Oil-gas separation device for offshore oil and gas engineering

Abstract

The invention discloses an oil-gas separation device for offshore oil and gas engineering, and relates to the field of oil exploitation, the oil-gas separation device comprises a tank body used for providing a separation space, a settling tank is arranged in the tank body, and a sand discharge pipe is arranged on the settling tank; the sand discharging device further comprises a suction sand discharging mechanism, and the suction sand discharging mechanism is communicated with the sand discharging pipe and used for pumping sand in the settling tank out of the tank body. According to the oil-gas separation device for the offshore oil and gas engineering, the settling tank is arranged on the tank body, the sand discharging pipe is arranged on the settling tank, the sand discharging pipe is connected with the suction sand discharging mechanism, when sand discharging needs to be conducted on the tank body, the suction sand discharging mechanism is started, and the sand discharging pipe is started; on one hand, the sand discharging efficiency can be improved, and on the other hand, the sand discharging pipe can be prevented from being blocked as much as possible.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil exploitation, in particular to an oil liquid gas separation device for offshore oil and gas engineering. BACKGROUND

[0002] It is known that offshore oil and gas engineering refers to the technology and engineering of oil and gas resource exploration, exploitation, storage, transportation, processing and environmental management in marine environment. It includes offshore drilling platforms, subsea production systems, oil and gas pipelines, offshore engineering structures and risk management, etc. When processing oil and gas, a three-phase separator is preferentially used to separate oil, water and gas. In the processing process, sand contained in crude oil settles on the bottom wall of the three-phase separator and needs to be treated.

[0003] For example, a three-phase separator with better sand discharge effect, with publication number CN222376466U and publication date 2025-01-21, has a barrel with a sand deposition cavity. The top of the sand deposition cavity is provided with a material inlet. A sand flushing pipe is arranged in the sand deposition cavity, and the pipe inlet of the sand flushing pipe is located outside the barrel. The part of the sand flushing pipe located in the barrel is provided with a plurality of sand flushing nozzles. The bottom of the sand deposition cavity is provided with a sand storage chamber. The sand storage space of the sand storage chamber is lower than the bottom of the sand deposition cavity. The bottom of the sand storage chamber is provided with a sand discharge port. The present application can effectively discharge the deposited sand in the three-phase separator, and ensure the service life and processing capacity of the three-phase separator.

[0004] The existing technology has the following disadvantages. When cleaning the sand and stones on the bottom wall of the barrel, the sand and stones are discharged from the barrel in a straight discharge manner. As the sand and stones deposit, the sand and stones may be hardened. The hardened sand and stones may block the liquid discharge pipe during straight discharge, so that the sand and stones cannot be normally discharged. SUMMARY

[0005] The present application aims to provide an oil liquid gas separation device for offshore oil and gas engineering to solve the above-mentioned problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: An oil liquid gas separation device for offshore oil and gas engineering, comprising a barrel for providing a separation space, wherein a settling tank is arranged inside the barrel, and a sand discharge pipe is arranged on the settling tank. Further comprising a suction sand discharge mechanism in communication with the sand discharge pipe, which is used to suck the sand and stones in the settling tank out of the barrel.

[0007] The oil liquid gas separation device for offshore oil and gas engineering, wherein the suction sand discharge mechanism comprises a vacuum pump and a transfer tank in communication with the vacuum pump. The transfer tank is in communication with the sand discharge pipe, and a first valve is arranged on the sand discharge pipe.

[0008] The oil-gas separation device for offshore oil and gas engineering has a blowdown port arranged on the transfer tank.

[0009] The oil-gas separation device for offshore oil and gas engineering has a transfer pipe arranged in the settling tank and arranged in correspondence with the position of the sand discharge pipe.

[0010] The oil-gas separation device for offshore oil and gas engineering has a rectifier arranged in the tank body, and the sand discharge pipe is arranged at the front side of the rectifier.

[0011] The oil-gas separation device for offshore oil and gas engineering has a mist eliminator arranged on the tank body, and a liquid collecting tank arranged in the tank body and located below the mist eliminator.

[0012] The oil-gas separation device for offshore oil and gas engineering has a liquid discharge pipe arranged between the liquid collecting tank and the transfer tank, and a second valve arranged on the liquid discharge pipe.

[0013] The oil-gas separation device for offshore oil and gas engineering has a suction sand discharge mechanism having a first state for discharging sand and a second state for discharging liquid.

[0014] The oil-gas separation device for offshore oil and gas engineering has a scraper slidingly arranged on the mist eliminator, and a power assembly arranged between the liquid collecting tank and the mist eliminator and used to drive the scraper to slide horizontally.

[0015] The oil-gas separation device for offshore oil and gas engineering has a sliding seat fixedly arranged in the liquid collecting tank, a transmission rod slidingly arranged on the sliding seat, an elastic member arranged between the sliding seat and the transmission rod, a connecting rod arranged between the transmission rod and the scraper, an expansion part arranged on the liquid discharge pipe, and a blocking part arranged on the transmission rod and matched with the expansion part.

[0016] In the above technical solution, the oil-gas separation device for offshore oil and gas engineering has a settling tank arranged on a tank body, a sand discharge pipe arranged on the settling tank, and a suction sand discharge mechanism connected with the sand discharge pipe. When the tank body needs to be discharged, the suction sand discharge mechanism is started to suck out the sand and stones in the sand discharge pipe and the settling tank. This can improve the sand discharge efficiency and avoid the blockage of the sand discharge pipe. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only show some embodiments of the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0018] Figure 1 The overall structural schematic diagram provided by the embodiment of the present application is shown in the figure. Figure 2 The front view structural schematic diagram provided by the embodiment of the present application is shown in the figure. Figure 3 The sectional view structural schematic diagram provided by another embodiment of the present application is shown in the figure. Figure 4 The sectional view structural schematic diagram provided by another embodiment of the present application is shown in the figure. Figure 3 The enlarged schematic diagram of the local structure at A in the figure is shown in the figure. Figure 5 The overall structural schematic diagram of the demister and the liquid collecting tank provided by another embodiment of the present application is shown in the figure. Figure 6 The connection structural schematic diagram of the transmission rod and the scraper provided by another embodiment of the present application is shown in the figure. Figure 7 The sectional view structural schematic diagram provided by another embodiment of the present application is shown in the figure. Figure 8 The sectional view structural schematic diagram provided by another embodiment of the present application is shown in the figure. Figure 7 The enlarged schematic diagram of the local structure at B in the figure is shown in the figure.

[0019] Explanation of reference signs: 1, tank body; 2, settling tank; 3, sand discharge pipe; 4, vacuum pump; 5, transfer tank; 6, first valve; 7, pollution discharge port; 8, transfer pipe; 9, auxiliary hole; 10, rectifier; 11, demister; 12, liquid collecting tank; 13, liquid discharge pipe; 14, second valve; 15, scraper; 16, sliding seat; 17, transmission rod; 18, elastic member; 19, connecting rod; 20, expansion part; 21, plugging part; 22, rotating seat; 23, protruding ring; 24, first section; 25, second section; 26, driving groove; 27, driving rod; 28, cleaning frame; 29, limiting strip; 30, limiting groove; 31, gas outlet; 32, oil outlet; 33, water outlet; 34, cleaning part. DETAILED DESCRIPTION

[0020] In order to make those skilled in the art better understand the technical solutions of the present application, the following will further introduce the present application in combination with the drawings.

[0021] In the description of the present application, it should be understood that the Figure 4The position of the gas outlet 31 relative to the sump 12 is upper, and vice versa. The terms "center", "longitudinal", "transverse", "length", "width", "degree", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0022] Referring to Figures 1-8 The oil-gas separation device for offshore oil and gas engineering provided by the embodiment of the present application comprises a tank body 1 for providing a separation space, a settling tank 2 is arranged inside the tank body 1, and a sand discharge pipe 3 is arranged on the settling tank 2. The oil-gas separation device further comprises a sand suction and discharge mechanism which is communicated with the sand discharge pipe 3 and is used to suck and discharge the sand and stones in the settling tank 2 from the tank body 1.

[0023] Specifically, the tank body 1 is horizontally arranged in a circular tank type structure, and the tank body 1 is respectively provided with a liquid inlet, a water outlet 33, an oil outlet 32, a gas outlet 31, and a sand discharge port. Crude oil enters the inside of the tank body 1 from the liquid inlet. According to the different characteristics of the densities of gas, water, and oil, the three are divided into three layers in the vertical direction. The gas naturally rises to the top, the water naturally settles to the bottom, and the oil collects in the middle layer. The gas is discharged through the gas outlet 31 at the top, the water is discharged through the water outlet 33 at the bottom, and the oil is sucked out from the tank body 1 after overflow, so as to realize the separation of the three of oil, water, and gas. The sand and stones contained in the crude oil settle at the bottom of the water layer, and a slope or sand flushing pipe (not shown) or the like structure is arranged at the bottom of the tank body 1 to make the sand and stones collect in the settling tank 2 and be uniformly discharged through the sand discharge pipe 3. This is the prior art, and no further description is given (see the patent document with the authorization announcement number CN222376466U). One of the core innovations of the embodiment of the present application is that the settling tank 2 is arranged on the tank body 1, the bottom of the settling tank 2 is in an arc-shaped barrel structure, the sand discharge pipe 3 is arranged at the bottom of the settling tank 2, and the sand discharge pipe 3 is connected with the sand suction and discharge mechanism. The sand suction and discharge mechanism can be a conveying mechanism such as a pump. The setting has the effect that when it is necessary to discharge sand from the tank body 1, the sand suction and discharge mechanism is started, so that the sand and stones in the sand discharge pipe 3 and the settling tank 2 are sucked out by the sand suction and discharge mechanism. On the one hand, the sand discharge efficiency can be improved, and on the other hand, the sand discharge pipe 3 can be prevented from being blocked as much as possible.

[0024] It should be noted that the sand is easily rubbed with the internal components of the mud pump by pumping the sand, thereby easily causing damage to the pump, preferably, the sand pumping mechanism comprises a vacuum pump 4 and a transfer tank 5 communicated with the vacuum pump 4, the transfer tank 5 is communicated with the sand discharge pipe 3, and the first valve 6 is arranged on the sand discharge pipe 3. Specifically, the transfer tank 5 is preferably a sealed structure, and the first valve 6 is preferably a pneumatic valve. The effect of such arrangement is that during normal separation process, the first valve 6 is always in a closed state, when sand needs to be discharged, the transfer tank 5 is pumped into a negative pressure state by the vacuum pump 4, then the first valve 6 is opened, at this time, under the action of negative pressure in the transfer tank 5, the sand in the settling tank 2 and the sand discharge pipe 3 is instantly sucked into the transfer tank 5, when the sand is discharged, the first valve 6 is closed, thereby avoiding the entry of subsequent liquid for the next sand discharge. The benefits of such arrangement are that, first, the response speed is fast, that is, when the first valve 6 is opened, the sand will be immediately pumped out, second, the sand will not directly enter the vacuum pump 4, thereby the damage to the vacuum pump 4 can be avoided as much as possible, third, the negative pressure pressure of the vacuum pump 4 can be adjusted according to the amount of sand in the settling tank 2, that is, when the sand is more, the negative pressure pressure is larger, when the sand is less, the negative pressure pressure is smaller, the sand discharge effect is more accurate, fourth, the sand can be discharged without stopping, thereby improving the efficiency of crude oil separation.

[0025] Further, the transfer tank 5 is provided with a blow-off port 7. The bottom of the transfer tank 5 is funnel-shaped, and the blow-off port 7 can also be provided with a valve. After the sand is pumped into the transfer tank 5 and the first valve 6 is closed, the valve of the blow-off port 7 is opened to automatically discharge the sand from the transfer tank 5, so that the transfer tank 5 can be used continuously.

[0026] It should be noted that due to the viscosity of oil is much larger than that of water, which makes the rising speed of oil in water much larger than the falling speed of water in oil. As another embodiment of the present application, the settling tank 2 is provided with a transfer pipe 8, which is arranged corresponding to the position of the sand discharge pipe 3. Specifically, the transfer pipe 8 is a vertically arranged tubular structure, the bottom end of the transfer pipe 8 is fixed in the settling tank 2 through the radial arrangement of the cross bar along the settling tank 2, the space between adjacent cross bars can be used for sand falling, and the transfer pipe 8 is coaxially arranged with the sand discharge pipe 3, the top end of the transfer pipe 8 is located at the position of the oil-water separation layer, and a plurality of auxiliary holes 9 are formed in the side wall near the top end of the transfer pipe 8. The effect of such arrangement is that during the sand discharge process, part of the pressure of the sand discharge pipe 3 will act on the inside of the transfer pipe 8, thereby the oil-water mixture at the position of the top end of the transfer pipe 8 can be pumped into the settling tank 2, and the oil in the oil-water mixture quickly moves upward under the action of buoyancy, thereby the speed of oil-water separation can be accelerated during the sand discharge process.

[0027] The transfer pipe 8 is preferably a telescopic pipe, i.e. its top end position is adjustable, when the oil content in the crude oil is small, the top end of the transfer pipe 8 is higher, when the oil content in the crude oil is more, the top end of the transfer pipe 8 is lower.

[0028] Further, the tank body 1 is internally provided with a flow regulator 10, and the sand discharge pipe 3 is arranged at the front side of the flow regulator 10. Specifically, the flow regulator 10 is a plurality of vertically stacked corrugated plate structures, which has the effect of reducing the flow rate of crude oil and defoaming due to its structural characteristics, which is prior art and will not be described here. The front side here refers to the front side of the horizontal flow direction of the crude oil, i.e. the sand discharge pipe 3 is arranged between the liquid inlet and the flow regulator 10, so as to reduce the influence of the fluctuations generated during the sand discharge process on the liquid level at the rear side of the flow regulator 10 as much as possible, so that the crude oil at the rear side can be normally separated.

[0029] It should be noted that the gas outlet 31 and the demister 11 are usually arranged at one end close to the oil outlet 32, and the liquid droplets and impurities (hereinafter referred to as liquid droplets for convenience of description) captured by the demister 11 will directly fall into the oil layer, thereby reducing the purity of the oil. Further, the tank body 1 is provided with a demister 11, and the tank body 1 is internally provided with a liquid collecting groove 12 located below the demister 11. Specifically, the demister 11 is arranged inside the gas outlet 31, which is a plurality of square corrugated plates arranged vertically and equidistantly, and has a gap between adjacent corrugated plates for gas to pass through. The liquid collecting groove 12 is preferably funnel-shaped (which can be circular funnel-shaped or square funnel-shaped), and the area of the top end of the liquid collecting groove 12 is larger than the area of the demister 11, so that the liquid collecting groove 12 can cover the entire bottom of the demister 11, and the liquid collecting groove 12 can also be fixed to the oil layer and the demister 11 by a cross bar, i.e. one end of the cross bar is fixed to the inner wall of the tank body 1, and the other end is fixed to the outer circumferential surface of the liquid collecting groove 12. The purpose of such arrangement is that during the process of discharging gas from the gas outlet 31, the water and solid impurities contained in the gas will be blocked on the surface of the demister 11, among which the water will gather into liquid droplets and fall into the liquid collecting groove 12, and the solid impurities will fall into the liquid collecting groove 12 together with the liquid droplets, so as to be uniformly discharged subsequently, and the liquid droplets will not fall into the oil layer, so as to improve the purity of the oil as much as possible.

[0030] Further, a drain pipe 13 is arranged between the collecting tank 12 and the transfer tank 5, and a second valve 14 is arranged on the drain pipe 13. Specifically, the drain pipe 13 is arranged at the bottom end of the collecting tank 12, and extends through the bottom wall of the tank body 1 to the outside of the tank body 1. The second valve 14 is preferably a pneumatic valve, and is arranged on the part of the drain pipe 13 outside the tank body 1. In this way, during normal separation, the second valve 14 is closed. When it is necessary to drain the liquid droplets in the collecting tank 12 (whether it is necessary to drain the liquid droplets can be determined by a liquid level meter or other structure for monitoring the liquid level), the transfer tank 5 is subjected to negative pressure operation by the vacuum pump 4, and then the second valve 14 is opened. At this time, under the action of negative pressure, the substances in the collecting tank 12 are quickly sucked into the transfer tank 5, and then discharged through the blowdown opening 7. After the suction is completed, the second valve 14 is closed for the next suction.

[0031] Further, the suction and sand discharge mechanism has a first state for discharging sand and a second state for discharging liquid. Specifically, in the first state, only the first valve 6 is opened after the vacuum pump 4 is subjected to negative pressure, and at this time, the suction effect only acts on the sand discharge. In the second state, only the second valve 14 is opened after the vacuum pump 4 is subjected to negative pressure, and at this time, the suction effect only acts on the liquid discharge. Since the force required for sand discharge is greater than the force required for liquid discharge, the negative pressure force provided by the suction and sand discharge mechanism in the first state is greater than the negative pressure force provided by the suction and sand discharge mechanism in the second state.

[0032] As another embodiment of the present application, a scraper 15 is arranged to slide on the demister 11, and a power assembly is arranged between the collecting tank 12 and the demister 11 to drive the scraper 15 to slide horizontally. Specifically, the scraper 15 is preferably a vertically arranged plate structure, and a plurality of through holes are formed in the scraper 15 to match the demister 11. The scraper 15 is preferably two, and the two scrapers 15 are symmetrically arranged about the demister 11. The power assembly can be an existing reciprocating driving assembly such as an electric push rod. In this way, when the scraper 15 is not working, the two scrapers 15 are respectively located at the two ends of the demister 11. When the demister 11 is demisted, the two scrapers 15 are simultaneously controlled by the power assembly to slide toward the middle of the demister 11. In the process of sliding of the scraper 15, the edge position of the through hole can scrape and wash the surface of the demister 11 to scrape the liquid droplets attached to the surface of the demister 11 into the collecting tank 12. After the scraping and washing are completed, the scraper 15 is controlled to slide reversely to realize resetting.

[0033] As the above-mentioned alternative scheme of the electric push rod controlling the active sliding of the scraper 15, preferably, the power assembly comprises a sliding seat 16 fixedly connected in the sump 12, a transmission rod 17 is arranged on the sliding seat 16 in a sliding mode, and an elastic element 18 is arranged between the sliding seat 16 and the transmission rod 17. A connecting rod 19 is arranged between the transmission rod 17 and the scraper 15. An expansion part 20 is arranged on the drain pipe 13, and a blocking part 21 adapted to the expansion part 20 is arranged on the transmission rod 17. Specifically, the sliding seat 16 is in a cylindrical structure, which is fixedly arranged inside the sump 12 through a plurality of fixing rods. The top of the transmission rod 17 is in a disc shape, and the upper surface of the transmission rod 17 and the lower surface of the scraper 15 are both provided with rotating seats 22. The two ends of the connecting rod 19 are rotatably connected with the two rotating seats 22 respectively, and the rotating seat 22 and the connecting rod 19 are symmetrically provided with two groups respectively. The radial dimension of the transmission rod 17 is smaller than that of the drain pipe 13, and the transmission rod 17 is provided with a convex ring 23. A vertical groove is formed in the inside of the sliding seat 16, and the convex ring 23 is in a sliding connection with the vertical groove. The elastic element 18 is preferably a spring, which is sleeved on the transmission rod 17, and one end thereof is fixedly connected with the top wall in the vertical groove, and the other end thereof is fixedly connected with the upper surface of the convex ring 23. The expansion part 20 is preferably in an inverted circular table shape, and the blocking part 21 is in a circular table shape, the radial dimension of the bottom of which is greater than that of the top end opening of the expansion part 20, and the top end of the blocking part 21 is inserted into the opening above the expansion part 20. The setting function is that, under the action of the elasticity of the elastic element 18, the outer circumferential surface of the blocking part 21 is attached to the opening above the expansion part 20 to block the top end opening of the expansion part 20, so that the falling of the liquid can be avoided, thereby achieving the secondary sealing effect of the liquid (the second valve 14 is the primary sealing). When the liquid needs to be drained, the intermediate transfer tank 5 is operated by negative pressure, and then the second valve 14 is opened. Under the action of the negative pressure suction, the blocking part 21 and the transmission rod 17 move downward, and the elastic element 18 is charged, so that the top end opening of the expansion part 20 is opened to make the liquid drops in the sump 12 be sucked into the intermediate transfer tank 5, thereby achieving the effect of draining the liquid. During the downward movement of the transmission rod 17, the bottom end of the connecting rod 19 is pulled to move downward, and under the action of the connecting rod 19, the two scrapers 15 are passively slid toward the middle part of the demister 11 to achieve the passive cleaning of the demister 11. When the liquid is drained, the elasticity of the elastic element 18 is released to drive the transmission rod 17 and the blocking part 21 to move upward to achieve the reset. During the reset, the liquid drops scraped off will bring some gas to fall into the sump 12. The part of the liquid drops is blocked in the sump 12 by the reset blocking part 21, and then rises to the gas outlet 31 to be discharged, thereby the waste of the gas can be avoided as much as possible.

[0034] As another embodiment of the present application, the transmission rod 17 comprises a first segment 24 and a second segment 25 which are rotationally connected with each other, a driving slot 26 is formed on the sliding seat 16, a driving rod 27 is fixedly connected on the second segment 25, the driving rod 27 is slidably connected with the driving slot 26, a cleaning frame 28 is rotationally arranged on the sliding seat 16, and the second segment 25 is throughly connected with the cleaning frame 28. Specifically, the first segment 24 is located above the second segment 25, and a limiting structure for preventing the first segment 24 and the second segment 25 from being separated from each other is arranged between the first segment 24 and the second segment 25, the connecting rod 19 is arranged at the top end of the first segment 24, the blocking part 21 is located at the bottom end of the second segment 25, the driving rod 27 is a cylindrical rod which is arranged along the radial direction of the second segment 25, the driving slot 26 is obliquely arranged along the inner wall of the sliding seat 16, the cleaning frame 28 is preferably a cross-shaped structure, one end of the cleaning frame 28 which is away from the central axis is provided with a rod-shaped cleaning part 34 which is attached to the inner wall of the liquid collecting groove 12, and a circular hole which is adapted to the second segment 25 is formed in the center of the cleaning frame 28, a limiting strip 29 is arranged on the outer circumferential surface of the second segment 25, a limiting groove 30 which is adapted to the limiting strip 29 is formed on the inner wall of the circular hole, and the limiting strip 29 is slidably connected with the limiting groove 30. The purpose of such arrangement is that, during the liquid discharge, the transmission rod 17 and the blocking part 21 will be driven to move downward under the action of negative pressure, so as to open the top opening of the expansion part 20, and during this process, the driving rod 27 will be synchronously moved downward, the second segment 25 will be passively rotated under the action of the sliding connection between the driving rod 27 and the driving slot 26, and the cleaning frame 28 will be synchronously rotated under the action of the sliding connection between the limiting strip 29 and the limiting groove 30. The benefits brought by such arrangement are that, first, the bottom of the liquid collecting groove 12 can be passively cleaned by the cleaning part 34 during the rotation of the cleaning frame 28, second, the compacted impurities inside the liquid collecting groove 12 can be broken up, so as to facilitate the subsequent liquid discharge process, and third, the transmission rod 17 will be moved upward when the elastic force of the elastic member 18 is released, the liquid drops scraped off by the scraper 15 will fall onto the rotating cleaning frame 28, and the liquid drops will be subjected to a gas-liquid separation effect under the impact of the cleaning frame 28, so as to separate the gas carried by the liquid drops and discharge the gas from the gas outlet 31, thereby reducing the waste of gas.

[0035] The above only describes certain exemplary embodiments of the present application by way of illustration, and it is needless to say that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above drawings and descriptions are illustrative in nature and should not be understood as limiting the scope of protection of the claims of the present application.

Claims

1. An oil-liquid-gas separation device for marine oil and gas engineering, comprising a tank for providing a separation space, wherein a settling tank is provided inside the tank, characterized in that, The settling tank is equipped with a sand discharge pipe; It also includes a sand suction and discharge mechanism, which is connected to the sand discharge pipe and is used to extract sand and gravel from the settling tank from the tank body.

2. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 1, characterized in that, The suction and sand removal mechanism includes a vacuum pump and a transfer tank connected to the vacuum pump. The transfer tank is connected to the sand removal pipe, and a first valve is installed on the sand removal pipe.

3. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 2, characterized in that, The transfer tank is equipped with a sewage outlet.

4. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 2, characterized in that, The settling tank is equipped with a transfer pipe, and the transfer pipe is arranged in a corresponding position to the sand discharge pipe.

5. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 2, characterized in that, The tank is equipped with a rectifier, and the sand discharge pipe is located in front of the rectifier.

6. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 2, characterized in that, The tank is equipped with a demister, and a liquid collection tank is located inside the tank, below the demister.

7. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 6, characterized in that, A drain pipe is provided between the collection tank and the transfer tank, and a second valve is provided on the drain pipe.

8. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 7, characterized in that, The suction and sand removal mechanism has a first state for sand removal and a second state for liquid removal.

9. The oil-liquid-gas separation device for marine oil and gas engineering according to claim 7, characterized in that, A scraper is slidably mounted on the demister, and a power assembly for driving the scraper to slide horizontally is provided between the liquid collection tank and the demister.

10. An oil-liquid-gas separation device for marine oil and gas engineering according to claim 9, characterized in that, The power assembly includes a sliding seat fixed in the liquid collection tank, a transmission rod slidably disposed on the sliding seat, an elastic element disposed between the sliding seat and the transmission rod, a connecting rod disposed between the transmission rod and the scraper, an expansion portion disposed on the drain pipe, and a sealing portion disposed on the transmission rod that is adapted to the expansion portion.

Images