Water stripping treatment device for CO2 injection flooding produced water

Abstract

The utility model discloses a CO2 injection flooding produced water stripping treatment device which comprises a first reaction tank and a second reaction tank which are communicated with each other, a flocculation flow separation tank, a steam stripping filler tank and a stirring overflow tank are sequentially arranged in the first reaction tank, a water inlet pipe is arranged on the side wall of the first reaction tank, a dosing pipe is arranged at the top of the first reaction tank, a flow guide assembly is arranged in the flocculation flow separation tank, a first filler bin is arranged in the steam stripping filler tank, and a first stirring assembly is arranged in the stirring overflow tank; a sludge discharge groove communicated with the stirring overflow tank is formed in the upper part of the side wall of the first reaction tank; the side wall of the second reaction tank is communicated with an air inlet pipe and a water outlet pipe, a second filler bin and a third filler bin are sequentially arranged in the second reaction tank from bottom to top, and a second stirring assembly is further arranged in the second reaction tank. According to the CO2 injection flooding produced water stripping treatment device provided by the utility model, the two reaction tanks are arranged, so that the problem of gas waste caused by the fact that the N2 gas quantity of the existing device is not easy to control is solved.

Description

Technical Field

[0001] This utility model belongs to the field of oil production engineering technology and relates to a CO2 injection-driven produced water stripping treatment device. Background Technology

[0002] In oil production engineering, carbon dioxide flooding (CFD) technology involves injecting carbon dioxide into the oil reservoir to improve oil recovery. Initially, carbon dioxide does not form a miscible phase upon first contact with the formation crude oil. However, under suitable pressure, temperature, and crude oil composition conditions, carbon dioxide can form a miscible front. Supercritical fluids extract heavier hydrocarbons from the crude oil and continuously concentrate the gas at the displacement front. Thus, carbon dioxide and crude oil become a miscible liquid, forming a single liquid phase, which effectively displaces the formation crude oil into the production well.

[0003] Produced water from oilfields contains a variety of complex organic and inorganic substances. Its quality is influenced by many factors, such as the oilfield's geographical location, geological conditions, lifespan, and the chemical composition of the wastewater. These factors can all affect the physical and chemical properties of the produced water. Carbon dioxide produced water wastewater contains large amounts of dissolved carbon dioxide and H2S, resulting in a low pH level. This causes corrosion and scaling problems in oilfield equipment and renders conventional produced water treatment processes inadequate for meeting treatment standards. While achieving higher oil recovery rates, the carbon dioxide in the produced water leads to severe equipment corrosion.

[0004] Steam stripping is a key technology in wastewater treatment, frequently used to remove volatile organic compounds (VOCs) such as ammonia nitrogen and tetrachloromethane. To achieve higher mass transfer efficiency, the gas-liquid contact area needs to be increased; therefore, packing materials are typically added to the reactor during the stripping process enhancement. However, current applications of stripping technology in treating produced water from carbon dioxide flooding are still imperfect, with issues such as difficulty in controlling N2 gas volume, leading to gas waste and increased costs. Utility Model Content

[0005] The purpose of this invention is to provide a CO2 injection-driven produced water stripping treatment device. By setting up two reaction tanks, it solves the problem that the N2 gas volume of existing devices is not easy to control, resulting in gas waste and increased costs.

[0006] The technical solution adopted in this utility model is a CO2 injection-driven produced water stripping treatment device, which includes a first reaction tank and a second reaction tank that are interconnected.

[0007] The first reaction tank is sequentially configured with a flocculation isolation tank, a stripping packing tank, and a stirring overflow tank. The upper side wall of the first reaction tank is equipped with an inlet pipe connected to the flocculation isolation tank, and the top of the first reaction tank is equipped with a dosing pipe connected to the flocculation isolation tank. The flocculation isolation tank is equipped with a flow guiding component, the stripping packing tank is equipped with a first packing chamber, the stirring overflow tank is equipped with a first stirring component, and the upper side wall of the first reaction tank is also equipped with a sludge discharge trough connected to the stirring overflow tank.

[0008] The second reaction tank has an air inlet pipe and a water outlet pipe connected to its side wall. The second reaction tank is equipped with a second packing chamber and a third packing chamber from bottom to top. The second reaction tank is also equipped with a second stirring assembly.

[0009] The features of this utility model also include:

[0010] The first reaction tank and the second reaction tank are connected by a gas guide pipe and a drain pipe. The gas guide pipe is Z-shaped, with one end connected to the bottom of the first reaction tank and the other end connected to the upper side wall of the second reaction tank. The drain pipe is L-shaped, with one end connected to the upper part of the first reaction tank and the other end connected to the upper part of the second reaction tank.

[0011] Baffles are provided between the flocculation isolation tank and the stripping packing tank, and between the stripping packing tank and the stirred overflow tank. The baffle between the flocculation isolation tank and the stripping packing tank is fixedly installed at the top of the inner wall of the first reaction tank, and the baffle between the stripping packing tank and the stirred overflow tank is fixedly installed at the bottom of the inner wall of the first reaction tank. The length of the baffle is less than the height of the first reaction tank.

[0012] The flow guiding assembly includes several sets of first and second flow guiding plates arranged in a cross pattern. The first flow guiding plates are set on the inner wall of the first reaction tank, and the second flow guiding plates are set on the partition between the flocculation isolation tank and the stripping packing tank. The first and second flow guiding plates have the same length and are smaller than the width of the flocculation isolation tank.

[0013] The first packing bin is located in the middle of the stripping packing pool, and permeable mesh plates are installed above and below the first packing bin.

[0014] The first stirring assembly includes a first stirring motor, which is mounted on the outer wall of the top of the stirring overflow tank. The output shaft of the first stirring motor passes through the top wall of the first reaction tank and is connected to a stirring rod, which is mounted inside the stirring overflow tank.

[0015] Both the second and third packing chambers are equipped with permeable mesh panels on the top and bottom.

[0016] The second stirring assembly includes a second stirring motor, which is located on the outer wall of the top of the second reaction tank. The output shaft of the second stirring motor passes through the second reaction tank, and several sets of stirring blades are provided on the output shaft of the second stirring motor. The two sets of stirring blades located in the middle are respectively arranged inside the second packing chamber and the third packing chamber.

[0017] The first packing chamber is located above the part where the air inlet pipe connects to the first reaction tank. The air inlet pipe is connected to the bottom of the second reaction tank, and the water outlet pipe is connected to the upper part of the second reaction tank. The air inlet pipe and the water outlet pipe are located on the same side of the second reaction tank.

[0018] The beneficial effects of this utility model are:

[0019] This utility model of CO2-driven produced water stripping treatment device, by setting up two reaction tanks, can perform two stripping treatments on CO2-driven produced water. The N2 used in the second stripping can be reused in the first stripping. In addition, with the help of flocculation and polypropylene multi-faceted hollow spheres, the stripping effect can be further improved, ultimately achieving the goal of saving N2 usage and greatly reducing costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the CO2 injection-driven produced water stripping treatment device of this utility model;

[0021] Figure 2 This is a schematic cross-sectional view of the internal structure of the first reaction tank in the CO2 injection-driven produced water stripping treatment device of this utility model.

[0022] Figure 3 This is a schematic cross-sectional view of the internal structure of the second reaction tank in the CO2 injection-driven produced water stripping treatment device of this utility model.

[0023] In the diagram, 1. First reaction tank, 11. Inlet pipe, 12. Dosing pipe, 13. Baffle plate;

[0024] 2. Second reaction tank; 21. Air inlet pipe; 22. Air guide pipe; 23. Water outlet pipe; 24. Second stirring motor; 25. Stirring blades;

[0025] 3. Flocculation baffle tank; 31. First guide plate;

[0026] 4. Stripping packing tank; 41. First packing bin;

[0027] 5. Mixing overflow tank; 51. Drain pipe; 52. Mixing rod; 53. Sludge discharge trough;

[0028] 6. Second stuffing box, 7. Third stuffing box. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] This utility model relates to a CO2 injection-driven produced water stripping treatment device, such as... Figure 1 As shown, it includes a first reaction tank 1 and a second reaction tank 2 that are interconnected.

[0031] Specifically, the first reaction tank 1 and the second reaction tank 2 are connected by a gas guide pipe 22 and a drain pipe 51. The gas guide pipe 22 is Z-shaped, with one end connected to the bottom of the first reaction tank 1 and the other end connected to the upper side wall of the second reaction tank 2. The drain pipe 51 is L-shaped, with one end connected to the upper part of the first reaction tank 1 and the other end connected to the upper part of the second reaction tank 2.

[0032] like Figure 2 As shown, the first reaction tank 1 is sequentially configured with a flocculation isolation tank 3, a stripping packing tank 4, and a stirring overflow tank 5. The upper side wall of the first reaction tank 1 is provided with an inlet pipe 11 connected to the flocculation isolation tank 3. The top of the first reaction tank 1 is provided with a dosing pipe 12 connected to the flocculation isolation tank 3. The flocculation isolation tank 3 is provided with a flow guiding component. The stripping packing tank 4 is provided with a first packing chamber 41. The stirring overflow tank 5 is provided with a first stirring component. The upper side wall of the first reaction tank 1 is also provided with a sludge discharge trough 53 connected to the stirring overflow tank 5.

[0033] Among them, baffles 13 are provided between the flocculation baffle 3 and the stripping packing tank 4, and between the stripping packing tank 4 and the stirring overflow tank 5. The baffle 13 between the flocculation baffle 3 and the stripping packing tank 4 is fixedly installed at the top of the inner wall of the first reaction tank 1, and its bottom extends to near the bottom of the inner wall of the first reaction tank 1. The baffle 13 between the stripping packing tank 4 and the stirring overflow tank 5 is fixedly installed at the bottom of the inner wall of the first reaction tank 1. The length of the baffle 13 is less than the height of the first reaction tank 1.

[0034] The flow guiding assembly includes several sets of cross-arranged first flow guiding plates 31 and second flow guiding plates. The first flow guiding plates 31 are disposed on the inner wall of the first reaction tank 1, and the second flow guiding plates are disposed on the partition 13 between the flocculation isolation tank 3 and the stripping packing tank 4, with the top extending to near the top of the first reaction tank. The lengths of the first flow guiding plates 31 and the second flow guiding plates are the same and smaller than the width of the flocculation isolation tank 3. This design creates an S-shaped flow inside the flocculation isolation tank 3, ensuring that the liquid can be fully mixed.

[0035] The first packing chamber 41 is located in the middle of the stripping packing tank 4. The first packing chamber 41 is equipped with permeable mesh plates at both the top and bottom. The first packing chamber 41 is filled with polypropylene multifaceted hollow spheres with a diameter of 30~50cm.

[0036] The first stirring assembly includes a first stirring motor, which is installed on the outer wall of the top of the stirring overflow tank 5. The output shaft of the first stirring motor passes through the top wall of the first reaction tank 1 and is connected to a stirring rod 52, which is installed inside the stirring overflow tank 5.

[0037] like Figure 3As shown, an air inlet pipe 21 and a water outlet pipe 23 are connected to the side wall of the second reaction tank 2 respectively. The second reaction tank 2 is provided with a second packing chamber 6 and a third packing chamber 7 from bottom to top. The second reaction tank 2 is also provided with a second stirring assembly.

[0038] The second packing chamber 6 and the third packing chamber 7 are equipped with permeable mesh panels at the top and bottom. The second packing chamber 6 is filled with polypropylene multifaceted hollow spheres with a diameter of 20-40cm, and the third packing chamber 7 is filled with polypropylene multifaceted hollow spheres with a diameter of 10-30cm.

[0039] The second stirring assembly includes a second stirring motor 24, which is mounted on the outer wall of the top of the second reaction tank 2. The output shaft of the second stirring motor 24 passes through the second reaction tank 2 and extends to the bottom of the second reaction tank 2. Several sets of stirring blades 25 are provided on the output shaft of the second stirring motor 24. The two sets of stirring blades 25 located in the middle are respectively arranged inside the second packing chamber 6 and the third packing chamber 7. It is worth noting that since the polypropylene multifaceted hollow spheres in the second packing chamber 6 and the third packing chamber 7 are relatively light, the stirring blades 25 inside the second packing chamber 6 and the third packing chamber 7 can rotate freely in actual operation.

[0040] The first packing chamber 41 is located above the part where the air guide pipe 22 connects to the first reaction tank 1. The air inlet pipe 21 is connected to the bottom of the second reaction tank 2, and the water outlet pipe 23 is connected to the upper part of the second reaction tank 2. The air inlet pipe 21 and the water outlet pipe 23 are located on the same side of the second reaction tank 2.

[0041] Working principle:

[0042] In use, CO2-driven produced water is first injected into the first reaction tank 1 through the inlet pipe 11, and polyaluminum chloride (PAC) is added through the dosing pipe 12. The produced water and PAC are fully mixed when they are guided inside the flocculation isolation tank 3. Then, it enters the stripping packing tank 4. Gas is introduced through the air inlet pipe 21 on the second reaction tank 2, so that the produced water is stripped by mixing with the polypropylene multi-faceted hollow spheres inside the first packing tank 41 to remove carbon dioxide from the produced water. Then, it enters the stirring overflow tank 5, and overflow is completed while the stirring rod 52 is stirring. Oil sludge and floating impurities are discharged through the sludge discharge tank 53.

[0043] The produced water then enters the second reaction tank 2, and N2 is injected simultaneously. While the stirring blades 25 are stirring, the polypropylene multifaceted hollow spheres in the second packing chamber 6 and the third packing chamber 7 are mixed and stripped. The mixed gas with N2 as the main component discharged through the gas guide pipe 22 enters the first reaction tank 1 for recycling, thereby realizing the secondary utilization of N2 and ultimately achieving the goal of saving N2 consumption and greatly reducing costs. Finally, the treated produced water is discharged through the water outlet pipe 23.

[0044] Ultimately, under the condition of a hydraulic retention time of 30 min, the carbon dioxide removal effect was good, the stirring speed was 80 rpm, the PAC concentration was 50 mg / L, and the gas-to-water ratio was 5:1. The cost per ton of water treated was 0.6 yuan / m³. 3 The effluent pH is neutral, CO2 content is controlled below 30 mg / L, oil content is not higher than 5.0 mg / L, suspended solids content is not higher than 1.0 mg / L, and median diameter is not higher than 1.0 μm. Ultimately, this achieves the goal of saving N2 usage and greatly reduces costs.

[0045] Example 1

[0046] This utility model relates to a CO2 injection-driven produced water stripping treatment device, such as... Figure 1 As shown, it includes a first reaction tank 1 and a second reaction tank 2 that are interconnected.

[0047] like Figure 2 As shown, the first reaction tank 1 is sequentially configured with a flocculation isolation tank 3, a stripping packing tank 4, and a stirring overflow tank 5. The upper side wall of the first reaction tank 1 is provided with an inlet pipe 11 connected to the flocculation isolation tank 3. The top of the first reaction tank 1 is provided with a dosing pipe 12 connected to the flocculation isolation tank 3. The flocculation isolation tank 3 is provided with a flow guiding component. The stripping packing tank 4 is provided with a first packing chamber 41. The stirring overflow tank 5 is provided with a first stirring component. The upper side wall of the first reaction tank 1 is also provided with a sludge discharge trough 53 connected to the stirring overflow tank 5.

[0048] like Figure 3 As shown, an air inlet pipe 21 and a water outlet pipe 23 are connected to the side wall of the second reaction tank 2 respectively. The second reaction tank 2 is provided with a second packing chamber 6 and a third packing chamber 7 from bottom to top. The second reaction tank 2 is also provided with a second stirring assembly.

[0049] The first packing chamber 41 is located above the part where the air guide pipe 22 connects to the first reaction tank 1. The air inlet pipe 21 is connected to the bottom of the second reaction tank 2, and the water outlet pipe 23 is connected to the upper part of the second reaction tank 2. The air inlet pipe 21 and the water outlet pipe 23 are located on the same side of the second reaction tank 2.

[0050] Example 2

[0051] Based on the structure of Example 1, the first reaction tank 1 and the second reaction tank 2 are connected by a gas guide pipe 22 and a drain pipe 51. The gas guide pipe 22 is Z-shaped, with one end connected to the bottom of the first reaction tank 1 and the other end connected to the upper side wall of the second reaction tank 2. The drain pipe 51 is L-shaped, with one end connected to the upper part of the first reaction tank 1 and the other end connected to the upper part of the second reaction tank 2.

[0052] Example 3

[0053] Based on the structure of Example 1, this embodiment provides baffles 13 between the flocculation isolation tank 3 and the stripping packing tank 4, and between the stripping packing tank 4 and the stirring overflow tank 5. The baffle 13 between the flocculation isolation tank 3 and the stripping packing tank 4 is fixedly installed at the top of the inner wall of the first reaction tank 1, and its bottom extends to near the bottom of the inner wall of the first reaction tank 1. The baffle 13 between the stripping packing tank 4 and the stirring overflow tank 5 is fixedly installed at the bottom of the inner wall of the first reaction tank 1. The length of the baffle 13 is less than the height of the first reaction tank 1.

[0054] Example 4

[0055] Based on the structure of Embodiment 1, the flow guiding component includes several sets of cross-arranged first flow guiding plates 31 and second flow guiding plates. The first flow guiding plates 31 are disposed on the inner wall of the first reaction tank 1, and the second flow guiding plates are disposed on the partition 13 between the flocculation isolation tank 3 and the stripping packing tank 4, with the top extending to near the top of the first reaction tank. The lengths of the first flow guiding plates 31 and the second flow guiding plates are the same and smaller than the width of the flocculation isolation tank 3. This design enables an S-shaped flow inside the flocculation isolation tank 3, ensuring that the liquid can be fully mixed.

[0056] Example 5

[0057] Based on the structure of Example 1, the first packing chamber 41 is located in the middle of the stripping packing tank 4. The first packing chamber 41 is equipped with permeable mesh plates at both the top and bottom. The first packing chamber 41 is filled with polypropylene multifaceted hollow spheres with a diameter of 30~50cm.

[0058] Example 6

[0059] Based on the structure of Embodiment 1, the first stirring assembly includes a first stirring motor, which is installed on the outer wall of the top of the stirring overflow tank 5. The output shaft of the first stirring motor passes through the top wall of the first reaction tank 1 and is connected to a stirring rod 52, which is installed inside the stirring overflow tank 5.

[0060] Example 7

[0061] Based on the structure of Example 1, this embodiment has permeable mesh plates on both the upper and lower parts of the second packing chamber 6 and the third packing chamber 7. The second packing chamber 6 is filled with polypropylene multifaceted hollow spheres with a diameter of 20-40cm, and the third packing chamber 7 is filled with polypropylene multifaceted hollow spheres with a diameter of 10-30cm.

[0062] The second stirring assembly includes a second stirring motor 24, which is located on the outer wall of the top of the second reaction tank 2. The output shaft of the second stirring motor 24 passes through the second reaction tank 2 and extends to the bottom of the second reaction tank 2. Several sets of stirring blades 25 are provided on the output shaft of the second stirring motor 24. The two sets of stirring blades 25 located in the middle are respectively arranged inside the second packing chamber 6 and the third packing chamber 7.

Claims

1. A CO2 injection-driven produced water stripping treatment device, characterized in that, It includes a first reaction tank (1) and a second reaction tank (2) that are interconnected. The first reaction tank (1) is arranged in sequence as a flocculation isolation tank (3), a stripping packing tank (4), and a stirring overflow tank (5). The upper part of the side wall of the first reaction tank (1) is provided with an inlet pipe (11) connected to the flocculation isolation tank (3). The top of the first reaction tank (1) is provided with a dosing pipe (12) connected to the flocculation isolation tank (3). The flocculation isolation tank (3) is provided with a flow guiding component. The stripping packing tank (4) is provided with a first packing chamber (41). The stirring overflow tank (5) is provided with a first stirring component. The upper part of the side wall of the first reaction tank (1) is also provided with a sludge discharge trough (53) connected to the stirring overflow tank (5). The second reaction tank (2) is connected to an air inlet pipe (21) and a water outlet pipe (23) on its side wall. The second reaction tank (2) is provided with a second packing chamber (6) and a third packing chamber (7) from bottom to top. The second reaction tank (2) is also provided with a second stirring assembly.

2. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, The first reaction tank (1) and the second reaction tank (2) are connected by a gas guide pipe (22) and a drain pipe (51). The gas guide pipe (22) is Z-shaped, with one end connected to the bottom of the first reaction tank (1) and the other end connected to the upper side wall of the second reaction tank (2). The drain pipe (51) is L-shaped, with one end connected to the upper part of the first reaction tank (1) and the other end connected to the upper part of the second reaction tank (2).

3. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, A partition (13) is provided between the flocculation isolation tank (3) and the stripping packing tank (4), and between the stripping packing tank (4) and the stirring overflow tank (5). The partition (13) between the flocculation isolation tank (3) and the stripping packing tank (4) is fixedly installed at the top of the inner wall of the first reaction tank (1), and the partition (13) between the stripping packing tank (4) and the stirring overflow tank (5) is fixedly installed at the bottom of the inner wall of the first reaction tank (1). The length of the partition (13) is less than the height of the first reaction tank (1).

4. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, The flow guiding component includes several sets of first flow guiding plates (31) and second flow guiding plates arranged in a cross pattern. The first flow guiding plate (31) is set on the inner wall of the first reaction tank (1), and the second flow guiding plate is set on the partition (13) between the flocculation isolation tank (3) and the stripping packing tank (4). The lengths of the first flow guiding plate (31) and the second flow guiding plate are the same and smaller than the width of the flocculation isolation tank (3).

5. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, The first packing bin (41) is located in the middle of the stripping packing pool (4), and permeable mesh plates are provided above and below the first packing bin (41).

6. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, The first stirring assembly includes a first stirring motor, which is installed on the outer wall of the top of the stirring overflow tank (5). The output shaft of the first stirring motor passes through the top wall of the first reaction tank (1) and is connected to a stirring rod (52). The stirring rod (52) is installed inside the stirring overflow tank (5).

7. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, Both the second packing chamber (6) and the third packing chamber (7) are equipped with permeable mesh panels on the top and bottom.

8. The CO2 injection-driven produced water stripping treatment device according to claim 7, characterized in that, The second stirring assembly includes a second stirring motor (24), which is located on the outer wall of the top of the second reaction tank (2). The output shaft of the second stirring motor (24) passes through the second reaction tank (2). Several sets of stirring blades (25) are provided on the output shaft of the second stirring motor (24). The two sets of stirring blades (25) located in the middle are respectively located inside the second packing bin (6) and the third packing bin (7).

9. The CO2 injection-driven produced water stripping treatment device according to claim 1, characterized in that, The first packing chamber (41) is located above the part where the air guide pipe (22) connects to the first reaction tank (1). The air inlet pipe (21) is connected to the bottom of the second reaction tank (2). The water outlet pipe (23) is connected to the upper part of the second reaction tank (2). The air inlet pipe (21) and the water outlet pipe (23) are located on the same side of the second reaction tank (2).

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