Oil field emulsified oil treatment system

Abstract

The utility model discloses an emulsified oil treatment system for an oil field. The emulsified oil treatment system comprises a buffer tank, a heater, a compact electric field coalescence demulsifier, a static settling tank, a three-phase centrifugal machine and a high-frequency high-voltage electric dehydrator which are sequentially connected through a pipeline. An outlet of the compact electric field coalescence demulsifier is provided with two pipelines, one pipeline is connected with an inlet of the three-phase centrifugal machine, and the other pipeline is connected with an inlet of the static settling tank. The system disclosed by the utility model can realize oil-water-solid three-phase separation of emulsified oil, can operate continuously, is large in treatment capacity and high in treatment efficiency, enables separated crude oil to be low in water content, can meet the output requirement, and improves the economic benefit of an oil field.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield waste oil treatment, in particular to an oilfield emulsified oil treatment system. Background Art

[0002] Emulsified oil is a complex emulsion produced in the production process of the petroleum industry that contains a large amount of chemicals, water, clay and inorganic salts, and is in a stable state. The emulsified oil components often contain a large amount of asphaltene, colloid and solid impurities. It is severely emulsified, has stable performance, a high water content, and is extremely difficult to handle.

[0003] The problem of emulsified oil has always been a common problem in the production process of offshore oil fields. There is currently no suitable means of treatment. It is only stored in FPSO (Floating Production Storage and Offloading) oil tanks or circulated repeatedly in the process. However, the continuous accumulation and circulation in the production process will cause a decrease in processing capacity. In addition, for FPSO, emulsified oil will occupy a large amount of tank capacity, and even cause production pressure in severe cases. Moreover, the crude oil in the emulsified oil usually accumulates at the oil-water interface of the electric dehydrator, which is easy to cause "electric field collapse" or plate breakdown, affecting oil field production.

[0004] As emulsified oil continues to accumulate in oil fields, it is necessary to develop an efficient treatment system to solve the above problems. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides an oilfield emulsified oil processing system.

[0006] The utility model is realized by adopting the following technical solutions.

[0007] An oilfield emulsified oil processing system comprises a buffer tank, a heater, a compact electric field coalescence demulsifier, a static sedimentation tank, a three-phase centrifuge and a high-frequency high-voltage electric dehydrator which are sequentially connected through pipelines.

[0008] Furthermore, a heating device and a stirrer are provided in the buffer tank.

[0009] Furthermore, a chemical agent addition port is provided at the outlet of the buffer tank.

[0010] Furthermore, a delivery pump A is provided on the connecting pipeline between the buffer tank and the heater.

[0011] Furthermore, the outlet of the compact electric field coalescence demulsifier is provided with two pipelines, one of which is connected to the inlet of the three-phase centrifuge, and the other is connected to the inlet of the static sedimentation tank.

[0012] Furthermore, a delivery pump B is provided on the connecting pipeline between the static sedimentation tank and the three-phase centrifuge.

[0013] Furthermore, the static sedimentation tank is also connected to a sewage discharge pipeline, and the sewage discharge pipeline is connected to a water treatment system.

[0014] Furthermore, the three-phase centrifuge is also connected to the slag tank and the sewage discharge pipeline respectively, and the sewage discharge pipeline is connected to the water treatment system.

[0015] Furthermore, the high-frequency and high-voltage electric dehydrator is also connected to a sewage discharge pipeline, and the sewage discharge pipeline is connected to a water treatment system.

[0016] The utility model obtains the following beneficial effects.

[0017] The utility model system can run continuously, has a large processing capacity, high processing efficiency, and separates crude oil with low water content, which can meet the requirements of external transmission and improve the economic benefits of the oil field. The utility model system has simple connection of various devices, good processing effect and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] Among them: 1. Buffer tank; 1-1. Heating device; 1-2. Agitator; 2. Delivery pump A; 3. Heater; 4. Compact electric field coalescing demulsifier; 5. Static sedimentation tank; 6. Delivery pump B; 7. Three-phase centrifuge; 8. High-frequency and high-voltage electric dehydrator; 9. Slag tank. DETAILED DESCRIPTION

[0020] The technical solution of the utility model will be clearly and completely described below through specific implementation methods.

[0021] like Figure 1 As shown, an oilfield emulsified oil processing system includes a buffer tank 1, a delivery pump A 2, a heater 3, a compact electric field coalescing demulsifier 4, a static sedimentation tank 5, a delivery pump B 6, a three-phase centrifuge 7, and a high-frequency high-voltage electric dehydrator 8 connected in sequence.

[0022] The buffer tank 1 is provided with a heating device 1 - 1 and a stirrer 1 - 2 ; the buffer tank 1 is also provided with a chemical agent adding port at the outlet thereof for adding chemical agents.

[0023] The outlet of the compact electric field coalescence demulsifier 4 (CNOOC (Tianjin) Oilfield Chemical Co., Ltd., model: GE2051) is divided into two paths, one path is connected to the static sedimentation tank 5, and the other path is connected to the three-phase centrifuge 7.

[0024] The static sedimentation tank 5, the three-phase centrifuge 7 and the high-frequency high-voltage electric dehydrator 8 (CNOOC (Tianjin) Oilfield Chemical Co., Ltd., model: CEC2041) are all connected to a sewage discharge pipeline, and the sewage discharge pipeline is connected to a water treatment system. The sewage in the static sedimentation tank 5, the three-phase centrifuge 7 and the high-frequency high-voltage electric dehydrator 8 eventually enters the water treatment system for subsequent treatment.

[0025] The three-phase centrifuge 7 is also connected to a slag pot 9 , and the slag pot 9 is used to receive the solid phase residue separated by the three-phase centrifuge 7 .

[0026] Based on the above-mentioned oilfield emulsified oil processing system, the present application also provides an oilfield emulsified oil processing method, which comprises mixing the emulsified oil and the demulsifier in a certain proportion; heating the fluid by a steam heater; demulsifying the heated emulsified oil using a high-voltage and high-frequency pulse electric field; reacting the demulsified emulsified oil with the demulsifier in a buffer tank; separating the reacted emulsified oil by a three-phase centrifuge; and dehydrating the separated crude oil by a high-frequency electric dehydrator to finally obtain qualified crude oil.

[0027] The specific steps include:

[0028] (1) Feeding: using a pump to transport the emulsified oil from the storage tank or tank to the buffer tank 1;

[0029] (2) Transportation: Add chemical agents from the outlet of buffer tank 1, pressurize them through delivery pump A2, and transport them to the subsequent process;

[0030] (3) Heating: The emulsified oil with added chemicals enters the heater 3 and is heated to the required temperature;

[0031] (4) Electric field demulsification: The heated emulsified oil enters the compact electric field coalescence demulsifier 4, which destroys the stability of the emulsion through the action of a high-frequency and high-voltage electric field, promotes the coalescence of small water droplets, and facilitates subsequent sedimentation and separation;

[0032] (5) Static sedimentation: After the emulsified oil has passed through the electric field, it enters the static sedimentation tank 5, where the chemical agent reacts with the emulsified oil to form sedimentation layers, and the sedimented water is directly discharged into the water treatment system;

[0033] (6) Three-phase separation: There are two ways for the emulsified oil to enter the three-phase centrifuge 7. One way is to enter the three-phase centrifuge directly after passing through the compact electric field coalescing demulsifier 4. The other way is to enter the three-phase centrifuge 7 through the static sedimentation tank through the delivery pump B 6. Under the centrifugal force generated by the high-speed rotation of the drum of the three-phase centrifuge 7, the solid phase in the emulsion settles to the inner wall of the drum to form a solid ring layer, and the two oil phases and water phases with different densities form concentric cylinders. The lighter oil phase is in the inner layer, and the heavier water phase is in the outer layer. The thickness of different liquid ring layers can be precisely adjusted by designing an adjustable overflow plate. The solid phase deposited on the drum wall is transported to the small end of the drum by the internal screw conveyor, and is bidirectionally squeezed at the conical end of the drum to further reduce the water content of the slag phase. Finally, it is discharged from the body at the slag outlet at the small end of the drum and collected in the slag tank 9. The separated oil phase enters the high-frequency high-voltage electric dehydrator 8 for further dehydration. The separated water phase is discharged to the water treatment system;

[0034] (7) Electric dehydration: The oil phase of the three-phase centrifuge 7 enters the high-frequency high-voltage electric dehydrator 8 for further dehydration. The qualified crude oil after treatment is transported to the crude oil tank / tank for storage, and the water phase is discharged to the water treatment system.

[0035] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the technical requirements.

Claims

1. An oilfield emulsified oil treatment system, characterized in that: The invention comprises a buffer tank (1), a heater (3), a compact electric field coalescence demulsifier (4), a static sedimentation tank (5), a three-phase centrifuge (7) and a high-frequency high-voltage electric dehydrator (8) which are sequentially connected through pipelines.

2. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The buffer tank (1) is provided with a heating device (1-1) and a stirrer (1-2).

3. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The outlet of the buffer tank (1) is also provided with a chemical agent addition port.

4. The oilfield emulsified oil treatment system according to claim 1, characterized in that: A delivery pump A (2) is provided on the connecting pipeline between the buffer tank (1) and the heater (3).

5. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The outlet of the compact electric field coalescence demulsifier (4) is provided with two pipelines, one of which is connected to the inlet of the three-phase centrifuge (7), and the other is connected to the inlet of the static sedimentation tank (5).

6. The oilfield emulsified oil treatment system according to claim 1, characterized in that: A delivery pump B (6) is provided on the connecting pipeline between the static sedimentation tank (5) and the three-phase centrifuge (7).

7. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The static sedimentation tank (5) is also connected to a sewage discharge pipeline, and the sewage discharge pipeline is connected to a water treatment system.

8. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The three-phase centrifuge (7) is also connected to the slag tank (9) and the sewage discharge pipeline respectively, and the sewage discharge pipeline is connected to the water treatment system.

9. The oilfield emulsified oil treatment system according to claim 1, characterized in that: The high-frequency and high-voltage electric dehydrator (8) is also connected to a sewage discharge pipeline, and the sewage discharge pipeline is connected to a water treatment system.

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