Divergent coalescence double-rectifying-plate efficient dehydration method and device

Abstract

The invention relates to the technical field of crude oil dehydration methods and devices, in particular to a divergent coalescence double-rectifying-plate efficient dehydration device and method.Crude oil flows rightwards in a coalescence area in an S shape, namely S-shaped divergent flow channels are formed among coalescence balls distributed at intervals in a matrix mode in the fluid flowing direction, and when the crude oil flows through the S-shaped divergent flow channels, the crude oil flows through the S-shaped divergent flow channels under the action of buoyancy, and the crude oil is separated from the coalescence balls. Large oil drops formed by collision gradually float to the top of the coalescence area and then enter the settling area for settling separation. According to the divergent coalescence double-rectifying-plate efficient dehydration device, the S-shaped divergent flow channel is designed, large oil drops formed by collision can gradually float upwards to the top of a coalescence area under the action of buoyancy, fluid flow is not limited in a fixed flow channel space formed by different layers of corrugated plates any more, and therefore the collision probability of the oil drops is greatly increased, and meanwhile, the oil drops are prevented from falling off. Double rectifying plates are designed, the effect of rectifying, energy dissipation and vortex reduction is utilized, disordered flow in a settlement area is eliminated to the maximum extent, and separation and settlement time is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crude oil dehydration method and device, and is a divergent coalescence double rectification plate high-efficiency dehydration device, and also includes a dehydration method. BACKGROUND

[0002] In the oil and gas industry, crude oil dehydration is a ground engineering verification link, and the oil-water two-phase separation principle is based on the density difference between oil and water using the principle of gravity settling. In order to improve the separation efficiency, the industry mainly focuses on the structure of the separator and the coalescence filler. The current traditional corrugated plate crude oil dehydration flow channel and fluid single rectification plate design have certain limitations. With the proposal of the "double carbon" target, the crude oil dehydration field needs to achieve "improve crude oil dehydration efficiency", "energy saving and improve energy efficiency", and "reduce carbon emissions of ground systems". Low-carbon transformation is imminent. In this background, more efficient separation methods and equipment are extremely important.

[0003] Xinjiang Fuman oilfield is a major discovery of oil exploration in Tarim oilfield in recent years, and is the main block of crude oil production and reserve increase. With the exploration breakthrough of carbonate reservoirs in Fuman oilfield, the proven reserves exceed 1 billion tons. Tarim Oilfield Company plans to deploy 10 million tons of production capacity in Fuman oilfield from 2022 to 2030, with stable production of 4 million tons / year. The development mode is depletion development, mainly self-suction wells, and water injection to replace oil to supplement formation energy in the later stage. The life cycle of single wells in the same fault zone is not uniform, and the decline rate of single wells is fast. The yield and geological prediction index have large differences. The oil well yield and water content change greatly. The conventional dehydration process has long process, high energy consumption and long dehydration time.

[0004] Xinjiang Mahu oilfield is located in the center of Mahu depression in Junggar basin. The proven geological reserves are 1.54 billion tons, which is the key development and construction area of the group company in the future. The oilfield mainly uses horizontal wells + hydraulic fracturing development. Mahu tight oil volume fracturing development has many points and wide aspects. The oilfield block layer is multiple, and the heterogeneity is strong. The volume fracturing formula has many types and large differences. The tight oil produced liquid contains a large amount of fracturing flowback fluid, and the emulsification is serious. The oil-water system is stable. The condensation point of oil product is high (7.4-23.7℃). The formula of fracturing fluid used in different development blocks is different, and the produced liquid composition is extremely complex, containing guanidine gum, formaldehyde and other organic additives. The viscosity reaches 5mpa·s, and the COD is about 10000mg / L. It is a complex multiphase dispersion system. Crude oil dehydration is difficult, the conventional dehydration process technology is not matched, the dehydration process is long, and the dehydration temperature is high.

[0005] The conventional crude oil dehydration technology in the art is as follows: the separator is generally a flow field with three combined structures of straightening plate, straightening plate-corrugated plate and straightening plate-corrugated plate-inclined plate, and the separator adopts a four-section structure (liquid inlet washing chamber, coalescence zone, sedimentation zone and oil chamber), which can be specifically seen in pages 147 and 148 of Oilfield Mine Separation Technology and Equipment and page 246 of Bohai Bay Oil and Gas Exploration and Development Engineering Technology Papers (14th Collection), in addition, according to Fluent simulation, various models have various velocity distribution maps, which can be specifically seen in pages 141 to 145 of Oilfield Mine Separation Technology and Equipment.

[0006] From the current technical status, although domestic and foreign scholars have carried out a large amount of research on the structure of the coalescence zone and have achieved fruitful results, coalescence fillers are usually installed in the separator to achieve the effect of strengthening separation, and there are three common forms of coalescence fillers at present: bulk coalescence filler, plate-type coalescence filler and filter core coalescence filler.

[0007] (1) Bulk coalescence filler: a certain size range of coalescence material with a specific shape is filled in the coalescence separator, and these coalescence materials are randomly distributed in the coalescence separator. The coalescence material is generally oleophilic material, which can better capture oil droplets on its surface to grow. Common bulk materials generally include Rasching ring filler, metal rectangular saddle ring material, etc. The coalescence separation section composed of randomly filled dispersed particles will form countless tortuous microchannels, and the probability of mutual collision of small droplets to form large droplets increases during the movement of small droplets in the microchannels, thereby improving the separation efficiency.

[0008] (2) Plate-type coalescence filler: there are various forms of plate-type fillers, such as flat plate, inclined plate, serpentine plate, corrugated plate, L-shaped plate, etc. Through research, the plate-type coalescence filler can combine "coalescence technology" and "shallow pool principle" to develop more efficient two-phase separation equipment. The plate-type coalescence filler is composed of multiple layers of plates and has a bent channel, which can increase the floating area of oil droplets in a certain volume and shorten the floating time of oil droplets, thereby improving the processing capacity of the equipment. At the same time, the flow direction of the oil-containing wastewater changes regularly during the flow in the bent channel, the probability of mutual collision of oil droplets to form large droplets increases, and it is more easy to float to the upper layer, thereby improving the separation efficiency. In addition, the plate-type coalescence filler has a straightening effect on the flow of fluid, which reduces the instability of the flow. This kind of filler can achieve high separation precision and good separation effect. It is mainly used for coarse separation before fine separation in oil-water separation occasions.

[0009] (3) Filter core coalescing packing: The filter core packing is mainly woven by some oil-wet materials with good physical properties, such as oil-wet nanofibers, sintered mesh, and woven cloth. The internal pore of the coalescing packing composed of filter cores is more complex, and the fiber filaments are randomly distributed in space, which is more likely to capture oil droplets. In the microchannels formed therein, the liquid droplets are also more likely to collide and coalesce with each other.

[0010] Among the above three packing forms, the filter core coalescing packing achieves the best separation effect, but due to the compact internal structure of the packing, the flux is small, causing the fluid pressure drop to increase, and it is easy to be blocked in the application process; the bulk coalescing packing has a large specific surface area and good separation effect, but its density distribution is uneven, and it is also prone to blockage and other problems in use, and its stability is poor; therefore, at present, the oil-water separation field in industry is mainly based on various types of plate combination, and the flow of mixed fluid is mainly along the fixed horizontal flow channel formed between the plate groups; the divergent flow channel in space is completely different from the conventional packing in theory, and compared with the conventional horizontal flow channel, it can form a more complex "horizontal + vertical" spatial flow channel, and the oil droplets will form a large impulse as the flow direction changes, which will increase the probability of collision between adjacent oil droplets to form larger oil droplets, thereby improving the separation effect. At present, there is no research report on the space communication S-shaped divergent flow channel separator, and the single flow straightener is arranged in front of the coalescing area in the conventional equipment. The main function of the flow straightener is to reduce the kinetic energy transmission in the oil-water separation process at the rear end. After the fluid is straightened, it flows along the flow channel formed by the corrugated plate in the direction, and the oil droplets repeatedly collide during the coalescing process at a certain angle with the horizontal direction. This non-horizontal flow is not conducive to oil-water separation in the settling zone, and there is no research report on the double flow straightening effect.

[0011] At present, the oil-water separation field in industry mainly uses plate structure packing. Among the many plate structure packings, the corrugated plate coalescing separator was first applied in the United States and has received extensive attention from industry researchers and engineering technicians since its inception. The corrugated plate coalescing separator effectively combines gravitational sedimentation and coalescing technology, and has many advantages, such as simple structure, low energy consumption, high separation efficiency, and easy operation. Based on these advantages, the corrugated plate coalescing separator has been widely used around the world, and researchers have conducted in-depth research on it. There are many factors that affect the flow in the corrugated plate, and different corrugated plate structure parameters such as plate spacing, corrugated plate inclination angle, and plate length will have a great influence on the internal flow and two-phase separation efficiency. The longer the length of the corrugated plate, the more conducive to oil-water separation, and it can adapt to more complex working conditions. By increasing the number of plates to reduce the plate spacing and the tortuous channel, the separation efficiency can be significantly improved.

[0012] Lü Yuling (Lü Yuling et al., Numerical simulation of flow field in gravity separator with different components [J], Oil Machinery, 2008, No. 2) analyzed the internal velocity vector and flow field of the separator with six different aggregation components using Fluent software. The results showed that the snake-shaped plate and the staggered lapping plate have good oil-water separation characteristics. Zhang Liming (Zhang Liming et al., Performance of oil-water separator with aggregation components [J], Chemical Engineering of Universities, 2009, No. 2) designed a separator with aggregation plates and measured the particle size separation efficiency of oil-water emulsion under different flow rates and operating conditions. The results showed that the aggregation plates can significantly improve the oil-water separation efficiency, and the structure of the aggregation plates has a great influence on the sedimentation. However, when the flow rate and flow velocity are large, the separation effect of the aggregation plates decreases significantly, so the structure of the aggregation plates should be selected reasonably according to the specific conditions. Liang Long (Liang Long, Numerical simulation of the influence of corrugated plate structure parameters on the flow field and separation performance in the plate [C], The 13th National Heterogeneous Separation Academic Exchange Meeting and the National Filtration and Separation Academic Seminar and New Technology and Equipment Exchange Meeting of Environmental Protection Industry, 2017, 363-368) simulated the staggered corrugated plate using Fluent and compared the oil droplet size before and after the plate, separation efficiency, flow field in the plate, and oil droplet concentration distribution. The simulation results showed that the oil content at the water outlet changes with the height of the corrugated plate. When the plate height is small, the oil content at the water outlet is low, and the oil-water separation efficiency is high, but the risk of filling the corrugated plate is increased. The opening on the corrugated plate can effectively improve the oil-water separation effect and shorten the oil droplet residence time. Yang Tao (Yang Tao, Numerical simulation of oil-water separation flow field of double-dimensional string wave aggregation plate [J], Chemical Machinery, Vol. 47, No. 5) simulated the flow field of four different sizes of double-dimensional string wave aggregation plates using computational models and numerical simulation methods. The results showed that when the wave amplitude, period, and plate spacing of the double-dimensional string wave aggregation plate are 10 mm, 100 mm, and 25 mm, respectively, the separation efficiency is the highest. Cao Jian-shu et al. (Application research of new corrugated plate oil-water separator [J], Fluid Machinery, 2005, Vol. 33, No. 9) used inclined channel corrugated aggregation plates as the internal structure to study the new oil-water separator. The results showed that different principles can be combined to improve the separation efficiency of the separator. Sun et al. investigated three different plate types: mesh corrugated plate, open-hole corrugated plate, and non-hole corrugated plate. By comparing the oil droplet residence time, oil phase concentration distribution, and oil droplet size change before and after the plate, it was found that the mesh corrugated plate has the best separation effect, the open-hole corrugated plate is second, and the non-hole corrugated plate has the worst separation effect, indicating that different plate types have a great influence on the separation efficiency.Wang et al. studied the separation efficiency of corrugated plates with different structural parameters, and pointed out that the opening rate, plate angle, plate spacing and plate length of the corrugated plate would affect the separation efficiency. When the plate angle is 45°, the smaller the plate spacing, the higher the separation efficiency. However, when the plate spacing becomes smaller, the separated oil phase and small solid particles are easy to block the flow channel, affecting the normal operation of the equipment. In order to solve the problem of easy blockage in the corrugated plate, Wang et al. drilled small holes at the angle of the corrugated plate, which can promote the floating of oil droplets and make small solid particles settle to the bottom of the separator, improving the fluidity of the fluid in the plate. In order to further improve the separation efficiency, a combined oil-water separator was developed by researchers in 2005, which is divided into flat plate area and inclined plate area. By optimizing the related parameters of flat plate and inclined plate, the purpose of improving separation efficiency can be achieved, but the device operation and installation are complex, and further research is still needed. Sun Zhiqian et al. compared the effects of different assembly methods of corrugated plates on the separation efficiency of homogeneous phase separation through experiments; Cao Jian-shu et al. studied the effect of inclined channel corrugated plate on oil-water separation efficiency. At the same time, different plate types will also affect the internal flow field and separation efficiency of the corrugated plate. The open-hole corrugated plate has higher separation efficiency than the staggered corrugated plate. The plate spacing of the staggered corrugated plate changes with the change of the folded plate peak height, and the smaller the folded plate peak height, the more conducive to improving the separation efficiency, but it will increase the pressure drop in the corrugated plate. The structural parameters of the corrugated plate not only affect the internal flow field, but also affect the distribution of the dispersed phase in it. The flow of fluid in the corrugated plate is complex, especially in the staggered corrugated plate. Studies have shown that this chaotic flow is very conducive to the collision of liquid droplets and improves the separation efficiency.

[0013] From the current technical status, although scholars at home and abroad have carried out a lot of research on the structure of the coalescence zone, the structure is mainly composed of various types of plates, and the flow of oil-water mixed fluid is mainly along the fixed flow channel formed between the plate groups.

[0014] And it is well known that the oil and gas two-phase separation sedimentation separation principle relies on the density difference of oil droplets and gas, and in calculation, it is divided into laminar flow region, transition region and turbulent flow region according to the flow state, wherein the greater the calculation result of the uniform sedimentation velocity of the droplets, the smaller the required separator diameter, and according to the actual design experience, the flow state is designed in the laminar flow region, which is beneficial to separation, and for the oil and water two-phase separation principle, the gravity sedimentation principle is used according to the density difference between oil and water. In order to improve the separation efficiency, the industry mainly carries out research on the structure of the separator, coalescence filler and the like. In view of the present situation that the traditional corrugated plate crude oil dehydration flow channel and the fluid single rectifier plate design have certain limitations, and the crude oil dehydration efficiency needs to be further improved, the present application is based on the numerical simulation of FLUENT, and the coalescence flow channel and the rectifier plate are designed and researched, aiming at further improving the dehydration efficiency of the separator through the construction of the complex intercommunication type divergent flow channel and the double rectifier plate flow stabilizing effect, forming a low-temperature and high-efficiency dehydration method and device, and meeting the demand of improving the crude oil dehydration efficiency of the separator in each oil field. SUMMARY

[0015] The present application provides a divergent coalescence double rectifier plate high-efficiency dehydration device and method, which overcomes the shortcomings of the prior art and solves the problem of vortex formation and interference with sedimentation separation caused by single rectifier plate.

[0016] One of the technical solutions of the present application is realized by the following measures: a divergent coalescence double rectifier plate high-efficiency dehydration device, comprising a tank body, a first rectifier plate, a second rectifier plate and a partition plate are arranged in the tank body from left to right to divide the tank body into a liquid inlet area, a coalescence area, a sedimentation area and an oil chamber from left to right, a spacing is arranged between the top end of the partition plate and the top end of the tank body; a liquid inlet pipe is arranged on the tank body and communicates with the liquid inlet area, coalescence balls are arranged in the coalescence area in a matrix interval, along the fluid flow direction, S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval, a water outlet is arranged at the bottom of the sedimentation area close to the partition plate, and an oil outlet is arranged at the lower part of the oil chamber.

[0017] The following is a further optimization or / and improvement of the above-mentioned one of the technical solutions of the present application: The coalescence balls arranged in a matrix interval in the coalescence area, along the fluid flow direction, S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval, and the S-shaped divergent flow channels are interconnected in the entire coalescence area.

[0018] The position of a certain coalescence ball is taken as the setting position, and other coalescence balls are arranged in a matrix interval above, below, in front of, behind, to the left of and to the right of the coalescence ball (except the coalescence ball closest to the inner wall of the coalescence area).

[0019] The diameter of the coalescence ball is d, and the coalescence balls are arranged at a horizontal interval of 1.5d to 2.5d and a vertical interval of 0.75d to d.

[0020] The upper side, lower side, front side, rear side, left side and right side of each of the above-mentioned coalescence balls are provided with outer support rods, and adjacent coalescence balls are connected to each other by corresponding outer support rods which are connected to each other by connecting portions.

[0021] The first and second rectifying plates are provided with through holes; and the top of the tank body corresponding to the oil chamber is provided with a gas outlet.

[0022] The liquid distribution device is arranged in the liquid inlet area and is in communication with the liquid inlet pipe, and the liquid distribution device is provided with liquid distribution holes.

[0023] The second technical solution of the present application is realized by the following measures: a dehydration method using the divergent coalescence double-rectifying-plate high-efficiency dehydration device of the first technical solution, comprising: The crude oil enters the coalescence area through the liquid inlet area, and the coalescence balls arranged in the coalescence area in a matrix interval manner make the crude oil flow rightwards in an S shape, i.e. along the flow direction of the fluid, and the S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval manner, and the large oil droplets formed by collision gradually float to the top of the coalescence area by the action of buoyancy, and then enter the settling area for settling separation, the water separated by settling is discharged through the water outlet at the bottom of the settling area, the oil separated by settling gradually floats and gathers at the upper part of the settling area, and finally the separated oil enters the oil chamber and is discharged through the oil outlet of the oil chamber.

[0024] The S-shaped divergent flow channels of the divergent coalescence double-rectifying-plate high-efficiency dehydration device can make the large oil droplets formed by collision gradually float to the top of the coalescence area by the action of buoyancy, so that the fluid flow is no longer limited in the fixed flow channel space formed by different layers of corrugated plates, thereby greatly increasing the collision probability of oil droplets and breaking the conventional separation method that can only coalesce with the flow channel fluid, and then gradually float and gather at the upper part of the tank body in the settling area, and at the same time, the double rectifying plates are designed to reduce the action of vortex flow by rectifying and energy dissipation, so as to maximize the elimination of chaotic flow in the settling area and reduce the separation and settling time. BRIEF DESCRIPTION OF DRAWINGS

[0025] ATTACHMENT Figure 1 It is a front perspective structure schematic diagram of the divergent coalescence double-rectifying-plate high-efficiency dehydration device.

[0026] ATTACHMENT Figure 2 It is a front perspective structure diagram of the divergent coalescence double-rectifying-plate high-efficiency dehydration device.

[0027] ATTACHMENT Figure 3 It is a front partial enlarged structure schematic diagram of the arrangement of coalescence balls.

[0028] ATTACHMENT Figure 4 It is a fluid velocity vector comparison diagram of the conventional single rectifying plate and the double rectifying plate.

[0029] Figure 2 is a schematic diagram of the flow lines of the fluid flowing in an S shape. Figure 5 Figure 3 is a schematic diagram of the flow lines of the fluid flowing in an S shape.

[0030] Figure 4 is a schematic diagram of the flow lines of the fluid flowing in an S shape. Figure 6 Figure 5 is a schematic diagram of the structure of the corrugated plate coalescing separator.

[0031] Figure 7 Figure 6 is a schematic diagram of the flow lines in the corrugated plate coalescing separator.

[0032] Figure 8 Figure 7 is a schematic diagram of the flow lines in the divergent coalescing double rectification plate high-efficiency dehydration device.

[0033] Figure 9 Figure 8 is a schematic diagram of the velocity vector in the corrugated plate coalescing separator.

[0034] Figure 10 Figure 9 is a schematic diagram of the velocity vector in the divergent coalescing double rectification plate high-efficiency dehydration device.

[0035] Figure 11 Figure 10 is a schematic diagram of the oil-water volume fraction in the coalescing zone of the divergent coalescing double rectification plate high-efficiency dehydration device and the corrugated plate coalescing separator.

[0036] Figure 12 Figure 11 is a schematic diagram of the oil phase concentration contour in the settling zone of the novel divergent regular coalescing separator and the corrugated plate coalescing separator.

[0037] Figure 4 Figure 12 is a schematic diagram of the velocity vector in the corrugated plate coalescing separator, wherein (a) is the velocity vector behind the single rectification plate corrugated plate, and (b) is the velocity vector behind the double rectification plate.

[0038] Figure 9 Figure 13 is a schematic diagram of the corrugated plate coalescing separator, wherein (a) is the coalescing zone, and (b) is the settling zone.

[0039] Figure 10 Figure 14 is a schematic diagram of the corrugated plate coalescing separator, wherein (a) is the coalescing zone, and (b) is the settling zone.

[0040] Figure 11 Figure 15 is a schematic diagram of the oil-water volume fraction in the coalescing zone of the corrugated plate coalescing separator and the divergent coalescing double rectification plate high-efficiency dehydration device, wherein (a) is the oil-water volume fraction in the coalescing zone of the corrugated plate coalescing separator, and (b) is the oil-water volume fraction in the coalescing zone of the divergent coalescing double rectification plate high-efficiency dehydration device.

[0041] Figure 12 Figure 16 is a schematic diagram of the oil phase concentration contour in the settling zone of the corrugated plate coalescing separator and the divergent coalescing double rectification plate high-efficiency dehydration device, wherein (a) is the oil phase concentration contour in the settling zone of the corrugated plate coalescing separator, and (b) is the oil phase concentration contour in the settling zone of the divergent coalescing double rectification plate high-efficiency dehydration device.

[0042] The codes in the drawings are as follows: A is the liquid inlet zone, B is the coalescing zone, C is the settling zone, and D is the oil chamber. 1 is the liquid inlet pipe, 2 is the liquid distribution device, 3 is the first rectifier plate, 4 is the manhole, 5 is the partition plate, 6 is the air outlet, 7 is the water outlet, 8 is the oil outlet, 9 is the tank body, 10 is the second rectifier plate, 11 is the coalescing ball, 12 is the external support rod, and 13 is the connector. Detailed Implementation

[0043] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0044] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0045] The present invention will be further described below with reference to embodiments: Example 1: As Figures 1 to 2 As shown, this dehydration method uses a divergent coalescing dual-rectifier plate high-efficiency dehydration device to dehydrate crude oil. The device, from left to right, is arranged with an inlet zone A, a coalescing zone B, a settling zone C, and an oil chamber D. Coalescing zone B contains coalescing spheres 11 arranged in a matrix. The method includes: Crude oil enters coalescence zone B through inlet zone A. As the crude oil flows to the right, coalescing balls 11 are distributed in a matrix at intervals within coalescence zone B, causing the crude oil to flow to the right in an S-shape. That is, along the direction of fluid flow, the coalescing balls 11, distributed in a matrix at intervals, form an S-shaped diverging channel. As the crude oil flows through the S-shaped diverging channel, the large oil droplets formed by the collisions due to buoyancy gradually float to the top of coalescence zone B. This allows the crude oil fluid flow to no longer be confined to the fixed flow channel space formed by different layers of corrugated plates, thus greatly increasing the collision probability of oil droplets. This breaks the conventional rule that oil droplets can only coalesce with fluids in the same flow channel. Then, the oil enters sedimentation zone C for sedimentation and separation. The water separated by sedimentation is drained through outlet 7 at the bottom of sedimentation zone C. The oil separated by sedimentation gradually floats up and accumulates at the top of sedimentation zone C. Finally, the separated oil enters oil chamber D and is discharged through oil outlet 8 of oil chamber D.

[0046] The coalescence zone B channel adopts an S-shaped divergent flow channel. Utilizing buoyancy, the large oil droplets formed by collisions can gradually float to the top of coalescence zone B, so that the fluid flow is no longer confined to a fixed flow channel. When the miscible fluid flows along the curved S-shaped divergent flow channel, the flow channel length increases, and the fluid flow channel changes from a conventional straight line to an S-shaped flow. The probability of oil droplet collision is greatly increased, and the velocity change within the device is more uniform and gentle, reducing the number and intensity of vortices in the settling zone C, which is more conducive to natural settling. The oil phase in coalescence zone B exhibits stratification, which is more in line with the gravity settling separation mechanism using the density difference between oil and water, and reduces the separator volume.

[0047] This invention utilizes an S-shaped diverging flow channel to enhance the mixing degree between different fluids, increase the probability of oil droplets colliding and coalescing, and improve oil-water separation efficiency.

[0048] Example 2: As Figures 1 to 3 As shown, the divergent coalescing dual-rectifier plate high-efficiency dehydration device includes a tank 9. Inside the tank 9, from left to right, there are a first rectifier plate 3, a second rectifier plate 10, and a partition plate 5 that divide the tank 9 into an inlet zone A, a coalescing zone B, a settling zone C, and an oil chamber D. A gap is provided between the top of the partition plate 5 and the top of the tank 9. An inlet pipe 1 connected to the inlet zone A is provided on the tank 9. In the coalescing zone B, coalescing balls 11 are distributed in a matrix at intervals. Along the fluid flow direction, the coalescing balls 11 distributed in a matrix at intervals form an S-shaped divergent flow channel. A water outlet 7 is provided at the bottom of the settling zone C near the partition plate 5, and an oil outlet 8 is provided at the lower part of the oil chamber D.

[0049] The design incorporates a first rectifier plate 3 and a second rectifier plate 10 for double rectifier flow. This rectifier can reduce the effect of eddies by dissipating energy, thereby minimizing the turbulent flow in the settling zone C and reducing the separation and settling time.

[0050] By fully utilizing the smooth fluid flow effect of the rectifier plates, the non-horizontal flow of fluid before and after the coalescence zone B is reduced. The first rectifier plate 3 reduces kinetic energy transfer and ensures the oil phase stratification effect in the coalescence zone B. The second rectifier plate 10 makes the flow in the settling zone C more uniform and orderly, with the fluid basically flowing horizontally and the overall flow being smooth and basically in a stable laminar state. This reduces the generation of vortices in the settling zone C and forms a double rectification effect. Multiple functions such as liquid inlet, coalescence, and settling do not interfere with each other, which is conducive to improving the separation effect and shortening the distance in the settling zone C.

[0051] To understand the effect of dual rectifiers and clarify the role of the second rectifier 10, a comparison is made between the fluid velocity vector diagrams after a conventional corrugated plate and those after the second rectifier 10. Figure 4 As shown.

[0052] Depend on Figure 4 It can be seen that the fluid flows out of the corrugated plate accumulation area (see...) Figure 4 (a) When the fluid still flows along the flow channel formed by the corrugated plates, it forms a certain angle with the horizontal direction. This non-horizontal flow is not conducive to the oil-water separation in the settling zone C. However, the fluid is further rectified after passing through the second rectifier plate 10 (see...). Figure 4 (b) makes the flow in the settling zone C more uniform and orderly, and the fluid flows basically horizontally. Therefore, the structure of the double rectifier plate is beneficial to improving the separation effect and shortening the distance of the settling zone C, and has a good double rectification effect.

[0053] Example 3: As Figure 3As shown, as the optimization of embodiment 2, the coalescence spheres 11 arranged in a matrix interval in the coalescence zone B form S-shaped divergent flow channels between the coalescence spheres 11 arranged in a matrix interval along the fluid flow direction, and the S-shaped divergent flow channels are interconnected in the whole coalescence zone B.

[0054] When the crude oil fluid encounters the spheres (coalescence spheres 11), the original flow direction of the crude oil fluid is changed, and the crude oil fluid flows in an S-shaped manner along the S-shaped divergent flow channels formed outside the spheres (as shown in Figure 5 The flow of the fluid is no longer limited in the fixed flow channel, the length of the flow channel is lengthened, and the flow of the fluid is changed from the conventional straight line type to the S-shaped flow. When the miscible fluid flows in a bending manner along the S-shaped divergent flow channels between the small spheres, the collision probability of the oil droplets is greatly increased.

[0055] The traditional corrugated plate divides the flow channel of the coalescence zone B into a plurality of independent flow channels, and the scattered filler cannot form a fixed flow channel, the density distribution is uneven, and problems such as blockage are prone to occur in use, and the stability is poor.

[0056] Embodiment 4: According to the needs, as the optimization of embodiment 3, the diameter of the coalescence spheres 11 is d, and the coalescence spheres 11 are arranged at a horizontal interval of 1.5d to 2.5d and a vertical interval of 0.75d to d.

[0057] When the coalescence spheres 11 in the coalescence zone B are arranged to satisfy the horizontal interval L of 1.5d to 2.5d and the vertical interval H of 0.75d to d, the coalescence separation effect can be better.

[0058] The arrangement of the horizontal interval and the vertical interval can make the line connecting the centers of the three coalescence spheres 11 in the same vertical row, that is, the upper coalescence sphere 11 and the two adjacent coalescence spheres 11 below the coalescence sphere 11, form a non-equilateral triangle (see Figure 3 The red triangle). Through this non-equilateral arrangement, the fluid is prevented from flowing through the flow channel with smaller resistance and flowing in an S-shaped flow channel.

[0059] If the horizontal interval and the vertical interval are less than the above range, the width of the S-shaped divergent flow channel formed is too small, which can increase the flow rate under the same crude oil treatment capacity, thereby affecting the settling effect of the flow rate entering the settling zone C, and under the same treatment effect, the treatment capacity needs to be reduced. If the horizontal interval and the vertical interval are greater than the above range, the S-shaped divergent flow channel cannot be effectively formed, the fluid cannot flow in an S-shaped manner to the right, and large oil droplets cannot be effectively coalesced.

[0060] Embodiment 5: As shown in Figure 3As shown, as the optimization of the above embodiment, the upper side, the lower side, the front side, the rear side, the left side and the right side of each coalescence ball 11 are provided with outer support rods 12, and adjacent coalescence balls 11 are connected with each other through corresponding outer support rods 12 which are connected with each other through connecting parts.

[0061] The connecting part of adjacent two coalescence balls 11 is a joint 13, the outer support rod 12 connected with the joint 13 is provided with a thread at one end, and the corresponding outer support rod 12 is connected through the joint 13.

[0062] The coalescence ball 11 can be a hydrophilic and oleophobic coalescence ball known in the art, such as a coalescence ball made of aluminum, ceramic or the like.

[0063] The length of the outer support rod 12 and the joint 13 is determined according to actual needs, and the distance between the coalescence balls 11 can be controlled through the outer support rod 12 and the joint 13, which can provide fixed support for the formation of the S-shaped diverging flow channel, so as to enhance the adaptability of the S-shaped diverging flow channel and improve the dehydration efficiency of crude oil. The size of the S-shaped diverging flow channel can be adjusted to meet the needs of dehydration of crude oil with different water content and different physical properties.

[0064] Embodiment 6: as shown in Figure 1 As an optimization of embodiment 2, the first flow regulating plate 3 and the second flow regulating plate 10 are provided with through holes; and the top of the tank 9 corresponding to the oil chamber D is provided with a gas outlet 6.

[0065] Embodiment 7: as shown in Figure 1 As an optimization of embodiment 2, the liquid inlet area A is provided with a liquid distribution device 2 which is in communication with the liquid inlet pipe 1, and the liquid distribution device 2 is distributed with liquid distribution holes.

[0066] The diverging coalescence double flow regulating plate high-efficiency dehydration device described in the application is compared with the conventional corrugated plate coalescence separator as follows: Flow field analysis Under the condition that the arrangement of the flow regulating plate in the corrugated plate coalescence separator and the diverging coalescence double flow regulating plate high-efficiency dehydration device described in the application and the length of the coalescence area B are consistent, the flow and separation of oil-water two-phase in the above two separators are compared. The structure of the corrugated plate coalescence separator is as shown in Figure 6 .

[0067] The flow field and the volume fraction of two-phase in the area between the first flow regulating plate 3 at the inlet and the partition plate 5 are analyzed.

[0068] From Figure 7 and Figure 8The streamline diagram of the present application can be seen that the velocity distribution in the divergent coalescence double rectification plate high-efficiency dehydration device is more uniform and gentle as a whole. The streamline diagram of the corrugated plate coalescence separator can be seen that the velocity distribution in the corrugated plate is not a single change rule, and the velocity difference is large, sometimes large and sometimes small. The velocity change of the coalescence zone B of the divergent coalescence double rectification plate high-efficiency dehydration device presents a single trend of gradually increasing from bottom to top, and this distribution rule can also be seen from the velocity vector diagram of the coalescence zone B of the present application. Figure 9 (a) and Figure 10 (a) the velocity vector diagram of the coalescence zone B of the present application can be seen.

[0069] At the same time, from Figure 9 (b) and Figure 10 It can also be seen from (b) that the fluid of the corrugated plate coalescence separator forms two obvious vortex zones in the lower part and the right side after flowing out of the coalescence zone B and passing through the second rectification plate 10, and the flow velocity of the coalesced fluid is large, which is caused by the coalescence collision principle in the horizontal flow channel of the conventional corrugated plate. Even if the double rectification plate effect is used to reduce the vortex generation and reduce the disturbance to the rear gravity sedimentation zone C, the appearance of the vortex is not conducive to the rear gravity sedimentation. The fluid in the sedimentation zone C of the divergent coalescence double rectification plate high-efficiency dehydration device flows gently and basically presents a stable laminar flow state, which shows that the flow condition in the sedimentation zone C of the divergent coalescence double rectification plate high-efficiency dehydration device is obviously better than that of the corrugated plate coalescence separator, and is more conducive to the further separation of oil and water.

[0070] In order to further compare the separation effect of the divergent coalescence double rectification plate high-efficiency dehydration device and the corrugated plate coalescence separator on oil and water two-phase, the volume fraction distribution of oil and water two-phase in the above two separators is analyzed.

[0071] From Figure 11It can be seen that when the coalescence zone B is the corrugated plate, the small oil droplets are continuously coalesced and enlarged during the movement, and through the effects of wetting, adsorption and coalescence, an oil film is formed on the lower surface of the corrugated plate and moves along the plate surface, falls off, and the water phase is settled under the action of gravity and reaches the upper surface of the lower corrugated plate, so that the rapid oil-water separation is finally realized. Compared with the corrugated plate, the oil phase aggregation effect in the coalescence zone B of the divergent coalescence double rectification plate high-efficiency dehydration device is not so obvious, but since the flow channels in the coalescence zone B of the divergent coalescence double rectification plate high-efficiency dehydration device are connected, the large oil droplets formed by collision can gradually float to the top of the coalescence zone B under the action of buoyancy. Therefore, although the volume fraction of the oil phase in the coalescence zone B of the divergent coalescence double rectification plate high-efficiency dehydration device is relatively low, the oil phase at the top of the coalescence zone B of the divergent coalescence double rectification plate high-efficiency dehydration device has a clear layered state, and the thickness of the oil phase layer increases with the direction of flow. This shows that the divergent coalescence double rectification plate high-efficiency dehydration device realizes oil droplet coalescence in the coalescence zone B, and the connected flow channels provide the possibility of using gravity to realize the layering of oil and water, so that the overall length of the separator can be further reduced while ensuring the separation effect.

[0072] From Figure 12 It can be seen that the concentration contour in the settling zone C of the divergent coalescence double rectification plate high-efficiency dehydration device is denser than that of the corrugated plate separator, which shows that the oil-water separation effect of the divergent coalescence double rectification plate high-efficiency dehydration device is better than that of the traditional corrugated plate coalescence separator.

[0073] In summary, from the double rectification effect, flow field analysis and the like, the divergent coalescence double rectification plate high-efficiency dehydration device has better oil-water separation effect than the corrugated plate separator, and has the potential to further reduce the length of the separator.

[0074] The divergent coalescence double rectification plate high-efficiency dehydration device is suitable for normal temperature (10-25 DEG C) pre-dehydration, is mainly used for crude oil oil-gas-water three-phase separation, and can be used as a pre-dehydration separation (free water removal) device for medium-high water cut crude oil (water content ≥40%), and is also suitable for pre-dehydration of crude oil at other temperatures, the water content at the oil outlet can be controlled to be 15-30%, and the dehydration efficiency is increased by more than 30%.

[0075] The divergent coalescence double rectification plate high-efficiency dehydration device is also suitable for high-temperature (≥40 DEG C) deep dehydration, and can be used as a thermal chemical dehydration (emulsified water removal) device for low water cut crude oil (water content ≤30%), and can be used in combination with electric dehydration, the oil outlet reaches the oil interchange index, and the water content at the oil outlet can be controlled to be less than 0.5%.

[0076] Application example The crude oil gas water three-phase separation, the liquid temperature is 25 DEG C, the liquid contains water > 85%, the crude oil property is seen in table 1, the coalescence ball 11 of the divergent coalescence double rectifier plate high-efficiency dehydration device described in the application is selected from ceramic coalescence ball with stable chemical properties, smooth surface, no crack, hard texture, low wear rate, developed micropore, strong hydrophilic and oil-repellent type.

[0077] The coalescence ball 11 is a small ball with a diameter d of 30 mm to 60 mm, and is arranged alternately according to a horizontal spacing of 1.5d to 2.5d and a vertical spacing of 0.75d to d.

[0078] The liquid distribution device 2 is 0.1D to 0.3D away from the first rectifier plate 33.

[0079] The distance between the first rectifier plate 3 and the second rectifier plate 10 is not less than 0.1D.

[0080] The divergent coalescence double rectifier plate high-efficiency dehydration device is applied to the largest domestic onshore crude oil processing station, No. 81 joint station of the Second Oil Production Plant of Xinjiang Oilfield Company, and the 1# separator, the 3# separator and the 4# separator of the processing station all adopt the divergent coalescence double rectifier plate high-efficiency dehydration device.

[0081] From table 2 to table 4, it can be seen that the maximum liquid processing capacity of the separator is 210 m 3 / h, which can meet the liquid requirements under the pre-dewatering design conditions (dosing concentration: 30 mg / L; dehydration temperature: normal temperature; water content in crude oil after dehydration: ≤15%; free water oil content: ≤500 mg / L; settling time: 30 min).

[0082] The above technical features constitute the embodiments of the application, which have strong adaptability and implementation effect, and can increase or decrease unnecessary technical features according to actual needs to meet the needs of different situations.

Claims

1. A diverging coalescing dual rectifier plate high efficiency dewatering device characterized by The application relates to a tank body, a first rectifier plate, a second rectifier plate and a partition plate are arranged in the tank body from left to right, the tank body is divided into a liquid inlet area, a coalescence area, a sedimentation area and an oil chamber from left to right, a spacing is arranged between the top end of the partition plate and the top end of the tank body; a liquid inlet pipe is arranged on the tank body and communicates with the liquid inlet area, coalescence balls are arranged in the coalescence area in a matrix interval mode, S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval mode along the fluid flow direction, a water outlet is arranged at the bottom of the sedimentation area close to the partition plate, and an oil outlet is arranged at the lower part of the oil chamber.

2. The diverging coalescing dual rectifier plate high efficiency dewatering device of claim 1, wherein The coalescence balls arranged in a matrix interval mode in the coalescence area form S-shaped divergent flow channels between the coalescence balls arranged in a matrix interval mode along the fluid flow direction, and the S-shaped divergent flow channels are interconnected in the whole coalescence area.

3. The diverging coalescing dual rectifier plate high efficiency dewatering device of claim 1 or 2, wherein The coalescence balls are arranged at a horizontal interval of 1.5d to 2.5d and a vertical interval of 0.75d to d.

4. The diverging coalescing dual rectifier plate high efficiency dewatering device of claim 1 or 2, wherein The upper side, the lower side, the front side, the back side, the left side and the right side of each coalescence ball are provided with outer support rods, and adjacent coalescence balls are connected with each other through corresponding outer support rods, and the corresponding outer support rods are connected with each other through connecting portions.

5. The diverging coalescing dual rectifier plate high efficiency dewatering device of claim 3, wherein The upper side, the lower side, the front side, the back side, the left side and the right side of each coalescence ball are provided with outer support rods, and adjacent coalescence balls are connected with each other through corresponding outer support rods, and the corresponding outer support rods are connected with each other through connecting portions.

6. The diverging coalescing dual rectifier plate high efficiency dewatering device of claim 1 or 2 or 5, wherein The first rectifier plate and the second rectifier plate are provided with through holes penetrating left and right; and the top of the tank body corresponding to the oil chamber is provided with an air outlet.

7. The diverging coalescing dual flow plate high efficiency dewatering device of claim 3, wherein The first rectifier plate and the second rectifier plate are provided with through holes penetrating left and right; and the top of the tank body corresponding to the oil chamber is provided with an air outlet.

8. The diverging coalescing dual flow plate high efficiency dewatering device of claim 4, wherein The first rectifier plate and the second rectifier plate are provided with through holes penetrating left and right; and the top of the tank body corresponding to the oil chamber is provided with an air outlet.

9. The diverging coalescing dual flow plate high efficiency dewatering device of any one of claims 1 to 8, wherein A liquid distribution device is arranged in the liquid inlet area and communicates with the liquid inlet pipe, and the liquid distribution device is provided with liquid distribution holes.

10. A dehydration method using the diverging coalescence double rectifier plate high-efficiency dehydration device according to any one of claims 1 to 9, characterized by The application relates to a tank body, a first rectifier plate, a second rectifier plate and a partition plate are arranged in the tank body from left to right, the tank body is divided into a liquid inlet area, a coalescence area, a sedimentation area and an oil chamber from left to right, a spacing is arranged between the top end of the partition plate and the top end of the tank body; a liquid inlet pipe is arranged on the tank body and communicates with the liquid inlet area, coalescence balls are arranged in the coalescence area in a matrix interval mode, S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval mode along the fluid flow direction, a water outlet is arranged at the bottom of the sedimentation area close to the partition plate, and an oil outlet is arranged at the lower part of the oil chamber. Crude oil enters the coalescence area through the liquid inlet area, the coalescence balls arranged in a matrix interval mode in the coalescence area make the crude oil flow in an S shape, that is, S-shaped divergent flow channels are formed between the coalescence balls arranged in a matrix interval mode along the fluid flow direction, large oil drops formed by collision gradually float to the top of the coalescence area by the action of buoyancy during the flow of the crude oil through the S-shaped divergent flow channels, then enter the sedimentation area for sedimentation separation, water separated by sedimentation is discharged through the water outlet at the bottom of the sedimentation area, oil separated by sedimentation gradually floats and gathers at the upper part of the sedimentation area, and finally the separated oil enters the oil chamber and is discharged through the oil outlet of the oil chamber.

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