A multi-stage cavitation jet self-circulating flotation treatment device

Abstract

The utility model relates to the technical field of produced water treatment on the surface of oil fields, and in particular discloses a multi-stage cavitation jet self-circulating flotation treatment device, comprising a tank body and two partitions arranged in the inner cavity of the tank body, the two partitions divide the inner cavity of the tank body into a floating oil chamber, a flotation chamber and a clean water chamber, a plurality of ejectors and releasers are arranged in the flotation chamber, the plurality of ejectors are connected to the outlet end of a centrifugal pump, a natural gas outlet is arranged on the tank body, and the natural gas outlet is connected to the ejector. The utility model performs flotation treatment of produced water through the flotation chamber, the dirty oil generated by flotation enters the floating oil chamber, the produced water after flotation treatment enters the clean water chamber, the water for flotation is extracted from the clean water chamber by a booster pump, the gas for flotation uses the natural gas inside the tank body, the recycling of natural gas and produced water is realized, resources are saved, energy consumption is saved, and costs are reduced, the flotation treatment is carried out in a closed manner in the tank body, the emission problem of VOCs is effectively solved, and pollution to the environment is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield surface produced water treatment, in particular to a multi-stage cavitation jet self-circulating air flotation treatment device. Background Art

[0002] With the continuous development of oil fields, most of the old oil fields have entered the development stage of high water content. The amount of produced water during oil field exploitation has increased year by year. With the improvement of national environmental protection measures on VOCs emission requirements, higher requirements have been put forward for the treatment of oil field produced water. At present, the flotation process used in the oil field produced water treatment system in the existing technology is mostly a normal pressure flotation process, which cannot achieve closed treatment, resulting in VOCs emissions that cannot meet the standards and serious pollution. In addition, the number of air compressors, dissolved air tanks and other equipment supporting the flotation process is large, resulting in more control points and high energy consumption.

[0003] Therefore, it is necessary to propose an improvement of a multi-stage cavitation jet self-circulation flotation treatment device to overcome the defects of the prior art. Utility Model Content

[0004] The utility model aims to solve the problems in the prior art and provides a multi-stage cavitation jet self-circulating air flotation treatment device.

[0005] The technical solution of the utility model is:

[0006] A multi-stage cavitation jet self-circulating flotation treatment device comprises a tank body and two partitions arranged in the inner cavity of the tank body, wherein the two partitions divide the inner cavity of the tank body into a floating oil chamber, an air flotation chamber and a clean water chamber which are arranged in sequence, wherein a plurality of ejectors and releasers are arranged in the air flotation chamber, wherein the ejectors and releasers are connected in one-to-one correspondence, wherein the plurality of ejectors are connected in parallel to the outlet end of a centrifugal pump, and a natural gas outlet is arranged on the tank body, wherein the natural gas outlet is connected to the ejectors.

[0007] Preferably, the tank body is provided with a plurality of ejector water inlet pipes adapted to the ejector, and the plurality of ejector water inlet pipes are connected in parallel to the outlet end of the centrifugal pump;

[0008] Each ejector is connected to an ejector water inlet pipe, which are connected in parallel to the outlet of the centrifugal pump. After the centrifugal pump pressurizes the flotation water, a high-speed water flow is ejected through the nozzle of the ejector, so that a negative pressure is formed in the suction chamber of the ejector.

[0009] Preferably, a purified produced water pipe is provided on the tank body, the purified produced water pipe is connected to the clean water chamber, and a circulation pipe is provided at the inlet end of the centrifugal pump, the circulation pipe is connected to the purified produced water pipe;

[0010] The purified produced water pipe discharges the produced water after flotation treatment from the clean water chamber, and the centrifugal pump draws the produced water after flotation treatment from the purified produced water pipe through the circulation pipe to achieve the recycling of produced water.

[0011] Preferably, the tank body is provided with a plurality of ejector air inlet pipes adapted to the ejector, and the plurality of ejector air inlet pipes are connected to the natural gas outlet in parallel;

[0012] After negative pressure is generated in the suction chamber of the ejector, the natural gas in the tank is distributed through the natural gas outlet and enters the corresponding ejector through multiple ejector air inlet pipes arranged in parallel for gas-water mixing.

[0013] Preferably, a produced water inlet pipe is provided on the tank body, and the produced water inlet pipe is connected to the air flotation chamber;

[0014] Produced water is introduced into the flotation cavity of the tank body through the produced water inlet pipe for flotation treatment.

[0015] Preferably, a gas phase pipe is provided on the tank body;

[0016] The oil and gas separation equipment is connected to the outside through the gas phase pipe, and the natural gas separated by the oil and gas separation equipment is introduced into the tank body to maintain the pressure balance in the tank body and replenish the loss of gas used for flotation.

[0017] Preferably, an oil floating pipe is provided on the tank body, and the oil floating pipe is connected with the oil floating chamber;

[0018] The floating oil produced by flotation is discharged through the floating oil pipe and discharged into the waste oil pool for centralized treatment.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] 1. The tank body is divided into an air flotation chamber, an oil floating chamber and a clean water chamber. The air flotation chamber is used to flotate produced water. The dirty oil produced by air flotation enters the oil floating chamber. The produced water after air flotation treatment enters the clean water chamber. The water for air flotation is extracted from the clean water chamber by a booster pump. The gas for air flotation uses the natural gas inside the tank body, so as to realize the recycling of natural gas and produced water, save resources, save energy consumption and reduce costs. The flotation treatment of produced water is carried out in a closed tank body, which effectively solves the emission problem of VOCs, avoids pollution to the environment and improves the safety of produced water treatment.

[0021] 2. The whole is integrated into a skid, with a high degree of integration, which reduces the number of equipment, simplifies the overall structure, occupies a small area, is easy to control, and has low energy consumption;

[0022] 3. The tank uses the natural gas generated by the external oil and gas separation equipment as the gas source for flotation and maintains the air pressure balance inside the tank, which further saves gas boosting equipment, reduces energy consumption, and realizes the full utilization of natural gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the utility model.

[0024] Among them, 1. tank body; 2. partition; 3. floating oil chamber; 4. air flotation chamber; 5. clean water chamber; 6. ejector; 7. releaser; 8. ejector water inlet pipe; 9. ejector air inlet pipe; 10. centrifugal pump; 11. natural gas outlet; 12. produced water inlet pipe; 13. floating oil pipe; 14. gas phase pipe; 15. purified produced water pipe; 16. circulation pipe. DETAILED DESCRIPTION

[0025] In order to make the technical means, technical features, utility model objectives and technical effects achieved by the utility model easy to understand, the utility model is further explained below with reference to specific illustrations.

[0026] like Figure 1 As shown, a multi-stage cavitation jet self-circulating flotation treatment device comprises a tank body 1, two partitions 2 are welded in the inner cavity of the tank body 1, and the inner cavity of the tank body 1 is divided into three areas by the two partitions 2. The three areas are respectively an oil floating chamber 3, an air flotation chamber 4 and a clean water chamber 5 arranged in sequence. The air flotation chamber 4 is used for flotation treatment of produced water. A produced water inlet pipe 12 connected to the inside of the air flotation chamber 4 is installed on the tank body 1, and produced water to be treated is injected into the tank body 1 through the produced water inlet pipe 12. A plurality of ejectors 6 and releasers 7 are installed in the air flotation chamber 4, and the ejectors 6 and releasers 7 are connected one by one. An ejector water inlet pipe 8 and an ejector air inlet pipe 9 adapted to the plurality of ejectors 6 are installed on the tank body 1, and the ejector water inlet pipe 8 and the ejector air inlet pipe 9 are connected in series. The ejector 6 is connected in parallel and connected to the outlet end of the centrifugal pump 10 through a pipeline. The centrifugal pump 10 provides pressurized water flow to the ejector 6, so that the suction chamber of the ejector 6 forms a negative pressure. The ejector air inlet pipe 9 is also connected in parallel and connected to the natural gas outlet 11 installed on the tank body 1 through a pipeline. The natural gas outlet 11 is connected to the inside of the tank body 1. The suction chamber of the ejector 6 generates a negative pressure under the action of the high-speed water flow. The natural gas of the tank body 1 is absorbed through the ejector air inlet pipe 9 and the natural gas outlet 11, so that a gas-water mixture is formed in the ejector 6, and the natural gas in the tank body 1 is repeatedly recycled. The gas-water mixture formed by the ejector 6 is released into the flotation chamber 4 after being depressurized by the releaser 7, and the produced water in the flotation chamber 4 is subjected to flotation treatment.

[0027] like Figure 1As shown, a purified produced water pipe 15 is installed on the tank body 1, and the purified produced water pipe 15 is connected to the clean water chamber 5 of the tank body 1. The produced water after flotation treatment enters the clean water chamber 5 and is discharged to the designated external position through the purified produced water pipe 15. A circulation pipe 16 is connected to the purified produced water pipe 15, and the circulation pipe 16 is connected to the inlet end of the centrifugal pump 10. The centrifugal pump 10 extracts the produced water after flotation treatment from the clean water chamber 5 through the purified produced water pipe 15 and the circulation pipe 16 as flotation water, thereby realizing the recycling of produced water, saving resources and saving costs.

[0028] like Figure 1 As shown, a gas phase pipe 14 is installed on the tank body 1, and the gas phase pipe 14 is connected to the inside of the tank body 1. The gas phase pipe 14 is used to connect an external oil and gas separation device (not shown in the figure). The natural gas separated by the oil and gas separation device is introduced into the tank body 1 through the gas phase pipe 14 to meet the gas consumption required for flotation, supplement the gas consumption of flotation, and maintain the pressure balance in the tank body 1. The oil and gas separation device does not belong to the scope of protection of the present utility model, and its specific structure will not be repeated here.

[0029] like Figure 1 As shown, an oil floating pipe 13 is connected to the tank body 1, and the oil floating pipe 13 is connected to the interior of the oil floating chamber 3. The floating oil generated after the flotation treatment is collected by the oil collecting tank (not shown in the figure) and enters the oil floating chamber 3, and is discharged to the outside into the waste oil pool through the oil floating pipe 13 for unified treatment.

[0030] The working principle of the utility model is:

[0031] When in use, the gas phase pipe 14 is connected to the oil and gas separation equipment, and natural gas is introduced into the tank body 1 to provide a gas source for the flotation of produced water and maintain the pressure balance in the tank body 1, thereby avoiding waste of resources. The floating oil pipe 13 is connected to the waste oil pool, and the untreated produced water enters the flotation chamber 4 of the tank body 1 through the produced water inlet pipe 12. The centrifugal pump 10 is started, and the centrifugal pump 10 draws the treated produced water from the clean water chamber 5 through the purified produced water pipe 15 and the circulation pipe 16. After being pressurized by the centrifugal pump 10 and distributed through the manifold, the pressurized water flows through the ejector inlet pipe 8 into the corresponding ejector 6. The suction chamber of the ejector 6 forms a negative pressure under the action of the high-speed water flow. The natural gas in the tank body 1 is sucked out from the natural gas outlet 11 under the action of the negative pressure and is distributed to the ejector. It is injected into the air pipe 9 and enters the corresponding ejector 6 for sufficient gas-water mixing. Energy is exchanged in the throat section of the ejector 6. The gas is crushed into tiny bubbles and enters the diffusion section of the ejector 6 to further compress the bubbles and increase the solubility of the gas in water. The dissolved gas liquid at the outlet of the ejector 6 is released by the releaser 7 to generate a large number of micron-sized bubbles. The impurities such as emulsion and tiny suspended particles in the produced water adhere to the bubbles and float to the water surface with the bubbles. They are collected by the oil collecting tank and enter the floating oil chamber 3. The produced water after flotation treatment enters the clean water chamber 5 and is transported outward through the purified produced water pipe 15. A part of the produced water enters the centrifugal pump 10 through the circulation pipe 16 and participates in the flotation treatment after being pressurized by the centrifugal pump 10 to realize the recycling of the produced water.

[0032] The above description is only a preferred embodiment of the utility model, and is not intended to limit the scope of implementation of the utility model. That is, all equivalent changes and modifications made according to the content of the patent application scope of the utility model should belong to the technical scope of the utility model.

Claims

1. A multi-stage cavitation jet self-circulating flotation treatment device, characterized in that: The invention comprises a tank body (1) and two partitions (2) arranged in the inner cavity of the tank body (1), wherein the two partitions (2) divide the inner cavity of the tank body (1) into an oil floating cavity (3), an air flotation cavity (4) and a clean water cavity (5) which are arranged in sequence, wherein a plurality of ejectors (6) and releasers (7) are arranged in the air flotation cavity (4), wherein the ejectors (6) and releasers (7) are connected in a one-to-one correspondence, wherein the plurality of ejectors (6) are connected in parallel to the outlet end of a centrifugal pump (10), and a natural gas outlet (11) is arranged on the tank body (1), wherein the natural gas outlet (11) is connected to the ejectors (6).

2. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with a plurality of ejector water inlet pipes (8) adapted to the ejector (6), and the plurality of ejector water inlet pipes (8) are connected in parallel to the outlet end of the centrifugal pump (10).

3. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with a plurality of ejector air intake pipes (9) adapted to the ejector (6), and the plurality of ejector air intake pipes (9) are connected in parallel to the natural gas outlet (11).

4. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with a purified produced water pipe (15), the purified produced water pipe (15) being in communication with the clean water chamber (5); a circulation pipe (16) is provided at the inlet end of the centrifugal pump (10), the circulation pipe (16) being in communication with the purified produced water pipe (15).

5. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with a produced water inlet pipe (12), and the produced water inlet pipe (12) is in communication with the air flotation chamber (4).

6. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with a gas phase pipe (14).

7. The multi-stage cavitation jet self-circulation flotation treatment device according to claim 1 is characterized in that: The tank body (1) is provided with an oil floating pipe (13), and the oil floating pipe (13) is connected to the oil floating chamber (3).

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