A skid-mounted oil and gas mixed transportation device

Abstract

The application discloses a skid-mounted oil-gas mixed transportation device, which is characterized in that the device inlet is connected with the lower end inlet of a plug flow buffer vertical pipe, the upper end outlet of the plug flow buffer vertical pipe is connected with a transverse distribution pipe, a first-stage cyclone liquid inlet pipe is symmetrically connected along the length direction of the transverse distribution pipe, the outlet of each first-stage cyclone liquid inlet pipe is connected with the middle part of a first-stage cyclone separation pipe, the top gas outlet of each first-stage cyclone separation pipe is connected with a cyclone separation gas phase pipe, the lower end liquid outlet of each first-stage cyclone separation pipe is connected with a first-stage cyclone liquid outlet pipe, the middle part outlet of the first-stage cyclone liquid outlet pipe is connected with the bottom of a second-stage buffer separation pipe, the lower part circumferential liquid outlet of the second-stage buffer separation pipe is connected with the oil inlet pipe of an oil-gas mixer through a liquid outlet pipeline, and the outlet of the cyclone separation gas phase pipe is connected with the air mixing port of the oil-gas mixer. The device can improve the stability of oil-gas mixed transportation, improve the gathering and transportation efficiency, and can accurately measure the gas phase and the liquid phase, thereby facilitating the accurate measurement of block production.

Description

TECHNICAL FIELD

[0001] The present application relates to an oil and gas conveying device, in particular to a skid-mounted oil and gas mixed conveying device, and belongs to the technical field of oil and gas conveying. BACKGROUND

[0002] The oil and gas conveying process of an oilfield mainly includes two types: one is that oil and gas is conveyed from a wellhead pipeline to a joint station to enter a three-phase separator, and after oil and gas separation, oil is conveyed by a pump and gas is conveyed by a compressor; the other is that oil and gas is directly conveyed by an oil and gas mixed conveying pump. The first mode is limited by the length of the system pipeline, and some remote wells cannot meet the requirement of conveying crude oil to the station for on-site oil and gas separation, so the second mode is generally adopted for direct conveying.

[0003] At present, the oil and gas mixed conveying device used in the oilfield site mainly includes a screw pump or a positive displacement pump, which uses the change of the volume of the pump cylinder to convey liquid. However, when conveying high-gas-rate well production liquid, the stator of the screw pump is severely dry ground, the failure rate of the stator and the rotor is high, the service life is short, and the maintenance cost is high; after a long time, the stator rubber wears out, the pressure-bearing capacity of the pump decreases, and the leakage increases, resulting in a decrease in pump efficiency. Moreover, the screw pump has no flow capacity when it is stopped, and abnormal pump stoppage can easily cause pressure build-up at the inlet end, and there is a risk of pipeline pressure build-up leakage. The positive displacement pump also has problems such as high cost and easy damage of components.

[0004] In addition, in the face of complex oil and gas field gas-liquid working conditions, oil and gas metering relies on the work diagram to measure oil, and the measurement error of some wells is large, which cannot meet the requirement of yield calibration of the block transfer station library, and yield metering has become a big problem. Therefore, there is an urgent need to invent a high-performance oil and gas mixed conveying device that can simultaneously solve the problems of oil and gas mixed conveying and metering, and is beneficial to the optimization and reconstruction of the station library. SUMMARY

[0005] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0007] The purpose of the present application is to overcome the problems existing in the prior art, such as low efficiency, high cost, short service life, high maintenance difficulty, high management difficulty, and inability to be applied to unstable flow conditions of oil and gas mixed conveying, and to provide a skid-mounted oil and gas mixed conveying device, which can improve the stability of oil and gas mixed conveying, improve the gathering and conveying efficiency, accurately measure the gas phase and the liquid phase, and facilitate accurate measurement of block yield.

[0008] To solve the above technical problems, the present application discloses a pry-mounted oil and gas mixed conveying device, which comprises a device inlet, the device inlet is connected with the lower end inlet of a plug flow buffer vertical pipe through an inlet valve, the upper end outlet of the plug flow buffer vertical pipe is connected with the middle section bottom of a horizontal distribution pipe, a first-stage cyclone liquid inlet pipe is symmetrically connected along the length direction of the horizontal distribution pipe, the outlet of each first-stage cyclone liquid inlet pipe is connected with the middle section of a first-stage cyclone separation pipe, and the top gas outlet of each first-stage cyclone separation pipe is connected with a cyclone separation gas phase pipe.

[0009] The lower end liquid outlet of each first-stage cyclone separation pipe is connected with a first-stage cyclone liquid outlet pipe, the middle section outlet of the first-stage cyclone liquid outlet pipe is connected with the bottom inlet of a second-stage buffer separation pipe, and the lower section circumferential liquid outlet of the second-stage buffer separation pipe is connected with a liquid outlet pipeline.

[0010] The outlet of the liquid outlet pipeline is connected with the oil inlet pipe of an oil and gas mixer, the outlet of the cyclone separation gas phase pipe is connected with the air mixing port of the oil and gas mixer, and the outlet of the oil and gas mixer is connected with a mixed conveying pipeline.

[0011] Further, the diameter of the plug flow buffer vertical pipe gradually increases from bottom to top, the ascending liquid flow is gradually decompressed and decelerated, so that the plug flow is changed into laminar flow, the gas-liquid interface is formed, and preliminary gas-liquid phase separation is achieved.

[0012] Further, the top gas outlet of the second-stage buffer separation pipe is also connected with the cyclone separation gas phase pipe, the outlet of the cyclone separation gas phase pipe is provided with a gas flow meter and is connected with the inlet of an air mixing pipeline.

[0013] Further, the outlet of the liquid outlet pipeline is provided with a mass flow meter and is connected with the inlet of a liquid booster pump through a liquid outlet valve, the outlet pipeline of the liquid booster pump is connected with the oil inlet pipe of the oil and gas mixer,

[0014] Further, the first-stage cyclone liquid inlet pipe is a rectangular tapered square pipe, the cross section of the rectangular tapered square pipe is rectangular and the height is greater than the width, the area gradually decreases along the fluid advancing direction, the pressure difference is generated during the oil liquid flowing along the rectangular tapered square pipe, under the action of the pressure difference, the gas dissolved in the liquid moves to the low pressure area, condenses into large bubbles, forms a stable gas-liquid interface, and preliminary separation is achieved.

[0015] Further, the end of the rectangular tapered square pipe is inclined downward and is tangentially connected to the middle section circumference of the first-stage cyclone separation pipe.

[0016] Further, the device inlet is also connected with the inlet of a bypass valve, the outlet of the bypass valve is connected with the middle section inlet of a liquid outlet tee joint, the main inlet of the liquid outlet tee joint is connected with the outlet of the liquid outlet valve, and the outlet of the liquid outlet tee joint is connected with the inlet of the liquid booster pump.

[0017] Further, the bottom center of the primary cyclone separation tube is provided with an inverted cone with thin top and thick bottom, and the oil liquid forms a cyclone around the inverted cone under the action of centrifugal force, gravity and collision force, the liquid phase with large density flows along the wall of the primary cyclone separation tube to the bottom liquid outlet, and the gas phase with small density forms a gas core in the center of the cyclone and rises to the top gas outlet.

[0018] Further, the upper end outlet of the secondary buffer separation tube is provided with a gas control valve, and the lower end outlet of the secondary buffer separation tube is provided with a liquid control valve; the inner cavity of the secondary buffer separation tube is provided with a floating ball in the middle part, and the opening and closing of the gas control valve and the liquid level valve are controlled by the floating ball to keep the balance of the gas-liquid two-phase.

[0019] Further, the upper part of the gas control valve is provided with a gas control valve seat, the center of the gas control valve seat is provided with an exhaust hole, the lower end of the exhaust hole is provided with a downward-opening horn mouth, the lower part of the gas control valve seat is provided with a gas control valve core, and the upper end of the gas control valve core is provided with a conical sealing surface matched with the horn mouth of the gas control valve seat.

[0020] Further, the lower part of the liquid control valve is provided with a liquid control valve seat, the center of the liquid control valve seat is provided with a liquid outlet hole, the upper end of the liquid outlet hole is provided with an upward-opening horn mouth, the upper part of the liquid control valve seat is provided with a liquid control valve core, and the lower end of the liquid control valve core is provided with a conical sealing surface matched with the horn mouth of the liquid control valve seat.

[0021] Further, the upper end of the floating ball is connected with the gas control valve core through a gas control valve rod, and the upper part of the gas control valve rod passes through the center hole of a gas control valve rod guide seat; the lower end of the floating ball is connected with the liquid control valve core through a liquid control valve rod, and the lower part of the liquid control valve rod passes through the center hole of a liquid control valve rod guide seat, and the gas control valve rod guide seat and the liquid control valve rod guide seat are supported on the inner wall of the secondary buffer separation tube.

[0022] Further, when the liquid level in the secondary buffer separation tube is high, the floating ball floats up, the gas control valve rod pushes the gas control valve core to rise and seat on the horn mouth of the gas control valve seat to close the gas control valve and close the gas phase outlet; at the same time, the liquid control valve core rises and separates from the horn mouth of the liquid control valve seat to open the lower liquid phase outlet, and the gas gathered pushes the liquid out of the secondary buffer separation tube, thereby reducing the liquid level.

[0023] Further, when the liquid level in the secondary buffer separation tube is low, the floating ball sinks, the liquid control valve rod pushes the liquid control valve core to descend and seat on the horn mouth of the liquid control valve seat to close the liquid control valve and close the liquid phase outlet; at the same time, the gas control valve core descends and separates from the horn mouth of the gas control valve seat to open the upper gas phase outlet, and the gathered gas is discharged from the tube to reduce the pressure in the secondary buffer separation tube and promote the liquid level to return to the normal liquid level.

[0024] Further, the oil-gas mixer is provided with a large-diameter mixer barrel, a top part of the middle part of the mixer barrel is provided with an air mixing port connected with the outlet of the air mixing pipeline; the outlet of the mixer barrel is connected with a tapered section, the outlet of the tapered section is connected with a small-diameter throat section, the inlet end of the mixer barrel is closed and the oil inlet pipe is inserted in the center of the inlet end of the barrel, the end of the oil inlet pipe is provided with a reduced nozzle, the nozzle is located in the center of the tapered section and faces the throat section for injection; the end of the throat section is connected with a gradually expanding section, the outlet of the gradually expanding section is a mixed outlet.

[0025] Further, the slug flow buffer vertical pipe, the transverse distribution pipe, the first-stage cyclone liquid inlet pipe, the first-stage cyclone separation pipe and the second-stage buffer separation pipe are all placed in a water bath heating box; the circulating water outlet of the water bath heating box is connected with the water inlet of a gas water heater through a cold water pipe, the water outlet of the gas water heater is connected with the circulating water inlet of the water bath heating box through a high-temperature water supply pipe, and a hot water circulating pump is arranged in the cold water pipe or the low-temperature water supply pipe; the gas source pipeline of the gas water heater is connected with the cyclone separation gas phase pipe.

[0026] Further, a multi-circuit one-way valve is arranged in the air mixing pipeline, the center of the multi-circuit one-way valve is a main channel with a square cross section, a plurality of groups of bifurcated branch channels are arranged along the flow direction of the main channel, each bifurcated branch channel comprises an upward flow separation inclined section, an arc turning section and a downward flow convergence inclined section which are connected in series and integrated, and the outlet of the downward flow convergence inclined section is located above the inlet of the upward flow separation inclined section.

[0027] Further, the bifurcated branch channels are arranged in a heart shape in left-right symmetry at one height of the main channel, and are arranged in a heart shape in front-back symmetry at another height adjacent to the main channel, and a plurality of groups are staggered along the height direction of the main channel.

[0028] Further, the angle between the upward flow separation inclined section and the main channel is 50°, and the angle between the downward flow convergence inclined section and the main channel is 40°.

[0029] Compared with the prior art, the present application has the following beneficial effects: 1. The oil well liquid is subjected to gas-liquid separation, an oil-gas separation metering module is added, the gas phase and the liquid phase are accurately metered respectively, and then are re-mixed and delivered; not only the yield metering of a single well in an oil field can be realized, but also the large liquid yield calibration of a block transfer station can be realized, the instability and inaccuracy of the conventional metering method are solved, and the technical short board of small liquid processing range of the conventional cyclone oil-gas separation device is made up for.

[0030] 2. The diameter of the upper end of the slug flow buffer vertical pipe gradually increases, so that the slug flow becomes laminar flow, a gas-liquid interface is formed, and preliminary gas-liquid phase separation is achieved.

[0031] 3. The downward-sloping pipe at the inlet of the first-stage cyclone separator is designed as a rectangular tapered square pipe, which facilitates the second pre-separation of oil at the downward-sloping pipe and effectively improves the oil-gas separation efficiency.

[0032] 4. The bottom center of the first-stage cyclone separator is equipped with a reverse flow cone, which facilitates the rapid formation of cyclone by the oil under the action of centrifugal force, gravity and collision force. It can lift the gas nucleus and reduce the entrainment of liquid phase into gas phase.

[0033] 5. The float valve, pneumatic valve and hydraulic valve in the secondary cyclone separator can continuously adjust the liquid level and pressure in real time, and maintain a balanced state through mutual compensation between the gas and liquid phases.

[0034] 6. This device can achieve on-site self-sufficiency in natural gas and can implement heat preservation measures for the oil-gas separation system without the need for energy supply;

[0035] 7. The one-way flow design of the gas-mixing pipeline utilizes the internal space structure of the multi-loop check valve to promote gas flow, helping gas to be mixed into the liquid and preventing liquid backflow. Compared with traditional check valves, it has no moving parts, which can effectively extend the service life of the device, and it can also reduce the flow resistance that the check valve generates for the fluid.

[0036] 8. In the oil-gas mixed transport device of the present invention, the booster pump transports a pure liquid medium, avoiding the use of expensive mixed transport volume pumps, etc. Compared with the traditional mixed transport device that uses an oil-gas mixed transport pump to directly transport the oil-gas mixture, it can effectively improve pump efficiency, reduce purchase costs, prevent dry running, and reduce failure rate. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit the present invention. Wherein:

[0038] Figure 1 The three-dimensional skid-mounted oil and gas mixed transportation device of the present invention Figure 1 ;

[0039] Figure 2 The three-dimensional skid-mounted oil and gas mixed transportation device of the present invention Figure 2 ;

[0040] Figure 3 The three-dimensional representation of the invention with the water bath heating box concealed. Figure 1 ;

[0041] Figure 4 The three-dimensional representation of the invention with the water bath heating box concealed.Figure 2 ;

[0042] Figure 5 is a sectional view of the primary buffer separation pipe in the present application;

[0043] Figure 6 is a sectional view of the secondary buffer separation pipe in the present application;

[0044] Figure 7 is a schematic diagram of the multi-circuit one-way valve structure in the air entraining pipe line in the present application;

[0045] Figure 8 is a sectional view of the oil-gas mixer in the present application;

[0046] In the figure: 1. device inlet; 2. inlet valve; 3. bypass valve; 4. plug flow buffer vertical pipe; 5. transverse distribution pipe; 6. rectangular tapered square pipe; 7. primary cyclone separation pipe; 7a. reverse flow frustum; 8. secondary buffer separation pipe; 8a. air control valve rod guide seat; 8b. liquid control valve rod guide seat; 9. air control valve; 9a. air control valve core; 10. air control valve rod; 11. floating ball; 12. liquid control valve rod; 13. liquid control valve; 13a. liquid control valve core; 14. cyclone separation gas phase pipe; 14a. gas furnace gas supply pipe; 15. gas flow meter; 16. air entraining pipe line; 17. multi-circuit one-way valve; 17a. upward flow inclined section; 17b. arc turning section; 17c. downward flow inclined section; 18. primary cyclone liquid outlet pipe; 19. liquid outlet pipeline; 20. mass flow meter; 21. liquid outlet valve; 22. liquid outlet tee; 23. liquid booster pump; 24. oil-gas mixer; 24a. oil inlet pipe; 24b. nozzle; 24c. air entraining port; 24d. tapered section; 24e. throat section; 24f. expanding section; 24g. mixing outlet; 25. water bath heating box; 25a. manhole; 26. cold water pipe; 27. gas water heater; 28. hot water circulating pump; 29. high temperature water supply pipe; 30. water replenishing tank. DETAILED DESCRIPTION

[0047] In the following description of the present application, the terms "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not mean that the device must have a particular orientation.

[0048] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application will be further described below in combination with specific drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0050] like Figures 1 to 4 As shown, the skid-mounted oil-gas mixing and transportation device of the present invention includes an oil-gas separation and metering module and an oil-gas mixing and transportation module. The oil-gas separation and metering module includes a slug flow buffer riser 4, a transverse distribution pipe 5, a rectangular tapered square pipe 6, a primary cyclone separator 7, a secondary buffer separator 8, and a water bath heating box 25. The device inlet 1 is connected to the lower inlet of the slug flow buffer riser 4 through an inlet valve 2, and the upper outlet of the slug flow buffer riser 4 is connected to the transverse distribution pipe 5. The transverse distribution pipe 5 and the slug flow buffer riser 4 are arranged in a "T" shape, and the upper end of the slug flow buffer riser 4 is connected to the middle of the transverse distribution pipe 5. The two ends of the transverse distribution pipe 5 are respectively connected to rectangular tapered square pipes 6, or multiple rectangular tapered square pipe branches 6 can be symmetrically connected. The cross-section of the rectangular tapered square pipe 6 is rectangular and the height is greater than the width, and the area gradually decreases along the fluid forward direction; the rectangular tapered square pipe 6 is inclined downward and its end is tangentially connected to the middle circumference of the primary cyclone separator 7. The rectangular tapered square tube 6 creates a pressure difference in the oil during flow. Under the action of the pressure difference, the gas dissolved in the liquid moves to the low-pressure area, condenses into large bubbles, and forms a stable gas-liquid interface, thus achieving preliminary separation.

[0051] like Figure 5 As shown, to prevent the gas phase from being entrained by the liquid phase and discharged from the drain port at the bottom of the separation tube, a truncated cone 7a is provided at the center of the bottom of the first-stage cyclone separator 7. This facilitates the rapid formation of a vortex under the action of centrifugal force, gravity, and collision force. The denser liquid phase flows along the tube wall to the bottom drain port, while the less dense gas phase forms a gas nucleus along the center of the vortex and rises to the top exhaust port. The addition of the truncated cone can support the gas nucleus and reduce the entrainment of the liquid phase by the gas phase.

[0052] The top outlet of the first-stage cyclone separator 7 is connected to the cyclone separator gas phase pipe 14, the bottom outlet of the first-stage cyclone separator 7 is connected to the first-stage cyclone liquid outlet pipe 18, the middle outlet of the first-stage cyclone liquid outlet pipe 18 is connected to the bottom inlet of the second-stage buffer separator 8, the top outlet of the second-stage buffer separator 8 is also connected to the cyclone separator gas phase pipe 14, and the outlet of the cyclone separator gas phase pipe 14 is equipped with a gas flow meter 15 and connected to the gas mixing line 16.

[0053] The lower circumferential outlet of the secondary buffer separation pipe 8 is connected with the liquid outlet pipeline 19, the outlet of the liquid outlet pipeline 19 is provided with a mass flow meter 20 and is connected with the main inlet of a liquid outlet tee joint 22 through a liquid outlet valve 21, the device inlet 1 is also connected with the middle inlet of the liquid outlet tee joint 22 through a bypass valve 3; the outlet of the liquid outlet tee joint 22 is connected with the inlet of a liquid booster pump 23, the outlet pipeline of the liquid booster pump 23 is connected with the oil inlet pipeline 24a of an oil-gas mixer 24, the outlet of the air injection pipeline 16 is connected with the air injection port 24c on the circumference of the oil-gas mixer 24, and the outlet of the oil-gas mixer 24 is the mixed outlet 24g of the oil-gas mixture output.

[0054] As shown in Figure 8 The oil-gas mixer 24 is provided with a large-diameter mixer cylinder body, the middle circumferential top of the mixer cylinder body is provided with an air injection port 24c connected with the outlet of the air injection pipeline 16; the outlet of the mixer cylinder body is connected with a tapered section 24d, the outlet of the tapered section 24d is connected with a small-diameter throat section 24e, the inlet end of the mixer cylinder body is closed and is inserted with a coaxial oil inlet pipeline 24a, the end of the oil inlet pipeline 24a is provided with a reduced-diameter nozzle 24b, the nozzle 24b is located in the center of the tapered section 24d and sprays towards the throat section 24e, and the end of the throat section 24e is connected with a gradually expanding section 24f, and the outlet of the gradually expanding section 24f is the mixed outlet 24g.

[0055] The oil well liquid enters the lower end of the plug flow buffer vertical pipe 4 through the device inlet 1, gradually increases the pipeline space diameter, and gradually reduces the pressure and speed of the rising liquid flow, so that the plug flow becomes laminar flow, forms a gas-liquid interface, and achieves preliminary gas-liquid phase separation. After the influence of the plug flow is buffered and eliminated in the plug flow buffer vertical pipe 4, the oil liquid is distributed by the transverse distribution pipe 5, the oil liquid after distribution is obliquely cut into the first cyclone separation pipe 7 by the rectangular tapered square pipe 6, so as to form a cyclone, and the first cyclone separation pipe 7 separates the gas phase and the liquid phase from the produced liquid under the action of centrifugal force, gravity and collision force through the centrifugal sedimentation principle of cyclone generation. The liquid phase with large density flows along the pipe wall of the first cyclone separation pipe 7 to the bottom of the separation pipe, is introduced into the secondary buffer separation pipe 8 through the first cyclone liquid outlet pipe 18, and the gas phase with small density rises to the top of the first cyclone separation pipe 7 and enters the cyclone separation gas phase pipe 14.

[0056] The secondary buffer separation pipe 8 further improves the separation efficiency through the action of gravity separation, and a float control system is arranged in the secondary separation pipe, the gas phase and the liquid phase are controlled and adjusted through the float ball 11, the liquid level and the pressure are continuously adjusted in real time, and the gas-liquid phase balance is maintained.

[0057] The number of cyclone separation pipes can be freely selected according to the liquid amount on the site, the whole device not only meets the standard of the non-pressure container, but also improves the processing capacity and expands the application range.

[0058] A float ball 11 is provided in the middle of the inner cavity of the secondary buffer separation tube 8. The float ball 11 extends vertically. A pneumatic control valve 9 is provided at the upper outlet of the secondary buffer separation tube 8, and a hydraulic control valve 13 is provided at the lower outlet of the secondary buffer separation tube 8.

[0059] like Figure 6 As shown, the upper part of the pneumatic control valve 9 is provided with a pneumatic control valve seat, the center of the pneumatic control valve seat is provided with an exhaust hole, the lower end of the exhaust hole is provided with a flared mouth opening downwards, the lower part of the pneumatic control valve seat is provided with a pneumatic control valve core 9a, the upper end of the pneumatic control valve core 9a is provided with a conical sealing surface that matches the flared mouth of the pneumatic control valve seat.

[0060] The lower part of the hydraulic control valve 13 is provided with a hydraulic control valve seat, the center of the hydraulic control valve seat is provided with a drain hole, the upper end of the drain hole is provided with an upward-opening flared mouth, the upper part of the hydraulic control valve seat is provided with a hydraulic control valve core 13a, and the lower end of the hydraulic control valve core 13a is provided with a conical sealing surface that matches the flared mouth of the hydraulic control valve seat.

[0061] The upper end of float 11 is connected to pneumatic valve core 9a via pneumatic valve stem 10, with the upper part of pneumatic valve stem 10 passing through the central hole of pneumatic valve stem guide seat 8a. The lower end of float 11 is connected to hydraulic valve core 13a via hydraulic valve stem 12, with the lower part of hydraulic valve stem 12 passing through the central hole of hydraulic valve stem guide seat 8b. Pneumatic valve stem guide seat 8a and hydraulic valve stem guide seat 8b are supported on the inner wall of the secondary buffer separation tube. The distance between the top of pneumatic valve core 9a and the bottom of hydraulic valve core 13a is less than the distance between pneumatic valve seat and hydraulic valve seat.

[0062] The denser liquid phase flows along the wall of the first-stage cyclone separator 7 to its bottom, and then enters the lower inlet of the second-stage buffer separator 8 through the first-stage cyclone outlet pipe 18. In the second-stage buffer separator 8, the gas and liquid phases are further separated under the action of gravity separation, which improves the separation efficiency. The gas and liquid phases are controlled and regulated by the float switch liquid level valve to keep the gas and liquid phases in balance.

[0063] When the liquid level in the pipe is high, the float ball 11 rises, the pneumatic control valve rod 10 pushes the pneumatic control valve core 9a up and sits on the bell mouth of the pneumatic control valve seat to close the pneumatic control valve and shut off the gas phase outlet; at the same time, the liquid control valve core 13a rises and disengages from the bell mouth of the liquid control valve seat to open the liquid phase outlet, the gas accumulates and squeezes the liquid out of the secondary buffer separation pipe 8, thereby reducing the liquid level.

[0064] When the liquid level in the pipe is low, the float ball 11 floats down, and the hydraulic control valve rod 12 pushes the hydraulic control valve core 13a down and sits on the flared end of the hydraulic control valve seat to close the hydraulic control valve and shut off the liquid phase outlet; at the same time, the pneumatic control valve core 9a descends and disengages from the flared end of the pneumatic control valve seat to open the upper gas phase outlet, discharge the accumulated gas into the pipe, reduce the pressure inside the secondary buffer separation pipe 8, and promote the liquid level to return to normal.

[0065] The whole device adjusts liquid level and pressure in real time and continuously, and maintains balance by mutual compensation of gas-liquid two phases. The separated gas phase is metered by gas flow meter 15, and the separated liquid phase is metered by mass flow meter 20, and is discharged through liquid outlet valve 21.

[0066] The oil-gas separation system composed of plug flow buffer vertical pipe 4, transverse distribution pipe 5, rectangular tapered square pipe 6, first-stage cyclone separation pipe 7 and second-stage buffer separation pipe 8 is placed in water bath heating box 25, and is heated and kept warm by water bath heating, so as to prevent pipeline blockage and leakage caused by low temperature of the device.

[0067] Part of the natural gas separated by the oil-gas separation system enters the oil-gas mixed transportation module through cyclone separation gas phase pipe 14, and part of the natural gas is used as gas source for combustion of gas water heater 27.

[0068] The circulating water outlet of water bath heating box 25 is connected with the water inlet of gas water heater 27 through cold water pipe 26, the water outlet of gas water heater 27 is connected with the circulating water inlet of water bath heating box 25 through high-temperature water supply pipe 29, and the above components constitute a water circulation, and hot water circulating pump 28 is arranged in cold water pipe 26 or low-temperature water supply pipe to provide power for hot water circulation. The hot water circulation pipeline is connected with water supplement tank 30 through a water supplement valve to supplement the circulating loss of the water bath, and manhole 25a is arranged on the top of water bath heating box 25.

[0069] The gas source pipeline of gas water heater 27 is connected with cyclone separation gas phase pipe 14, and the gas phase separated by the system is supplied to gas water heater 27 through gas furnace gas supply pipe 14a to provide gas, and no external energy source is needed.

[0070] The high-temperature hot water heated by gas water heater 27 enters water bath heating box 25 through high-temperature hot water pipe to provide water bath heating and keeping warm for the oil-gas separation system, and the cooled water bath water returns to gas water heater 27 through cold water pipe 26 to be heated again. Gas water heater 27 is matched with a temperature control and water level control system to improve the stability of the device.

[0071] The outlet temperature of the oil-gas separation system is linked with gas water heater 27, and the outlet temperature of the oil-gas separation system is set to 50℃, when the temperature is lower than 50℃, gas water heater 27 is started to heat, and when the temperature is higher than 50℃, gas water heater 27 is stopped to heat, so as to ensure the temperature of the liquid for external transportation and reduce the energy consumption of the equipment.

[0072] The liquid level height in water bath heating box 25 is automatically and remotely controlled, the height of the water tank body is 2.2m, the height of the water outlet is 1.8m, when the water level is as low as 1.9m, remote alarm is prompted to supplement water, and when the water level is as high as 2.1m, remote alarm is prompted that the water level is too high, and water is prompted to be discharged.

[0073] As shown in FIG. 1, the oil-gas separation device is composed of oil-gas mixed transportation module 1, oil-gas separation system 2, water bath heating box 25, gas water heater 27 and water supplement tank 30. Figure 7As shown, the oil well fluid is separated and metered by the oil-gas separation metering module and then enters the oil-gas mixed transportation module, the separated gas enters the gas mixing pipeline 16, the gas mixing pipeline 16 is designed to be one-way conductive, and is internally provided with a multi-loop one-way valve 17, the center of the multi-loop one-way valve 17 is a main channel with a square cross section, a plurality of groups of bifurcated branch channels are arranged along the flow direction of the main channel, each bifurcated branch channel includes an upwardly diverging inclined section 17a, an arc turning section 17b and a downwardly converging inclined section 17c which are connected in series and integrated, and the outlet of the downwardly converging inclined section 17c is located above the inlet of the upwardly diverging inclined section 17a.

[0074] The bifurcated branch channels can be symmetrically arranged on the left and right sides of the main channel to form a heart shape, or symmetrically arranged on the front and back sides of the main channel to form a heart shape, or symmetrically arranged on the front, back, left and right sides of the main channel to form a cross-shaped heart shape.

[0075] The bifurcated branch channels can also be symmetrically arranged on the left and right sides of the main channel at one height to form a heart shape, and symmetrically arranged on the front and back sides of the main channel at another height to form a heart shape, and staggered along the height direction of the main channel. Experimental results show that the anti-backflow effect of this structure is better.

[0076] When the gas flows downward in the positive direction, most of the gas will flow along the vertical pipeline, the kinetic energy of the gas is almost not lost, and the flow resistance of the gas downward is very small, which is convenient for mixing with the liquid. When the liquid flows upward in the reverse direction, it will be divided into multiple flows at each branch port, and the liquid entering the branch will form a bend and converge with the liquid in the main channel to offset the kinetic energy. Since the flow direction of the divided liquid is opposite, a large flow resistance is formed when flowing, which plays a role in stopping the flow of the valve, preventing the liquid from flowing backward into the gas mixing pipeline 16, and avoiding the risk of oil entering the gas pipeline. The structure of the device is simple and has no moving parts, so it has a long service life.

[0077] Through simulation, when the angle between the upward diverging inclined section 17a and the main channel is 50° and the angle between the downward converging inclined section 17c and the main channel is 40°, the one-way conductive performance is optimal.

[0078] The liquid enters the optimized oil-gas mixer 24 after being pressurized by the liquid booster pump 23, the high-pressure liquid after pressurization is sprayed at high speed through the nozzle 24b, a low-pressure area is formed near the outlet of the nozzle 24b, thereby sucking the low-pressure gas in the gas mixing pipeline 16 into the oil-gas mixer 24 to mix with the liquid and then output, realizing the oil-gas mixed transportation function.

[0079] The automation control system comprises a linkage control system of the oil-gas separation metering module and the liquid booster pump 23, the displacement of the liquid booster pump 23 is adjusted by monitoring the liquid level of the secondary buffer separation pipe 8, and the problem that the mixed transport pump is difficult to manage is solved; the automatic control of the gas mixing pipeline is mixed, the multi-loop one-way valve 17 at the junction of the gas mixing pipeline and the liquid pipeline is controlled, the risk of oil entering the gas pipeline is avoided, and the operation stability of the device is improved.

[0080] The above only describes the preferred embodiments of the present application, shows and describes the basic principles, main features and advantages of the present application, and does not limit the patent protection scope of the present application. It should be understood by those skilled in the art that the present application is not limited by the above embodiments. In addition to the above embodiments, other embodiments can be implemented without departing from the spirit and scope of the present application. The present application can also have various changes and improvements. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present application. The scope of protection of the present application is defined by the appended claims and their equivalents. The technical features not described in the present application can be realized by or with the existing technology, and will not be described here.

Claims

1. A skid-mounted oil and gas multiphase flow device comprising a device inlet, characterised in that, The device inlet is connected with the lower end inlet of the plug flow buffer vertical pipe through an inlet valve, the upper end outlet of the plug flow buffer vertical pipe is connected with the middle section bottom of the transverse distribution pipe, a primary cyclone liquid inlet pipe is symmetrically connected along the length direction of the transverse distribution pipe, the outlet of each primary cyclone liquid inlet pipe is respectively connected with the middle section of a primary cyclone separation pipe, the top gas outlet of each primary cyclone separation pipe is respectively connected with a cyclone separation gas phase pipe; The lower end liquid outlet of each primary cyclone separation pipe is connected with a primary cyclone liquid outlet pipe, the middle section outlet of the primary cyclone liquid outlet pipe is communicated with the bottom inlet of a secondary buffer separation pipe, the lower section circumferential liquid outlet of the secondary buffer separation pipe is connected with a liquid outlet pipeline; The outlet of the liquid outlet pipeline is connected with the oil inlet pipe of an oil-gas mixer, the outlet of the cyclone separation gas phase pipe is connected with the air injection port of the oil-gas mixer, and the outlet of the oil-gas mixer is connected with a mixed transportation pipeline; The outlet of the liquid outlet pipeline is provided with a mass flow meter and is connected with the inlet of a liquid booster pump through a liquid outlet valve, and the outlet pipeline of the liquid booster pump is connected with the oil inlet pipe of the oil-gas mixer; The bottom center of the primary cyclone separation pipe is provided with an inverted truncated cone with a narrow top and a wide bottom, under the action of centrifugal force, gravity and collision force, the oil liquid rapidly forms a cyclone around the inverted truncated cone, the liquid phase with large density flows along the pipe wall of the primary cyclone separation pipe to the bottom liquid outlet, and the gas phase with small density forms a gas core along the cyclone center and rises to the top gas outlet; The diameter of the plug flow buffer vertical pipe gradually increases from bottom to top, the rising liquid flow is gradually decompressed and decelerated, so that the plug flow becomes a laminar flow, the gas-liquid interface is formed, and preliminary gas-liquid phase separation is achieved; The top gas outlet of the secondary buffer separation pipe is also connected with the cyclone separation gas phase pipe, the outlet of the cyclone separation gas phase pipe is provided with a gas flow meter and is connected with the inlet of an air injection pipeline; The primary cyclone liquid inlet pipe is a rectangular tapered square pipe, the cross section of the rectangular tapered square pipe is rectangular and the height is greater than the width, the area gradually decreases along the fluid advancing direction, and the oil liquid generates a pressure difference during the flow process in the rectangular tapered square pipe, under the action of the pressure difference, the gas dissolved in the liquid moves to the low pressure area, condenses into large bubbles, forms a stable gas-liquid interface, and preliminary separation is realized; The end of the rectangular tapered square pipe is inclined downward and is tangentially communicated to the middle section circumference of the primary cyclone separation pipe.

2. The skid-mounted oil and gas pigging apparatus of claim 1, wherein: The device inlet is also connected with the inlet of a bypass valve, the outlet of the bypass valve is connected with the middle section inlet of a liquid outlet tee joint, the main inlet of the liquid outlet tee joint is connected with the outlet of the liquid outlet valve, and the outlet of the liquid outlet tee joint is connected with the inlet of the liquid booster pump.

3. The skid-mounted oil and gas pigging apparatus of claim 1, wherein: The upper end outlet of the secondary buffer separation pipe is provided with an air control valve, the lower end outlet of the secondary buffer separation pipe is provided with a liquid control valve, and a floating ball is arranged in the middle section of the inner cavity of the secondary buffer separation pipe; the opening and closing of the air control valve and the liquid control valve are controlled through the floating ball, so that the gas-liquid two phases are kept in balance.

4. The skid-mounted oil and gas pigging apparatus of claim 3, wherein: The upper section of the air control valve is provided with an air control valve seat, the center of the air control valve seat is provided with an exhaust hole, the lower end of the exhaust hole is provided with a downward-opening horn, the lower section of the air control valve seat is provided with an air control valve core, and the upper end of the air control valve core is provided with a conical sealing surface matched with the horn of the air control valve seat.

5. The skid-mounted oil and gas pig launcher of claim 4, wherein: The lower part of the hydraulic control valve is provided with a hydraulic control valve seat, the center of the hydraulic control valve seat is provided with a drain hole, the upper end of the drain hole is provided with a trumpet mouth opening upward, the upper part of the hydraulic control valve seat is provided with a hydraulic control valve core, the lower end of the hydraulic control valve core is provided with a tapered sealing surface matched with the trumpet mouth of the hydraulic control valve seat.

6. The skid-mounted oil and gas pig launcher of claim 5, wherein: The upper end of the float ball is connected with the air control valve core through an air control valve rod, the upper part of the air control valve rod passes through the center hole of the air control valve rod guide seat; the lower end of the float ball is connected with the hydraulic control valve core through a hydraulic control valve rod, the lower part of the hydraulic control valve rod passes through the center hole of the hydraulic control valve rod guide seat, and the air control valve rod guide seat and the hydraulic control valve rod guide seat are supported on the inner wall of the secondary buffer separation pipe.

7. The skid-mounted oil and gas pigging apparatus of claim 6, wherein: When the liquid level in the secondary buffer separation pipe is high, the float ball floats up, the air control valve rod pushes the air control valve core up and seals on the trumpet mouth of the air control valve seat to close the air outlet, and at the same time, the hydraulic control valve core rises to separate from the trumpet mouth of the hydraulic control valve seat to open the lower liquid outlet, so that the gas gathers to squeeze the liquid out of the secondary buffer separation pipe, thereby reducing the liquid level.

8. The skid-mounted oil and gas pig launcher of claim 6, wherein: When the liquid level in the secondary buffer separation pipe is low, the float ball sinks, the hydraulic control valve rod pushes the hydraulic control valve core down and seals on the trumpet mouth of the hydraulic control valve seat to close the liquid outlet, and at the same time, the air control valve core descends to separate from the trumpet mouth of the air control valve seat to open the upper gas outlet, so that the gathered gas is discharged from the pipe to reduce the pressure in the secondary buffer separation pipe and promote the liquid level to return to the normal liquid level.

9. The skid-mounted oil and gas transfer apparatus of claim 1, wherein: The oil-gas mixer is provided with a large-diameter mixer cylinder, the top of the middle part of the mixer cylinder is provided with a gas mixing port connected with the outlet of the gas mixing pipeline; the outlet of the mixer cylinder is connected with a tapered section, the outlet of the tapered section is connected with a small-diameter throat section, the inlet end of the mixer cylinder is closed, and the oil inlet pipe is inserted into the center of the inlet end of the cylinder, the end of the oil inlet pipe is provided with a nozzle with a reduced diameter, the nozzle is located in the center of the tapered section and faces the throat section for injection, and the end of the throat section is connected with a gradually expanding section, and the outlet of the gradually expanding section is a mixed outlet.

10. The skid-mounted oil and gas transfer apparatus of claim 1, wherein: The plug flow buffer vertical pipe, the transverse distribution pipe, the primary cyclone liquid inlet pipe, the primary cyclone separation pipe and the secondary buffer separation pipe are placed in a water bath heating box; the circulating water outlet of the water bath heating box is connected with the water inlet of a gas water heater through a cold water pipe, the water outlet of the gas water heater is connected with the circulating water inlet of the water bath heating box through a high-temperature water supply pipe, and a hot water circulating pump is arranged in the cold water pipe or the high-temperature water supply pipe; the gas source pipeline of the gas water heater is connected with the cyclone separation gas phase pipe.

11. The skid-mounted oil and gas transfer apparatus of claim 1, wherein: A multi-circuit check valve is arranged in the gas mixing pipeline, the center of the multi-circuit check valve is a main channel with a square cross section, a plurality of groups of branch channels are arranged along the flow direction of the main channel, each branch channel comprises an upward flow separation inclined section, an arc turning section and a downward flow convergence inclined section connected in series, and the outlet of the downward flow convergence inclined section is located above the inlet of the upward flow separation inclined section.

12. The skid-mounted oil and gas pig launcher of claim 11, wherein: The branch channels are arranged in a heart shape at one height of the main channel and in a heart shape at another height of the main channel, and a plurality of groups of branch channels are arranged staggeredly along the height direction of the main channel.

13. The skid-mounted oil and gas transfer apparatus of claim 11, wherein: The upward flow inclined section is 50° with the main channel, and the downward flow inclined section is 40° with the main channel.

Images