CN112780249B - Underwater three-phase multi-stage gravity type separation injection-production system - Google Patents

Abstract

The invention discloses an underwater three-phase multi-stage gravity separation injection and production system, which belongs to the field of offshore oil and gas development. The separation injection and production system includes an integral support structure, a three-stage column-type gas-liquid cyclone separator and its support bracket, a horizontal three-phase gravity separator and its support bracket, three groups of booster delivery pumps, a transition liquid storage tank, and Corresponding connecting lines. Three-stage column gas-liquid cyclone separator and its supporting bracket, horizontal three-phase gravity separator and its supporting bracket, three groups of booster transfer pumps and transition liquid storage tanks are located in the overall bracket structure and connected by corresponding pipelines A three-phase multi-stage separation injection-production system is formed. Produced fluids from production wells can be directly passed through the seabed to achieve three-phase separation, so as to avoid lifting the produced fluids to the offshore platform for separation treatment, which not only reduces unnecessary energy consumption, but also saves valuable platform area for the offshore platform. At the same time, it also reduces the static pressure of the riser and the back pressure of the wellhead, improves the efficiency and stability of oil and gas production, and reduces the production cost.

Description

An underwater three-phase multi-stage gravity separation injection and production system

technical field

The invention belongs to the field of offshore oil and gas development, and in particular relates to an underwater three-phase multi-stage gravity separation injection-production system.

Background technique

In the initial process of offshore oil and gas exploration and development, the products produced from subsea oil wells are transported to offshore platforms or shore-based facilities through long-distance pipelines, followed by subsequent oil-gas-water separation treatment, and then onshore transportation to maximize comprehensive benefits. On the one hand, it is more efficient than building an underwater production system. However, as the mining time increases and the mining intensity increases, the water content of the deep-sea produced fluid will also increase. Long-distance transportation and treatment and re-injection will generate a lot of energy consumption and increase production costs. Increased pressure can also have serious effects on the entire production system. Therefore, with the gradual deepening of offshore oil and gas exploration and development, the construction of underwater production systems has become one of the key technologies for offshore oil and gas exploration. Among them, the underwater separation injection-production system is an important part of the underwater production system. At present, the research on the underwater separation injection-production system in my country is still in the preliminary planning and testing stage, and there are often problems such as simple equipment, weak liquid handling capacity, and low separation efficiency. The development of a reasonable and efficient underwater separation injection-production system can improve the production efficiency of offshore platforms, reduce economic costs, and play a positive role in solving a series of problems currently faced by the development of offshore oil and gas fields. In order to make up for the defects and blanks of my country's domestic offshore oil and gas development technology, the present invention proposes an underwater three-phase multi-stage gravity separation injection-production system, which can directly conduct oil-gas-water three-phase separation on the production well production fluid on the seabed. , so as to avoid lifting the produced fluid to the offshore platform for separation treatment, which not only reduces unnecessary energy consumption, but also saves valuable platform area for the offshore platform, and also reduces the riser static pressure and wellhead back pressure. The efficiency and stability of oil and gas exploitation are improved, and the production cost is reduced.

SUMMARY OF THE INVENTION

In order to solve the technical problem of underwater separation faced by the current offshore oilfield exploitation, the present invention provides an underwater three-phase multi-stage gravity separation injection-production system, which can directly conduct oil-gas-water on the production well production fluid on the seabed. Three-phase separation.

An underwater three-phase multi-stage gravity separation injection and production system, the separation injection and production system comprises an integral support structure, a three-stage column type gas-liquid cyclone separator, a horizontal three-phase gravity separator, and a gas-phase booster conveying pump , Water phase booster delivery pump, oil phase booster delivery pump and transition liquid storage tank, the three-stage column gas-liquid cyclone separator, horizontal three-phase gravity separator, gas phase booster delivery pump, water phase booster pump The pressure transfer pump, the oil phase booster transfer pump and the transition liquid storage tank are all located inside the overall support structure. The oil and gas well produced fluid on the seabed enters the three-stage column gas-liquid cyclone separator through the input pipeline of the separation injection-production system. , the liquid phase medium separated by the three-stage column gas-liquid cyclone separator enters the horizontal three-phase gravity separator through the connecting pipeline, and the horizontal three-phase gravity separator is provided with gas, water and oil The three-phase outlet and the separated water-phase medium are connected to the transition liquid storage tank through the water-phase outlet pipeline, and then transported to the water-phase booster pump through the connecting pipeline, and then injected back into the formation after being boosted by the water-phase booster pump. The separated oil-phase medium is connected to the oil-phase booster delivery pump through the oil-phase outlet and is lifted to the oil storage device on the seabed or offshore platform through the oil-phase booster delivery pump. The gas-phase medium separated by the separator and the gas-phase medium still remaining in the liquid-phase medium separated by the horizontal three-phase gravity separator are respectively merged into the same conveying pipeline through their respective gas-phase outlet pipelines, and then pressurized with the gas-phase medium. The delivery pump is connected and delivered to the gas phase processing station via the gas phase booster delivery pump.

Further, the three-stage column-type gas-liquid cyclone separator is composed of three single-stage column-type gas-liquid cyclone separators, and the first-stage column-type gas-liquid cyclone separator and the second-stage column-type gas-liquid cyclone Three-way valves are set between the cyclone separators and between the second-stage column-type gas-liquid cyclone separator and the third-stage column-type gas-liquid cyclone separator. The oil and gas well produced fluid on the seabed enters through the input pipeline The first-stage column-type gas-liquid cyclone separator, the liquid-phase outlet pipelines of the first-stage column-type gas-liquid cyclone separator and the second-stage column-type gas-liquid cyclone separator are divided into two pipelines after passing through the three-way valve , one pipeline is connected to the inlet pipeline of the next-stage column-type gas-liquid cyclone separator, and the other pipeline merges into the total liquid-phase outlet pipeline of the three-stage column-type gas-liquid cyclone separator. A two-way valve is set at the liquid phase outlet pipeline of the column type gas-liquid cyclone separator, and the separated liquid phase medium flows into the total liquid phase outlet pipeline after passing through the two-way valve, which is located in three single-stage column type gas-liquid cyclones. The gas-phase outlet line at the top of the separator is jointly merged into the gas-phase total outlet line of the three-stage column-type gas-liquid cyclone separator, and the gas-phase outlet line at the second-stage and third-stage column-type gas-liquid cyclone separators All have shut-off valves.

Further, the horizontal three-phase gravity separator consists of the main body of the separator, the fluid input pipeline of the horizontal gravity separator, the electrode control box, the gas phase outlet pipeline of the horizontal gravity separator, and the water phase outlet of the horizontal gravity separator. Pipeline, oil phase outlet pipeline of horizontal gravity separator, inlet circular hole baffle, arc blade movable rotor and its cylinder, rotatable blade baffle group, round hole baffle group, electrostatic coalescence electrode plate and weir The main body of the separator is composed of a cylinder in the middle and hemispheres on both sides. The fluid input pipeline of the horizontal three-phase gravity separator is connected to the interior of the horizontal separator along the direction parallel to the axis of the main body of the separator. Two mutually perpendicular semicircular inlet circular hole baffles are arranged in the area near the entrance of the main body of the separator, and the arc-shaped blade movable rotor and its cylinder are arranged below the inlet circular hole baffle, and the inlet area gradually penetrates into the interior of the separator. The rotatable vane baffle group, the circular hole baffle group, the electrostatic coalescence electrode plate and the weir plate are arranged in sequence, an electrode control box is arranged directly above the electrostatic coalescence electrode plate, and the top of the separator body is far from the inlet area. Set the gas phase outlet pipeline of the horizontal gravity separator, the oil phase outlet pipeline of the horizontal three-phase gravity separator is located at one end of the separator away from the inlet area, and the water phase outlet pipeline of the horizontal three-phase gravity separator is set at the end of the separator. middle.

Further, the round hole baffle group is composed of three groups of round hole baffle plates with different baffle spacing and round hole density, and the distance between each group of round hole baffle plates gradually changes along the direction of the separator axis gradually moving away from the inlet. Small, the density of round holes gradually becomes sparser.

Further, the electrostatic coalescence electrode plates are a group of parallel grid plate structures that are not equidistantly distributed along the direction perpendicular to the axis of the separator. The closer to the bottom of the separator, the greater the distance between the electrode plates.

Further, the weir plate is located at the rear end of the separator and has a semicircular baffle structure, and the water phase outlet pipeline of the horizontal gravity separator and the oil phase outlet pipeline of the horizontal gravity separator are respectively located on both sides of the weir plate.

Further, there are four water phase outlet pipelines of the horizontal gravity separator, which are distributed in the middle of the separator body at unequal intervals, and the closer to the oil phase outlet pipeline of the horizontal gravity separator, each horizontal gravity separation The spacing of the water phase outlet lines of the reactor is also smaller.

Further, the three-stage column-type gas-liquid cyclone separator, the horizontal three-phase gravity separator, the gas-phase booster delivery pump, the water-phase booster delivery pump and the oil-phase booster delivery pump have their own independent support brackets. .

Further, the overall support structure includes a bottom platform and an upper support, the bottom platform is a rectangular flat plate structure with two upper and lower layers, and the upper platform and the lower platform are separated from each other by a set blank groove structure. The gas-liquid cyclone separator and its support bracket, the horizontal three-phase gravity separator and its support bracket, three groups of booster delivery pumps, transition liquid storage tanks and connecting pipelines are placed on the upper platform.

Beneficial effects:

1) The underwater three-phase multi-stage gravity separation injection-production system is directly installed on the seabed, and the oil-gas-water three-phase separation can be performed on the produced fluid of the production well in the near-well area, without the need to separate the output through the riser in the traditional way. The liquid is transported to the offshore platform for separation treatment, which saves platform space, reduces energy consumption, reduces riser static pressure and wellhead back pressure, and improves production stability;

2) The underwater three-phase multi-stage gravity separation injection-production system can carry out multi-stage separation of oil and gas well production fluid, realize the three-phase separation of oil, gas and water to the greatest extent, and greatly improve the overall separation effect of the system;

3) The three-stage column-type cyclone separator is composed of three single-stage column-type gas-liquid cyclone separators. According to the amount of liquid to be processed and the gas content, it can be controlled by controlling the switch of the relevant valve. The number of stages of the column-type gas-liquid cyclone separators involved in the liquid volume treatment, so as to realize the reasonable configuration of the separation device and prolong the service life of the separation device;

4) In the horizontal three-phase gravitational separator, a relatively complete system consisting of an inlet circular hole baffle, an arc-shaped movable rotor, a rotatable blade baffle group, a circular hole baffle group and an electrostatic coalescence electrode plate is set up. The inlet component, the rectification component and the aggregation component can achieve a relatively complete oil-water separation for the oil-water mixture entering the separator. At the same time, the electrostatic coalescence separation technology is adopted. Compared with the conventional gravity separation, the electrostatic coalescence separation can accelerate the oil-water separation. Coagulation of small droplets in the emulsion, thereby improving the efficiency of oil-water gravity separation;

5) The three-stage column type gas-liquid cyclone separator and the oil-water horizontal three-phase gravity separator are installed on the same platform through the overall support structure. The structure is simple and compact, and can be lowered to the seabed as a whole during installation, avoiding the need for separate fixed placement and The steps of interconnection can be lifted as a whole during maintenance, which greatly simplifies the difficulty of operation. At the same time, the gas-liquid separator and the oil-water separator have their own independent brackets, which can also be hoisted for individual maintenance and repair when a fault occurs.

Description of drawings

Figure 1 is a three-dimensional schematic diagram of an underwater three-phase multi-stage gravity separation injection-production system;

Fig. 2 is the top view of the underwater three-phase multi-stage gravity separation injection-production system;

Figure 3 is a side view of an underwater three-phase multi-stage gravity separation injection-production system;

Figure 4 is a front view of an underwater three-phase multi-stage gravity separation injection-production system;

5 is a three-dimensional schematic diagram of a three-stage column-type gas-liquid cyclone and its supporting bracket;

Fig. 6 is the side view of three-stage column type gas-liquid cyclone separator and its support bracket;

Fig. 7 is the top view of three-stage column type gas-liquid cyclone separator and its support bracket;

Fig. 8 is the rear view of three-stage column type gas-liquid cyclone separator and its support bracket;

9 is a three-dimensional schematic diagram of a horizontal three-phase gravity separator and its supporting bracket;

Figure 10 is a side view of a horizontal three-phase gravity separator and its supporting bracket;

Figure 11 is a top view of a horizontal three-phase gravity separator and its supporting bracket;

12 is a schematic cross-sectional view of a horizontal three-phase gravity separator;

Figure 13 is a front view of the arc-shaped blade movable rotor;

Figure 14 is a top view of the movable rotary character of the arc-shaped blade;

Figure 15 is a schematic diagram of the three-dimensional structure of the movable blade baffle;

Figure 16 is a front view of the movable vane baffle;

FIG. 17 is a schematic diagram of the three-dimensional structure of the circular hole baffle.

1. Overall support structure, 2. Supporting bracket for horizontal three-phase gravity separator, 3. Horizontal three-phase gravity separator, 4. Supporting bracket for three-stage column gas-liquid cyclone separator, 5. Three-stage column Type gas-liquid cyclone separator, 6. System input pipeline, 7. Connection pipeline between horizontal gravity separator and column type gas-liquid cyclone separator, 8. Gas-phase booster delivery pump, 9. Water-phase booster delivery pump , 10, transition liquid storage tank, 11, oil phase booster delivery pump, 12, support bracket for booster delivery pump, 301, fluid input pipeline of horizontal gravity separator, 302, electrode control box, 303, horizontal gravity The gas phase outlet pipeline of the separator, 304, the water phase outlet pipeline of the horizontal gravity separator, 305, the oil phase outlet pipeline of the horizontal gravity separator, 306, the inlet circular hole baffle, 307, the curved blade movable rotor and Its cylinder, 308, rotatable vane baffle group, 309, round hole baffle group, 310, electrostatic coalescence electrode plate, 311, weir plate, 501, inlet pipeline of three-stage column gas-liquid cyclone separator, 502, first-stage column type gas-liquid cyclone separator, 503, first-stage stop valve, 504, second-stage column type gas-liquid cyclone separator, 505, second-stage stop valve, 506, third-stage column Type gas-liquid cyclone separator, 507, first-stage three-way valve, 508, second-stage three-way valve, 509, two-way valve, 510, the total gas phase outlet pipeline of the three-stage column gas-liquid cyclone separator, 511. The total liquid phase outlet pipeline of the three-stage column gas-liquid cyclone separator.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

As shown in Figure 1, Figure 2, Figure 3, Figure 4, the underwater three-phase multi-stage gravity separation injection and production system includes: overall support structure 1, three-stage column type gas-liquid cyclone separator 5, three-stage column type Support bracket 4 of gas-liquid cyclone separator, horizontal three-phase gravity separator 3, support bracket 2 of horizontal three-phase gravity separator, gas phase booster delivery pump 8, water phase booster delivery pump 9, oil phase booster pump The pressure transfer pump 11, the transition liquid storage tank 10 and the corresponding connecting pipeline. Among them, the three-stage column type gas-liquid cyclone separator 5, the support bracket 4 of the three-stage column type gas-liquid cyclone separator, the horizontal three-phase gravity separator 3, and the support bracket 2 of the horizontal three-phase gravity separator are provided. In the overall support structure 1, the three-stage column-type gas-liquid cyclone separator 5 and the horizontal three-phase gravity separator 3 are connected through the connecting pipeline 7 between the horizontal-type gravity separator and the column-type gas-liquid cyclone separator. stand up.

The overall support structure 1 includes a bottom platform and an upper support. The bottom platform is a rectangular plate structure with two upper and lower layers. The upper platform and the lower platform are separated from each other by a blank groove structure. All separation devices and connecting pipelines are placed on the upper platform. The purpose of the trough structure is to avoid direct contact between the upper platform and the seabed, so as to protect the separation device and pipeline placed on the upper platform to a certain extent. The upper bracket is located on the bottom platform, the four square bracket poles of the upper bracket are fixed at the four square corners of the bottom platform, four square poles perpendicular to each other are set on the top of the upper bracket, and above the square poles are set. Four arched rings are used for the entire separation injection and production system for overall installation and maintenance.

The gas phase booster delivery pump 8, the water phase booster delivery pump 9, the oil phase booster delivery pump 11 and the support bracket 12 of the booster delivery pump are also arranged in the overall support structure 1. The support bracket 12 of the booster delivery pump The structure is similar to the overall support structure 1, and is also constructed with a rectangular support as the main body, and a plurality of horizontal square poles and vertical square poles are intersected. The main functions of the gas phase booster delivery pump 8 , the water phase booster delivery pump 9 , and the oil phase booster delivery pump 11 are to boost the corresponding separated phase and transport it to the next link for further processing. The gas-phase booster delivery pump 8 is connected to the gas-phase collection pipeline composed of the gas-phase outlet pipeline 510 of the three-stage column-type gas-liquid cyclone separator and the gas-phase outlet pipeline 303 of the horizontal three-phase gravity separator, and is used for booster delivery and separation. The gas phase separated from the injection-production system; the water-phase booster pump 9 is connected to the outlet pipeline of the transition liquid storage tank 10, and is used to pressurize the water-phase separated from the separation injection-production system back into the formation, thereby starting To maintain the formation pressure, the transition liquid storage tank 10 mainly plays the role of temporarily storing excess water phase and reducing the workload of the water phase booster pump 9; while the oil phase booster pump 11 is the same as the horizontal The oil phase outlet pipeline 305 of the three-phase gravity separator is connected to each other, and plays the role of pressurizing and conveying the oil phase separated by the separation injection-production system.

As shown in Figure 5, Figure 6, Figure 7, Figure 8, the support bracket 4 of the three-stage column type gas-liquid cyclone separator is a cuboid bracket as the main body, wherein the cuboid bracket is a plurality of horizontal square rods and vertical square rods It is constructed by intersecting the columns. A square column is arranged along the diagonal of the rectangle on both sides of the square frame. At the same time, the upper and lower parts of the bracket are provided with square columns and columns for supporting the column separator. For the disc type support, a plurality of support rings for supporting pipelines are set on the square pole at the upper part, and four rings are set on the top of the rectangular support for suspending the gas-liquid separator for installation and maintenance.

The three-stage column-type gas-liquid cyclone separator 5 is composed of a first-stage column-type gas-liquid cyclone separator 502, a second-stage column-type gas-liquid cyclone separator 504 and a third-stage column-type gas-liquid cyclone separator Composed of 506, three single-stage column gas-liquid cyclone separators are the main places for realizing gas-liquid separation of mixtures. The gas-liquid mixture enters the single-stage column gas-liquid cyclone separators through the inclined tangential inlet. Under the combined action of gravity and buoyancy, the denser liquid phase is pushed to the outside in the radial direction, and moves downwards and is discharged from the liquid phase outlet at the bottom of the separator, while the less dense gas phase moves to the central area, and Float upward from the gas phase outlet at the top of the separator.

In the first-stage single-stage column-type gas-liquid cyclone separator 502 and the second-stage single-stage column-type gas-liquid cyclone separator 504 and the second-stage single-stage column-type gas-liquid cyclone separator 504 and the third-stage single-stage A first-stage three-way valve 507 and a second-stage three-way valve 508 are respectively set between the column-type gas-liquid cyclone separator 506, which are used to control the liquid-phase outlet pipeline of the gas-liquid separator of this stage and the gas-liquid separator of the lower stage. The connection between the mixture inlet pipeline and the total liquid phase outlet pipeline 511 of the three-stage column-type gas-liquid cyclone separator, in the third-stage single-stage column-type gas-liquid cyclone separator 506 The liquid-phase outlet pipeline and the three-stage column-type gas-liquid cyclone A two-way valve 509 is set between the total liquid phase outlet pipeline 511 of the gas-liquid cyclone separator to control the liquid phase outlet pipeline of the third-stage single-stage column type gas-liquid cyclone separator 506 and the three-stage column type gas-liquid outlet pipeline. Connection of the total liquid phase outlet line 511 of the hydrocyclone. The gas phase outlet pipeline of the second-stage single-stage column-type gas-liquid cyclone separator 504 and the gas-phase outlet pipeline of the third-stage single-stage column-type gas-liquid cyclone separator 506 are combined with the three-stage column-type gas-liquid cyclone separator. A first-stage shut-off valve 503 and a second-stage shut-off valve 505 are respectively set between the gas phase outlet pipelines 510 to control the second-stage single-stage column gas-liquid cyclone 504 and the third-stage single-stage column gas-liquid The communication relationship between the gas phase outlet line of the cyclone 506 and the total gas phase outlet line 510 of the gas-liquid separator.

The produced liquid from the production well enters the three-stage column gas-liquid cyclone separator 3 through the inlet line 501, and then realizes gas-liquid separation in the single-stage column gas-liquid cyclone separator, and the separated gas phase passes through each single-stage gas-liquid cyclone. The gas-phase outlet of the column-type gas-liquid cyclone separator is aggregated to the total gas-phase outlet line 510 of the three-stage column-type gas-liquid cyclone separator, and then transported to the next stage through the transportation pipeline for subsequent processing, and the separated liquid phase Then, the liquid phase outlet of each single-stage column type gas-liquid cyclone separator is collected to the total liquid phase outlet pipeline, and then transported to the horizontal three-phase gravity separator 3 through the connecting pipeline 7 for oil-water two-phase separation.

In the process of gas-liquid separation, the number of stages of the single-stage column gas-liquid cyclone separators involved in the gas-liquid separation can be adjusted according to the amount of the treated liquid. When the amount of liquid to be treated is very small, the processing capacity of the single-stage column-type gas-liquid cyclone separator 502 is sufficient. At this time, the first-stage column-type gas-liquid cyclone is separated by controlling the first-stage three-way valve 507 The liquid phase outlet of the separator is connected with the total liquid phase outlet pipeline 511 of the three-stage column-type gas-liquid cyclone separator, and the second-stage column-type gas-liquid is blocked by controlling the second-stage three-way valve 504 and the two-way valve 509 The communication between the liquid phase outlet pipeline of the cyclone separator 504 and the third-stage column type gas-liquid cyclone separator 506 and the total liquid phase outlet pipeline 511 of the three-stage column type gas-liquid cyclone separator is controlled by controlling the first The first-stage shut-off valve 503 and the second-stage shut-off valve 505 are used to block the gas phase outlet pipeline of the second-stage column type gas-liquid cyclone separator 504 and the third-stage column type gas-liquid cyclone separator 506 and the third-stage column type gas-liquid cyclone The communication between the total gas phase outlet line 510 of the liquid cyclone separator is to prevent the gas phase separated in the first-stage column-type gas-liquid cyclone separator 502 from flowing back to the second-stage column-type gas-liquid cyclone separator 504 and In the third stage column type gas-liquid cyclone separator 506 . When the amount of liquid to be processed increases and requires a two-stage column-type gas-liquid cyclone to process, the first-stage column-type gas-liquid cyclone can be adjusted by adjusting the first-stage three-way valve 507 and the second-stage three-way valve 508. The liquid phase outlet pipeline of the flow separator 502 is connected with the inlet pipeline of the lower-stage gas-liquid separator, and the liquid phase outlet pipeline of the second-stage column-type gas-liquid cyclone separator 504 is connected with the three-stage column-type gas-liquid cyclone separator. The total outlet pipeline 511 is connected, and the liquid phase outlet pipeline of the third-stage column-type gas-liquid cyclone separator 508 and the total liquid-phase outlet pipeline of the third-stage column-type gas-liquid cyclone separator are blocked by controlling the two-way valve 509 511, by controlling the second-stage shut-off valve 505 to block the communication between the gas-phase outlet line and the total gas-phase outlet line 510 of the third-stage column type gas-liquid cyclone separator 506, so as to prevent the first-stage column type The gas phase separated by the gas-liquid cyclone separator 502 and the second-stage column-type gas-liquid cyclone separator 504 is returned to the third-stage column-type gas-liquid cyclone separator 506 . When the amount of liquid to be processed continues to increase and requires a three-stage column-type gas-liquid cyclone to process, the first-stage three-way valve 507 and the second-stage three-way valve 508 are controlled to make the first stage and the second stage. The liquid phase outlet pipeline of the column-type gas-liquid cyclone separator is connected with the inlet pipeline of the lower-stage separator. By adjusting the two-way valve 509, the liquid-phase outlet pipeline of the third-stage column-type gas-liquid cyclone separator can be The total liquid phase outlet line 511 of the type gas-liquid cyclone separator is connected.

As shown in Figure 9, Figure 10, Figure 11, the support bracket 2 of the horizontal three-phase gravity separator is mainly composed of a cuboid bracket, and the cuboid bracket is constructed by intersecting a plurality of horizontal square poles and vertical square poles. Four lifting rings are arranged on the top of the circular poles located at the four square corners of the support bracket for suspending the gas-liquid separator for installation and decoration.

The horizontal three-phase gravity separator 3 is composed of a separator main body, a fluid input pipeline 301 of the horizontal gravity separator, and an outlet pipeline corresponding to each separation. The fluid input line 301 of the horizontal gravity separator is connected to the interior of the separator along a direction parallel to the axis of the separator. The gas phase outlet line 303 of the horizontal three-phase gravity separator is at the top of the horizontal separator, the oil phase outlet line 305 of the horizontal three-phase gravity separator is at the end of the separator away from the inlet area, and the horizontal three-phase gravity separator There are four water phase outlet pipelines 304, which are distributed in the middle of the separator at unequal intervals. The closer to the oil phase outlet pipeline 305 of the horizontal three-phase gravity separator, the smaller the interval of each water phase outlet pipeline.

As shown in Figure 12, the inlet circular hole baffle 306 located in the inlet area is a component of the inlet component of the horizontal three-phase gravity separator 3. It consists of two mutually perpendicular semicircular circular hole baffles, located in the inlet circular The arc-shaped blade movable rotor at the bottom of the hole baffle 306 and its supporting cylinder 307 are also part of the inlet member of the horizontal three-phase gravity separator 3. The arc-shaped blade movable rotor is shown in Figures 13 and 14. The inlet component of the horizontal three-phase gravity separator 3 is formed, which reduces and stabilizes the flow rate of the fluid entering the separator through the inlet pipeline 301, changes the direction of the liquid flow, and prevents it from entering the dead liquid area. Each group of blade baffles of the rotatable blade baffle group 308 is composed of four blades from top to bottom that can rotate around a circular axis fixed on the inner wall of the separator. The structure of the rotatable blade baffle is shown in Figures 15 and 16 , when no liquid flow enters the separator, the vanes in the rotatable vane baffle group 308 do not have any angular offset, and the directions of the vanes and the separator axis are perpendicular to each other. When the liquid enters the separator through the inlet pipeline 301 and the inlet member In the device, the liquid will transfer part of its own kinetic energy to the rotatable vane baffle group 308, so that the blades of the rotatable vane baffle group 308 are offset by a certain angle, and the rotatable blade baffle group 308 belongs to the horizontal three A part of the rectifying member of the phase gravity separator 3 mainly plays the role of reducing the kinetic energy of the fluid and stabilizing the flow field. The round hole baffle group 309 is composed of three groups of round hole baffle plates with different spacing and different round hole densities. The round hole baffle plate structure is shown in Figure 17, and each group of round hole baffle plates is gradually away from the inlet along the axis of the separator. The distance between them gradually becomes smaller, and the density of the round holes also gradually becomes sparser. The round hole baffle group 309 mainly plays the role of stabilizing the flow field and accelerating the coalescence of droplets. For structural parts, the spacing of the circular hole baffles and the density of the circular holes can be adjusted according to the required amount of processing liquid. The electrostatic coalescence electrode plate 310 is a group of parallel grid plate structures that are not equidistantly distributed along the direction perpendicular to the separator. The positive and negative ions are ionized, thereby accelerating the polymerization and coagulation speed of the small droplets in the mixed oil-water emulsion, thereby accelerating the separation speed and improving the separation efficiency. The electrostatic coalescence electrode plate 310 belongs to the horizontal gravity separator 3. The number and spacing of electrode plates can be adjusted according to the amount of treatment liquid required and the water content. The electrode control box 302 located above the electrostatic coalescence electrode plate 310 can be used to control the working state of the electrode plate. The weir plate 311 at the rear end of the separator is a semi-circular baffle structure. The water phase outlet pipeline 304 and the oil phase outlet pipeline 305 are located on both sides of the weir plate 311. The weir plate 311 can prevent channeling between oil and water and improve separation. efficiency.

The working process of the underwater three-phase multi-stage gravity separation injection-production system: the oil and gas well produced fluid on the seabed is input into the whole gravity separation injection-production system through the input pipeline 6 of the separation injection-production system. The inlet pipeline 501 of the gas-liquid cyclone separator enters into the three-stage column-type gas-liquid cyclone separator 5 for gas-liquid separation. According to the amount of liquid to be processed and the gas content, the first-stage three-way valve can be controlled by 507. The opening and closing of the second-stage three-way valve 508, the two-way valve 509, the first-stage stop valve 503, and the second-stage stop valve 505 are used to control the operation of the single-stage column-type gas-liquid cyclone that participates in the gas-liquid separation. The number of stages, so as to achieve a reasonable configuration of the separation device, the separated gas phase is aggregated to the total gas phase outlet pipeline 510 of the three-stage column type gas-liquid cyclone separator through the gas phase outlet pipeline of each single-stage column type gas-liquid cyclone separator. It is then sent to the next link for processing. The separated liquid phase is aggregated to the total liquid phase outlet pipeline 511 of the three-stage column type gas-liquid cyclone separator through the liquid phase outlet pipeline of each single-stage column type gas-liquid cyclone separator, and then transported to the horizontal outlet through the connecting pipeline 7. The three-phase gravity separator 3 is used for oil-water two-phase separation. The oil-water mixture first passes through the inlet member formed by the inlet circular hole baffle 306, the movable rotor with arc-shaped blades and its cylindrical cylinder 307. The inlet member mainly functions to slow down the flow velocity of the liquid, change the direction of the liquid flow, and prevent the liquid flow from directly entering the separation. the rear end of the device to avoid the formation of a dead liquid area. Then the oil-water mixture will pass through the rectifying member and the poly-structural member formed by the rotatable vane baffle group 308 , the circular hole baffle group 309 , and the electrostatic coalescence electrode plate 310 in sequence. By transferring the kinetic energy to the blades of the rotatable vane baffle group 308 and the kinetic energy consumed when passing through the circular holes of the circular hole baffle group 309, the flow field in the separator is gradually stabilized, and the liquid flow in the separator is prolonged. The residence time is longer, and the separation effect of the gravity separator is improved. Under the electrostatic coalescence effect of the electrostatic coalescence electrode plate 310 , the coalescence speed of the small droplets can be accelerated, thereby further improving the speed and effect of gravity separation of oil and water. Under the action of the rectifying member and the polymer structure, the oil and water gradually begin to stratify, and the water phase with a relatively high density mainly settles at the bottom of the separator, and is transported to the overall support structure through the water phase outlet pipeline 304 on the left side of the weir plate 311. The transition liquid storage tank 10 on 1 is then transported to the water phase transport booster pump 9 through the corresponding pipeline, and then injected back into the formation after being boosted by the water phase transport booster pump 9, thereby maintaining the formation pressure. The oil phase with relatively low density floats on the surface layer of the liquid flow. When the liquid flow height reaches a certain level, the oil phase overflows the weir plate 311 and enters the end of the separator, and passes through the horizontal type on the right side of the weir plate 311. The oil phase outlet line 305 of the gravity separator is transported to the oil phase transfer booster pump 11 located on the overall support structure 1, and the separated oil phase is lifted to the seabed or offshore platform after being pressurized by the oil phase transfer booster pump 11 oil storage device. The gas phase remaining in the oil-water mixture passes through the gas phase outlet line at the top of the separator and is separated from the total gas phase outlet line 510 of the three-stage gas-liquid cyclone separator. The gas-phase conveying booster pump 8 on the upper side is also conveyed to the next link for the next step after being pressurized by the gas-phase conveying booster pump 8 .

Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention should also belong to the present invention. the scope of protection of the invention.

Claims (8)

1. an underwater three-phase multi-stage gravity separation injection-production system, is characterized in that, described separation injection-production system comprises integral support structure, three-stage column type gas-liquid cyclone separator, horizontal three-phase gravity separator , gas phase booster delivery pump, water phase booster delivery pump, oil phase booster delivery pump and transition liquid storage tank, the three-stage column gas-liquid cyclone separator, horizontal three-phase gravity separator, gas phase booster The delivery pump, water phase booster delivery pump, oil phase booster delivery pump and transition liquid storage tank are all located inside the overall support structure. Gas-liquid cyclone separator, the liquid phase medium separated by the three-stage column gas-liquid cyclone separator enters the horizontal three-phase gravity separator through the connecting pipeline, and the horizontal three-phase gravity separator is provided with There are three-phase outlets of gas, water and oil, and the separated aqueous medium is connected to the transition liquid storage tank through the aqueous outlet pipeline, and then transported to the aqueous phase booster delivery pump through the connecting pipeline, after being boosted by the aqueous phase booster delivery pump. The oil storage device that is injected back into the formation, and the separated oil phase medium is connected to the oil phase booster pump through the oil phase outlet and lifted to the seabed or offshore platform by the oil phase booster pump. The gas-phase medium separated by the column-type gas-liquid cyclone separator and the gas-phase medium still remaining in the liquid-phase medium separated by the horizontal three-phase gravity separator are respectively merged into the same conveying pipeline through their respective gas-phase outlet pipelines. connected with the gas-phase booster delivery pump and transported to the gas-phase processing station through the gas-phase booster delivery pump; The three-stage column-type gas-liquid cyclone is composed of three single-stage column-type gas-liquid cyclone separators, and the first-stage column-type gas-liquid cyclone separator is separated from the second-stage column-type gas-liquid cyclone. Three-way valves are set between the second-stage column-type gas-liquid cyclone separator and the third-stage column-type gas-liquid cyclone separator. Column gas-liquid cyclone separator, the liquid phase outlet pipeline of the first-stage column-type gas-liquid cyclone separator and the second-stage column-type gas-liquid cyclone separator is divided into two pipelines after passing through the three-way valve. The pipeline is connected with the inlet pipeline of the next-stage column-type gas-liquid cyclone separator, and the other branch line merges into the total liquid phase outlet pipeline of the three-stage column-type gas-liquid cyclone separator. A two-way valve is set at the liquid-phase outlet pipeline of the liquid cyclone, and the separated liquid-phase medium flows into the total liquid-phase outlet pipeline after passing through the two-way valve, which is located at the top of the three single-stage column gas-liquid cyclone separators. The gas phase outlet pipelines of the three-stage column type gas-liquid cyclone separator are jointly merged into the gas phase general outlet pipeline of the three-stage column type gas-liquid cyclone separator, and the gas-phase outlet pipelines at the second and third stage column type gas-liquid cyclone separators are set. Shut-off valve. 2. A kind of underwater three-phase multi-stage gravity separation injection and production system according to claim 1, is characterized in that: described horizontal three-phase gravity separator is input by the fluid of separator main body, horizontal gravity separator Pipeline, electrode control box, gas phase outlet pipeline of horizontal gravity separator, water phase outlet pipeline of horizontal gravity separator, oil phase outlet pipeline of horizontal gravity separator, inlet circular hole baffle, curved blade movable rotor It is composed of cylinder body, rotatable blade baffle group, circular hole baffle group, electrostatic coalescence electrode plate and weir plate. The main body of the separator is composed of a cylinder in the middle and hemispheres on both sides. The fluid input line of the separator is connected to the interior of the horizontal separator along the direction parallel to the axis of the separator main body. Two mutually perpendicular semicircular inlet circular hole baffles are arranged in the area near the inlet of the separator main body. An arc-shaped blade movable rotor and its cylinder are arranged below the baffle, and the rotatable blade baffle group, the circular hole baffle group, the electrostatic coalescence electrode plate and the weir plate are arranged in sequence from the inlet area to the inside of the separator. The electrode control box is arranged directly above the electrostatic coalescence electrode plate, the gas phase outlet pipeline of the horizontal gravity separator is arranged at the top of the separator body away from the inlet area, and the oil phase outlet pipeline of the horizontal three-phase gravity separator is located in the separation area. The end of the separator far from the inlet area, and the water phase outlet pipeline of the horizontal three-phase gravity separator is arranged in the middle of the separator. 3. A kind of underwater three-phase multi-stage gravity separation injection-production system according to claim 2, it is characterized in that: described circular hole baffle group is made up of three groups of circular hole baffles with different baffle spacing and circular hole density The distance between each group of circular hole baffles gradually becomes smaller along the direction of the separator axis gradually away from the inlet, and the density of the circular holes also gradually becomes sparse. 4. An underwater three-phase multi-stage gravity separation injection-production system according to claim 2, characterized in that: the electrostatic coalescence electrode plate is a group of parallel non-equidistant distribution along the direction perpendicular to the axis of the separator. The grid structure, the closer to the bottom of the separator, the greater the spacing between the electrode plates. 5. An underwater three-phase multi-stage gravity separation injection-production system according to claim 2, characterized in that: the weir plate is located at the rear end of the separator and has a semicircular baffle structure, and the horizontal gravity separator The water phase outlet pipeline of the horizontal gravity separator and the oil phase outlet pipeline of the horizontal gravity separator are located on both sides of the weir plate, respectively. 6. A kind of underwater three-phase multi-stage gravity separation injection and production system according to claim 2 is characterized in that: the water phase outlet pipelines of the horizontal gravity separator are four, and are distributed at unequal intervals in In the middle of the separator main body, the closer it is to the oil phase outlet pipeline of the horizontal gravity separator, the smaller the distance between the water phase outlet pipelines of each horizontal gravity separator. 7. An underwater three-phase multi-stage gravity separation injection-production system according to one of claims 1-6, characterized in that: the three-stage column type gas-liquid cyclone separator, the horizontal three-phase gravity type Separator, gas phase booster delivery pump, water phase booster delivery pump and oil phase booster delivery pump have their own independent support brackets. 8. The underwater three-phase multi-stage gravity separation injection and production system according to one of claims 1 to 6, wherein the overall support structure comprises a bottom platform and an upper support, and the bottom platform is an upper and lower platform. Two-layer rectangular plate structure, the upper platform and the lower platform are separated from each other by the set blank groove structure, three-stage column type gas-liquid cyclone separator and its support bracket, horizontal three-phase gravity separator and its support The brackets, three groups of booster delivery pumps, transitional liquid storage tanks and connecting pipelines are all placed on the upper platform.

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