Three-phase separator combined device and separation method

Abstract

A liquid inlet is formed in one end of a tank body, a water outlet pipe opening is formed in the bottom of the other end of the tank body, and a gas-liquid separation chamber, a plurality of self-adaptive rotational flow core pipes and a coalescence plate group module are sequentially arranged in the tank body in the fluid flowing direction; a gas liquid removal module and a gas pipe are arranged at the top of the gas-liquid separation chamber, and a sand removal pipeline is arranged at the bottom; the self-adaptive rotational flow core pipe comprises a main separation pipe and an auxiliary separation pipe; the coalescence plate group module comprises a parallel steady flow plate, a stepped guide plate and a corrugated coalescence plate; and the top or the tail part of the tank body is provided with an oil bag or an oil collecting chamber for collecting an oil phase. The invention also discloses a three-phase separation method. According to the invention, a treated object with a complex incoming liquid working condition is efficiently and rapidly separated; the device has an excellent effect on a high-turbidity-content treatment object, the high separation efficiency is guaranteed, meanwhile, the technological process is remarkably shortened, the occupied area of a treatment system is effectively reduced, and use of a large number of chemical agents is omitted or reduced.

Description

A three-phase separator assembly and separation method Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to a three-phase separator assembly and separation method. Background Technology

[0002] Large quantities of oily wastewater are generated in industries such as petrochemicals, coal chemicals, metallurgy, machinery manufacturing, textile printing and dyeing, pharmaceuticals, food processing, and catering. This oily wastewater is not only widely sourced but also complex in composition. Globally, 50 to 100 million tons of oil enter water bodies annually, causing significant harm to marine and river aquatic environments and soil environments. Current oily wastewater treatment technologies typically only address the oil content; however, actual oily wastewater, especially from oil and gas extraction and petrochemical industries, often contains large amounts of dissolved and undissolved hydrocarbon gases or acidic gases.

[0003] Taking degassing and oil removal in water as an example: Oil in water generally exists in free, dispersed, emulsified, and dissolved states. Free oil is an aggregated oil phase, which is relatively easy to separate. Dispersed oil, due to its micron-scale particle size (generally less than 100 micrometers), often exhibits oil-in-water emulsions. Emulsified oil exists in water in either an oil-in-water or oil-in-water state, with oil droplets typically ranging from 3 to 50 micrometers in diameter. Gas in water generally exists as entrained gas and microbubbles. Due to the high surface tension of the liquid phase, the resistance to gas buoyancy is increased, making it almost impossible for microbubbles to separate solely by buoyancy. Simultaneously, small oil droplets coalesce around the bubbles, further hindering their upward movement and increasing the difficulty of gas-liquid separation. Furthermore, under this operating pressure, some dissolved gas also exists in the water, which can lead to resource loss and other problems in downstream equipment. Therefore, employing efficient degassing and oil removal technologies is crucial.

[0004] Currently, the requirements for oil-water separators mainly focus on small footprint, high separation efficiency, ease of maintenance and cleaning, large processing capacity, and good economic benefits. Among current degassing and oil removal equipment, technologies utilizing swirling flow fields for separation, such as hydrocyclones and tubular separators, are widely used due to their compact structure and lack of moving parts. However, a major factor limiting their development is their narrow optimal operating flow range, requiring relatively strict control of the equipment's processing capacity. Furthermore, liquid-gas separation and liquid-liquid separation are often carried out in different equipment, frequently within pressurized vessels. Multiple pressure vessels not only increase manufacturing costs but also enlarge the footprint, increase operational difficulty, and have inconsistent service lives, making rework more challenging.

[0005] Therefore, there is an urgent need for efficient and high-capacity degassing and deoiling three-phase separation methods and devices. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a combined device and separation method suitable for three-phase separation, so as to adapt to various scenarios.

[0007] To achieve the above objectives, a first aspect of the present invention provides a three-phase separator assembly, comprising a horizontal tank, wherein one end of the tank is provided with a liquid inlet and the bottom of the other end is provided with a water outlet, and the tank is provided with a gas-liquid separation chamber, a plurality of adaptive cyclone core tubes, and a coalescing plate assembly module arranged sequentially in the direction of fluid flow; the gas-liquid separation chamber is provided with a gas deliquescence module and a gas pipe at the top and a sand removal pipeline at the bottom; the adaptive cyclone core tube includes a main separation tube and a secondary separation tube; the coalescing plate assembly module includes a parallel flow stabilizer plate, a stepped guide plate, and a corrugated coalescing plate; and an oil collection chamber or oil collection chamber for collecting the oil phase is provided at the top or tail of the tank.

[0008] Preferably, the gas dehydration module is horizontally installed in an independent chamber at the top of the tank, directly above the gas-liquid separation chamber, and a manhole is provided on the side of the chamber.

[0009] Preferably, the sand removal pipeline consists of two parallel DN50 pipelines laid on the central axis of the bottom of the tank. Each sand removal pipeline has nozzles arranged at equal intervals along the axial direction, and each cross section has two nozzles with spraying directions at 45° and 90° angles to the pipeline axis, respectively.

[0010] The adaptive swirl core tubes are vertically parallel and their axes are perpendicular to the tank axis; or, the adaptive swirl core tubes are horizontally parallel and distributed in a circular or annular array within the tank.

[0011] The adaptive cyclone core tubes are arranged in a multi-stage series. The main separation tube of the upper stage adaptive cyclone core tube is connected to the main separation tube inlet of the lower stage adaptive cyclone core tube through a pipe. Except for the last stage, each stage of the adaptive cyclone core tube has a built-in oil collection structure in the tail cavity.

[0012] The corrugated coalescing plate is made of hydrophobic and oleophilic material, with a contact angle with water droplets in the air greater than 105°, a spacing of 3 to 50 mm between adjacent plates, and multiple openings on the plate body, with the opening rate distributed from low to high.

[0013] The oil receiving chamber is separated from the main tank by a weir plate. The weir plate is vertically installed at the bottom of the rear of the tank, and its height is greater than two-thirds of the tank diameter. The bottom is connected to the oil outlet through a pipe.

[0014] A second aspect of the present invention provides a three-phase separation method using the apparatus described above, comprising the following steps:

[0015] S1: Preliminary gas-liquid-solid separation: The incoming liquid enters from the inlet, and the gas-liquid separation chamber is activated based on the gas-liquid ratio of the incoming liquid.

[0016] S2: Cyclone Enhanced Separation: The liquid phase enters the adaptive cyclone core tube. Under the action of cyclone centrifugal force, the oil phase and trace residual gas as light phases gather towards the center and enter the oil tank or oil collection chamber through the secondary separation tube; the water phase as heavy phase flows out from the main separation tube.

[0017] S3: Rectification and solid phase removal: Heavy phase is stabilized and fine solid phase is removed by parallel flow stabilizer and stepped guide plate;

[0018] S4: Coalescing Depth Separation: As the liquid flows through the corrugated coalescing plate, small oil droplets coalesce and grow into large oil droplets, which then float to the surface and flow into the oil phase collection device. The water phase sinks and is discharged from the outlet pipe.

[0019] Preferably, in step S1, if the gas-liquid ratio of the incoming liquid is ≥1, the incoming liquid enters the gas-liquid separation chamber for preliminary separation; if the gas-liquid ratio of the incoming liquid is <1, the incoming liquid directly enters the adaptive cyclone core tube.

[0020] In step S2, the single-tube processing capacity of the adaptive cyclone core is 5 m³ / h or 10 m³ / h, and the pressure drop during operation is ≤0.2 MPa.

[0021] In step S3, the parallel flow stabilizer plate adjusts its angle with the horizontal plane from 0° to 90° according to the incoming liquid pressure and flow rate, and with an adjacent plate spacing of 3 to 50 mm, to eliminate liquid turbulence.

[0022] In step S4, the low porosity section of the corrugated coalescing plate promotes the initial coalescence of small oil droplets, while the high porosity section accelerates the coalescence and causes large oil droplets to float upwards.

[0023] The present invention has the following beneficial effects:

[0024] 1. This invention achieves three-phase separation of oil, gas and water through a gas-liquid separation chamber, an adaptive cyclone core tube and a coalescing plate module coupling structure, enabling efficient and rapid separation of processing objects with complex influent conditions (high gas content, violent fluctuations in influent liquid and high concentration of suspended impurities).

[0025] 2. The present invention has an oil phase removal efficiency of over 90% in water and a gas phase removal efficiency of over 70% in oil, and has extremely high operational flexibility in terms of the target material and processing capacity (maximum operational flexibility 0-160%). It is highly effective for high turbidity targets. While ensuring high separation efficiency, it significantly shortens the process flow, effectively reduces the floor space of the treatment system, and eliminates or reduces the use of a large number of chemical reagents, thus making up for the shortcomings of the prior art. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the first combination method and device for a three-phase separator;

[0027] Figure 2 is a left view of a single adaptive swirl core tube;

[0028] Figure 3 is a top view of the transverse arrangement of single-pole adaptive swirling core tubes;

[0029] Figure 4 shows a cross-sectional view of the coalescing plate assembly, where Figure 4A is a cross-sectional view of the parallel flow stabilizer, Figure 4B is a cross-sectional view of the stepped guide plate, and Figure 4C is a cross-sectional view of the corrugated coalescing plate.

[0030] Figure 5 is a top view of the corrugated coalescing plate;

[0031] Figure 6 shows a schematic diagram of the second combination method (longitudinal distribution of core tubes) of the three-phase separator and the structure of the device;

[0032] Figure 7 is a left view of a longitudinally arranged single-pole adaptive swirling core tube;

[0033] Figure 8 is a left view of another arrangement of longitudinally arranged single-pole adaptive swirling core tubes;

[0034] Figure 9 shows a schematic diagram of the third combination method (multi-stage core tube arrangement) of the three-phase separator and the structure of the device;

[0035] Figure 10 is a left view of the transverse arrangement of multi-pole adaptive swirl core tubes;

[0036] Figure 11 is a schematic diagram of the fourth combination method of the three-phase separator (without gas-liquid separation chamber) and the structure of the device;

[0037] Figure 12 is a schematic diagram of the fifth combination method of the three-phase separator (oil collection at the tail of the tank) and the structure of the device. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of the present invention.

[0039] Example 1: Three-phase separator assembly

[0040] 1.1 The first combination of the three-phase separator combination device

[0041] As shown in Figure 1, the three-phase separator assembly of this embodiment has a horizontal tank as its main body. One end of the tank has an inlet 1 for introducing the gas-liquid-solid three-phase mixture to be treated, and the bottom of the other end has an outlet 6 for discharging the separated aqueous phase. Inside the tank, in the direction of fluid flow, a gas-liquid separation chamber 2, an adaptive cyclone core tube 3, and a coalescing plate assembly module 4 are arranged sequentially, wherein:

[0042] The gas-liquid separation chamber 2 is located at the front end of the tank. Its core function is to perform preliminary gas, liquid, and solid separation of the three-phase mixture. A gas deliquencing module 21 (refer to CN118526919A) and a gas pipe 22 are provided on the top of the tank corresponding to the gas-liquid separation chamber 2. The gas deliquencing module 21 is horizontally installed in an independent chamber directly above the gas-liquid separation chamber 2 on the top of the tank. A manhole is provided on the side of the chamber for easy disassembly and maintenance of the module. In addition to being able to enter and exit through the manhole, the gas deliquencing module 21 is mainly used to remove liquid droplets with a particle size of 3μm or larger entrained in the gas phase, with a removal rate of over 90%, achieving deep gas purification. Its outlet is connected to the gas pipe 22, which extends along the top of the tank to the outside for discharging the purified gas. The gas-liquid separation chamber 2 is equipped with an outlet pipe for introducing the pre-separated liquid phase (containing trace amounts of gas and fine solid phase with a particle size <50μm) into the adaptive cyclone core tube 3, while the larger solid phase with a particle size >50μm is deposited at the bottom of the gas-liquid separation chamber 2 due to gravity and subsequently discharged through the sand removal pipeline 7.

[0043] The adaptive cyclone core tube 3 preferably adopts the integrated separation core tube disclosed in CN112387013A, which is used to further separate the gas phase, oil phase, and solid phase (suspended solids, SS) of the mixture after gas-liquid separation. As shown in Figure 2, the adaptive cyclone core tube 3 includes a main separation tube 31, a secondary separation tube 32, a connecting main and secondary tube 33, and a connector 34. The main separation tube 31 and the secondary separation tube 32 are arranged in parallel left and right, and their axes are perpendicular to the tank axis (see Figure 3 for a top view of the unipolar transverse arrangement of the adaptive cyclone core tube). The parameters and materials of the adaptive cyclone core tube 3 are highly selective: the optional materials include, but are not limited to, 316L stainless steel, carbon steel, PP (polypropylene), PTFE (polytetrafluoroethylene), and high-strength aerospace resin; the specifications are divided into two types with a single tube processing capacity of 5 m³ / h and a single tube processing capacity of 10 m³ / h, and a single unit can be configured with 1 to 200 tubes depending on the processing scale; the pressure drop during operation is ≤0.2MPa, which can reduce energy consumption while achieving high-efficiency separation. After the liquid phase enters the main separation tube 31, it undergoes secondary separation under the action of high-speed swirling centrifugal force: the oil phase and trace residual gas, due to their lower density, accumulate towards the center as light phases and flow into the oil tank 5 through the light phase outlet of the secondary separation tube 32; the aqueous phase (containing trace amounts of oil and fine solid phase SS with a particle size <50μm), due to its higher density, flows out from the heavy phase outlet of the main separation tube 31 as a heavy phase and enters the coalescing plate assembly module 4. In this assembly, the adaptive swirling core tube 3 adopts a horizontal arrangement structure and is connected to the outlet pipe of the gas-liquid separation chamber 2 through the connector 34, adapting to the longitudinal space of the horizontal tank.

[0044] As shown in Figure 4, the coalescing plate module 4 includes three core components: a parallel flow stabilizer plate 41, a stepped flow guide plate 42, and a corrugated coalescing plate 43. The component form can be selected according to the working conditions, including but not limited to the above three. Wherein: the parallel flow stabilizer plate 41 is used for rectification and distribution, eliminating turbulence interference when the liquid flows out of the adaptive vortex core tube 3, so that the liquid flows uniformly and stably backward; the stepped guide plate 42 guides the liquid flow direction and uses gravity to further remove fine solid phase SS (particle size <50μm), reducing the processing load of the subsequent corrugated coalescing plate 43; the corrugated coalescing plate 43 (see Figure 4C for cross-sectional view and Figure 5 for top view) is made of hydrophobic and oleophilic material, with a contact angle of more than 105° with water droplets in air, and the spacing between adjacent plates can be adjusted to 3~50mm according to the oil content of the incoming liquid. It is provided with multiple openings 431, and the opening ratio of the plate body is distributed from low to high. The low opening ratio section first promotes the initial coalescence of small oil droplets, and the high opening ratio section accelerates the coalescence and then the large oil droplets float upward. When the liquid flows through the corrugated coalescing plate 43, the path length is extended, the probability of oil droplet collision is significantly increased, and small oil droplets coalesce and grow into large oil droplets, which then float up from the crest opening and flow into the oil pack 5; the water phase sinks to the bottom of the tank from the trough opening and is finally discharged from the outlet pipe 6.

[0045] Oil pack 5 is a cylindrical cavity used to collect the oil phase generated in each separation stage. Its structural parameters must meet the oil phase residence requirements: the diameter is less than half the diameter of the tank, the volume of a single oil pack meets the requirement of an oil phase residence time of more than 0.5 minutes, and the total oil phase space volume of the tank (including oil packs and related oil collection areas) meets the requirement of an oil phase residence time of more than 5 minutes, to ensure that the oil phase is fully collected and that no water phase is entrained.

[0046] A sand removal pipeline 7 is arranged along the length of the bottom of the tank. Its structure is referenced in CN202508938U. Specifically, it consists of two parallel DN50 pipelines laid parallel to each other on the central axis of the bottom of the tank. The minimum material requirement is 316L stainless steel to withstand the erosion and corrosion of sand-containing liquids. Each sand removal pipeline has nozzles 71 arranged at equal intervals along the axial direction. Each cross-section has two nozzles 71, and the spraying directions are at angles of 45° and 90° with the pipeline axis, respectively. The spraying coverage area is 700~900mm. Solid impurities (such as sand particles) deposited at the bottom of the tank can be periodically removed by high-pressure flushing and discharged through the sand discharge port.

[0047] 1.2 The second combination of the three-phase separator combination device

[0048] The main structure of the second combination is basically the same as that of the first combination. The core difference lies in the arrangement of the adaptive swirl core tubes 3—changing from a horizontal arrangement to a vertical arrangement to adapt to space-constrained scenarios (such as offshore platforms). The specific structure is as follows:

[0049] As shown in Figure 6, the adaptive cyclone core tubes 3 are arranged vertically in a circular array within the tank. Several main separation tubes 31 are vertically arranged, with their top inlets connected to the liquid phase outlet of the gas-liquid separation chamber 2 via pipes. The bottom heavy phase outlet is connected to the parallel flow stabilizer plate 41 of the rectifier distribution module via pipes. The light phase outlet of the secondary separation tubes 32 is also connected to the oil tank 5 via pipes. Connectors 34 fix the adaptive cyclone core tubes 3 to the inner wall of the tank. A left view of the vertically arranged adaptive cyclone core tubes 3 is shown in Figure 7. Another arrangement is a ring arrangement (left view shown in Figure 8), where the main separation tubes 31 are distributed in a ring around the central axis of the tank, further optimizing space utilization.

[0050] The core advantage of this combination is that it makes full use of the tank height space: compared with the horizontal arrangement of the first combination (which occupies space in the length direction of the tank), the vertical arrangement can significantly shorten the total length of the device and reduce the floor space by about 30% to 50%, making it more suitable for space-constrained scenarios such as offshore oil and gas fields and small onshore processing stations. Moreover, the material, specifications, pressure drop and other key parameters of the adaptive cyclone core tube 3 are completely consistent with the first combination, ensuring that the separation efficiency is not reduced.

[0051] 1.3 The third combination of three-phase separator combination devices

[0052] The main structure of the third combination is basically the same as that of the first combination. The core difference is that the adaptive swirl core tube 3 adopts a multi-stage series structure to cope with the incoming liquid with more complex composition and higher oil phase content. The specific structure is as follows:

[0053] As shown in Figure 9, the adaptive cyclone core tube 3 adopts a multi-stage (≥2 stages) series arrangement: the heavy phase outlet of the main separation tube 31 of the previous stage adaptive cyclone core tube is connected to the inlet of the main separation tube 31 of the next stage adaptive cyclone core tube through a pipeline; except for the last stage, each stage adaptive cyclone core tube has a built-in oil collection structure in the tail cavity (specifically, an oil collection tank is set on the inner side of the cavity, and the oil collection tank is connected to the oil tank 5 through a pipeline). Each stage core tube is connected to the oil tank 5 as an oil collection device, which can collect the oil phase separated from each stage in a timely manner, preventing the oil phase from entering the next stage with the heavy phase and reducing the load of subsequent processing. The heavy phase outlet of the last stage adaptive cyclone core tube is connected to the coalescing plate group module 4, and the light phase outlet of each stage of the secondary separation tube 32 and the oil collection structure in the tail cavity are all connected to the oil tank 5 through pipelines. The left view of the horizontal arrangement of the multi-stage adaptive cyclone core tubes is shown in Figure 10. The incoming liquid contains gas but does not require deep purification, so the gas deliquescence module 21 is omitted, and the gas pipe 22 is retained.

[0054] The core advantage of this combination is improved separation efficiency and oil phase recovery rate: For complex liquids with oil concentration >5000mg / L or containing trace amounts of emulsified oil, single-stage cyclone separation is difficult to completely remove oil, while multi-stage series separation can achieve "step-by-step oil removal" - the first stage separates 60%~70% of the oil phase, the second stage separates the remaining 50%~60% of the oil phase, and the final oil phase recovery rate is 20%~30% higher than that of single-stage separation. Moreover, the material, specifications, pressure drop and other parameters of the adaptive cyclone core tube 3 are still consistent with the first combination, ensuring operational stability.

[0055] 1.4 The fourth combination of three-phase separator combination devices

[0056] The main structure of the fourth combination is basically the same as that of the first combination. The core difference is that the gas-liquid separation chamber 2 and the gas deliquencing module 21 at the top are removed. It is suitable for low gas-liquid ratio conditions. The specific structure is as follows:

[0057] As shown in Figure 11, when the gas-liquid ratio in the incoming liquid is <1 (low gas content, no separate preliminary separation is required), the inlet 1 is directly connected to the inlet of the main separation pipe 31 of the adaptive cyclone core tube 3 via a pipeline. The three-phase mixture to be treated directly enters the adaptive cyclone core tube 3 for separation. The adaptive cyclone core tube 3 can simultaneously process trace amounts of gas (by using centrifugal force to separate trace amounts of gas and oil together as a light phase to the oil tank 5), without the need for an additional gas-liquid separation step. The configuration of the remaining components is basically the same as the first combination.

[0058] The core advantages of this combination are its simplified structure and space saving: compared with the first combination, by eliminating the gas-liquid separation chamber 2, the tank length can be shortened by about 20% to 25%, the manufacturing cost can be reduced by 15% to 20%, and the redundant design of the gas-liquid separation chamber 2 under low gas-liquid ratio conditions is avoided, making it suitable for oily wastewater treatment scenarios with low associated gas content in onshore oil fields.

[0059] 1.5 The fifth combination of three-phase separator combination devices

[0060] The main structure of the fifth combination is basically the same as that of the first combination. The core difference is that the oil tank 5 at the top of the tank is removed and replaced by the oil receiving chamber 9 at the rear of the tank. It is suitable for scenarios where the space at the top of the tank is limited. The specific structure is as follows:

[0061] As shown in Figure 12, the weir plate 8 is vertically installed at the bottom of the tank's rear. The height of the weir plate 8 is greater than two-thirds of the tank's diameter. The water phase is on its left side, and the oil phase floats above the weir plate 8 and enters the oil collection chamber 9. The volume of the oil collection chamber 9 ensures that the oil phase residence time is greater than 5 minutes (consistent with the total oil phase space residence time requirement of the first combination). The bottom of the weir plate 8 is connected to the oil outlet 10 via a pipe to discharge the collected oil phase. Furthermore, the gas does not require deep purification, eliminating the need for the gas dehydration module 21; only the gas pipe 22 is retained. The configuration of the remaining components is basically the same as in the first combination.

[0062] The core advantage of this combination is its adaptability to scenarios with limited top space: when other equipment (such as pressure gauges and valve groups) needs to be installed above the tank, resulting in no space at the top to set up the oil tank 5, the oil collection chamber 9 at the tail can utilize the length space at the tail of the tank to collect the oil phase, and the structure is simpler (no need to weld the top cylindrical oil tank), and the manufacturing cost is reduced by 10%~15% compared to the first combination, making it suitable for modular integrated processing equipment.

[0063] Example 2: Three-phase separation method

[0064] The three-phase separation method in this embodiment uses a step-coupling process to achieve efficient separation of gas, oil, and water phases. The separation effect is enhanced by the synergistic effect of multi-stage processing modules. The specific steps are as follows:

[0065] S1: Preliminary gas-liquid-solid separation

[0066] The incoming liquid enters the system through inlet 1. First, the gas-liquid separation chamber 2 is activated based on the gas-liquid ratio of the incoming liquid.

[0067] If the gas-liquid ratio is ≥1: the incoming liquid enters the gas-liquid separation chamber 2, where preliminary separation is achieved through gravity settling. The gas phase rises to the top of the gas-liquid separation chamber 2 due to the density difference, and is purified by the gas de-liquid module 21 (removing droplets larger than 3μm with a removal rate ≥90%) before being discharged from the gas pipe 22. Larger solid phases (such as sand particles) with a particle size >50μm are deposited at the bottom of the gas-liquid separation chamber 2 due to gravity, and are subsequently flushed out through the high-pressure nozzles 71 (spraying at 45° and 90° angles, covering a range of 700~900mm) of the sand removal pipeline 7. The liquid phase after preliminary separation (containing trace amounts of gas, fine solid phase SS with a particle size <50μm, and oil phase) is introduced into the adaptive cyclone core tube 3 through a pipeline. Under this condition, the width of the gas-liquid separation chamber 2 must be ≥800mm to ensure that the gas phase residence time is >30s.

[0068] If the gas-liquid ratio is <1: omit the gas-liquid separation chamber 2, and the incoming liquid directly enters the adaptive cyclone core tube 3 through the liquid inlet 1, where the trace gas phase is processed synchronously by the cyclone module.

[0069] S2: Swirl-enhanced separation

[0070] After the liquid phase (or a mixture containing trace amounts of gas) enters the adaptive cyclone core tube 3, it undergoes secondary separation under the action of cyclone centrifugal force: the oil phase and trace residual gas have lower densities (oil phase density < water phase, gas density is the lowest), and as light phases, they gather upwards and enter the oil tank 5 (or the tail oil collection chamber 9) through the secondary separation tube 32 of the core tube; the water phase (containing trace amounts of oil and fine solid phase SS) has higher densities, and as heavy phases, it flows downwards and enters the rectification and distribution module.

[0071] In this step, the configuration of the adaptive cyclone core tube 3 needs to match the processing capacity: the single tube processing capacity is divided into two specifications: 5 m³ / h and 10 m³ / h. A single unit can be configured with 1 to 200 tubes. During operation, the pressure drop is ≤0.2MPa (low energy consumption operation). If the incoming liquid composition is complex (such as high oil content, high emulsion oil), a multi-stage series arrangement of adaptive cyclone core tubes 3 can be used (see Figures 9 to 10). Except for the last stage, each stage has a built-in oil collection structure at the tail cavity to collect the oil phase separated from each stage in a timely manner and avoid secondary mixing of the oil phase with the water phase.

[0072] S3: Rectification and Solid-phase Removal

[0073] After the re-phase enters the rectification and distribution module, it achieves "current stabilization + deconsolidation" through the combined action of the parallel flow stabilizer 41 and the stepped flow guide 42 (see Figure 4 for the module structure).

[0074] The parallel flow stabilizer plate 41 can adjust its angle with the horizontal plane (0°~90°) according to the incoming liquid pressure and flow rate, and cooperate with the adjacent plate spacing of 3~50mm. When the incoming liquid flow rate is large, the angle is increased (e.g., 60°~90°) and the spacing is widened (e.g., 30~50mm) to accelerate the liquid flow speed; when the incoming liquid flow rate is small, the angle is decreased (e.g., 0°~30°) and the spacing is narrowed (e.g., 3~10mm) to ensure smooth liquid flow, and finally eliminate liquid turbulence, so that the flow state tends to be stable.

[0075] The stepped guide plate 42 guides the liquid to be evenly distributed through the stepped structure, while using gravity to remove some fine solid phase SS (particle size <50μm). The solid phase is deposited at the bottom of the step due to gravity and is periodically discharged with the flushing fluid of the sand removal pipeline 7, reducing the risk of solid phase blockage in the subsequent coalescing plate module 4.

[0076] The liquid phase after rectification and desolidification (containing trace amounts of oil phase and basically no solid phase) is fed into coalescing plate module 4 for deep separation.

[0077] S4: Cohesion Depth Separation

[0078] After the liquid enters the corrugated coalescing plate 43 (see Figures 4-5 for the plate structure), the oil phase is deeply removed through the special design of the plate: the corrugated coalescing plate 43 is made of hydrophobic and oleophilic material (contact angle with water droplets in air >105°), and the porosity of the plate is distributed from low to high. The low porosity section (inlet side) first promotes the initial coalescence of small oil droplets (avoiding small oil droplets from flowing out directly with the water phase), and the high porosity section (outlet side) accelerates the coalescence and the rise of large oil droplets; at the same time, the corrugated structure extends the liquid flow path, significantly increases the probability of oil droplet collision, and promotes the coalescence and growth of small oil droplets (emulsified oil droplets with a particle size of 3~50μm) into large oil droplets (particle size >100μm).

[0079] Finally, the oil droplets after coalescence and separation float at the crest opening due to their hydrophobicity, and flow into the oil collection tank 5 (see Figures 1, 6, 9, and 11) or the tail oil collection chamber 9 (see Figure 12) through the oil collection tank. After merging with the oil phase collected in step S2, they are discharged from the oil outlet. The water phase sinks at the trough opening, is collected in the bottom water collection tank, and is discharged from the water outlet 6.

[0080] The separation efficiency of this step must reach: oil phase removal efficiency in water > 90%, gas phase removal efficiency in oil > 90%, water removal efficiency in oil > 70%, and the entire separation method has great operational flexibility (0~160%), which can flexibly adapt to the working conditions of produced fluid with a wide range of gas content, oil phase concentration and suspended solids content.

[0081] Example 3: Device compatibility verification under different operating conditions

[0082] This embodiment verifies the device's adaptability in complex scenarios through customized device combinations and parameter settings for three typical working conditions, as detailed below:

[0083] 3.1 High gas content operating conditions (gas-liquid ratio = 2)

[0084] The device shown in Figure 1 (including a complete gas-liquid separation chamber) is used. The width of the gas-liquid separation chamber is set to 800 mm to ensure that the residence time of the gas phase in the chamber reaches 35 s, which meets the initial separation requirements of high gas content feed. The adaptive cyclone core tube adopts a horizontal arrangement structure, with a total of 10 tubes, and the design capacity of each tube is 10 m³ / h, which is adapted to the flow rate of the feed. The adjacent spacing of the corrugated plates of the coalescing plate module is adjusted to 10 mm to enhance the oil droplet coalescence effect.

[0085] The treatment target is produced fluid containing gaseous crude oil, with an oil content of 5% and a solid content of 1%. During operation, the feed enters the gas-liquid separation chamber through the inlet. The gas phase naturally rises to the top and is processed by the gas deliquidation module, achieving a 90% removal rate for droplets with a particle size ≥3μm. The water content of the purified gas phase is controlled below 10 mg / m³, and it is finally discharged through the gas pipe. The liquid phase is guided to the adaptive cyclone core tube by the bottom guide plate, where oil and water are separated under the action of cyclone. The oil phase recovery rate reaches 93%, and it is collected through the oil bag and discharged from the oil outlet. The water phase enters the coalescing plate module for further treatment, and the final oil content is ≤45mg / L, which fully meets the requirements of subsequent wastewater treatment.

[0086] 3.2 Low gas content and high sand content working conditions (gas-liquid ratio = 0.5, sand content 3%)

[0087] The device shown in Figure 11 (gas-liquid separation chamber omitted) is used to simplify the structure and reduce the equipment load; the adaptive cyclone core tube adopts a horizontal arrangement structure, with a total of 20 tubes, and the single tube has a processing capacity of 5 m³ / h. The solid-liquid separation efficiency is improved by increasing the number of core tubes; the sand removal pipeline is set to automatically flush once every 30 minutes, and the nozzle pressure is maintained at 0.6 MPa during flushing to ensure timely removal of sand settled at the bottom of the tank.

[0088] The treatment target is produced fluid with high sand content. The feed enters the adaptive cyclone core tube directly from the inlet. Under the action of centrifugal force, solid particles are thrown to the outside of the core tube and deposited at the bottom of the tank. After periodic flushing by the desanding pipeline, the solid removal rate can reach 96%, and there is no obvious sand accumulation at the bottom of the tank. The oil phase gathers in the central area under the action of cyclone, with a recovery rate of 91%. Due to the vertical arrangement structure, the centrifugal effect is enhanced, and the amount of solid phase entrained in the oil phase is controlled within 1%. After further treatment by the coalescing plate group, the water phase has an oil content of ≤75mg / L, which meets the standard for reinjection water in onshore oilfields.

[0089] 3.3 Space-Confined Scenarios (Offshore Platforms)

[0090] The device shown in Figure 6 (with vertically arranged adaptive cyclone core tubes) is combined with the tail oil collection structure shown in Figure 12. The overflow weir plate of the tail oil collection is 2 / 3 the height of the tank diameter, ensuring effective oil phase collection. This combined structure reduces the overall footprint of the equipment by 40% compared to traditional horizontal separators, making it suitable for the space constraints of offshore platforms.

[0091] When the throughput fluctuates within 40% to 160% of the design value, the unit operates with good stability: the oil phase recovery rate remains stable at 89% to 91% without significant changes due to flow fluctuations; the oil content in the aqueous phase remains between 60 and 80 mg / L, requiring no additional adjustment of the chemical reagent dosage; during 30 days of continuous operation, no blockages occurred in any of the functional modules, and the maintenance cycle is extended by 50% compared to traditional units, significantly reducing the maintenance costs and workload of offshore platforms and fully adapting to their compact space and inconvenient maintenance characteristics.

[0092] Example 4: Comparative Verification of Key Modules

[0093] Using the controlled variable method, comparative tests were conducted on the adaptive cyclone core tube arrangement, coalescing plate material, and the function of the gas-liquid separation chamber to clarify the impact of each module on the separation effect, as detailed below:

[0094] 4.1 Influence of Adaptive Swirl Core Arrangement

[0095] Under the same conditions of a throughput of 100 m³ / h, the performance differences between the two structures shown in Figure 2 (horizontal arrangement) and Figure 6 (vertical arrangement) were compared. In terms of space utilization, the vertical arrangement, through longitudinal stacking of the core tubes, saves 30% of the tank length compared to the horizontal arrangement, making it more suitable for space-constrained scenarios such as offshore platforms. Regarding pressure loss, the system pressure drop is 0.15 MPa in the horizontal arrangement, while the pressure drop in the vertical arrangement is 0.18 MPa due to the additional resistance generated by the multiple fluid turns. The difference is 0.03 MPa, which is within an acceptable range for actual operation. In terms of separation efficiency, the oil phase recovery rates of both arrangements are basically the same, remaining between 92% and 93%, indicating that the vertical arrangement optimizes space utilization without negatively impacting the separation effect.

[0096] 4.2 Influence of Cohesion Board Material

[0097] A comparison was made between corrugated coalescing plates made of a hydrophobic and oleophilic material (water droplet contact angle 110°) and ordinary stainless steel plate (water droplet contact angle 80°) (all other parameters remained the same). Test results showed that the coalescing plate made of the hydrophobic and oleophilic material had a stronger adsorption capacity for oil droplets, with an oil droplet collision and coalescence efficiency of 75% between the plates, resulting in an oil content of ≤50mg / L in the aqueous phase outlet after treatment. In contrast, the coalescing plate made of ordinary stainless steel plate, due to its stronger hydrophilicity, had an oil droplet coalescence efficiency of only 50%, resulting in an oil content of ≥85mg / L in the aqueous phase outlet. Therefore, the hydrophobic and oleophilic material significantly reduces the oil content in the aqueous phase by increasing the coalescence efficiency by 25% by enhancing oil droplet adsorption capacity.

[0098] 4.3 Verification of the necessity of the gas-liquid separation chamber

[0099] For produced fluid with a gas-liquid ratio of 1.5, the treatment effects with and without a gas-liquid separation chamber were compared. When the gas-liquid separation chamber was configured (Figure 1), after preliminary separation, the gas phase content at the inlet of the adaptive cyclone core tube was ≤5%, the core tube load was stable, and the oil phase recovery rate reached 92%. When the gas-liquid separation chamber was omitted, the cyclone core tube needed to directly process the high gas content liquid phase. The gas phase formed gas resistance within the core tube, causing the oil phase recovery rate to drop to 78%. Simultaneously, due to increased gas-liquid impact, the wear rate of the core tube increased by 20%. The verification results show that the gas-liquid separation chamber can effectively reduce the operating load of the cyclone core tube and is a key pretreatment module for ensuring separation efficiency and equipment lifespan under high gas content conditions.

[0100] The above verification results show that, through modular combination design and targeted adjustment of core parameters, this invention can adapt to complex working conditions with gas-liquid ratios of 0-5, oil content of 1%-30%, and solid content of 0-5%. It has high separation efficiency and an operational flexibility range of 0-160%, which can fully meet the compact and low-cost processing needs of onshore and offshore oil and gas fields.

[0101] The above description is merely a preferred embodiment for explaining the present invention and is not intended to limit the present invention in any way. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included within the scope of protection intended by the present invention.

Claims

1. A three-phase separator assembly, characterized in that, The system includes a horizontal tank with a liquid inlet at one end and a water outlet at the bottom of the other end. Inside the tank, arranged sequentially in the direction of fluid flow, are a gas-liquid separation chamber, several adaptive cyclone core tubes, and a coalescing plate module. The gas-liquid separation chamber has a gas deliquidation module and a gas pipe at the top and a sand removal pipeline at the bottom. The adaptive cyclone core tube includes a main separation tube and a secondary separation tube. The coalescing plate module includes a parallel flow stabilizer plate, a stepped guide plate, and a corrugated coalescing plate. An oil collection chamber or oil receiving chamber for collecting the oil phase is provided at the top or tail of the tank.

2. The three-phase separator assembly according to claim 1, characterized in that, The gas dehydration module is horizontally installed in an independent chamber at the top of the tank, directly above the gas-liquid separation chamber. A manhole is provided on the side of this chamber.

3. The three-phase separator assembly according to claim 1, characterized in that, The sand removal pipeline consists of two parallel DN50 pipelines laid on the central axis of the bottom of the tank. Each sand removal pipe has nozzles arranged at equal intervals along the axial direction, and each cross section has two nozzles. The spraying directions are at angles of 45° and 90° with the pipe axis, respectively.

4. The three-phase separator assembly according to claim 1, characterized in that, The adaptive swirl core tubes are vertically parallel and their axes are perpendicular to the tank axis; or, the adaptive swirl core tubes are horizontally parallel and distributed in a circular or annular array within the tank.

5. The three-phase separator assembly according to claim 1 or 4, characterized in that, The adaptive cyclone core tubes are arranged in a multi-stage series. The main separation tube of the upper stage adaptive cyclone core tube is connected to the main separation tube inlet of the lower stage adaptive cyclone core tube through a pipe. Except for the last stage, each stage of the adaptive cyclone core tube has a built-in oil collection structure in the tail cavity.

6. The three-phase separator assembly according to claim 1, characterized in that, The corrugated coalescing plate is made of hydrophobic and oleophilic material, with a contact angle with water droplets in the air greater than 105°, a spacing of 3 to 50 mm between adjacent plates, and multiple openings on the plate body, with the opening rate distributed from low to high.

7. The three-phase separator assembly according to claim 1, characterized in that, The oil receiving chamber is separated from the main tank by a weir plate. The weir plate is vertically installed at the bottom of the rear of the tank, and its height is greater than two-thirds of the tank diameter. The bottom is connected to the oil outlet through a pipe.

8. A three-phase separation method, employing the apparatus described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Preliminary gas-liquid-solid separation: The incoming liquid enters from the inlet, and the gas-liquid separation chamber is activated based on the gas-liquid ratio of the incoming liquid. S2: Cyclone Enhanced Separation: The liquid phase enters the adaptive cyclone core tube. Under the action of cyclone centrifugal force, the oil phase and trace residual gas as light phases gather towards the center and enter the oil tank or oil collection chamber through the secondary separation tube; the water phase as heavy phase flows out from the main separation tube; S3: Rectification and Solid Phase Removal: The heavy phase passes through the parallel flow stabilizer plate and the stepped guide plate to achieve flow stabilization and removal of fine solid phases; S4: Coalescing Depth Separation: The liquid flows through the corrugated coalescing plate. Small oil droplets coalesce and grow into large oil droplets before floating and flowing into the oil phase collection device, while the water phase sinks and is discharged from the outlet pipe.

9. The three-phase separation method according to claim 8, characterized in that, In step S1, if the gas-liquid ratio of the incoming liquid is ≥1, the incoming liquid enters the gas-liquid separation chamber for preliminary separation; if the gas-liquid ratio of the incoming liquid is <1, the incoming liquid directly enters the adaptive cyclone core tube.

10. The three-phase separation method according to claim 8, characterized in that, In step S2, the single-tube processing capacity of the adaptive cyclone core is 5 m³ / h or 10 m³ / h, and the pressure drop during operation is ≤0.2 MPa.

11. The three-phase separation method according to claim 8, characterized in that, In step S3, the parallel flow stabilizer plate adjusts its angle with the horizontal plane from 0° to 90° according to the incoming liquid pressure and flow rate, and with an adjacent plate spacing of 3 to 50 mm, to eliminate liquid turbulence.

12. The three-phase separation method according to claim 8, characterized in that, In step S4, the low porosity section of the corrugated coalescing plate promotes the initial coalescence of small oil droplets, while the high porosity section accelerates the coalescence and causes large oil droplets to float upwards.

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