, the motor drives the driving gear 10 to rotate. The driving gear 10 rotates synchronously with the driving screw rotor 6, and the driving gear 10 drives the driven gear 11 to rotate. The driven gear 11 rotates synchronously with the driven screw rotor 7, so the driving screw rotor 6 and the driven screw rotor 7 rotate in opposite directions. During the rotation of the screw rotors, a sealing cavity is gradually established, sucking the material outside the pump and pushing it to the outlet of the screw pump.

[0053] Furthermore, one end of the driving screw rotor 6 and the driven screw rotor 7 are respectively connected to a driving shaft 8 and a driven shaft 9, and the driving gear 10 and the driven gear 11 are respectively arranged around the driving shaft 8 and the driven shaft 9. That is, during rotation, there is no relative rotation between the driving gear 10 and the driving shaft 8, and between the driven gear 10 and the driven shaft 9. Gear covers are arranged at the ends of the driving gear 10 and the driven gear 11 away from the driving screw rotor 6.

[0054] Furthermore, first bearings 12 and second bearings 13 are arranged at both ends of the driving gear 10 and the driven gear 11. The first bearing 12 is a cylindrical roller bearing and is arranged on the side close to the driving screw rotor 6. The second bearing 13 is a double-row angular contact bearing and is arranged on the side away from the driving screw rotor 6. The first bearing 12 and the second bearing 13 are arranged on a bearing seat 17, and the bearing seat 17 is fixedly arranged in the housing 2.

[0055] In order to prevent the material flow inside the two screw rotors from flowing into the gear system, a cartridge mechanical seal 14 is arranged between the driving screw rotor 6 and the driving gear 10, and between the driven screw rotor 7 and the driven gear 11. The two cartridge mechanical seals 14 are respectively sleeved on the driving shaft 8 and the driven shaft 9. The cartridge mechanical seal 14 does not rotate with the driving shaft 8 and the driven shaft 9.

[0056] Further, the pump body includes a housing 2, a first cover plate 3 and a second cover plate 4 disposed on both sides of the housing 2. The first cover plate 3 is disposed on the side close to the driving screw rotor 6, and the second cover plate 4 is disposed on the side close to the driving gear 10. The first cover plate 3 and the second cover plate 4 are detachably connected to the housing 2 by means of bolts. By providing the first cover plate 3 and the second cover plate 4, dust and other impurities from the outside are prevented from entering the pump body, thereby affecting the transmission efficiency of the gear system and the screw rotor.

[0057] Further, one end of the driving shaft 8 away from the driving screw rotor 6 extends out of the housing 2, that is, the driving shaft 8 passes through the second cover plate 4 and is connected to the motor output shaft. The driving shaft 8 is connected to the motor output shaft through a speed reduction device. The seal between the driving shaft 8 and the second cover plate 4 adopts a skeleton seal.

[0058] The present invention also discloses an oilfield special oil-gas mixed transportation skid-mounted device, which includes a metering module, a flow regulating module, a filtering module, and a boosting module arranged in sequence. The boosting module adopts the above-mentioned mixed transportation pump 24, and the metering module, the flow regulating module, the filtering module, and the boosting module are controlled by an electrical control module.

[0059] Further, the metering module includes a gas flowmeter 21, a liquid flowmeter 27 and their pipelines. The flow regulating module includes an inlet control valve 22 and its pipeline, and the inlet control valve 22 is a regulating valve for regulating the flow rate. The filtering module includes an inlet filter 23 and its pipeline, and the inlet filter 23 can be a basket filter or a tube filter.

[0060] Further, an inlet manifold 21 is provided downstream of the gas flowmeter 20 and the liquid flowmeter 27. The inlet control valve 22 is sequentially provided downstream of the inlet manifold 21. The inlet filter 23 and the mixed transportation pump 24 are provided downstream of the inlet control valve 22. An outlet control valve 25 and an outlet manifold 26 are sequentially provided downstream of the mixed transportation pump. In order to work continuously, the inlet control valve 22, the inlet filter 23, the mixed transportation pump 24, and the outlet control valve 25 are all one-for-one standby. The automatic control of all these devices is controlled by an electrical control cabinet 19, and all the devices are integrated on the skid base. When in use, only the skid base needs to be moved.

[0061] The gas and the liquid are respectively metered by the gas flowmeter 20 and the liquid flowmeter 27 and then enter the inlet manifold 21 for mixing, and then enter the inlet filter 23 to filter solid impurities after the flow rate is adjusted by the inlet control valve 22, and then enter the oil-gas mixed transportation pump 24 for boosting. After boosting, the outlet flow rate is controlled by the outlet control valve 25, and finally flows out through the outlet manifold 26.

[0062] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, variations, modifications, and substitutions made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A screw rotor, characterized in that: it includes a set of driving screw rotors (6) and driven screw rotors (7) that mesh with each other and have the same end face tooth profile; the end face tooth profile of the screw rotor is a cycloid ab, an arc bc, and an involute cf connected in sequence; the curve equation of the cycloid ab is as follows: x = [cos(λ - θ) - kcos(λ - 2θ)]d j ; y = [sin(λ - θ) - ksin(λ - 2θ)]d j ; the curve equation of the involute cf is as follows: x = [cosθ + θsinθ]d j ·k / 2; y = [sinθ - θcosθ]dj·k / 2; where k takes the value of 0.65, λ takes the value of 81°56'22”, and d j is the pitch diameter of the screw rotor; D = 1.3d j , d = 0.7d j ; where D is the tip circle diameter of the screw rotor, and d is the root circle diameter of the screw rotor.

2. The screw rotor according to claim 1, characterized in that: a rubber coating (5) is arranged on the outer side of the screw rotor in the axial direction, and the material of the rubber coating (5) is one or more of nitrile rubber, fluororubber, hydrogenated nitrile rubber, natural rubber, styrene-butadiene rubber, food nitrile rubber, ethylene-propylene rubber, and chlorosulfonated polyethylene rubber.

3. An oil and gas metering and mixing transportation pump, characterized in that: it includes a screw rotor according to claim 1 or 2, the driving screw rotor (6) is connected to a driving gear (10) through a driving shaft (8), the driven screw rotor (7) is connected to a driven gear (11) through a driven shaft (9), and the driving gear (10) meshes with the driven gear (11).

4. The oil and gas metering and mixing transportation pump according to claim 3, characterized in that: a cartridge mechanical seal (14) is arranged between the driving screw rotor (6) and the driving gear (10) and between the driven screw rotor (7) and the driven gear (11).

5. The oil and gas metering and mixing transportation pump according to claim 4, characterized in that: a cylindrical roller bearing is arranged on one side of the driving gear (10) and the driven gear (11) close to the cartridge mechanical seal (14); and / or, a double-row angular contact bearing is arranged on one side of the driving gear (10) and the driven gear (11) far from the cartridge mechanical seal (14).

6. The oil and gas metering and mixing transportation pump according to claim 3, characterized in that: it includes a housing (2), and a first cover plate (3) and a second cover plate (4) arranged on both sides of the housing (2) along the conveying direction of the screw rotor, and the first cover plate (3) and the second cover plate (4) are detachably connected to the housing (2).

7. An oilfield special oil and gas mixing transportation skid-mounted unit, characterized in that: it includes a metering module, a flow regulating module, a filtering module, and a boosting module arranged in sequence, the boosting module includes the mixing transportation pump (24) according to claims 3-6, and the metering module, the flow regulating module, the filtering module, and the boosting module are controlled by an electrical control module.

8. The oilfield special oil and gas mixing transportation skid-mounted unit according to claim 7, characterized in that: the metering module includes a gas flowmeter (20) and a liquid flowmeter (27), the flow regulating module includes an inlet control valve (22), the filtering module includes an inlet filter (23), and the inlet filter (23) includes a basket filter or a tube filter.

9. The oilfield special oil and gas mixing transportation skid-mounted unit according to claim 8, characterized in that: An inlet header (21) is provided downstream of the gas flowmeter (20) and the liquid flowmeter (27). The inlet control valve (22) is sequentially provided downstream of the inlet header (21). The inlet filter (23) and the multiphase pump (24) are provided downstream of the inlet control valve (22). The outlet control valve (25) and the outlet header (26) are sequentially provided downstream of the multiphase pump.

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