WO2023240756A1

WO2023240756A1 - Oilfield crude oil dehydration desalination collection and transportation process package

Info

Publication number: WO2023240756A1
Application number: PCT/CN2022/108381
Authority: WO
Inventors: 刘建春; 刘家诚; 王洪福; 韦伟; 姚磊; 王晓勇
Original assignee: 长江三星能源科技股份有限公司
Priority date: 2022-06-13
Filing date: 2022-07-27
Publication date: 2023-12-21
Also published as: CN114922607A; CN114922607B

Abstract

An oilfield crude oil dehydration, desalination, collection and transportation process package, characterized by comprising: a main-process device procedure and a supporting-process auxiliary agent system; each process section of the main-process device procedure involves a corresponding auxiliary agent being added by the supporting-process auxiliary agent system; the main-process device procedure comprises a crude oil dehydration and desalination treatment process section, an oily wastewater treatment and circulation process section and a post-dehydration post-desalination collection and transportation process section; by means of the wastewater treatment process procedure, the present process package performs separate wastewater purification and desalination treatment, achieving water quality satisfying requirements for the injection of fresh water in the electric desalination process, achieving cyclic use of water resources in an electric dehydration and desalination system, and solving the problem of insufficient low-salinity water in certain desert oilfields in the Middle East, Africa, etc. The procedure additionally recovers a portion of oil gas and crude oil resources, making it so that oil and gas resources separated from oilfield produced fluids are fully utilized, and avoiding the waste of direct torch burning.

Description

An oilfield crude oil dehydration, desalination, gathering and transportation process package

Technical field

The invention belongs to the technical field of oilfield crude oil treatment engineering, and specifically relates to an oilfield crude oil dehydration, desalination treatment and gathering and transportation process package.

Background technique

Oil fields are widely distributed in the world, not only offshore oil fields, but also onshore oil fields. The properties of crude oil in each oil field are very different. Even in the same oil field, in different oil areas and different stages of production, the properties of the crude oil produced are very different. The proportion of crude oil, natural gas and water in the liquid, the specific gravity of crude oil, water content, salt content, colloid, asphaltene content, etc. These directly affect the dehydration, desalination and external transportation of crude oil. Special processes need to be adopted according to different working conditions to ensure that the water content in the crude oil after treatment is less than 0.5% and the salt content is less than 100 mg/L. In the Middle East and Africa, where reserves of various types of crude oil are abundant, often in deserts or Gobi deserts, one common feature is the lack of fresh water. In the crude oil desalination process, it is necessary to add 3-6% of the crude oil processing capacity and low salt water content with a salt content of no more than 200mg/L. These low salt water contents are often transported to the site from external freshwater rivers by tank trucks. This For an oil field with an annual output of 500,000 tons, it is a huge task, which consumes a lot of manpower, material and financial resources, and has become a pain point and difficult problem that has not been solved for a long time in oil fields lacking fresh water.

The operating temperature of oilfield equipment is relatively low, which has also become an influencing factor and restriction on the final processing effect of crude oil. If a higher operating temperature is required, more heat sources will be needed, and additional investment in heating furnaces needs to be considered. More importantly, In the subsequent crude oil stabilization process, in order to ensure the Reynolds vapor pressure of the crude oil, it is necessary to lower the temperature of the crude oil through a huge heat exchange network. This is because at higher operating temperatures, a large amount of light hydrocarbons are evaporated. It is also necessary to add a light hydrocarbon recovery system, which will greatly increase engineering investment. In addition, in some oil fields, when determining higher operating temperatures, the impact on sewage treatment and reinjection into the formation will also be considered. In the production process of general oil fields , sewage is generally biodegraded and reinjected into the formation. The organism here is a type of bacteria, which can withstand relatively low temperatures. After comprehensively considering various factors, some oil fields require that the operating temperature of electric dehydration and desalination be controlled at a lower temperature to achieve dehydration and desalination.

At lower operating temperatures, the produced crude oil emulsion is more stable, especially in some oil fields that produce medium and heavy crude oil. The properties of crude oil include high specific gravity, high viscosity, high acid value, high water content and other heavy properties. Characteristics of inferiority. According to the STOCKS water droplet settlement formula, the difference in specific gravity and viscosity of oil and water are not conducive to the separation of oil and water. The factor with a greater impact is that it is easy to form a stubborn emulsified layer with high conductivity at the oil-water interface, which often leads to high voltage in the electrodehydration and desalting equipment. The transformer loses power, and even the high-voltage electric field short-circuit or breakdown prevents traditional equipment from operating normally. This puts forward higher requirements for electric dehydration and electric desalination equipment, which are used to check the technical indicators of oilfield crude oil for export after treatment. In this case, the research and development of electric dehydration and desalting equipment under low-temperature operating conditions must be carried out based on the properties of the oil and operating conditions to meet the technical requirements for crude oil dehydration and desalting treatment in oil fields using low operating temperatures, and to ensure that exported crude oil qualified.

The invention patent with application number CN202110942445.1 "An offshore thermal recovery heavy oil gathering and transportation processing technology package" is a process technology specifically used for heavy oil treatment in offshore oil fields. It is mainly used for later use in offshore heavy oil fields, such as high-temperature and high-pressure steam. forced mining methods such as flooding and polymer flooding. It is mainly used for heavy oil with high viscosity, large changes in gas and liquid volume, and relatively high sand content. Therefore, the main features of this process package are that more heat exchangers and heaters are designed to flexibly control the temperature, and more desanders are designed to reduce the amount of sediment in crude oil and water. However, there is no technological innovation in the core electro-dehydration process. When extracting crude oil in the later stages of oil fields, it is often difficult to transmit power to the electro-dehydration and desalination equipment due to the high viscosity and high conductivity of the crude oil, and even the transformer may short-circuit or trip. The process of this process package does not include a process for how to deal with possible unqualified oil samples, and there are certain flaws or incompleteness in the design of the process package. At the same time, due to the limitations and particularities of offshore oil production platforms, the design of this process package did not consider how to conduct preliminary process treatment of substandard sewage generated due to substandard treatment of its own process equipment, so that it can be discharged to subsequent sewage treatment. device.

Contents of the invention

The purpose of the present invention is to provide an oil field crude oil dehydration, desalination, gathering and transportation process package, which is mainly used in the crude oil extraction, processing, gathering and transportation process flow of onshore oil fields.

The process package provided by the invention includes a main process equipment flow and a supporting process aid system. The main process equipment flow is divided into three process sections, including a crude oil dehydration and desalination treatment process section, an oily sewage treatment and circulation process section, and a post-dehydration and desalination gathering and transportation process. In the process section, the supporting process additive system adopts a skid-mounted multiple process additive system.

The crude oil dehydration and desalination treatment process section includes a plug flow collector, separator, electric dehydrator, electric desalter and crude oil stabilization tower.

The produced fluid extracted from the oil field is collected through each branch pipeline and connected to the inlet of the plug flow collector. The outlet of the plug flow collector is connected to the inlet of the heating heat exchanger. After being processed by the plug flow collector, , the stable produced liquid flows into the heating heat exchanger through the outlet of the plug flow collector. The outlet of the heating heat exchanger is connected with the inlet of the three-phase separator. The heating heat exchanger can be heated by a gas heating furnace, an oil heating furnace or a mixed fuel. The furnace is used as a heat exchange heat source. The gas used in the gas heating furnace uses the oil and gas separated from the oil field production fluid as fuel. Oil fields with low oil and gas volumes use oil-fired heating furnaces; the separator is based on the water content of the produced fluid. , one-stage separator and two-stage separator can be designed. The two-stage separation is connected in series mode to separate the gas phase and liquid phase of the produced liquid; the top of the separator is equipped with a protruding columnar collector. The gas bag collects the oil and gas in the produced liquid; the water chamber and the oil chamber inside the separator are respectively equipped with water phase liquid level gauges and oil phase liquid level gauges, and the gas phase part of the produced liquid is collected into the gas collecting bag , the gas collection bag is connected to the raw material air inlet pipeline of the gas heating furnace, and the separated oil and gas enters the gas heating furnace as gas. A pressure control regulating valve is provided on the gas collection bag and the raw material gas inlet pipeline of the gas heating furnace. When the pressure in the gas collection bag reaches the set pressure, the pressure control regulating valve will automatically switch to realize the collection and discharge of the gas phase in the gas collection bag; there is a drainage pipe at the bottom of the water chamber in the separator tank. The drainage pipe is connected to the sewage drainage pipeline. There is a flow regulating valve on the sewage drainage pipeline. The flow regulating valve is associated with the liquid level gauge. According to the water phase liquid level set by the liquid level gauge, the opening of the flow regulating valve is controlled to realize water flow. phase discharge, thereby controlling the height of the water phase in the separation tank; an oil discharge pipe is provided at the bottom of the oil chamber in the separator tank, and the oil discharge pipe is connected to the oil outlet line of the separator, and the oil outlet line is provided with Flow control valve, the flow control valve is interlocked with the oil-water interface instrument to realize automatic control of oil phase flow; the oil outlet pipeline is connected to the inlet of the booster pump, and the outlet of the booster pump is connected to the oil inlet pipeline of the electric dehydrator; The electric dehydrator is a low-temperature electric dehydrator, and the operating temperature is generally not greater than 60°C; the electric dehydrator adopts AC or AC-DC or high-frequency or intelligent response control power supply; the internal electric field structure of the electric dehydrator Using horizontal plates, the internal electric field structure can be divided into two structural units, a horizontal high-strength electric field structural unit and a horizontal weak electric field structural unit. The horizontal high-strength electric field structural unit generally adopts AC or AC-DC or intelligent response control power supply. , the horizontal weak electric field structural unit uses a high-frequency power supply; the technical indicators of the electric dehydrator include water content after dehydration ≤ 0.5%, oil content in the discharged water ≤ 1000ppm; after the produced liquid is processed by the electric dehydrator, oil will be produced from it The pipeline flows through the heat exchanger and is heated again to reach the design operating temperature of the electric desalting device. A mixing unit is provided on the oil inlet pipeline of the electric desalting device. The mixing unit includes a static mixer and a mixing valve. The above-mentioned electric desalination device uses AC or DC or intelligent response control power supply, and the electric field structure in the tank adopts vertical plates; the above-mentioned electric desalination device is designed with an automatic backwash system, which can not only use its own drainage to perform the water flushing process, but also The water flushing process of the separator and electric dehydrator effectively saves water; the oil outlet pipeline of the electric desalter is connected to the inlet pipeline of the crude oil stabilization tower. The crude oil stabilization tower can use negative pressure according to the different properties of the crude oil in the oil field. Separation method or heating flash stabilization method or fractionation stabilization method or multi-stage separation stabilization method; the assessment indicators of crude oil after separation by crude oil stabilization tower include crude oil water content ≯0.2%, crude oil salt content ≯3mgNaCl/L.

The gathering and transportation process section after dehydration and desalination includes qualified oil tanks, unqualified oil tanks, crude oil export pumps and metering systems.

Crude oil that meets the assessment indicators is pumped into qualified oil tanks through crude oil pumps, while crude oil that does not meet assessment indicators is pumped into unqualified oil tanks. After the crude oil in the qualified oil tank is stored to a certain amount, it is transported to the metering system by the crude oil export pump. The qualified oil tank and the crude oil export pump are automatically controlled through a liquid level gauge interlock. The metering system includes Measuring skid, calibration volume pipe skid and control system; the metering skid selects different types of flowmeters according to different measurement media, including speed type, volumetric type, mass type, ultrasonic type, etc.; the calibration volume The tube skid is made of stainless steel and uses a special stainless steel processing technology, which eliminates the risk of reduced accuracy and repeatability due to layer shedding and ensures the repeatability of the calibration volume tube; the control system integrates the metering skid and Batch processing measurement function and volume tube inspection function of the flow meter on the metering skid; the control system adopts a full set of redundant design, using a flow computer and a PLC with redundant functions, which greatly improves the reliability of the entire module operation With the improvement, the control system realizes pairwise redundant backup between flow computers and solves the communication problem between flow computers and PLCs of different products. The measurement accuracy of the metering system can reach 0.15%, and the repeatability of the calibration volume pipe skid can reach 0.02%, reaching the industry's advanced level. The unqualified crude oil in the unqualified oil storage tank will re-enter the crude oil pipeline through the pipeline. , the unqualified crude oil enters the plug flow trap again from the crude oil pipeline for multiple circulation processes.

The oily sewage treatment and circulation process section includes an oily sewage treatment device, a booster pump, a water purification and desalination treatment system, a water storage tank and a water injection pump. The oily sewage produced in the crude oil dehydration and desalination treatment process section mainly includes the drainage of the separator, the drainage of the electric dehydrator, the drainage of the electric desalter and the drainage of the unqualified oil tank. It is collected through the sewage pipeline and combined with the oily sewage treatment device. The inlet pipeline is connected. The oily sewage treatment device is divided into multiple functional chambers, including a rapid cyclone separator chamber, a gathering separation chamber, and an oil and gas gathering steam drum. The gathering separation chamber is equipped with different fillers, including fixed ones. Type packing and bulk packing, the fixed packing can adopt a honeycomb structure or a corrugated structure; the bulk packing can adopt annular packing or spherical packing; the oil and gas accumulation drum is arranged in a sewage treatment There is a protruding cylindrical gas collecting bag on the top of the tank. The gas phase part in the oil and gas gathering steam drum is collected into the gas collecting bag. The gas collecting bag is connected to the raw material air inlet pipeline of the gas heating furnace. The separated oil and gas are used as gas again. Entering the gas heating furnace, the oil phase outlet pipeline of the oily sewage treatment device is connected to the unqualified tank in the gathering and transportation process section after dehydration and desalination. The water phase outlet pipeline of the oily sewage treatment device enters the water purification and desalination treatment system after passing through the booster pump. The water purification and desalination treatment system includes an ultrafiltration system and a reverse osmosis system. A single ultrafiltration system or a single reverse osmosis system or a combination mode of an ultrafiltration system and a reverse osmosis system can be reasonably selected according to needs; the ultrafiltration system The system and reverse osmosis system can be designed into a single group or multi-group series mode according to the water treatment capacity. The water phase processed by the water purification and desalination treatment system is stored in a water storage tank for later use. The water stored in the water storage tank can be used as water injection for the electric desalination device, backwash water for the water purification system, or as water for other process devices. For industrial water, a heat exchanger is installed in the water injection pipeline from the water storage pipe to the electric desalter to heat the purified water injection, thereby ensuring that the temperature of the water injected into the electric desalter is sufficient and avoiding the emulsification of crude oil caused by cold water injection.

The supporting process aid system includes a skid-mounted compact multi-functional agent injection device and related process aids. The skid-mounted compact multifunctional medicament injection device includes a medicament feed pump, a medicament storage tank, and a medicament filling device. The inlet of the pharmaceutical feed pump adopts a quick connector to facilitate the connection of the incoming pipeline, and the outlet is respectively connected to the entrance pipeline of the pharmaceutical storage tank; the pharmaceutical storage tank adopts a square structure and is divided into multiple independent ones by using partitions. Storage space. According to the physical and chemical properties of different medicines, different storage spaces are made of materials or treated with lining or spraying to meet the requirements for storing medicines; the medicine filling device can use a single head according to the type and quantity of medicines. Pump, double-head pump or multi-head pump is used as a medicine filling pump. The medicine filling pump adopts a high-precision metering pump. There is a calibration column on the outlet pipeline of the metering pump, and the medicine injection amount is accurately tested through the calibration column. The relevant process chemicals mentioned in the flow mainly include water-soluble demulsifiers, defoaming agents, water purifiers, reverse demulsifiers, oil-soluble demulsifiers, viscosity reducers, pour point demulsifiers, etc. The injection points of the relevant process aids are generally set on the inlet pipelines of each device. The injection points of the water-soluble demulsifier include the inlet pipelines of plug flow traps, separators, electric dehydrators, and electric desalters. On the above, the injection point of defoaming agent and water purifier is set on the inlet pipeline of the separator, the injection point of reverse demulsifier is set on the inlet pipeline of electric dehydrator and electric desalter, and the injection point of oily demulsifier is It is set on the inlet pipeline of the electric desalter, and the injection point position of the viscosity reducer and pour point depressant is set on the external pipeline of the calibration volume pipe skid.

beneficial effects

Adopting the above technical solutions, the present invention has the following advantages:

1. The crude oil dehydration and desalination treatment process section designed by the present invention can ensure qualified dehydration and desalination effects for light crude oil, medium crude oil and heavy crude oil produced in different oil fields or different oil areas, especially when facing oil fields. For oil-water separation at low temperatures, it can still achieve good dehydration and desalination indicators and achieve qualified transportation of crude oil.

2. The oily sewage treatment and recycling process section designed by the present invention makes full use of the large amount of oily wastewater in the oil field produced liquid. After the sewage treatment process, the oily sewage is deoiled, purified and desalted. The treated sewage is That is, low-salt fresh water, which can meet the water quality requirements of fresh water injected in the electric desalination process. The recycling of water resources is realized in the electric desalination system, which solves the problem of the lack of fresh water and low salt water for electric desalination injection in some desert oil fields in the Middle East and Africa. problems, reducing the pressure on oilfield sewage treatment; at the same time recovering some oil, gas and crude oil resources.

3. The oil and gas recovery process designed by the present invention uses the collected oil and gas resources as raw materials for the heat source heating furnace. Due to the different proportions of oil and gas in the oil field produced fluid, there are certain differences in the form and effect of its utilization. However, the overall effect is to fully utilize the separated oil and gas resources in the oil field produced fluid and avoid direct flare combustion. waste.

4. The oil product gathering and transportation process section designed by the present invention not only realizes the precise transportation of qualified oil products, but also makes reasonable process flow processing for unqualified oil products to avoid the transportation of unqualified oil products.

5. The skid-mounted multi-functional compact pharmaceutical injection system designed by the present invention realizes the multi-functionality of one skid, so that the pharmaceutical filling devices originally distributed in different areas are concentrated into one skid-mounted equipment, which greatly facilitates the on-site management of pharmaceuticals and reduces the cost of It reduces human resource costs and at the same time ensures accurate filling of various chemicals.

6. The process flow package designed by the present invention can optimize the combination of process flows according to the different properties of oil field produced fluids and customer needs, and reasonably optimize some equipment or devices in the process package to achieve the best process flow. .

Therefore, the present invention can be widely used in crude oil extraction, processing, gathering and transportation processes on land, in water-deficient deserts, and in oil fields in Africa.

Description of the drawings

Figure 1 is a schematic flow diagram of an oilfield crude oil dehydration, desalination, gathering and transportation process package;

Figure 2 is a distribution view of the skid-mounted compact multifunctional chemical injection system;

Figure 3 is a single-chamber flow chart of the skid-mounted compact multifunctional chemical injection system;

In the picture; 1. Crude oil pipeline, 2. Plug flow trap, 3. Primary separator, 4. Secondary separator, 5. Electric dehydrator, 6. Electric desalter, 7. Crude oil stabilization tower, 8 , Qualified oil tank, 9. Unqualified oil tank, 10. Oily sewage treatment device, 11. Booster pump, 12. Ultrafiltration system, 13. Reverse osmosis system, 14. Water storage pipe, 15. Water injection pump, 16. Measurement Skid, 17. Volume pipe, 18. Crude oil export pipe, 19. Heat exchanger, 20. Water flushing pump, 21. Crude oil pump, 22. Crude oil export pump, 23. Heating furnace, 30. Compact multi-variety chemicals Injection system, 301, water-soluble demulsifier, 302, defoaming agent, 303, water purifier, 304, pour point depressant, 305, viscosity reducer, 306, oil-soluble demulsifier, 307, reverse demulsifier.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

Crude oil pipeline 1, plug flow collector 2, primary separator 3, secondary separator 4, electric dehydrator 5, electric desalter 6, crude oil stabilization tower 7, qualified oil tank 8, unqualified oil tank 9, Oily sewage treatment device 10, booster pump 11, ultrafiltration system 12, reverse osmosis system 13, water storage pipe 14, water injection pump 15, metering skid 16, volume pipe 17, crude oil export pipe 18, heat exchanger 19, water flushing Pump 20, crude oil pump 21, crude oil export pump 22, compact multi-variety agent injection system 30, water-soluble demulsifier 301, defoaming agent 302, water purifier 303, pour point depressant 304, viscosity reducer 305, oil-soluble demulsifier Emulsion 306, reverse demulsifier 307.

Implementation example one

To illustrate the implementation examples of the present invention, the production fluid produced by oil production drilling is transported to the production fluid manifold of the joint station through pipelines. The main component of the production fluid is oil-water emulsion, containing a small amount of oil and gas, in which the water in the oil-water emulsion The content reaches 70-80%. The produced liquid is connected to the inlet pipeline of the plug flow collector 2 through the crude oil pipeline 1. After being stabilized by the plug flow collector 2, the produced liquid is smoothly output to the heat exchanger 18, and passes through the heat exchanger 18 After the temperature rises to 60-70°C, it enters the first-level separator 3 to achieve three-phase separation. The oil and gas are collected into the gas collection bag at the top of the first-level separator 3. The oil and gas are discharged through the automatic adjustment switch of the air pressure control valve. The oil and gas are recovered as The raw material of the gas heating furnace 23, the emulsion water content separated by the primary separator 3 is about 5%-10%, enters the secondary separator 4 for three-phase separation again, and the oil and gas in the secondary separator 4 are recovered again Utilize, the water content of the separated emulsion meets the technical index requirements of the crude oil at the outlet of the separator, and the water content is ≯ 2%. The oil outlet pipeline of the secondary separator 4 uses the booster pump 11 to remove the crude oil with a water content less than 2%. It enters the electric dehydrator 5 through the booster pump 11. Due to the influence of the oil and gas content of the oil field produced liquid, the heat source of the gas heating furnace 23 can barely heat the produced liquid to 60-70°C. The design of the electric dehydrator 5 adopts a low temperature The technology of electric dehydration uses a horizontal plate electric field structure in the tank, and the power supply adopts an intelligent response control power supply. At the same time, a high-frequency electric field mechanism is set up at the oil-water interface. Through reasonable electric field design and layout in the tank, the electric dehydrator 5. The water content of exported crude oil reaches the target requirement of <0.2%. At the same time, since the salt content of the produced liquid is <50 mgNaCl/L, after the produced liquid is treated by the electric dehydrator 5, it flows from the oil flow line through the heat exchanger 19 and is heated again to reach the design operating temperature of the electric desalter 6 , the electric desalter 6 uses AC or DC or intelligent response control power supply, and the electric field structure in the tank adopts vertical plates; the electric desalter 6 is equipped with a water flushing pump 20, which can use its own drainage to carry out the water flushing process, and at the same time, it also controls the separator. The water flushing process is carried out with the electric dehydrator 5. The oil outlet pipeline of the electric desalter 6 is connected to the inlet pipeline of the crude oil stabilizing tower 7. The crude oil stabilizing tower 7 adopts the negative pressure separation method according to the different properties of the crude oil in the oil field and separates through the crude oil stabilizing tower 7. The crude oil water content of the final crude oil is ≯0.2%, and the crude oil salt content is ≯3mgNaCl/L. It is directly transported to the export qualified oil tank 8. The crude oil that does not meet the standard enters the unqualified oil tank 9. After being stored for a certain period of time, the qualified oil tank 8 After the crude oil in the oil reaches the reserve amount of crude oil for export, the qualified crude oil is transported to the metering skid 16 and the volume pipe 117 calibration device through the crude oil export pump 22, thereby realizing accurate crude oil export.

The oily sewage separated by the separator, electric dehydrator 5, electric desalter 6 and unqualified oil tank 9 controls the opening of the sewage regulating valve through the interface instrument installed inside the tank to achieve the stability of the oil-water interface. The discharged sewage is collected through the sewage pipeline to the oily sewage treatment device. After the oil and water are separated by the oily sewage treatment device 10, a small amount of oil and gas generated is collected through the gas collection bag on the top of the oily sewage treatment device 10, and is discharged to the gas heating furnace as raw material through the oil and gas pipeline. twenty three. The separated oil phase is used as unqualified oil and is discharged to the unqualified oil tank 9 through the oil outlet pipeline. The water phase separated by the oily sewage treatment device 10 reaches the design index, and the oil content in the water is ≯ 150 ppm. After passing through the booster pump 11, it enters the water purification and desalination treatment system, and passes through the ultrafiltration system 12 and reverse osmosis system in the water purification and desalination treatment system. 13. The water is purified, and the purified water enters the water storage tank 14. The water in the water storage tank 14 repeatedly flushes the ultrafiltration system 12 and the reverse osmosis system 13, and also injects water into the electric desalination device 6.

Implementation example two

To illustrate the implementation examples of the present invention, the produced liquid produced by oil production drilling near the joint station is transported to the produced liquid manifold of the joint station through pipelines. The main component of the produced liquid is oil-water emulsion, containing a small amount of oil and gas, in which oil and water The water content of the emulsion reaches 70-80%. The produced liquid is connected to the inlet pipeline of the plug flow collector 2 through the crude oil pipeline 1. After being stabilized by the plug flow collector 2, the produced liquid is smoothly output to the heat exchanger 18, and passes through the heat exchanger 18 After the temperature rises to 60-70°C, it enters the primary separator 3 to achieve three-phase separation. The oil and gas are collected into the gas collection bag at the top of the primary separator 3. The oil and gas are discharged through the automatic adjustment switch of the air pressure control valve. The oil and gas are recovered as The raw material of the gas heating furnace 23, the emulsion water content separated by the primary separator 3 is about 5%-10%, enters the secondary separator 4 for three-phase separation again, and the oil and gas in the secondary separator 4 are recovered again Utilize, the water content of the separated emulsion meets the technical index requirements of the crude oil at the outlet of the separator, and the water content is ≯ 2%. The oil outlet pipeline of the secondary separator 4 uses the booster pump 11 to remove the crude oil with a water content less than 2%. It enters the electric dehydrator 5 through the booster pump 11. Due to the influence of the oil and gas content of the oil field produced liquid, the heat source of the gas heating furnace 23 can barely heat the produced liquid to 60-70°C. The design of the electric dehydrator 5 adopts a low temperature The technology of electric dehydration uses a horizontal plate electric field structure in the tank, and the power supply adopts an intelligent response control power supply. At the same time, a high-frequency electric field mechanism is set up at the oil-water interface. Through reasonable electric field design and layout in the tank, the electric dehydrator 5. The water content of exported crude oil reaches the target requirement of <0.2%. At the same time, since the salt content of the produced fluid is less than 50 mgNaCl/L, the electric desalter 6 process is omitted from the design process of this process package and is directly transported to the external qualified oil tank 8. After a certain period of storage, when the reserve amount of crude oil for export is reached, the qualified crude oil is transported to the metering skid 16 and the volume pipe 117 calibration device through the crude oil export pump 22, thereby realizing accurate crude oil export.

The oily sewage separated by the separator, the electric dehydrator 5 and the electric desalter 6 controls the opening of the sewage regulating valve through the interface instrument installed inside the tank to achieve the stability of the oil-water interface. The discharged sewage is collected through the sewage pipeline to the oily sewage treatment device. After the oil and water are separated by the oily sewage treatment device 10, a small amount of oil and gas generated is collected through the gas collection bag on the top of the oily sewage treatment device 10, and is discharged to the gas heating furnace as raw material through the oil and gas pipeline. twenty three. The separated oil phase is used as unqualified oil and is discharged to the unqualified oil tank 9 through the oil outlet pipeline. The water phase separated by the oily sewage treatment device 10 reaches the design index, and the oil content in the water is ≯ 150 ppm, and can be directly discharged to the oil field sewage treatment unit through the sewage pipeline.

Since this process package does not design an electric desalter process and does not involve electric desalination water injection (industrial water), the sewage treatment process section has also been appropriately optimized and the ultrafiltration system and reverse osmosis system have been streamlined.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims

An oilfield crude oil dehydration, desalination, gathering and transportation process package, which is characterized in that it includes a main process equipment flow and a supporting process aid system. Each process section in the main process equipment flow is filled with the corresponding process aid system. Auxiliary, the main process equipment flow includes a crude oil dehydration and desalination treatment process section, an oily sewage treatment and circulation process section, and a dehydration and desalination post-gathering and transportation process section. The crude oil dehydration and desalination treatment process section includes a plug flow collector and a separator. , electric dehydrator, electric desalter and crude oil stabilization tower. The described gathering and transportation process section after dehydration and desalination includes qualified oil tanks, unqualified oil tanks, crude oil export pumps and metering systems. The described oily sewage treatment and circulation process The end section includes oily sewage treatment equipment, booster pumps, water purification and desalination treatment systems, water storage tanks and water injection pumps.
An oilfield crude oil dehydration, desalination, gathering and transportation process package according to claim 1, characterized in that the inlet end of the plug flow collector is connected to the crude oil pipeline, and the outlet end of the plug flow collector is connected to the separation The separator includes a primary separator and a secondary separator. The inlet end of the primary separator is connected to the plug flow collector, and the outlet end of the primary separator is connected to the secondary separator. connected, the inlet end of the secondary separator is connected to the primary separator, and the outlet end of the secondary separator is connected to the electric dehydrator through a booster pump. Both the primary separator and the secondary separator are equipped with There is an air outlet end and a water outlet end. The electric dehydrator is a horizontal plate electric dehydrator. The inlet end of the electric dehydrator is connected to the secondary separator. The outlet end of the electric dehydrator is connected to the electric desalination device through a heat exchanger. The electric dehydrator is provided with a water outlet. The electric desalter is a vertical plate electric dehydrator. The inlet end of the electric desalter is connected to the electric dehydrator. The outlet end of the electric desalter is connected to the crude oil stabilizing tower. The electric desalter is equipped with a water outlet end. There is a circulation flushing end and a water outlet end. The inlet end of the crude oil stabilizing tower is connected to the electric desalter. The outlet end of the crude oil stabilizing tower is connected to the crude oil pump. The crude oil stabilizing tower is equipped with a gas outlet, and the gas outlet is located at the top. , the gas outlet end is connected to the gas heating furnace, the water outlet end is located at the bottom, the water outlet end is connected to the oily sewage treatment device, the circulation flushing end is connected to the primary separator, the secondary separator, and the electric separator respectively through the water flushing pump. The dehydrator is connected to the electric desalinator.
An oil field crude oil dehydration, desalination and gathering and transportation process package according to claim 2, characterized in that the crude oil pump is connected to the qualified oil tank and the unqualified oil tank respectively, and the inlet end of the qualified oil tank is connected to the original oil tank. The oil pump is connected, the outlet end of the qualified oil tank is connected to the metering system through the crude oil export pump, the inlet end of the unqualified oil tank is connected to the crude oil pump, the outlet end of the unqualified oil tank is connected to the crude oil pipeline, and the metering The system includes a metering skid, a volume pipe skid and a control system. The inlet end of the metering skid is connected to the crude oil export pump. The outlet end of the metering skid is connected to the volume pipe skid. The outlet end of the volume pipe skid is connected to the crude oil pump. The pipeline is connected, and the unqualified oil tank is provided with a water outlet, and the water outlet is connected to the oily sewage treatment device.
An oil field crude oil dehydration and desalination gathering and transportation process package according to claim 3, characterized in that the inlet end of the oily sewage treatment device is connected with a primary separator, a secondary separator, an electric dehydrator and an electric desalter The outlet end of the oily sewage treatment device is connected to the unqualified oil tank. The outlet end of the oily sewage treatment device is connected to the ultrafiltration system through a booster pump. The outlet end of the oily sewage treatment device is connected to the gas heating furnace. The inlet end of the ultrafiltration system is connected to the oily sewage treatment device, the outlet end of the ultrafiltration system is connected to the reverse osmosis system, the inlet end of the reverse osmosis system is connected to the ultrafiltration system, and the outlet end of the reverse osmosis system is connected to the injection The water pump is connected, the ultrafiltration system and the reverse osmosis system are both equipped with a return end, the outlet end of the water injection pump is connected to the return end of the ultrafiltration system and the reverse osmosis system, the outlet end of the water injection pump is connected to the electric dehydrator and The heat exchangers between the electric desalters are connected at the rear, and a heat exchanger is provided between the water injection pump and the crude oil dehydration and desalting treatment process section.
An oil field crude oil dehydration, desalination, gathering and transportation process package according to claim 4, characterized in that the supporting process aid system includes a skid-mounted compact multi-functional chemical injection device and process aids, and the skid The mounted compact multifunctional chemical injection device is equipped with a certain number of process aids. The skid-mounted compact multifunctional chemical injection device is connected to the inlet end of the plug flow collector and the outlet end of the plug flow collector respectively. , the outlet end of the primary separator, the outlet end of the secondary separator, the outlet end of the electric dehydrator, the outlet end of the volume tube skid and the inlet end of the oily sewage treatment device are connected.
An oil field crude oil dehydration and desalination gathering and transportation process package according to claim 2, characterized in that the gas heating furnace is connected to the heat exchanger in the crude oil dehydration and desalination treatment process section and the oily sewage treatment and circulation process section.
An oil field crude oil dehydration and desalination gathering and transportation process package according to claim 5, characterized in that the plug flow collector, separator, electric dehydrator, electric desalter, crude oil stabilization tower, qualified oil tank , unqualified oil tanks, crude oil export pumps, metering systems, oily sewage treatment devices, booster pumps, water purification and desalination treatment systems, water storage tanks and water injection pumps are all equipped with independent solenoid valves on the outer pipelines.
An oil field crude oil dehydration, desalination, gathering and transportation process package according to claim 5, characterized in that the process aids include water-soluble demulsifiers, defoaming agents, water purifiers, pour point depressants, viscosity reducers, oil Soluble demulsifiers and reverse demulsifiers.