Reverse washing water dosing and desilting device of offshore oilfield production water fine treatment system

Abstract

The utility model discloses a backwashing water dosing and desilting device of an offshore oilfield production water fine treatment system. The backwashing water dosing and desilting device comprises a dosing mechanism, a settling mechanism and a centrifugal machine, wherein the dosing mechanism consists of a medicament tank I and a medicament tank II; the settling mechanism consists of a settling tank I and a settling tank II; an outlet of the medicament tank I is respectively communicated with dosing ports of the settling tank I and the settling tank II through a pipeline and a delivery pump I; an outlet of the medicament tank II is respectively communicated with a dosing port of the first-stage settling tank and a dosing port of the second-stage settling tank through a pipeline and a delivery pump II; a first-stage sludge outlet of the first-stage settling tank is communicated with an inlet of the second-stage settling tank through a pipeline and a first-stage sludge pump; a second-stage sludge outlet of the second-stage settling tank is communicated with an inlet of the centrifugal machine through a pipeline and a second-stage sludge pump, and a second-stage clear liquid outlet of the second-stage settling tank is communicated with the first-stage settling tank through a pipeline and a second-stage transfer pump. According to the utility model, the 140m < 3 > settling tank is used for realizing backwashing water treatment of the production water fine treatment system with daily treatment capacity of 18000m < 3 >, a large amount of equipment installation space and comprehensive cost are saved for design, construction and operation of the offshore oilfield production water fine treatment system, the universality is high, and the operation process is simple.

Description

Technical Field

[0001] This utility model belongs to the field of fine treatment technology for offshore oilfield production water, specifically relating to a backwash water chemical dosing and sludge removal device for a fine treatment system of offshore oilfield production water. Background Technology

[0002] As offshore oil and gas field development enters its mid-to-late stages, the water content of downhole produced fluids continues to rise. After oil-water separation, a large amount of oily wastewater is generated that fails to meet environmental protection requirements and needs treatment. Simultaneously, there is a significant demand for reservoir water injection to increase production. To meet the production water treatment needs of offshore oil fields, facilities with a daily treatment capacity of 18,000 m³ / s have been successively constructed and put into operation. 3 and 30000m 3 Large-scale production water fine treatment systems can solve the environmental problem of large-scale oily wastewater discharge and achieve the recycling of production water, addressing the water source needs of large reservoirs for injection. However, the solid-liquid separation of backwash water in production water treatment systems is affected by factors such as the flocculation and sedimentation effect of chemical agents, sedimentation time, and system processing speed. The quality of the backwash water chemical desludge removal process significantly impacts the system's construction scale, treatment efficiency, investment, and operating costs. Currently, onshore oilfields, not limited by equipment installation space, generally construct numerous sedimentation tanks to extend the sedimentation time of backwash water to achieve solid-liquid separation. However, offshore oilfields, due to limited platform space, cannot install sedimentation tanks of sufficient capacity, leading to difficulties in backwash water desludge removal. Utility Model Content

[0003] This utility model is proposed to solve the problem that the existing offshore oilfield production water fine treatment system has a short backwash water settling time and cannot effectively remove mud due to the limited space of the offshore platform and the small capacity of the settling tank. Its purpose is to provide a backwash water chemical dosing and mud removal device for offshore oilfield production water fine treatment system.

[0004] This utility model is achieved through the following technical solution:

[0005] A backwash water chemical dosing and sludge removal device for a fine treatment system of offshore oilfield production water includes a dosing mechanism, a settling mechanism, and a centrifuge. The dosing mechanism includes a No. 1 chemical tank and a No. 2 chemical tank. The settling mechanism includes a primary settling tank and a secondary settling tank. The outlet of the No. 1 chemical tank is connected to the dosing ports of the primary and secondary settling tanks via pipelines and a No. 1 transfer pump, respectively. The outlet of the No. 2 chemical tank is connected to the dosing ports of the primary and secondary settling tanks via pipelines and a No. 2 transfer pump, respectively. The primary sludge outlet of the primary settling tank is connected to the inlet of the secondary settling tank via a pipeline and a primary sludge pump. The secondary sludge outlet of the secondary settling tank is connected to the inlet of the centrifuge via a pipeline and a secondary sludge pump, and its secondary clear liquid outlet is connected to the primary settling tank via a pipeline and a secondary transfer pump.

[0006] In the above technical solution, the side wall of the first-stage settling tank is provided with a backwash water inlet, and the system backwash water is connected to the backwash water inlet of the first-stage settling tank through the incoming water pipeline.

[0007] In the above technical solution, a Class I sludge outlet is provided at the bottom of the Class I settling tank.

[0008] In the above technical solution, the No. I reagent tank, the No. II reagent tank, the first-stage settling tank, and the second-stage settling tank are all equipped with a stirring device.

[0009] In the above technical solution, the outlets of the No. I and No. II medicine tanks are located at the bottom of the tanks.

[0010] In the above technical solution, the dosing ports of the Class I settling tank and the Class II settling tank are located at the top of the tank.

[0011] The beneficial effects of this utility model are:

[0012] This utility model provides a backwash water chemical dosing and sludge removal device for a fine treatment system of offshore oilfield production water, using a 140m³... 3 The settling tank achieves a daily processing capacity of 18,000 m³. 3 The production water fine treatment system for backwash water treatment saves a significant amount of equipment installation space and overall costs in the design, construction, and operation of offshore oilfield production water fine treatment systems. It is universally applicable to different oilfield water qualities and designed treatment capacities. The matching function can be achieved by adjusting appropriate parameters through on-site bottle tests. It has high versatility and simple operation process. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model.

[0014] in:

[0015] 1. Chemical tank No. I; 2. Chemical tank No. II; 3. Settling tank No. I; 4. Settling tank No. II; 5. Centrifuge; 6. Transfer pump No. I; 7. Transfer pump No. II; 8. Transfer pump No. II; 9. Sludge pump No. II; 10. Sludge pump No. I.

[0016] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1As shown, a backwash water dosing and sludge removal device for a fine treatment system of offshore oilfield production water includes a dosing mechanism, a settling mechanism, and a centrifuge 5;

[0019] The dosing mechanism includes a No. 1 medicine tank and a No. 2 medicine tank;

[0020] The settling mechanism includes a Class I settling tank 3 and a Class II settling tank 4;

[0021] The outlet of the No. I reagent tank 1 is connected to the dosing ports of the Class I settling tank 3 and the Class II settling tank 4 via pipelines and the No. I delivery pump 6, respectively.

[0022] The outlet of the No. II reagent tank 2 is connected to the dosing ports of the No. I settling tank 3 and the No. II transfer pump 7 via pipelines and the dosing ports of the No. II settling tank 4, respectively.

[0023] The side wall of the first-stage settling tank 3 is provided with a backwash water inlet, and the system backwash water is connected to the backwash water inlet of the first-stage settling tank 3 through the incoming water pipeline;

[0024] The bottom of the first-stage settling tank 3 is provided with a first-stage sludge outlet, and the first-stage sludge outlet is connected to the inlet of the second-stage settling tank 4 through a pipeline and a first-stage sludge pump 10.

[0025] The first-stage settling tank 3 is equipped with a first-stage clear liquid outlet, and the clear liquid outlet is transferred to the clear liquid filtration equipment for treatment via pipeline;

[0026] The secondary settling tank 4 is equipped with a secondary clear liquid outlet and a secondary sludge outlet. The secondary sludge outlet is connected to the inlet of the centrifuge 5 through a pipeline and a secondary sludge pump 9. The secondary clear liquid outlet is connected to the primary settling tank 3 through a pipeline and a secondary transfer pump 8.

[0027] The No. 1 reagent tank, No. 2 reagent tank, the No. 1 settling tank, and the No. 4 settling tank are all equipped with a stirring device.

[0028] The outlets of the No. 1 and No. 2 medicine containers are located at the bottom of the containers.

[0029] The dosing ports of the Class I settling tank 3 and Class II settling tank 4 are located at the top of the tanks.

[0030] In this embodiment, the reagent selected for reagent tank I is PAC, with a concentration of 100 mg / L to 300 mg / L; the reagent selected for reagent tank II is PAM, with a concentration of 10 mg / L to 30 mg / L. The optimal dosing concentration can be determined by bottle testing based on the on-site water quality. The dosing flocculation effect is determined based on the settling of flocs and the transparency of the supernatant.

[0031] The processing technology using this utility model is as follows:

[0032] i. Prepare a PAC solution with a concentration of 250 mg / L in reagent tank 1 and a PAM solution with a concentration of 10 mg / L in reagent tank 2. The PAC solution and PAM solution are used for adding chemicals to the settling tank.

[0033] ii. The system backwash water enters the first-stage settling tank 3 through the incoming water pipeline, stands for 5 minutes, and is skimmed off with water.

[0034] iii. After skimming off the oil, PAC solution and PAM solution are added to the first-stage settling tank 3 through transfer pump 6 and transfer pump 7, respectively. After adding the solution, the tank is stirred and allowed to settle for 15 minutes.

[0035] iv. After the reagents settle in the first-stage settling tank 3, the flocculated sludge is transported to the second-stage settling tank 9 by the first-stage sludge pump 10; the supernatant after settling in the first-stage settling tank 3 is transferred to the clear liquid filtration equipment for treatment through pipelines.

[0036] After receiving a certain amount of flocculated sludge in the V and II stage settling tanks, a certain amount of PAC solution is added through pump I 6 and stirred for secondary settling, which lasts for 15 minutes.

[0037] vi. After secondary settling, the sludge is transported to centrifuge 5 by the Class II sludge pump 9 for centrifugal dewatering. The moisture content of the dewatered sludge is <80%.

[0038] vii. The dewatered sludge is transported to the sludge tank via a screw conveyor for onshore treatment; the supernatant remaining in the stage II settling tank is transported to the stage I settling tank 3 via stage II transfer pump 8 for recycling.

[0039] The entire treatment process is repeated cyclically, solving the problem that backwash water cannot remove sludge.

[0040] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] The applicant declares that the above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model fall within the protection and disclosure scope of the present utility model.

Claims

1. A backwash water chemical dosing and sludge removal device for a fine treatment system of offshore oilfield production water, characterized in that: The system includes a dosing mechanism, a settling mechanism, and a centrifuge (5); the dosing mechanism includes a No. 1 reagent tank (1) and a No. 2 reagent tank (2); the settling mechanism includes a first-stage settling tank (3) and a second-stage settling tank (4); the outlet of the No. 1 reagent tank (1) is connected to the dosing ports of the first-stage settling tank (3) and the second-stage settling tank (4) via a pipeline and a No. 1 transfer pump (6); the outlet of the No. 2 reagent tank (2) is connected to the dosing port of the second-stage settling tank (7) via a pipeline and a No. 2 transfer pump (7). The first-stage sludge outlet of the first-stage settling tank (3) and the second-stage settling tank (4) are respectively connected to the dosing ports of the first-stage settling tank (3); the first-stage sludge outlet of the first-stage settling tank (3) is connected to the inlet of the second-stage settling tank (4) through a pipeline and a first-stage sludge pump (10); the second-stage sludge outlet of the second-stage settling tank (4) is connected to the inlet of the centrifuge (5) through a pipeline and a second-stage sludge pump (9), and its second-stage clear liquid outlet is connected to the first-stage settling tank (3) through a pipeline and a second-stage transfer pump (8).

2. The backwash water dosing and sludge removal device of the offshore oilfield production water fine treatment system according to claim 1, characterized in that: The side wall of the first-stage settling tank (3) is provided with a backwash water inlet, and the system backwash water is connected to the backwash water inlet of the first-stage settling tank (3) through the incoming water pipeline.

3. The backwash water dosing and sludge removal device of the offshore oilfield production water fine treatment system according to claim 1, characterized in that: The bottom of the Class I settling tank (3) is provided with a Class I sludge outlet.

4. The backwash water dosing and sludge removal device of the offshore oilfield production water fine treatment system according to claim 1, characterized in that: The No. I reagent tank (1), No. II reagent tank (2), Class I settling tank (3), and Class II settling tank (4) are all equipped with a stirring device.

5. The backwash water dosing and sludge removal device of the offshore oilfield production water fine treatment system according to claim 1, characterized in that: The outlets of the No. I medicine container (1) and the No. II medicine container (2) are located at the bottom of the container.

6. The backwash water dosing and desludge removal device of the offshore oilfield production water fine treatment system according to claim 1, characterized in that: The dosing ports of the Class I settling tank (3) and Class II settling tank (4) are located at the top of the tank.

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