CN108018071B - Ultrasonic demulsification oil-gas-water separator and separation method - Google Patents

Abstract

The invention relates to an ultrasonic demulsification oil-gas-water separator and a separation method, wherein a main structure consists of a liquid inlet pipe, an oil phase pipe, a gas phase pipe, a first inclined vertical pipe, a second inclined vertical pipe, a gas collecting pipe and an ultrasonic transducer, wherein inclined plate bundles of the liquid inlet pipe and the oil phase pipe are respectively arranged in the liquid inlet pipe and the oil phase pipe, a plurality of inclined plate support rods are arranged on the inclined plate bundles, the support rods are tightly connected with the inner wall of a pipeline, the first inclined vertical pipe and the second inclined vertical pipe are arranged between the liquid inlet pipe and the oil phase pipe, and the gas collecting pipe is arranged between the oil phase pipe and the gas phase pipe. The invention can realize the multi-stage oil-gas-water separation and descaling effect, does not cause the problem of re-emulsification, obviously improves the oil-water-gas separation production efficiency, shortens the time, improves the quality of petroleum crude oil, reduces the loss of petroleum crude oil, increases the demulsification efficiency of demulsifiers, reduces the use amount and reduces the requirement on the environment.

Description

Ultrasonic demulsification oil-gas-water separator and separation method

Technical Field

The invention belongs to the technical field of petroleum exploitation, and particularly relates to an ultrasonic demulsification oil-gas-water separator and a separation method.

Background

With the entering of many oil fields in China into secondary and tertiary oil recovery, the quality of crude oil becomes worse, chemical components and oil-water emulsion structures become more complex, the crude oil extracted from the oil fields is mainly in the form of emulsion, the emulsion dispersion structure is quite complex, and the oil-in-water (O/W), water-in-oil (W/O), water-in-oil-in-oil (O/W/O) and oil-in-water-oil-in-water (W/O/W) are adopted as main materials, and the secondary oil recovery is mainly in oil-in-water (O/W) as main materials. Salt impurities and water in crude oil can seriously affect the processing and production process of crude oil, and can increase transportation cost, increase energy consumption and cause production accidents. For example, electrical desalination plants often trip, resulting in catalyst poisoning, severely impacting normal production, and causing significant waste.

The method comprises the steps of analyzing the reasons of scaling of oilfield gathering pipelines, wherein first, oilfield water contains high-concentration salt ions which are easy to scale, the temperature and the pressure are continuously reduced in the exploitation process, and the original material balance state is broken, so that scaling is caused; secondly, when two or more kinds of incompatible water are mixed, incompatible ions in the incompatible water chemically react to form scale; finally, when crude oil is extracted, no matter what substances are extracted, the original substance balance state in the crude oil can be broken, and scaling is easy to occur. The three reasons are different from each other in different kinds of oil fields, and generally, after scaling occurs, deposited substances are slightly soluble salts or indissoluble salts with abnormal solubility, and the substances have fixed crystal lattices, meanwhile, the scale density of the monomer is higher and very hard, and the saturation degree of the salts and each process of salt crystallization are influenced by the generated scale.

The influence of scaling on the oil field gathering pipeline can bring a certain harm when the oil field gathering pipeline has scaling problem, firstly, the cross section area of the gathering pipeline is continuously reduced due to scaling, the conveying resistance is increased, and the power consumption of an oil conveying pump is increased; secondly, scaling has the problem of scaling corrosion and even perforation of a gathering pipeline; if the heat exchange equipment is scaled, the heat transfer effect is affected, and the energy consumption of the equipment is increased; finally, during the process of increasing the pressure, substances generated after scaling can corrode and block the pipeline, even cause serious consequences such as bursting.

From the analysis, the problem of scaling of the oilfield gathering pipeline system is unavoidable, and serious consequences can be caused if the oilfield gathering pipeline system is not well treated.

The common heating method and weight sedimentation method can only treat oil drops and water drops with larger diameters, and have poor separation effect on emulsion; the demulsifier method demulsifies the emulsion, which not only easily causes environmental pollution, but also has strong specificity. In addition, the scaling phenomenon of the gathering pipeline and the oil-water separation equipment is also a common problem, so that not only is the conveying resistance increased, but also the oil-water separation effect of the separation equipment is seriously affected. The conventional desalting and dewatering method adopting heating, weight sedimentation and demulsifier is more and more difficult to meet the requirement of oil-water separation standard. The Chinese patent with application number 201510474087.0 discloses a pipeline type oil-gas-water separation device and a separation method, wherein an isosceles triangle structure is adopted, a liquid inlet pipe is arranged at the vertex position of the upper end of the triangle, and an oil phase outlet is arranged at the other side of the liquid inlet pipe; the water phase outlet pipe is positioned at the vertex of the lower end of the triangle; the liquid inlet pipe is connected with the water phase outlet pipe through a plurality of inclined vertical pipes. In order to increase the oil-water-gas separation effect, a plurality of layers of inclined plates are arranged in the water phase outlet pipe and the inclined vertical pipe by utilizing the principle of shallow pool effect. The oil-water-gas separation device realizes three times of separation in theory, and has good separation effect. However, as seen from the drawing of the patent, the multi-layer inclined plate in the water phase outlet pipe is tightly connected with the pipeline, and the structure completely isolates the pipeline into a plurality of small spaces, so that the enrichment of upper oil and the enrichment of lower water are not utilized; in addition, the inclined plate sedimentation technology only increases the horizontal projection area of a runner in unit volume, and has very weak demulsification function on emulsion of crude oil, and only has good separation effect on larger oil drops and water drops; more critical is that the implementation of the technology cannot avoid the trouble of scaling, which is a common problem of oil field gathering pipelines, especially the scaling problem in the current tertiary oil recovery stage is more serious, the inclined plate in the pipeline increases the scaling probability although increasing the oil-water-gas separation effect, the scaling on the inclined plate damages the running channels of oil drops and water drops, the separation effect is influenced, the channel is blocked when serious, the oil-water-gas separation is damaged, and the production stopping accident is caused.

Therefore, it is necessary to provide an oil-water-gas separation device which can prevent the influence of scaling, can fully break emulsion, has the advantages of low investment, small occupied area, convenient installation and use, no maintenance, energy conservation, high efficiency and continuous and stable operation. The oil-water-gas separation can be realized in a high efficiency under the flowing state of the produced liquid by only depending on a physical method in the pipeline conveying process of crude oil.

Disclosure of Invention

In view of the defects of low oil-water separation efficiency, serious scaling of oil-gas-water separation pipelines and the like in the prior art, the invention aims to provide an ultrasonic demulsification oil-gas-water separator and a separation method, which are used for improving the oil-gas-water separation efficiency and the quality of petroleum products, reducing the scaling of pipelines and reducing the transportation cost and the separation cost.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

the utility model provides an ultrasonic demulsification oil-gas-water separator, includes feed liquor pipe, oil phase pipe, gas phase pipe that are parallel to each other, swash plate bracing piece and ultrasonic wave vibration ring, the feed liquor pipe is connected rather than becoming 40 ~ 50 with the oil phase pipe that sets up above it through first inclined riser and second inclined riser, the gas phase pipe is connected with the oil phase pipe through two perpendicular gas collecting pipe group with the gas phase pipe, be equipped with in the feed liquor pipe with radial 40 ~ 50 feed liquor pipe swash plate bundle, it links to each other with the feed liquor pipe wall through the swash plate bracing piece, still be equipped with respectively in first inclined riser and the second inclined riser with inclined riser place direction parallel first swash plate bundle and second swash plate bundle, first inclined riser and second inclined riser are connected through swash plate bracing piece respectively, still be equipped with oil phase pipe bundle in the oil phase pipe, oil phase pipe bundle passes through the swash plate bracing piece and is connected with oil phase pipe wall, ultrasonic wave vibration ring sets up on the feed liquor pipe, first inclined riser and second inclined riser place, be equipped with the gas phase transducer, the gas phase transducer is equipped with one end, the gas phase transducer is equipped with the gas phase and is equipped with one end.

Preferably, the upper end of the first inclined plate bundle is designed at an angle of 5-10 degrees.

Preferably, the lower end of the second inclined plate bundle is designed at an angle of 5-10 degrees.

Preferably, flanges are arranged at two ends of the liquid inlet pipe, the oil phase pipe and the gas phase pipe.

Preferably, the distance between the inclined plates in the inclined plate bundle of the liquid inlet pipe and the inclined plate is 10-20mm, and the thickness of each inclined plate is 1mm.

Preferably, the plurality of ultrasonic demulsification oil-gas-water separators can be used in combination.

A separation method using an ultrasonic demulsification oil-gas-water separator comprises the following steps,

firstly, starting an ultrasonic transducer, feeding a stock solution mixed solution of oil, gas and water into an ultrasonic demulsification oil-gas-water separator through a stock solution inlet of a liquid inlet pipe, naturally layering larger oil drops and water phases on the inclined plate bundle of the liquid inlet pipe under the action of gravity, separating or demulsifiing and separating floating emulsion by the ultrasonic transducer, accelerating the polymerization of the oil drops adhered to the lower surface of each inclined plate of the liquid inlet pipe on one hand, floating an oil phase to the upper part of an inclined pipe and converging the oil drops on the first inclined plate bundle, sinking a water phase to the lower part of the inclined plate bundle of the liquid inlet pipe and converging the water phase in a pipeline, and flowing out from a water phase outlet, wherein a gas phase rises from the first inclined plate bundle;

step two, the mixed oil liquid after primary separation slowly rises along the first inclined plate bundle, ultrasonic demulsification is carried out, larger oil drops are demulsified and separated into oil drops and water drops, the oil drops float upwards and are converged and continuously rise to an oil phase pipe along the first inclined plate bundle, the water drops are converged and fall into a liquid inlet pipe along the first inclined plate bundle, and a gas phase rises to the oil phase pipe from the first inclined plate bundle;

step three, the mixed oil liquid after secondary separation rises into an oil phase pipe, the mixed liquid continues to separate oil from water under the action of the inclined plate bundle of the oil phase pipe and power ultrasonic energy, the separated gas is collected into a gas phase pipe through a gas collecting pipe group and discharged, other mixed liquid continues to flow forwards, and oil drops, water drops and emulsion are separated again at the moment;

and step four, when the crude oil mixed liquor meets the first and second inclined risers in the liquid inlet pipe, the mixed liquor of the oil-rich phase which is preliminarily separated in the front-section pipeline floats upwards along the flowing direction of the liquid in a throttling way, and the oil-gas-water separation in the steps one to three is carried out again.

The invention has the beneficial effects of positive progress:

(1) The purpose of setting the tail end of the first inclined plate bundle at an angle of 5-10 degrees with the axis of the oil phase pipe is to enable the mixed liquid of the water-rich phase which is preliminarily separated in the front-stage pipe to flow downwards along the flowing direction of the liquid in a throttling way, so that the separation of the water-rich phase of the oil phase pipe is facilitated; the lower end of the second inclined plate bundle is not parallel to the axis of the liquid inlet pipe pipeline, but has an inclination angle of 5-10 degrees, so that the mixed liquid of the rich oil phase which is initially separated in the front-stage pipeline flows upwards along the liquid flowing direction in a throttling way, thus being beneficial to the separation of the rich oil phase of the liquid inlet pipe,

(2) The inclined plate bundle forming an included angle of 40-50 degrees with the radial direction is arranged in the horizontal pipeline, so that the oil-water-gas separation effect is good;

(3) The high-power long-pulse frequency-conversion phase-shifting ultrasonic energy is applied to the pipeline and the inclined plate beam, the ultrasonic field intensity is uniform in radiation, the adjustable parameters are more, the problem of complex emulsification is avoided, and the demulsification and scale removal effects are good;

(4) The separation equipment is in a building block type modular design, the number and the structural form can be assembled at will, the volume can be enlarged at will, the field adaptability is strong, and the large-scale production expansion is not limited;

(5) The floor area is small, the field installation is simple and convenient, the maintenance is avoided in the operation, the influence of system scaling is avoided, and the long-term stable operation effect can be ensured.

(6) The oil-water-gas separation production efficiency is obviously improved, the time is shortened, the quality of petroleum crude oil is improved, the loss of petroleum crude oil is reduced, the demulsification efficiency of the demulsifier is increased, the use amount is reduced, and the requirement on the environment is reduced.

(7) At lower temperature, the oil-water-gas separation device realizes good oil-water-gas separation, can improve or change the original oil-water-gas separation system of an oil field, and can be applied to various petrochemical processes.

(8) And the ultrasonic wave is utilized to repeatedly demulsify and remove scale, so that the separation efficiency and the product quality are improved, the service life of the pipeline is prolonged, and the cost is reduced.

Drawings

FIG. 1 is a schematic diagram of an ultrasonic demulsification oil-gas-water separator.

Fig. 2 is a left side view of the structure of the ultrasonic demulsification oil-gas-water separator.

Fig. 3 is a schematic structural diagram of the connection between the upper end of the first inclined plate bundle and the oil phase pipe.

Fig. 4 is a schematic structural view of the connection of the lower end of the second inclined plate bundle and the liquid inlet pipe.

Fig. 5 is a schematic diagram of a combination of multiple sets of ultrasonic demulsification oil-gas-water separators.

Detailed Description

As shown in fig. 1 and 5, in actual operation, the invention is an oil-water-gas separation unit which is composed of a plurality of oil-water-gas separation modules shown in fig. 1 and is shown in fig. 5, the specific composition number is mainly determined by the characteristics of crude oil coming from the site, and meanwhile, the equipment conditions of other oil-water separation devices on the site are considered, in a word, the more the oil-water-gas separation modules in the oil-water-gas separation unit are, the better the separation effect is.

As shown in fig. 1-3, the invention discloses an ultrasonic demulsification oil-gas-water separator, which comprises a liquid inlet pipe 1, an oil phase pipe 2 and a gas phase pipe 3 which are parallel to each other, wherein the liquid inlet pipe 1 is connected with the oil phase pipe 2 arranged above the liquid inlet pipe through a first inclined vertical pipe 7 and a second inclined vertical pipe 8 at 40-50 degrees, the gas phase pipe 3 is connected with the oil phase pipe 2 through two gas collecting pipe groups 9 which are perpendicular to the gas phase pipe 3, an oil phase pipe inclined plate bundle 17 which is 40-50 degrees in radial direction is arranged in the liquid inlet pipe 1, the liquid inlet pipe is connected with the wall of the liquid inlet pipe 1 through an inclined plate support rod 12, a first inclined plate bundle 10 and a second inclined plate bundle 11 which are parallel to the direction of the inclined vertical pipes are respectively arranged in the first inclined vertical pipe 7 and the second inclined vertical pipe 8 are respectively arranged in the inclined vertical pipe 8, the oil phase pipe 2 is also internally provided with an oil phase pipe inclined phase pipe oil phase bundle 18 which is connected with the oil phase pipe 7 and the second inclined vertical pipe 8 through the inclined vertical pipe 12, an ultrasonic transducer is arranged at one end of the gas phase pipe 2, an ultrasonic transducer is arranged at one end of the inlet pipe 15, and an ultrasonic transducer is arranged at the other end of the inlet pipe 2 and the gas phase pipe 2 is arranged at the end of the inlet pipe 2, and an ultrasonic transducer is arranged at the end 15.

The upper end 13 of the first swash plate bundle 10 at the junction of the upper end with the oil phase pipe 2 is not horizontally designed but has an angle of 5 to 10 as shown in fig. 3.

The lower end 14 of the second inclined plate bundle 11 at the connection of the lower end and the liquid inlet pipe 1 is not horizontally designed, but has an angle of 5-10 degrees as shown in fig. 4.

Working process and principle

As shown in fig. 1 and 5, the unit is composed of 4 groups of oil-water-gas separation modules, crude oil liquid enters from the left side of the liquid inlet pipe 1, flows forward along the pipeline until the water phase outlet 4 flows out to the next process. A liquid inlet pipe inclined plate bundle 17 forming 40-50 degrees with a radial horizontal plane is arranged in the liquid inlet pipe 1, the distance between the inclined plate bundles is 10-20mm, the thickness of each inclined plate is 1mm, the liquid inlet pipe inclined plate bundles 17 are fixedly connected with the inclined plate support rods 12 and are tightly connected with the pipeline, and the inclined plate bundles and the support rods not only meet the corrosion protection requirement, but also have good elastic characteristics.

On each module feed liquor pipe 1, an ultrasonic vibration transmission ring 15 is arranged between the first inclined vertical pipe 7 and the second inclined vertical pipe 8, the ultrasonic transducer 16 is connected with the feed liquor pipe 1 through the ultrasonic vibration transmission ring 15, and the ultrasonic vibration transmission ring 15 can uniformly transmit power ultrasonic energy output by the ultrasonic transducer 16 to the feed liquor pipe 1 and generate power ultrasonic energy on metal equipment tightly connected with the power ultrasonic energy. Because the liquid inlet pipe inclined plate beam 17 is tightly connected with the liquid inlet pipe 1 through the inclined plate supporting rod 12, the power ultrasonic energy on the pipeline is transferred to the upper surface of the liquid inlet pipe inclined plate beam 17 through the inclined plate supporting rod 12, namely, the plate beam has certain power ultrasonic energy in normal working. The pipeline and the plate bundles in the pipeline have the advantages of power ultrasonic energy, good scale prevention and removal, acceleration of demulsification and the like, and the specific mechanism is as follows:

the oil-water mixed liquid is demulsified and scale-proof under the action of the inclined plate of the powered ultrasonic energy in the flowing process, the water phase with higher density is naturally layered under the action of gravity in the inclined plate environment and is sunk to the lower part of the inclined plate and is collected in the pipeline, the oil phase with lower density floats to the upper part of the inclined pipe and is collected in the pipeline, finally, the layered flowing of the oil phase and the water phase is formed, the gas phase in the crude oil liquid is continuously risen to the uppermost gas phase pipeline, and finally, the high-efficiency and rapid separation of oil, gas and water is realized.

Principle of ultrasonic demulsification

(1) Why ultrasound technology is needed to break emulsions

The natural emulsifying agent in the crude oil and the surfactant added during exploitation are adsorbed on an oil-water interface to form a viscoelastic film with certain strength, so that the oil-water interface energy is increased, the crude oil extracted from the oil field is mostly in the form of emulsion, the dispersion structure of the emulsion is very complex, and as many oil fields in China enter secondary and tertiary oil recovery, the quality of the crude oil is poor, the chemical components and the oil-water emulsion structure become more complex, and the kinetic barrier is caused for the coalescence of dispersed water drops. In particular, for heavy crude oil, the viscosity is high, the density is high, and demulsification and dehydration are more difficult than those of dilute oil. Conventional gravity separation methods are only capable of separating large droplets of water and mixtures of droplets of oil, and are ineffective for complex emulsions such as oil-in-water (O/W), water-in-oil (W/O), oil-in-water-in-oil (O/W/O), oil-in-water (W/O/W), and the like. It has been found that it is difficult to demulsify desalted and dewater crude oil by conventional methods, and that power ultrasound assisted methods can be used for desalting and dewatering such oils with good results.

(2) Ultrasonic demulsification mechanism and advantage

The ultrasonic demulsification mainly uses the mechanical vibration, shearing and thermal effects of ultrasonic waves to strengthen the collision and coalescence of water drops in the oil, thereby accelerating the separation of oil and water phases.

The mechanical vibration action of the ultrasonic waves causes the oil droplets or water droplets to coalesce, for example, when the ultrasonic waves pass through a crude oil medium having suspended water "particles" which are caused to vibrate with the crude oil medium. Because the water 'particles' with different sizes have different relative vibration speeds, the water 'particles' collide and adhere with each other, so that the volume and the weight of the particles are increased, and finally sedimentation and separation are carried out.

The shearing action of the ultrasonic wave can reduce the strength of the oil-water interface film or damage the interface film by diameter, and accelerate the liquid film drainage process, thereby promoting the coalescence and separation of water drops or oil drops.

The thermal action of ultrasonic wave reduces the strength of the oil-water interfacial film and the viscosity of crude oil, on one hand, the boundary friction increases the temperature at the oil-water interfacial position, which is favorable for the rupture of the interfacial film, and on the other hand, the acoustic energy of the absorption part of the crude oil is converted into heat energy, which can reduce the viscosity of the crude oil, and is favorable for the gravity sedimentation separation of water particles from oil to water. It was found that ultrasonic irradiation promoted coalescence of water droplets in the dirty oil emulsion. Compared with the traditional continuous ultrasonic radiation, the pulsed ultrasonic radiation can obtain better water drop coalescence effect.

(3) Inclined plate oil-water separation principle and existing problems

The oil-water separation effect generally depends on the characteristics of the coalescing element material and the structural characteristics of the internal components of the separation equipment, and the shallow pool principle of the inclined plate becomes an indispensable method in the oil-water separation technology.

According to the shallow pool principle, the inclined plate beam is arranged in the pipeline, so that the effective separation area of the oil separation pool is increased, the vertical rising distance of oil droplets is shortened, and the rectifying effect is improved. The action mechanism is that the flowing speed of fluid in the inclined plate is reduced, the residence time of the fluid in the pipeline is prolonged, so that the probability of collision and coalescence of discrete phase oil drops in the inclined plate is increased, the oil-water two phases are driven to move oppositely under the action of density difference, favorable conditions are provided for the floating and separation of the discrete phase oil drops in the mixed phase, the collision probability of small oil drops is increased, the oil-water separation efficiency is improved, and the physical oil-water separation technology of oil-water separation is achieved.

Experiments show that as stainless steel has good lipophilicity, oil drop particles with different particle diameters quickly adhere to the lower surface of the inclined plate after reaching the inclined plate made of the stainless steel without the action of ultrasonic waves, and further cover the whole inclined plate type coalescing plate; because adjacent oil drops are not quickly fused by surface tension, a continuous oil film is formed, and the adjacent oil drops are closely arranged together in the form of particles. With continuous mixing of dispersed phase oil drops, part of oil drop particles distributed on the surface of the coalescing plate are continuously increased, when the oil drops are sufficiently gathered, the oil drops are continuously combined with the oil drops adjacent to the upper side, then a flow channel is randomly formed, the oil phase is conveyed to the top end of the sloping plate, and the plate surface after the flow channel disappears returns to the initial state. The dispersed phase oil drops are adhered again in the area, and the dispersed phase oil drops are circulated continuously, so that coalescence and separation of the dispersed phase are realized.

Because the problem of scale formation of the gathering and transporting system of the oil field is very common, the scale formation and even the blockage are easy to occur among the inclined plate bundles under the conventional condition, and the separation effect is seriously influenced. Through the analysis of the separation process, the separation efficiency of the conventional inclined plate coalescence-separation technology is not high, and more importantly, the emulsion cannot be separated by the self gravity of oil drops and water drops, or the separation effect is very poor.

(4) Implementation of the principles and solution of the problems described above by the present invention

As shown in fig. 1, the left ends of the oil phase pipe 2 and the gas phase pipe 3 are sealed, when the device of the invention works normally, the ultrasonic transducer 16 is started first, and the ultrasonic energy couples the power ultrasonic energy to the pipeline of the liquid inlet pipe 1 through the ultrasonic vibration transmission ring 15 and is sequentially transmitted to the liquid inlet pipe inclined plate bundle 17, the first inclined plate bundle 10, the second inclined plate bundle 11, the oil phase pipe 2 and the oil phase pipe inclined plate bundle 18. The liquid inlet pipe inclined plate bundles 17 are tightly connected with the liquid inlet pipe 1 through the inclined plate supporting rods 12, the first inclined plate bundles 10 and the second inclined plate bundles 11 are tightly connected with the first inclined vertical pipe 7 and the second inclined vertical pipe 8 through the inclined plate supporting rods 12, and the oil phase pipe inclined plate bundles 18 are tightly connected with the oil phase pipe 2 through the inclined plate supporting rods 12, so that the power ultrasonic energy can be effectively transferred to each inclined plate bundle, namely, the inclined plate bundles and the pipeline always have the power ultrasonic energy during normal operation.

The ultrasonic technology used in the invention can realize the functions of frequency conversion, frequency sweep, long pulse and the like, and can control the ultrasonic energy in an optimal state before cavitation so as to realize the optimal demulsification and scale prevention functions.

The oil-gas-water separation multi-stage separation process comprises the following steps:

the crude oil enters the device of the invention from the left end of the 1 liquid inlet pipe, firstly, the crude oil passes through the coalescence and separation treatment of the liquid inlet pipe inclined plate bundles 17, firstly, larger oil drops float upwards and adhere to the lower surface of each liquid inlet pipe inclined plate bundle 17 under the action of gravity difference, and water drops drop downwards (the density of water is higher than that of oil), at this moment, the power ultrasonic energy emitted by the liquid inlet pipe inclined plate bundles 17 has good mechanical vibration, shearing and thermal effects, on one hand, the emulsion demulsification separation of the emulsion which is not separated or floats upwards between the pipeline plate bundles is accelerated, on the other hand, the oil drops which are adhered to the lower surface of each inclined plate are accelerated to be polymerized, and the ascending channel of an oil way is formed and maintained, so that the separation efficiency of oil and water gas is improved.

As shown in figure 2, a certain gap is reserved between the inclined plate bundles in the liquid inlet pipe 1 and the oil phase pipe 2 and the pipeline, so that a polymerization space is reserved for oil drops, water drops and gas, and ultrasonic energy is radiated into the liquid effectively through the inner wall of the pipeline, so that demulsification and scale prevention are better.

When the crude oil mixed liquid meets a first inclined vertical pipe 7 in the liquid inlet pipe 1, the separated oil phase liquid and gas phase and part of crude oil liquid come up along the first inclined vertical pipe 7, a first inclined plate bundle 10 is also arranged in the inclined vertical pipe, the first inclined plate bundle 10 is arranged at 40-50 degrees along the axis direction and the horizontal plane of the pipeline, the lengths of the first inclined vertical pipe 7 and the first inclined plate bundle 10 are about 800mm, the plate bundles are arranged in parallel, and the plate spacing is 10-20mm according to the characteristics of the liquid coming. The crude oil liquid which has been obtained with preliminary separation slowly rises between the first inclined plate bundles 10, and at this time, the principle of separation of oil droplets, water droplets and emulsion is the same as the above, except that the first inclined plate bundles 10 are long in distance, and the separation effect is better.

As shown in fig. 3, the upper end 13 of the first inclined plate bundle is not disposed in parallel with the pipe axis, but has an inclination angle of 5 ° to 10 °, in order to flow the mixture of the water-rich phase, which has been initially separated in the former stage pipe, downward in the liquid flow direction by means of throttling, thus facilitating the separation of the water-rich phase of the oil phase pipe 2.

At this time, the mixed liquid rising into the oil phase pipe 2 continues oil-water-gas separation under the action of the oil phase pipe inclined plate bundle 18 and the power ultrasonic energy, the separated gas is collected into the gas phase pipe 3 through the gas collecting pipe 9 and discharged, and the other mixed liquid continues to flow forward and is separated.

As shown in fig. 4, when the crude oil mixture encounters the first and second inclined risers 8 in the feed pipe 1, the lower ends 14 of the second inclined risers are not disposed parallel to the pipe axis, but have an inclination angle of 5 ° to 10 °, so as to flow the mixture of the oil-rich phases, which has been primarily separated in the former stage pipe, upward in the liquid flow direction by means of throttling, thus facilitating the separation of the oil-rich phases of the feed pipe 1, and the separation principle of the mixture in the second inclined risers 8 and the second inclined risers 11 is the same as described above.

The above-mentioned is a working process of a separation module, and in the actual production process, a plurality of modules shown in fig. 1 need to be formed into an oil-water-gas separation unit shown in fig. 5. FIG. 5 is a block set of 4 modules, and the number of wood blocks forming the block set can be flexibly mastered according to the characteristics of crude oil incoming liquid. The modules can be connected by flanges 19 or by welding or the like. Between each module, a certain gap is arranged between the inclined plate bundles in the horizontal pipeline, and the gap is used for redistributing the mixed liquid from each module to be mixed again, so that the efficient separation in the next module is facilitated. The water, oil and gas separated finally are discharged from the water phase outlet 4, the oil phase outlet 5 and the gas phase outlet 6 through the separation of the oil-water-gas separation modules, and the separation effect can completely meet the requirements of subsequent procedures.

In addition, in the normal working process of the oil-gas-water separation equipment, no matter the pipeline or the inclined plate coalescence plate bundles are always provided with power ultrasonic energy, the energy can continuously keep the pipeline and the plate bundles to have good shearing force, the shearing force can effectively prevent and remove scaling, any adverse effect on the equipment caused by the scaling is avoided, and therefore the oil-gas-water separation effect of oilfield produced liquid is maintained for a long time and efficiently. The viscosity of the crude oil can be reduced at a certain temperature, and the separation of oil, water and gas is facilitated. Therefore, the device is arranged in the subsequent flow of the heating furnace, and the heating system can be independently arranged to replace the original heating furnace system. If the inlet of the demulsifier is arranged at the inlet end of the equipment, better oil-water-gas separation effect can be obtained.

It will be appreciated by persons skilled in the art that the above embodiments are provided for illustration only and not for limitation of the invention, and that variations and modifications of the above described embodiments are intended to fall within the scope of the claims of the invention as long as they fall within the true spirit of the invention.

Claims (5)

1. An ultrasonic demulsification oil-gas-water separator is characterized in that: the ultrasonic vibration device comprises a liquid inlet pipe (1), an oil phase pipe (2) and a gas phase pipe (3) which are parallel to each other, wherein a sloping plate supporting rod (12) and an ultrasonic vibration transmission ring (15) are arranged in the liquid inlet pipe (1), the liquid inlet pipe (1) is connected with the oil phase pipe (2) arranged above the liquid inlet pipe (1) through a first sloping pipe (7) and a second sloping pipe (8), the liquid inlet pipe (1) forms an angle of 40-50 degrees with the first sloping pipe (7) and the second sloping pipe (8), the gas phase pipe (3) is connected with the oil phase pipe (2) through two gas collecting pipe groups (9) which are perpendicular to the gas phase pipe (3), a liquid inlet pipe sloping plate bundle (17) which forms an angle of 40-50 degrees with the radial direction of the gas phase pipe is arranged in the liquid inlet pipe (1), the liquid inlet pipe sloping plate bundle (17) is connected with the wall of the liquid inlet pipe (1) through the sloping plate supporting rod (12), the ultrasonic vibration transmission ring (15) is arranged on the liquid inlet pipe (1), an angle of 40-50 degrees is formed between the first sloping pipe (7) and the second sloping pipe (8), the gas phase pipe (3) is provided with an ultrasonic wave transducer, one end (4) is arranged at one end, and an ultrasonic liquid inlet (4) is arranged at the end;

a first inclined plate bundle (10) and a second inclined plate bundle (11) which are respectively parallel to the direction of the inclined vertical pipe are also arranged in the first inclined vertical pipe (7) and the second inclined vertical pipe (8), and the first inclined plate bundle (10) and the second inclined plate bundle (11) are respectively connected with the first inclined vertical pipe (7) and the second inclined vertical pipe (8) through inclined plate supporting rods (12); the upper end of the first inclined plate bundle (10) forms an angle of 5-10 degrees with the axis of the oil phase pipe; the lower end of the second inclined plate bundle (11) forms an angle of 5-10 degrees with the axis of the liquid inlet pipe;

the oil phase pipe (2) is internally provided with an oil phase pipe inclined plate bundle (18), and the oil phase pipe inclined plate bundle (18) is connected with the pipe wall of the oil phase pipe (2) through an inclined plate supporting rod (12).

2. The ultrasonic demulsification oil-gas-water separator as claimed in claim 1, wherein: flanges (19) are arranged at two ends of the liquid inlet pipe (1), the oil phase pipe (2) and the gas phase pipe (3).

3. The ultrasonic demulsification oil-gas-water separator as claimed in claim 1, wherein: the distance between the inclined plates in the liquid inlet pipe inclined plate bundle (17) is 10-20mm, and the thickness of each inclined plate is 1mm.

4. An ultrasonic demulsification oil-gas-water separator as claimed in claim 1 or 2 or 3, wherein the plurality of ultrasonic demulsification oil-gas-water separators are used in combination.

5. A separation method using the ultrasonic demulsification oil-gas-water separator as defined in claim 4, characterized in that: comprises the following steps of the method,

firstly, starting an ultrasonic transducer, feeding a stock solution mixed solution of oil, gas and water into an ultrasonic demulsification oil-gas-water separator through a stock solution inlet of a liquid inlet pipe, naturally layering larger oil drops and water phases on the inclined plate bundle of the liquid inlet pipe under the action of gravity, separating or demulsifiing and separating floating emulsion by the ultrasonic transducer, accelerating the polymerization of the oil drops adhered to the lower surface of each inclined plate of the liquid inlet pipe on one hand, floating an oil phase to the upper part of an inclined pipe and converging the oil drops on the first inclined plate bundle, sinking a water phase to the lower part of the inclined plate bundle of the liquid inlet pipe and converging the water phase in a pipeline, and flowing out from a water phase outlet, wherein a gas phase rises from the first inclined plate bundle;

step two, the mixed oil liquid after primary separation slowly rises along the first inclined plate bundle, ultrasonic demulsification is carried out, larger oil drops are demulsified and separated into oil drops and water drops, the oil drops float upwards and are converged and continuously rise to an oil phase pipe along the first inclined plate bundle, the water drops are converged and fall into a liquid inlet pipe along the first inclined plate bundle, and a gas phase rises to the oil phase pipe from the first inclined plate bundle;

step three, the mixed oil liquid after secondary separation rises into an oil phase pipe, the mixed liquid continues to separate oil from water under the action of the inclined plate bundle of the oil phase pipe and power ultrasonic energy, the separated gas is collected into a gas phase pipe through a gas collecting pipe group and discharged, other mixed liquid continues to flow forwards, and oil drops, water drops and emulsion are separated again at the moment;

and step four, when the crude oil mixed liquor meets the first and second inclined risers in the liquid inlet pipe, the mixed liquor of the oil-rich phase which is preliminarily separated in the front-section pipeline floats upwards along the flowing direction of the liquid in a throttling way, and the oil-gas-water separation in the steps one to three is carried out again.

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