Oil field crude oil microwave electromagnetic wave demulsification dehydration environment-friendly treatment equipment and technological process thereof

Abstract

The invention discloses oil field crude oil microwave electromagnetic wave demulsification dehydration environment-friendly treatment equipment and a technological process thereof, and relates to the technical field of oil field crude oil dehydration environment protection. The equipment consists of a square pipeline magnetron reactor total device (1000), a working cabinet system device (2000) and a cooling tower system device (3000) which are connected in sequence. The method overcomes the defects that the traditional crude oil dehydration process is complicated, the precipitation time is long (as long as 72 hours), the demulsifier is high in cost and the power consumption is serious (as high as 39 kw / m < 3 >). The method has the following advantages and positive effects: (1) the time for microwave and electromagnetic wave demulsification and dehydration of the crude oil is short (only 1 min), and complete demulsification can be achieved without adding any additive; (2) the microwave and electromagnetic wave demulsification and dehydration process of the crude oil is simple, complete dehydration can be completed by a microwave and electromagnetic wave and pressure cyclone oil-water separator, the dehydration rate reaches 99.67%, and the technical index for completing dehydration of the crude oil is 0.3%; and (3) the crude oil microwave and electromagnetic wave dehydration equipment is compact and efficient in structure, small in occupied area and low in operation cost, and the power consumption is only about 10-12kw / m < 3 >.

Description

Technical Field

[0001] The present invention relates to the environmental protection technology for crude oil dehydration in oil fields, and particularly to an environmental protection treatment equipment and its technological process for microwave electromagnetic wave demulsification dehydration of crude oil in oil fields. Background Art

[0002] During the production process of crude oil extraction, it is found that the problem of crude oil dehydration is a very serious problem and a stumbling block to the development and utilization of new energy. Using the traditional method of onshore oil field crude oil dehydration, it is no longer possible to completely dehydrate the crude oil to meet the standard of a water content less than 0.3%. After the problem was discovered and proposed, various units with research conditions have invested in research and pilot tests. Finally, it was found that "microwave radiation demulsification dehydration of crude oil" is a fast and good process method. It does not require the addition of demulsifiers, and it only takes about 1 minute to achieve complete dehydration, with a very small floor area. In contrast, the traditional crude oil dehydration process is complex, occupies a large area, and the sedimentation time is up to about 72 hours, which is an unbearable pain for newly developed oil fields.

[0003] The microwave test data and microwave processing methods for microwave dehydration of crude oil completed in the laboratory are very successful. Here comes the question: Can it be put into industrial production? Here lies the problem.

[0004] Crude oil often contains water, and the water content in crude oil poses great hazards to the storage, transportation, and refining of crude oil and will bring many problems. Selecting an efficient and energy-saving crude oil dehydration method has become increasingly important in oil field production and petroleum processing. The quality of crude oil dehydration technology directly affects the production cost of oil and the degree of environmental pollution. As a new type of efficient and energy-saving dehydration technology, microwave demulsification dehydration of crude oil is increasingly favored by oil users. Many domestic universities and research institutions have conducted many laboratory or small-scale on-site test studies on microwave demulsification dehydration technology of crude oil. The research results show that microwave electromagnetic wave demulsification dehydration is faster, more effective, energy-saving, and avoids secondary pollution compared with traditional chemical dehydration and heating dehydration methods. However, due to the bottleneck constraints of microwave high-power sources and microwave crude oil processing technology, this technology has not made effective progress in engineering applications.

[0005] How to convert the data obtained from laboratory research into industrial production is a very important link. First, a complete set of processes and equipment for industrialized crude oil dehydration must be developed. To achieve this process and equipment, the biggest problem in fluid microwave industrialization must be solved first.

[0006] What is the biggest problem in fluid microwave industrialization? There are two problems. One is that the fluid pipeline must be compact and the reception of microwave electromagnetic waves is a surface contact; the other is that the acceptance degree of fluid materials to the microwave source should be high. In other words, every drop of fluid material can receive microwaves.

[0007] The biggest problem in the industrialization of fluid microwave is the pipeline layout in the microwave cavity. The traditional method uses circular pipelines, which cannot be laid out for fluids with a flow rate of less than 1 m 3 / h, and it is even more difficult to support fluids with a large flow rate.

[0008] The microwave separation patent MST technology of Imperial Oil (IPRC) in the United States is a new and efficient crude oil dehydration method, which has the advantages of faster dehydration speed, higher efficiency and no secondary pollution. The MST technology equipment includes: microwave system, control system, power supply system, centrifugal separator, water cooling and emulsion analysis. The principle prototype and technical parameters of the classic microwave demulsification system are as Figure 12 shown.

[0009] Table 1 Technical Parameters of IPRC Vehicle-mounted Microwave Separation System

[0010]

[0011] The United States has taken the lead in the environmental protection process and equipment technology of microwave electromagnetic wave demulsification dehydration of crude oil in China, and realized the industrialization of fluid microwave electromagnetic wave demulsification dehydration more than a decade ago. Summary of the Invention

[0012] The purpose of the present invention is to overcome the serious problems of existing crude oil demulsification dehydration, and provide an environmental protection treatment equipment and its technological process for microwave electromagnetic wave demulsification dehydration of oilfield crude oil, so as to realize the industrialization of microwave electromagnetic wave dehydration of crude oil after the perfect data of microwave electromagnetic wave dehydration of crude oil in the laboratory.

[0013] The purpose of the present invention is achieved as follows:

[0014] The design of the square pipeline in the microwave cavity is as follows: for the crude oil fluid flow rate of 15 m 3 / h (0.0041666 m 3 / s), a square pipeline of 125 mm × 125 mm (0.0156 m 2 ) is adopted. The linear velocity of the fluid in the square pipeline is 0.267 m / s. Assuming that the fluid runs in the square pipeline for 1 min (60 s), the length of the square pipeline is 0.2627 × 60 = 16 m. Divide 16 m into 9 pipes to form a 9-square-hole square body, then the length is 16 / 9 = 1.777 m. Therefore, the total length of the designed square pipeline magnetron reactor device (1000) is 2000 mm.

[0015] Calculation formula for microwave electromagnetic wave power:

[0016]

[0017] P - consumed microwave power, kilowatt;

[0018] ΔT - Temperature rise of the material, degree;

[0019] C - Specific heat of the material, kcal / kg / °C

[0020] W - Weight of the material, kg;

[0021] t - Time of microwave action, hour

[0022] The calculation of the deformed microwave power formula is as follows:

[0023]

[0024] It should be noted here that the water content of the crude oil is 30%, and the oil content of the crude oil is 70%.

[0025] Definition

[0026] The specific heat capacity of water is 4200 J / (kg·°C).

[0027] It means that the heat absorbed when the temperature of 1 kg of water rises by 1°C is 4200 J.

[0028] The specific heat capacity of crude oil is very close to that of water, taking 4200 J.

[0029] The weight of crude oil in the pipeline = (16.02 x 0.0156) x 1000 = 249.912 (kg)

[0030] The running time of crude oil in the square pipeline = 1 min = 0.01666 (h)

[0031]

[0032] The length of the square pipeline in the microwave cavity is 0.2627 x 60 = 16 m, the total power is 240 kw, and the microwave temperature rise is 3.28 degrees.

[0033]

[0034] The microwave separation patent MST technology of Imperial Oil (IPRC) Company in the United States is a new and efficient crude oil dehydration method, which has the advantages of fast dehydration speed, high efficiency and no secondary pollution. The MST technology equipment includes: microwave system, control system, power supply system, centrifugal separator, water cooling and emulsion analysis. The principle prototype and technical parameters of the classic microwave demulsification system are as follows.

[0035] Table 1 Technical Parameters of IPRC Vehicle-mounted Microwave Separation System

[0036]

[0037] Compared with the microwave separation patent MST technology of Imperial Oil (IPRC) in the United States, the technical parameters are basically the same.

[0038] The calculation of the microwave separation patent MST technology of Imperial Oil (IPRC) in the United States is as follows:

[0039] The crude oil fluid flow rate is 7 m 3 / h (0.001944 m 3 / s). A square pipe with a diameter of 50 mm × 50 mm (0.01962 m 2 ) is used. The linear velocity of the fluid in the pipe is 0.99 m / s. Assuming the fluid runs in the square pipe for 1 minute (60 s), the length of the pipe is 0.99 × 60 = 59.4 m, and the weight of the material in the pipe is 116.5725 kg.

[0040]

[0041] The design parameters of a Chinese invention patent for a microwave electromagnetic wave demulsification reactor treatment system equipment and its process are very similar when compared with the technical parameters of the microwave separation patent MST technology of Imperial Oil (IPRC) in the United States. Our microwave temperature increase is:

[0042] 3.28 degrees, and the microwave temperature increase of Imperial Oil (IPRC) in the United States is: 2.19 degrees. This data shows that the microwave electromagnetic wave demulsification reactor not only has a thermal effect but also has a non-thermal effect.

[0043] Thermal effect: When microwaves are used for demulsification, a high-frequency electromagnetic field is formed. Since water molecules have a stronger ability to absorb microwaves than the oil molecules in the interfacial film, the internal phase water droplets absorb more energy and expand, causing the interfacial film to become thinner under the internal pressure. At the same time, the solubility of the oil in the interfacial film increases due to heat, making the mechanical strength of the interfacial film lower and easier to break.

[0044] Non-thermal effect: Polar water molecules and charged liquid droplets rotate rapidly or generate charge displacement with the change of the electric field, disturbing the orderly arrangement of charges at the liquid-liquid interface, thus leading to the destruction of the double electric layer structure and a sharp decrease in the Zeta potential. When the water (oil) molecules lose the effect of the Zeta potential, they move freely up and down, collide and coalesce, resulting in the separation of oil and water. In addition, the high-frequency magnetic field formed by microwaves magnetizes non-polar oil molecules, forming a vortex electric field at a certain angle with the axis of the oil molecules. This electric field can weaken the intermolecular attraction, reduce the viscosity of the oil, thereby increasing the density difference between oil and water and making the emulsion easier to demulsify and dehydrate.

[0045] The biggest advantage of this design is that the layout of the square pipe is compact and occupies a small area. If a circular pipe is used, the occupied area is so large that it is unacceptable and industrialization cannot be achieved.

[0046] Specifically:

[0047] 1. An environmental protection treatment device for demulsifying and dehydrating crude oil in oil fields by microwave electromagnetic waves

[0048] It is composed of a square pipeline magnetron reactor total device, a working cabinet system device, and a cooling tower system device connected in sequence.

[0049] 2. The technological process of environmental protection treatment for demulsifying and dehydrating crude oil in oil fields by microwave electromagnetic waves

[0050] See the specific implementation mode.

[0051] The present invention has the following advantages and positive effects:

[0052] ① The time for demulsifying and dehydrating crude oil by microwave electromagnetic waves is only 1 minute, and complete demulsification can be achieved without adding any additives;

[0053] ② The process of demulsifying and dehydrating crude oil by microwave electromagnetic waves is simple. Microwave electromagnetic waves + a pressure cyclone oil-water separator can complete complete dehydration, and the dehydration rate reaches 99.67%, meeting the crude oil dehydration technical index of 0.3%;

[0054] ③ The crude oil microwave electromagnetic wave dehydration equipment has a compact and efficient structure, a small floor area, and a low operating cost, consuming only 10 - 16 kw / m 3 ; while the traditional dehydration process is complex, the precipitation time is as long as 72 hours, the cost of demulsifier is high, and the power consumption is serious, reaching 39 kw / m 3 . Description of the Drawings

[0055] Figure 1 It is one of the structural schematic diagrams of the square pipeline magnetron reactor total device (1000);

[0056] Figure 2 It is the second structural schematic diagram of the square pipeline magnetron reactor total device (1000);

[0057] Figure 3 It is the part drawing of the square pipeline cross plate (1010) and the square pipeline longitudinal plate (1020);

[0058] Figure 4 It is the part drawing of the material inlet (1050) and the material outlet (1060) of the square pipeline;

[0059] Figure 5 It is the part drawing of the flanges (1030) at both ends of the square pipeline;

[0060] Figure 6 It is the distribution schematic diagram of the microwave afterwave receiving area (1200) of the square pipeline;

[0061] Figure 7It is a schematic diagram of a square pipeline with serial material flow and slots (1001), (1002), (1003) and (1004) on the left and right, up and down;

[0062] Figure 8 It is a part drawing of the working cabinet system device (2000);

[0063] Figure 9 It is a schematic diagram of the structure of a microwave electromagnetic wave magnetron;

[0064] Figure 10 It is an environmental protection process flow diagram for microwave electromagnetic wave demulsification of crude oil;

[0065] Figure 11 It is an environmental protection process flow diagram for microwave electromagnetic wave demulsification of oily sewage;

[0066] Figure 12 It is a schematic diagram of a prototype of the principle of a classic microwave demulsification system.

[0067] In the figure:

[0068] 1000 - Total device of square pipeline magnetron reactor,

[0069] 1010 - Horizontal plate of square pipeline,

[0070] 1020 - Vertical plate of square pipeline,

[0071] 1030 - Flanges at both ends,

[0072] 1040 - End plates at left and right,

[0073] 1050 - Connecting pipe,

[0074] 1060 - Material outlet connecting pipe, 1061 - Celestial square pipe orifice, 1062 - Terrestrial round pipe orifice,

[0075] 1070 - Connecting pipe locking nut,

[0076] 1080 - Fiberglass square box body,

[0077] 1090 - Shielding stainless steel square box body,

[0078] 1100 - Magnetron,

[0079] 1110 - Magnetron waveguide,

[0080] 1120 - Cooling water inlet pipe, 1121 - Connecting pipe of magnetron,

[0081] 1130 - Return water pipe;

[0082] 2000 - Working cabinet system device,

[0083] 2010 - Total device cabinet of square - pipe magnetron,

[0084] 2020 - Moving roller,

[0085] 2030 - Microwave power cord cabinet,

[0086] 2031 - Operation door of power cord cabinet,

[0087] 2040 - Water storage tank,

[0088] 2050 - Wire cabinet, 2051 - Operation door of wire cabinet,

[0089] 2060 - Electrical appliance cabinet,

[0090] 2070 - Base of working cabinet,

[0091] 3000 - Cooling tower system device (general equipment),

[0092] 3010 - Cooling tower body, 3011 - Cooling water valve, 3012 - Microwave power cord cooling water valve,

[0093] 3013 - Cooling water pipe, 3014 - Return pipe,

[0094] 3020 - Cooling water pump,

[0095] 3030 - Circulation pump, 3031 - Circulation water pipe. Detailed implementation mode

[0096] The following is a detailed description in conjunction with the drawings and embodiments:

[0097] I. Equipment

[0098] 1. Overall

[0099] This equipment is composed of a total device of square - pipe magnetron reactor 1000, a working cabinet system device 2000, and a cooling tower system device 3000, which are connected in sequence.

[0100] 1) Total device of square - pipe magnetron reactor 1000

[0101] As shown in, the total device of square - pipe magnetron reactor 1000 is composed of a square - pipe horizontal plate 1010, a square - pipe vertical plate 1020, two - end flanges 1030, left - and - right end plates 1040, a connecting pipe 1050, a material - outlet connecting pipe 1060, a sky - square pipe orifice 1061, a ground - round pipe orifice 1062, a connecting - pipe locking nut 1070, a fiberglass - reinforced plastic square box body 1080, a shielding stainless - steel square box body 1090, a magnetron 1100, a magnetron waveguide 1110, a cooling water inlet pipe 1120, a connecting pipe of the magnetron 1121, and a return water outlet pipe 1130; Figure 2 ​

[0102] Its position and connection relationship are as follows:

[0103] It consists of 4 square pipeline horizontal plates 1010 and four square pipeline vertical plates 1020 inserted into each other at 90 degrees to form a skeleton square box with 9 square holes, as shown in Figure 3 ;

[0104] Then, the front, back, top, and bottom four sides of the skeleton square box are wrapped with fiberglass for fiberglass processing to form a fiberglass square box 1080, so as to enhance the sealing and strength;

[0105] As Figure 7 , 9 shown, the 9 square holes (or 16 square holes) operate in series. Channels need to be opened on the left, right, top, and bottom between the 9 square holes. The material inlet water pipe 1050 is installed at the rear end of the first hole on the left side of the bottom layer, between the front ends of the first and second holes on the left side of the bottom layer, and a front left and right channel 1002 needs to be opened. Between the rear ends of the second and third holes on the left side of the bottom layer, a rear left and right channel 1006 needs to be opened. Between the front ends of the third and fourth holes on the right side of the bottom layer, a front left and right channel 1002 needs to be opened. Between the rear end of the fourth hole on the right side of the bottom layer and the rear end of the fourth hole on the right side of the second layer, a rear up and down channel 1003 needs to be opened. Between the front end of the fourth hole on the right side of the second layer and the fifth hole, a front left and right channel 1002 needs to be opened... and the holes are opened in sequence to the eighth hole. Between the front end of the eighth hole on the left side of the fourth layer and the ninth hole, a front left and right channel 1002 needs to be opened. The material outlet water pipe 1050 is installed at the rear left end of the fourth layer;

[0106] As Figure 2 shown, the front, back, top, and bottom four sides of the square box are wrapped with stainless steel for shielding to form a shielded stainless steel square box body 1090. At both ends of the shielded stainless steel square box body 1090, left and right end plates 1040 are welded at 90 degrees, and cooling inlet water pipes 1120 and return water outlet pipes 1130 are installed at the four corners of the left and right end plates 1040;

[0107] As Figure 5 shown, the two-end flanges 1030 are installed at both ends of the square box. 9 square blind grooves need to be opened on the front surface of the two-end flanges 1030, and the depth dimension is 2 / 3 of the plate thickness deep, as shown in Figure 2 , and rubber seals 1031 need to be filled before installation. The two-end flanges 1030 are connected to the square box by connecting bolts 1051;

[0108] As Figure 2 shown, N magnetrons 1100 are installed around the front, back, top, and bottom of the stainless steel shielded square box 1090, and waveguides 1110 are arranged between the magnetrons 1100 and the shielded stainless steel square box body 1090;

[0109] As Figure 9As shown, the water inlet 1105 of the magnetron 1100 is connected to the cooling water inlet pipe 1120 of the square box through a water inlet branch pipe, and the water outlet 1106 of the magnetron 1100 is connected to the return water outlet pipe 1130 of the square box;

[0110] As Figure 6 shown, the electromagnetic wave afterwave 1101 advances in a 90-degree spiral in the electromagnetic wave afterwave reaction area. A stainless steel spiral core rod 1102 is arranged in the square hole of the electromagnetic wave afterwave receiving area 1200. The electromagnetic wave afterwave will be reflected when it encounters metal.

[0111] 2) The working cabinet system device 2000

[0112] As Figure 8 shown, the working cabinet system device 2000 includes a reactor cabinet 2010, moving rollers 2020, a microwave power cord cabinet 2030, a power cord cabinet operation door 2031, a water storage tank 2040, a wire cabinet 2050, a wire cabinet operation door 2051, an electrical cabinet 2060, and a working cabinet base 2070;

[0113] Its position and connection relationship are:

[0114] The square pipe magnetron reactor total device 1000 is installed in the reactor cabinet 2010 of the working cabinet system device 2000, and the square pipe magnetron reactor total device 1000 is moved into place through the moving rollers 2020;

[0115] The microwave power cord device 2030 is installed in the microwave power cord cabinet 2031, the cable is installed in the cable cabinet 2051, the electrical device is installed in the electrical cabinet 2061, the cooling return water enters the water storage tank 2040, the water storage tank 2040 is arranged below the reactor cabinet 2010, and the lower part of the working cabinet system device 2000 is provided with a working cabinet base 2070;

[0116] 2. The cooling tower system device 3000

[0117] As Figure 1 shown, the cooling tower system device 3000 includes a cooling tower 3010, a cooling water valve 3011, a microwave power cord cooling water valve 3012, a cooling water pipe 3013, a return pipe 3014, a cooling water pump 3020, a circulating pump 3030, and a circulating water pipe 3031;

[0118] Its position and connection relationship are:

[0119] The inlet of the cooling water pump 3020 is connected to the outlet of the cooling tower 3010. The cooling water pump 3020 passes through the cooling water valve

[0120] 3011 is connected to the outlet of the cooling tower 3010. The outlet of the cooling water pump 3020 is connected to the cooling water inlet pipe 1120 through the cooling water pipe 3013. The cooling water pipe 3013 is also connected to the cooling water inlet of the microwave power supply line device 2030 through the cooling water valve 3012 of the microwave power supply line.

[0121] The return water of the return water pipe 3014 flows back to the water storage tank 2040.

[0122] The inlet of the circulating water pump 3030 is connected to the outlet of the water storage tank 2040. The outlet of the circulating water pump 3030 is connected to the inlet of the cooling tower 3010 through the water pipe 3031.

[0123] II. Process Flow

[0124] The industrial application of microwave electromagnetic wave demulsification is very extensive. As long as it is difficult to treat high-concentration wastewater, the demulsification process must be adopted. The best method for demulsification is microwave electromagnetic wave demulsification; especially the dehydration of crude oil in oil fields is the biggest bottleneck in current oil production; therefore, crude oil dehydration has always been an important content in oil extraction and processing. Due to the application of various enhanced oil recovery technologies such as thermal oil recovery, miscible flooding, chemical flooding, microbial flooding, and foam flooding, the produced crude oil mostly exists in the form of emulsion, and crude oil demulsification has become the key link in crude oil dehydration. Currently, the commonly used processes are thermochemical and electrochemical demulsification, which have the disadvantages of high energy consumption, large amount of demulsifier added, poor water quality after dehydration, and environmental pollution. Demulsifying and dehydrating crude oil is an important link in the oil processing process. Currently, thermochemical and electrochemical dehydration processes are commonly used in domestic oil fields. Due to the deficiencies of thermochemical and electrochemical methods such as high energy consumption, large amount of demulsifier added, poor water quality after dehydration, and environmental pollution, both at home and abroad are committed to developing a high-efficiency, low-consumption, pollution-free or low-pollution crude oil dehydration method. Microwave, as a clean and efficient energy source, has received increasing attention in recent decades.

[0125] 1. Process Flow of Microwave Electromagnetic Wave Demulsification and Dehydration of Crude Oil

[0126] As Figure 10 , its process flow is as follows:

[0127] Crude oil enters from the inlet valve 4001, with the inlet temperature around 85 degrees. Driven by the pressure of the sewage pump 4000, it enters the pipeline mixer 4002. Above the front end of the pipeline mixer 4002, there is a NaCl dosing port 4003. The outlet of the pipeline mixer 4002 is connected to the material inlet 1050 of the square pipeline magnetron reactor 1000. On the outlet pipeline of the material outlet 1060, there is a pressure gauge 4004 and a valve 4005 for controlling pressure. The material outlet 1060 is connected to the cyclone inlet 5001 of the pressure cyclone 5000, with the inlet temperature around 90 degrees. After the high-speed centrifugation of the pressure cyclone (5000), the dehydrated crude oil is discharged from the crude oil outlet 5002, and the oily sewage is discharged from the sewage outlet 5003. The key to crude oil dehydration lies in demulsification, and the key to demulsification lies in microwaves.

[0128] 2. Process flow of microwave electromagnetic wave demulsification and oil removal for oily sewage

[0129] As Figure 11 , its process flow is as follows:

[0130] Oily sewage enters from the inlet valve 4001, with a pH value of around 13. Driven by the pressure of the sewage pump 4000, it enters the pipeline mixer 4002. Above the front end of the pipeline mixer 4002, there is a PDMDAAC (organic polymer) dosing port 4003. The outlet of the pipeline mixer 4002 is connected to the material inlet 1050 of the total device of the square pipeline magnetron reactor 1000. Inside the square pipeline of the total device of the square pipeline magnetron reactor 1000, there is diatomite or activated carbon or zeolite 1003. Diatomite or activated carbon or zeolite 1003 is a "sensitizer" and a "hot spot" material. On the outlet pipeline of the material outlet 1060, there is a pressure gauge 4004 and a valve 4005 for controlling pressure. The material outlet 1060 is connected to the inlet valve 6011 of the automatic density gradient fiber cloth block filter 6000, and enters the filter inlet 6013 under the pressure of the filtration pump 6020. Before starting, the air in the fiber cloth block filter 6000 needs to be discharged through the exhaust hole 6015. When the fiber cloth block filter 6000 is working, the hydraulic cylinder 6012 rises to the upper dead point to compress the fiber cloth block filter material 6017. The oily sewage after filtration can fully meet various technical indicators and is discharged from the filtered water outlet 6014. When backwashing is required, the hydraulic cylinder 6012 descends to the lower dead point for backwashing, and the backwashing water is discharged from the backwashing water outlet 6016.

[0131] Microwave electromagnetic wave demulsification is to perform electromagnetic wave treatment on the emulsion with microwaves. Since microwave electromagnetic waves form a high-frequency changing electromagnetic field, polar molecules rotate at high speed, destroying the Zeta potential at the oil-water interface. When the liquid droplets lose the effect of the Zeta potential, they are prone to collide and coalesce, resulting in oil-water separation. At the same time, for water-in-oil (W / O) emulsions, because water molecules have a stronger ability to absorb microwaves than oil molecules (due to the large dielectric constant and loss angle of water), the internal phase water droplets absorb more energy and expand, thinning the interfacial film under internal pressure, thus reducing the mechanical strength of the interfacial film and making it easier to break. In addition, the magnetic field formed by microwaves can also magnetize non-polar oil molecules, forming a vortex electric field at a certain angle to the axis of the oil molecules. This electric field can weaken the intermolecular attraction, reduce the viscosity of the oil, and make the emulsion easier to demulsify and dehydrate. Through data investigation, it is found that after adding a "sensitizer" to the oily sewage and then performing microwave treatment, the effect is significantly better than that of single microwave treatment. This is related to the characteristics of microwave heating. Microwave heating is a selective heating, and diatomite or activated carbon or zeolite (1003) is sensitive to the action of microwaves. Once it receives microwaves, the temperature instantly rises to 1400 degrees, which is very beneficial for the regeneration and activation of diatomite or activated carbon or zeolite (1003). It can be regenerated and activated in just a few minutes, and diatomite or activated carbon or zeolite (1003) itself has a certain demulsifying and adsorbing effect.

[0132] III. Dehydration mechanism

[0133] Crude oil is also called high-viscosity oil and heavy crude oil. The content of light fractions of crude oil (especially straight-chain wax-containing hydrocarbons) is low, while the content of gum and asphaltene is high, and the contents of element compounds such as sulfur, oxygen, nitrogen and metals such as nickel and vanadium are also high. Therefore, crude oil has a large specific gravity, high viscosity and relatively low freezing point. The gum and asphaltene existing in crude oil are high-molecular surface active substances and are natural and high-performance oil-water emulsifiers. During the oilfield development and oil and gas gathering and transportation processes, oil, water and emulsifiers coexist together. They are fully contacted and mixed in the oil well borehole, choke, pipeline, valve parts and pumps (especially with the participation of associated gas in the oilfield, the stirring is more intense). Interfacial active substances such as asphaltene and gum are adsorbed on the oil-water interface of the emulsion, forming a firm interfacial film, thus forming a stable W / O emulsion. Moreover, the higher the contents of gum, asphaltene and wax, the more stable the W / O emulsion. At the same time, due to the large specific gravity of crude oil, the density difference with water is small, and the viscosity of crude oil is high, the sedimentation and aggregation speed of water droplets is slow. Therefore, the dehydration of crude oil has great technical difficulties.

[0134] Crude oil contains about 60 - 70% water. Part of it is the clear water formed after the condensation of thermal recovery steam. After removing the clear water, the water content of the crude oil is about 30 - 40%. These waters are mutually inclusive with the crude oil, forming a relatively stable emulsion. Judging from its macroscopic properties such as viscosity and fluidity, this emulsion is of the W / O type, showing a large density, high viscosity and poor fluidity, so deep dehydration is difficult.

[0135] At present, the dehydration of crude oil mainly adopts the method of adding chemical demulsifiers for heating and sedimentation separation dehydration. However, there are some disadvantages such as slow separation speed (about 50 - 70 h is required), low energy utilization rate, high cost, easy corrosion of equipment, and difficult recovery of oil products. Therefore, it is of great significance to study efficient, low-consumption and convenient demulsification and dehydration technologies.

[0136] Regarding the application of microwave energy in the demulsification and dehydration of crude oil, certain research has been carried out at home and abroad. The research shows that the application of microwave technology in crude oil dehydration is not only feasible, but also has incomparable advantages over other dehydration methods in terms of immediate dehydration rate, total dehydration rate, and sedimentation consumption time.

[0137] Generally, there are charges on the oil-water interface, and there are double electric layers and potential drops on both sides of the interface. The value of the diffusion layer potential of the aqueous phase is generally much higher than that of the oil phase. The charges mainly accumulate in the aqueous phase, and the surface potential can be large enough to stabilize the O / W type emulsion. For the W / O type dilute emulsion with large droplets, the surface potential also plays a certain role in its stability. Polar molecules can rotate in a microwave field. Water molecules are typical polar molecules. Under the action of microwaves with a frequency of 2450 MHz, water molecules undergo 4.9×10 9 changes from disorder to order per second. This high-frequency repeated rotation not only rapidly heats the molecules, but also destroys the original double electric layer at the oil-water interface. The decrease in the Zeta potential increases the chance of aggregation of dispersed phase particles, and then accelerates the separation process.

[0138] The microwave method for crude oil dehydration is a dehydration method proposed by taking advantage of the superiority of microwaves in demulsification. During microwave demulsification, a high-frequency changing electromagnetic field is formed, which makes polar molecules rotate at high speed and destroys the Zeta potential of the oil-water interface film; when water (oil) molecules lose the effect of the Zeta potential, they move freely up and down, collide and coalesce, resulting in the separation of oil and water. At the same time, because the ability of water molecules to absorb microwaves is stronger than that of oil molecules in the interface film, the inner-phase water droplets absorb more energy and expand, thinning the interface film under the internal pressure. On the other hand, the solubility of the oil in the interface film increases due to heating, making the mechanical strength of the interface film lower and easier to break. In addition, the magnetic field formed by microwaves also magnetizes non-polar oil molecules, forming a vortex electric field at a certain angle with the axis of the oil molecules. This electric field can weaken the intermolecular attraction, reduce the viscosity of the oil, and thus increase the density difference between oil and water. All these effects enable oil and water molecules to effectively collide and coalesce. When the water droplets coalesce to a certain extent, they settle to the bottom layer under the action of gravity, realizing the separation of oil and water.

[0139] Most of the salts in crude oil dissolve in the water contained in the crude oil, and the water and oil form a stable (W / 0) emulsion. Therefore, desalting and dehydration of crude oil are carried out simultaneously. The key to crude oil desalting lies in dehydration, and the key to dehydration lies in demulsification. For the dehydration of crude oil emulsion, various methods are first needed to reduce the Zeta potential at the oil-water interface, destroy the double electric layer structure at the oil-water interface, and break the oil-water interface film, that is, demulsification. Secondly, when the stable emulsification state formed by crude oil and water is destroyed, the tiny water droplets wrapped by the oil film are released. With the continuous increase of small water droplets, under the action of thermal motion or mechanical stirring, the small water droplets contact and merge with each other, aggregate into larger water droplets and produce coalescence. After the coalescence is completed, the large water droplets settle and separate from the crude oil by relying on the density difference with the crude oil and the action of gravity. Demulsification, coalescence and sedimentation separation together constitute the whole process of crude oil dehydration.

[0140] As a strong electrolyte, inorganic salt can quickly dissociate into freely moving ions in the emulsion, can strongly absorb microwaves as a catalyst, and quickly form a "hot spot" with a higher temperature than the surrounding temperature on the oil surface to accelerate the reaction, thus promoting the coalescence of the dispersed phase. After adding inorganic salt, on the one hand, it destroys the double electric layer at the emulsion interface, increases the density difference between the oil and water phases, and makes the internal phase water precipitate faster; on the other hand, the inorganic salt increases the polarity difference between the oil and water phases, reduces the solubility of oil in water, and accelerates the separation of oil and water. The dehydration effect of microwave electromagnetic waves on highly viscous crude oil is affected by factors such as microwave electromagnetic wave time, pressure, microwave power and standing time. The addition of NaCl has an obvious promoting effect on the dehydration of microwave electromagnetic waves. Under the action of NaCl, the dehydration rate of high-viscosity crude oil can reach 99.67%. For the highly viscous crude oil irradiated by microwaves, the separated water can be seen immediately. The demulsification and dehydration speed is so fast and the effect is so good that it cannot be compared with the methods of gravity sedimentation, chemical dehydration and heating dehydration.

Claims

1. An environmental protection treatment equipment for demulsifying and dehydrating crude oil in oil fields by microwave electromagnetic waves, characterized in that: It is composed of a square pipe magnetron reactor total device (1000), a working cabinet system device (2000) and a cooling tower system device (3000) connected in sequence.

2. The environmental protection treatment equipment for demulsifying and dehydrating crude oil in oil fields according to claim 1, characterized in that: The square pipe magnetron reactor total device (1000) is composed of a square pipe horizontal plate (1010), a square pipe vertical plate (1020), two end flanges (1030), left and right end plates (1040), a connecting pipe (1050), a material outlet connecting pipe (1060), a sky square pipe orifice (1061), a ground round pipe orifice (1062), a connecting pipe locking nut (1070), a fiberglass square box body (1080), a shielding stainless steel square box body (1090), a magnetron (1100), a magnetron waveguide (1110), a cooling water inlet pipe (1120), a connecting pipe of the magnetron (1121) and a return water outlet pipe (1130); Its position and connection relationship are: It is composed of 4 square pipe horizontal plates (1010) and 4 square pipe vertical plates (1020) inserted into each other at 90 degrees to form a 9-square-hole skeleton square box; Then, the front, back, top and bottom four sides of the skeleton square box are wrapped with fiberglass for fiberglass processing to form a fiberglass square box body (1080) to strengthen the sealing and strength; The 9 square holes are in series operation. Channels need to be opened on the left, right, top and bottom between the 9 square holes. The material inlet pipe (1050) is installed at the rear end of the first hole on the left side of the bottom layer, between the front end of the first hole and the second hole on the left side of the bottom layer, and a front left and right channel (1002) needs to be opened. Between the rear end of the second hole and the third hole on the left side of the bottom layer, a rear left and right channel (1006) needs to be opened. Between the front end of the third hole and the fourth hole on the right side of the bottom layer, a front left and right channel (1002) needs to be opened. Between the rear end of the fourth hole on the right side of the bottom layer and the rear end of the fourth hole on the right side of the second layer, a rear up and down channel (1003) needs to be opened. Between the front end of the fourth hole on the right side of the second layer and the fifth hole, a front left and right channel (1002) needs to be opened... and the holes are opened in sequence to the eighth hole. Between the front end of the eighth hole on the left side of the fourth layer and the ninth hole, a front left and right channel (1002) needs to be opened. The material outlet pipe (1050) is installed at the rear left end of the fourth layer; The front, back, top and bottom four sides of the square box are wrapped with stainless steel for shielding to form a shielding stainless steel square box body (1090). The left and right end plates (1040) are welded at 90 degrees at both ends of the shielding stainless steel square box body (1090), and the cooling water inlet pipe (1120) and the return water outlet pipe (1130) are installed at the four corners of the left and right end plates (1040); The two end flanges (1030) are installed at both ends of the square box. 9 square blind grooves need to be opened on the front of the two end flanges (1030), and the depth dimension is 2 / 3 of the plate thickness deep. Rubber seals (1031) need to be filled before installation. The connection between the two end flanges (1030) and the square box is connected by connecting bolts (1051); N magnetrons (1100) are installed around the front, back, top, and bottom of a stainless-steel shielded square box (1090). A waveguide (1110) is provided between the magnetron (1100) and the shielded stainless-steel square box body (1090). The water inlet (1105) of the magnetron (1100) is connected to the cooling water inlet pipe (1120) of the square box through a water inlet branch pipe, and the water outlet (1106) of the magnetron (1100) is connected to the return water outlet pipe (1130) of the square box. The residual electromagnetic wave (1101) propels in a 90-degree spiral in the residual electromagnetic wave reaction area. A stainless-steel spiral core rod (1102) is provided in the square hole of the residual electromagnetic wave receiving area (1200). The residual electromagnetic wave will reflect when it encounters metal.

3. The oilfield crude oil microwave electromagnetic wave demulsification and dehydration environmental protection treatment equipment according to claim 1, characterized in that: The working cabinet system device (2000) includes a reactor cabinet (2010), moving rollers (2020), a microwave power supply cable cabinet (2030), a power supply cable cabinet operation door (2031), a water storage tank (2040), a cable cabinet (2050), a cable cabinet operation door (2051), an electrical cabinet (2060), and a working cabinet base (2070). Its position and connection relationship are: The square pipe magnetron reactor total device (1000) is installed in the reactor cabinet (2010) of the working cabinet system device (2000), and the square pipe magnetron reactor total device (1000) is moved into place through the moving rollers (2020). The microwave power supply cable device (2030) is installed in the microwave power supply cable cabinet (2031), the cable is installed in the cable cabinet (2051), the electrical device is installed in the electrical cabinet (2061), the cooling return water enters the water storage tank (2040), the water storage tank (2040) is arranged below the reactor cabinet (2010), and the lower part of the working cabinet system device (2000) is provided with a working cabinet base (2070).

4. The oilfield crude oil microwave electromagnetic wave demulsification and dehydration environmental protection treatment equipment according to claim 1, characterized in that: The cooling tower system device (3000) includes a cooling tower (3010), a cooling water valve (3011), a microwave power supply cable cooling water valve (3012), a cooling water pipe (3013), a return water pipe (3014), a cooling water pump (3020), a circulating pump (3030), and a circulating water pipe (3031). Its position and connection relationship are: The inlet of the cooling water pump (3020) is connected to the outlet of the cooling tower (3010). The cooling water pump (3020) is connected to the outlet of the cooling tower (3010) through the cooling water valve (3011). The outlet of the cooling water pump (3020) is connected to the cooling water inlet pipe (1120) through the cooling water pipe (3013). The cooling water pipe (3013) is also connected to the cooling water inlet of the microwave power supply cable device (2030) through the microwave power supply cable cooling water valve (3012). The return water of the return water pipe (3014) flows back to the water storage tank (2040). The inlet of the circulating water pump (3030) is connected to the outlet of the storage water tank 2040, and the outlet of the circulating water pump (3030) is connected to the inlet of the cooling tower (3010) through a water pipe (3031).

5. The crude oil microwave electromagnetic wave demulsification and dehydration process flow of the equipment according to claim 1, 2, 3 or 4, characterized in that: The crude oil enters from the inlet valve (4001), and the inlet temperature is about 85 degrees. Driven by the pressure of the sewage pump (4000), it enters the pipeline mixer (4002). Above the front end of the pipeline mixer (4002), there is a NaCl dosing port (4003). The outlet of the pipeline mixer (4002) is connected to the material inlet (1050) of the square pipeline magnetron reactor (1000). On the outlet pipeline of the material outlet (1060), there is a pressure gauge (4004) and a valve (4005) for controlling the pressure. The material outlet (1060) is connected to the cyclone inlet (5001) of the pressure cyclone (5000). The inlet temperature is about 90 degrees. After high-speed centrifugation by the pressure cyclone (5000), the dehydrated crude oil is discharged from the crude oil outlet (5002), and the oily sewage is discharged from the sewage outlet (5003). The key to crude oil dehydration lies in demulsification, and the key to demulsification lies in microwave.

6. The oily sewage microwave electromagnetic wave demulsification and oil removal process flow of the equipment according to claim 1, 2, 3 or 4, characterized in that: The oily sewage enters from the inlet valve (4001), and the pH value is about 13. Driven by the pressure of the sewage pump (4000), it enters the pipeline mixer (4002). Above the front end of the pipeline mixer (4002), there is a PDMDAAC (organic polymer) dosing port (4003). The outlet of the pipeline mixer (4002) is connected to the material inlet (1050) of the square pipeline magnetron reactor assembly (1000). In the square pipeline of the square pipeline magnetron reactor assembly (1000), there is diatomite or activated carbon or zeolite (1003). Diatomite or activated carbon or zeolite (1003) is a sensitizer. On the outlet pipeline of the material outlet (1060), there is a pressure gauge (4004) and a valve (4005) for controlling the pressure. The material outlet (1060) is connected to the inlet valve (6011) of the automatic density gradient fiber cloth block filter (6000). Under the pressure of the filtration pump (6020), it enters the filter inlet (6013). Before starting, the fiber cloth block filter (6000) needs to discharge air through the exhaust hole (6015). When the fiber cloth block filter (6000) is working, the hydraulic cylinder (6012) rises to the upper dead center to press the fiber cloth block filter material (6017). The filtered oily sewage can fully meet the technical indicators and is discharged from the filtered water outlet (6014). When backwashing is required, the hydraulic cylinder (6012) descends to the lower dead center for backwashing, and the backwashing water is discharged from the backwashing water outlet (6016).

Images