Secondary oil-water separation device

Abstract

The utility model belongs to the technical field of oil-gas well production and separation, and particularly relates to a secondary oil-water separation device. Comprising a separation tank, a liquid inlet pipe is arranged on the side wall of the separation tank, the other end of the liquid inlet pipe is used for being connected with a crude oil storage tank, a liquid level meter is arranged on the side wall of the separation tank, an oil discharge pipe and a sewage discharge pipe are arranged at the bottom of the separation tank, the oil discharge pipe is used for being connected with the crude oil storage tank, and the sewage discharge pipe is used for being connected with a sewage tank. The secondary oil-water separation device is used for performing secondary separation on an oil-water mixture which is primarily separated in a crude oil storage tank, and sewage and crude oil are further separated through the secondary oil-water separation device, so that the content of crude oil in the sewage which enters a sewage tank from a blow-off pipe is greatly reduced, and the crude oil can be recycled into the crude oil storage tank to the greatest extent. After multiple cycles, the crude oil in the crude oil storage tank is high in purity, so that the quality of the crude oil in the crude oil storage tank is further guaranteed. According to the device, the crude oil treatment cost is not additionally increased while the sewage treatment difficulty is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas well production separation, and particularly relates to a secondary oil-water separation device. Background Art

[0002] During the production process of some oil and gas wells, the produced oil, gas and water mixture is separated into gas and liquid by the separator, and the liquid phase is discharged to the crude oil tank for oil-water separation. The crude oil has a low density and is located on the upper layer of the sewage. After oil-water separation, the sewage at the bottom of the crude oil tank is discharged to the sewage collection pool and then transported to the sewage tank by a pump.

[0003] At present, most crude oil storage tanks use natural sedimentation to achieve oil-water stratification, and the crude oil tanks are drained manually. During the drainage process, the on-duty personnel stop discharging sewage when they find that crude oil is discharged into the sewage pool. This causes part of the crude oil to be discharged into the collection pool, making it difficult to recover the crude oil and increasing the processing cost. The accumulation of crude oil in the sewage pool increases the difficulty and cost of sewage treatment. At the same time, crude oil is flammable and explosive, and there are safety risks such as fire and explosion when exposed in the sewage pool. Utility Model Content

[0004] The purpose of the utility model is to provide a secondary oil-water separation device to address the technical defect in the prior art that a certain amount of crude oil will enter the sewage pool along with the sewage during the sewage discharge from the crude oil tank, resulting in difficulty in sewage treatment in the sewage pool.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A secondary oil-water separation device comprises a separation tank body, a side wall of the separation tank body is provided with a liquid inlet pipe, the other end of the liquid inlet pipe is used to be connected to a crude oil storage tank, a side wall of the separation tank body is provided with a liquid level gauge, and an oil drain pipe and a sewage drain pipe are respectively provided at the bottom of the separation tank body, the oil drain pipe is used to be connected to the crude oil storage tank, and the sewage drain pipe is used to be connected to a sewage tank.

[0007] The utility model aims at the technical defects in the prior art that the sewage entering the sewage pool from the crude oil storage tank contains a large amount of crude oil, and the crude oil is difficult to recover from the sewage. A secondary oil-water separation device is proposed. The device is arranged between the crude oil storage tank and the sewage tank, and is used to perform secondary separation on the oil-water mixture initially separated in the crude oil storage tank. The sewage and crude oil are further separated by the secondary oil-water separation device, thereby greatly reducing the crude oil content in the sewage entering the sewage tank from the sewage pipe, and the crude oil can be recovered to the crude oil storage tank to the greatest extent. After multiple cycles, the crude oil in the crude oil storage tank has a high purity, which further guarantees the quality of the crude oil in the crude oil storage tank. The device reduces the difficulty of sewage treatment without increasing the cost of crude oil treatment.

[0008] In the technical solution of the utility model, the secondary oil-water separation device is used to perform secondary natural sedimentation of the oil-water mixture, and the oil-water separation interface in the secondary oil-water separation device is determined by a liquid level meter, and the oil-water interface can be observed in real time during the process of discharging sewage from the sewage pipe. The sewage pipe is closed in time.

[0009] As a preferred embodiment of the present invention, the separation tank is a cylindrical tank with a volume of 1m 3 -3m 3 .

[0010] Preferably, the interior of the separation tank is a sealed cavity.

[0011] As a preferred solution of the utility model, a first valve is provided on the sewage pipe.

[0012] As a preferred solution of the utility model, a second valve is provided on the oil drain pipe.

[0013] During the sewage discharge process, the first valve of the sewage discharge pipe is opened and the second valve is closed. During the crude oil discharge process, the second valve of the oil discharge pipe is opened and the first valve is closed.

[0014] As a preferred solution of the utility model, a fuel gas inlet pipe is provided on the top of the separation tank body, and a third valve is provided on the fuel gas inlet pipe. When the sewage in the device is discharged from the sewage pipe, the crude oil in the separation tank body returns to the crude oil storage tank from the oil discharge pipe. In this process, in order to efficiently and fully discharge the crude oil back to the crude oil storage tank, the third valve is opened, and the fuel gas is supplemented through the fuel gas pipeline to increase the pressure of the secondary oil-water separator. After the crude oil in the secondary oil-water separator is discharged, the third valve is closed, and the third valve is closed when the pressure gauge pressure drops to 0Mpa to complete the secondary oil-water separation.

[0015] As a preferred solution of the utility model, a pressure gauge is provided on the top of the separation tank.

[0016] As a preferred embodiment of the present invention, the liquid inlet pipe passes through the side wall of the separation tank body from the outside to the inside of the side wall. The part of the liquid inlet pipe located in the cavity of the separation tank body is vertically arranged, and a plurality of liquid outlet holes are arranged at intervals along the length direction of the vertical pipe body part. When the oil-water mixture enters the separation tank body from the crude oil storage tank, it enters the separation tank body evenly along the liquid outlet holes on the liquid inlet pipe.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0018] The device of the utility model is arranged between the crude oil storage tank and the sewage tank, and is used to perform secondary separation on the oil-water mixture initially separated in the crude oil storage tank. The sewage and crude oil are further separated by the secondary oil-water separation device, thereby greatly reducing the crude oil content in the sewage entering the sewage tank from the sewage pipe, and the crude oil can be recovered to the crude oil storage tank to the greatest extent. After multiple cycles, the crude oil in the crude oil storage tank has a high purity, which further ensures the quality of the crude oil in the crude oil storage tank. The device reduces the difficulty of sewage treatment without increasing the cost of crude oil treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model;

[0020] Figure 2 It is a schematic diagram of the structure of the utility model connected with a crude oil storage tank and a sewage tank;

[0021] Icon: 100-crude oil storage tank; 200-wastewater tank; 300-fuel gas tank;

[0022] 1-separation tank body; 2-liquid inlet pipe; 21-liquid outlet hole; 3-liquid level gauge; 4-oil drain pipe; 5-drain pipe; 6-fuel gas inlet pipe; 7-third valve; 8-first valve; 9-second valve; 10-pressure gauge. DETAILED DESCRIPTION

[0023] The utility model is described in detail below in conjunction with the accompanying drawings.

[0024] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0025] Example 1

[0026] This embodiment provides a secondary oil-water separation device, such as Figure 1-2 As shown, it includes a separation tank body 1, and a liquid inlet pipe 2 is provided on the side wall of the separation tank body 1. The other end of the liquid inlet pipe 2 is used to connect with the crude oil storage tank 100. Figure 2 As shown, the liquid inlet pipe 2 is used to discharge the oil-water mixture in the crude oil storage tank 100 into the separation tank body 1 , and the liquid inlet pipe 2 is arranged at the bottom side wall of the crude oil storage tank 100 .

[0027] The liquid inlet pipe 2 passes through the side wall of the separation tank body 1 from the outside to the inside of the side wall. The part of the liquid inlet pipe 2 located in the cavity of the separation tank body 1 is vertically arranged. The vertical pipe body part is provided with a plurality of liquid outlet holes 21 spaced apart along its length direction. When the oil-water mixture enters the separation tank body 1 from the crude oil storage tank, it enters the separation tank body 1 evenly along the liquid outlet holes 21 on the liquid inlet pipe 2.

[0028] A liquid level gauge 3 is provided on the side wall of the separation tank body 1. The secondary oil-water separation device is used to perform secondary natural sedimentation of the oil-water mixture, and the oil-water separation interface in the secondary oil-water separation device is determined by the liquid level gauge 3. During the process of discharging sewage from the sewage pipe 5, the oil-water interface can be observed in real time.

[0029] The bottom of the separation tank body 1 is provided with an oil drain pipe 4 and a sewage drain pipe 5, respectively. The oil drain pipe 4 is used to be connected to the crude oil storage tank 100, and the end of the oil drain pipe 4 connected to the crude oil storage tank 100 is arranged at the top of the crude oil storage tank 100. The sewage drain pipe 5 is used to be connected to the sewage tank 200.

[0030] As a more preferred embodiment, the sewage pipe 5 is provided with a first valve 8. The oil discharge pipe 4 is provided with a second valve 9. When the sewage pipe 5 is discharging sewage, the first valve 8 is opened and the second valve 9 is closed. When the oil discharge pipe 4 is discharging crude oil, the second valve 9 is in an open state and the first valve 8 is closed.

[0031] Furthermore, a pressure gauge 10 is provided on the top of the separation tank body 1 .

[0032] As a more preferred embodiment, a fuel gas inlet pipe 6 is provided on the top of the separation tank body 1, and a third valve 7 is provided on the fuel gas inlet pipe 6. When the sewage in the device is discharged from the sewage pipe 5, the crude oil in the separation tank body 1 returns to the crude oil storage tank 100 from the oil discharge pipe 4. In this process, in order to efficiently and fully discharge the crude oil back to the crude oil storage tank 100, the third valve 7 is opened, and the fuel gas is supplemented through the fuel gas pipeline to increase the pressure of the secondary oil-water separator. After the crude oil in the secondary oil-water separator is discharged, the third valve 7 is closed, and the third valve 7 is closed when the pressure of the pressure gauge 10 drops to 0Mpa, completing the secondary oil-water separation.

[0033] The utility model aims at the technical defects in the prior art that the sewage entering the sewage pool from the crude oil storage tank 100 contains a large amount of crude oil, and the crude oil is difficult to recover from the sewage. A secondary oil-water separation device is proposed. The device is arranged between the crude oil storage tank 100 and the sewage tank 200, and is used to perform secondary separation on the oil-water mixture preliminarily separated in the crude oil storage tank 100. The sewage and the crude oil are further separated by the secondary oil-water separation device, thereby greatly reducing the crude oil content in the sewage entering the sewage tank 200 from the sewage pipe 5, and the crude oil can be recovered to the crude oil storage tank 100 to the greatest extent. After multiple cycles, the crude oil in the crude oil storage tank 100 has a high purity, which further guarantees the quality of the crude oil in the crude oil storage tank 100. The device reduces the difficulty of sewage treatment without additionally increasing the cost of crude oil treatment.

[0034] In the technical solution of this embodiment, the separation tank body 1 is a cylindrical tank body, and the volume of the separation tank body 1 is 1m 3 -3m 3 The interior of the separation tank body 1 is a sealed cavity. The separation tank body 1 is made of steel as a whole.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A secondary oil-water separation device, characterized in that: The invention comprises a separation tank body (1), wherein a liquid inlet pipe (2) is arranged on the side wall of the separation tank body (1), and the other end of the liquid inlet pipe (2) is used to be connected to a crude oil storage tank (100); a liquid level gauge (3) is arranged on the side wall of the separation tank body (1); and an oil discharge pipe (4) and a sewage discharge pipe (5) are respectively arranged on the bottom of the separation tank body (1); the oil discharge pipe (4) is used to be connected to the crude oil storage tank (100), and the sewage discharge pipe (5) is used to be connected to a sewage tank (200).

2. The secondary oil-water separation device according to claim 1, characterized in that: The sewage discharge pipe (5) is provided with a first valve (8).

3. The secondary oil-water separation device according to claim 1, characterized in that: The oil drain pipe (4) is provided with a second valve (9).

4. The secondary oil-water separation device according to claim 1, characterized in that: A fuel gas inlet pipe (6) is provided on the top of the separation tank body (1), and a third valve (7) is provided on the fuel gas inlet pipe (6).

5. The secondary oil-water separation device according to claim 1, characterized in that: A pressure gauge (10) is provided on the top of the separation tank (1).

6. The secondary oil-water separation device according to any one of claims 1 to 5, characterized in that: The liquid inlet pipe (2) penetrates from the outside of the side wall of the separation tank body (1) to the inside of the side wall. The portion of the liquid inlet pipe (2) located in the cavity of the separation tank body (1) is vertically arranged. The vertical pipe body portion has a plurality of liquid outlet holes (21) arranged at intervals along its length direction.

7. The secondary oil-water separation device according to claim 6, characterized in that: The separation tank body (1) is a cylindrical tank body.

8. The secondary oil-water separation device according to claim 6, characterized in that: The volume of the separation tank (1) is 1m 3 -3m 3 .

9. The secondary oil-water separation device according to claim 6, characterized in that: The interior of the separation tank (1) is a sealed cavity.

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