Shale oil produced water treatment evaluation device

Abstract

The utility model discloses a shale oil produced water treatment evaluation device which is characterized in that a pre-oxidation pond, a biochemical pond, a flocculating settling pond and a sand filter tank are sequentially mounted on a skid-mounted base, an outlet of an oily sewage feeding pipe is connected with an inlet of a first-stage lifting pump, and an outlet of the first-stage lifting pump is connected with a water inlet of the pre-oxidation pond through a flow meter; a water outlet of the pre-oxidation pond is connected with a water inlet of the biochemical pond, a water outlet of the biochemical pond is connected with a water inlet of the flocculating settling pond, and a water outlet of the flocculating settling pond is connected with an upper inlet of the sand filtering tank through a secondary lifting pump; the outlet of the flow meter is further connected with a first bypass pipe, the water outlet of the pre-oxidation pond is further connected with a second bypass pipe, the water outlet of the biochemical pond is further connected with a third bypass pipe, the outlets of the first bypass pipe, the second bypass pipe and the third bypass pipe are respectively connected with an overrunning pipeline, and the outlet of the overrunning pipeline is connected with the inlet of a secondary lifting pump. According to the device, shale oil produced water treatment technology evaluation is carried out through different treatment process combinations, and targeted treatment is realized.

Description

Technical Field

[0001] The utility model relates to a shale oil produced water treatment evaluation device, belonging to the technical field of oilfield oily sewage treatment. Background Technique

[0002] With the gradual deepening of the exploration and development of oilfield shale oil, the effective treatment of shale oil well produced water has become an important part of the oilfield shale oil exploration process and the regional environmental carrying capacity. The shale oil produced water is mainly composed of fracturing fluid and formation water. The fracturing fluid is mainly composed of a large amount of water and a small amount of additives. The additive components generally include drag reducer, hydrochloric acid, oil washing agent, swelling inhibitor, high temperature corrosion inhibitor, breaker, etc.

[0003] Through water quality analysis and indoor treatment experiments, the following characteristics of shale oil produced water are preliminarily obtained: ① The produced liquid has high stability, poor flocculation and sedimentation effect, and the difficulty of water treatment increases; ② The produced liquid has a high degree of emulsification, difficult demulsification and dehydration, and the oil content of the deoiled sewage is difficult to meet the external discharge or reinjection index; ③ The difficulty of sewage treatment increases. After secondary oil removal, dosing, filtration and other processes, the oil content of the water station's exported sewage is still relatively high and special treatment is required; ④ The comprehensive treatment cost of the produced liquid increases.

[0004] At present, there are mainly two ways to treat shale oil produced water. One is to directly enter the conventional water treatment system, which can effectively save costs, but will increase the system load and even cause the decline of the water system treatment capacity. The other is to build a separate station for shale oil produced water. However, the shale oil produced water varies greatly with the formation (spatial position), fracturing process (the composition of the fluid injected into each well is complex and different) and time, resulting in difficult characteristic analysis and difficult in-depth understanding of the stabilization mechanism, and putting forward high requirements for the adaptability and unity of the treatment process.

[0005] At present, there is no unified shale oil produced water treatment process. Therefore, it is necessary to carry out evaluation experiments for shale oil produced water treatment. However, indoor experiments are limited by indoor water quality stability and water treatment continuity, etc., and cannot simulate on-site dynamic conditions, and cannot objectively evaluate the water treatment effect of the developed process technology, so it is necessary to carry out on-site pilot tests.

[0006] At present, the existing small-scale pilot devices for produced water treatment usually target conventional oily sewage, and cannot specifically evaluate the treatment effects of different treatment process combinations, nor can they evaluate the impact of shale oil produced water on the conventional water treatment system. Content of the Utility Model

[0007] The purpose of this part is to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and the title of the application of this application, and such simplifications or omissions shall not be used to limit the scope of the utility model.

[0008] In view of the above problems and / or those existing in the prior art, the present utility model is proposed.

[0009] The purpose of the present utility model is to provide an evaluation device for treating shale oil produced water, aiming at the problems of large differences in the composition of shale oil produced water and great difficulty in treatment. By adopting four units of pre-oxidation, biochemical treatment, flocculation and filtration, and through different treatment process combinations, the evaluation of shale oil produced water treatment technology is carried out to achieve targeted treatment of shale oil produced water.

[0010] To solve the above technical problems, an evaluation device for treating shale oil produced water of the present utility model includes a skid-mounted base, on which a pre-oxidation tank, a biochemical tank, a flocculation sedimentation tank and a sand filter tank are sequentially installed. The outlet of the oily sewage incoming pipe is connected to the inlet of the first-stage lift pump, and the outlet of the first-stage lift pump is connected to the inlet of the pre-oxidation tank through a flow meter. The outlet of the pre-oxidation tank is connected to the inlet of the biochemical tank, the outlet of the biochemical tank is connected to the inlet of the flocculation sedimentation tank, and the outlet of the flocculation sedimentation tank is connected to the upper inlet of the sand filter tank through a second-stage lift pump;

[0011] The outlet of the flow meter is also connected to a first bypass pipe, the outlet of the pre-oxidation tank is also connected to a second bypass pipe, the outlet of the biochemical tank is also connected to a third bypass pipe, the outlets of the first, second and third bypass pipes are respectively connected to a bypass pipeline, and the outlet of the bypass pipeline is connected to the inlet of the second-stage lift pump.

[0012] Further, the pre-oxidation tank is separated into a chemical addition area and an aeration area by a vertical partition board. The lower part of the chemical addition area is connected to the aeration area through a notch under the vertical partition board. An oxidation chemical tank is installed at the head end of the skid-mounted base, and the outlet of the oxidation chemical tank is connected to the inlet of the chemical addition area through an oxidant metering pump; a plurality of oxidation tank aeration components are evenly distributed at the bottom of the aeration area, and each oxidation tank aeration component is respectively connected to the outlet of a blower through an air supply pipeline.

[0013] Further, a combined filler for microbial attachment is evenly arranged in the biochemical tank, and a plurality of biochemical tank aeration components are evenly distributed at the bottom of the biochemical tank. Each biochemical tank aeration component is respectively connected to the outlet of a blower through an air supply pipeline.

[0014] Further, the flocculation sedimentation tank includes a flocculation reaction tank and a sedimentation tank with a communicating bottom. A mechanical stirring paddle is arranged in the flocculation reaction tank, a flocculant preparation tank is arranged above the flocculation reaction tank, and the bottom of the flocculant preparation tank is connected to the inlet of the flocculation reaction tank through a flocculant metering pump. A plurality of inclined plates are evenly arranged in the middle of the sedimentation tank.

[0015] Further, the bottoms of the pre-oxidation tank, the biochemical tank, the flocculation and sedimentation tank, and the sand filter tank are respectively connected to a sewage discharge pipe through sewage discharge valves.

[0016] Further, a clarified tank after filtration is installed at the end of the skid-mounted base. The lower outlet of the sand filter tank is connected to the upper inlet of the clarified tank after filtration, and the overflow outlet of the clarified tank after filtration is connected to a treated drain pipe.

[0017] Further, the bottom outlet of the clarified tank after filtration is connected to the sewage discharge pipe through a sewage discharge valve. The lower outlet of the clarified tank after filtration is connected to the inlet of a backwash pump. The outlet of the backwash pump is connected to the lower outlet of the sand filter tank through a backwash inlet valve. The top outlet of the sand filter tank is connected to the sewage discharge pipe through a backwash drain pipe and a backwash drain valve.

[0018] Further, the outlet of the treated drain pipe is connected to the sewage discharge pipe, and a total discharge valve is installed at the outlet of the sewage discharge pipe.

[0019] Further, a first bypass valve is provided on the bypass pipeline between the first bypass pipe and the second bypass pipe. A second bypass valve is provided on the bypass pipeline between the second bypass pipe and the third bypass pipe. A third bypass valve is provided on the bypass pipeline between the third bypass pipe and the inlet of the secondary lift pump.

[0020] Further, a vertical partition is provided in the biochemical tank to divide the biochemical tank into a first biochemical tank and a second biochemical tank. The overflow outlet of the first biochemical tank is connected to the lower part of the second biochemical tank through a vertical diversion pipe. The biochemical tank aeration assemblies of the first biochemical tank and the second biochemical tank are each provided with an aeration control valve.

[0021] Compared with the prior art, the present utility model has achieved the following beneficial effects: 1. It can simulate various wastewater treatment processes, facilitating the selection of the most suitable treatment process according to the concentration of shale oil produced water;

[0022] 2. The water quality of the produced water of the equipment is stable, with both oil and solid suspended particles less than 15 mg / L, and it can accurately evaluate the impact of shale oil produced water on conventional water treatment systems;

[0023] 3. It can achieve full-process automatic control and can operate unattended for 24 hours;

[0024] 4. It has high safety, with upper and lower limit alarms and interlock protection for pressure, and is equipped with a fault self-diagnosis system;

[0025] 5. It has a skid-mounted design, with a compact structure and convenient transportation, and is suitable for various production environments such as station depots and well sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the attached drawings required for the description of the embodiments. Obviously, the attached drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other attached drawings can be obtained based on these drawings. The attached drawings are only for reference and explanation, and are not used to limit the present utility model. Among them:

[0027] Figure 1 It is a schematic structural diagram of the shale oil produced water treatment evaluation device of the present utility model;

[0028] In the figure: 1. Oxidation reagent tank; 2. Pre-oxidation tank; 3. Biochemical tank; 4. Flocculation sedimentation tank; 5. Flocculant preparation tank; 6. Sand filter tank; 7. Filtered water clarification tank; Q1. Rotameter;

[0029] G1. Oil-containing sewage incoming pipe; G2. First bypass pipe; G3. Second bypass pipe; G4. Third bypass pipe; G5. Surpassing pipeline; G6. Drainage pipe; G7. Treated water drainage pipe; G8. Backwash drainage pipe;

[0030] B1. First-stage lift pump; B2. Second-stage lift pump; B3. Oxidant metering pump; B4. Flocculant metering pump; B5. Backwash pump;

[0031] V1. Pre-oxidation tank effluent valve; V2. Biochemical tank inlet valve; V3. Biochemical tank effluent valve; V4. Flocculation reaction inlet valve; V5. Sedimentation tank effluent valve; V6. Sand filter effluent valve; V7. First bypass valve; V8. Second bypass valve; V9. Third bypass valve; V10. Backwash inlet valve; V11. Backwash drainage valve; V12. Oxidation tank drain valve; V13. Biochemical tank drain valve; V14. Sedimentation tank drain valve; V15. Sand filter tank drain valve; V16. Filtered water tank drain valve; V17. Total discharge valve. Detailed implementation manners

[0032] In the following description of the present utility model, the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. are based on the orientation or positional relationships shown in the attached drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating that the device must have a specific orientation.

[0033] In order to make the technical means, creative features, achieved purposes and effects realized by the present utility model easy to understand, the following further elaborates the present utility model in conjunction with specific illustrations. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this utility model pertains. The terms used in the description of this utility model herein are for the purpose of describing specific embodiments only and are not intended to limit this utility model.

[0035] As Figure 1 shown, the shale oil produced water treatment evaluation device of this utility model belongs to a small multi-functional oily sewage treatment device, including 1 set of chemical dosing system, 1 set of pre-oxidation tank, 1 set of biochemical tank, 1 set of flocculation sedimentation tank, 1 set of filtration, 2 lifting pumps, 1 blower, 1 backwash pump, 2 chemical dosing pumps, 1 skid-mounted base, and 1 automatic control system. Specifically, on the skid-mounted base of the shale oil produced water treatment evaluation device, a pre-oxidation tank 2, a biochemical tank 3, a flocculation sedimentation tank 4, a flocculant preparation tank 5, a sand filter tank 6, and a clarified filtrate tank 7 are sequentially installed. The outlet of the oily sewage incoming pipe G1 is connected to the inlet of the first-stage lifting pump B1. The outlet of the first-stage lifting pump B1 is connected to the inlet of the pre-oxidation tank 2 through a rotameter Q1. The outlet of the pre-oxidation tank 2 is connected to the inlet of the biochemical tank 3. The outlet of the biochemical tank 3 is connected to the inlet of the flocculation sedimentation tank 4. The outlet of the flocculation sedimentation tank 4 is connected to the upper inlet of the sand filter tank 6 through a second-stage lifting pump B2.

[0036] The outlet of the rotameter Q1 is also connected to a first bypass pipe G2. The outlet of the pre-oxidation tank 2 is also connected to a second bypass pipe G3. The outlet of the biochemical tank 3 is also connected to a third bypass pipe G4. The outlets of the first, second, and third bypass pipes are respectively connected to a bypass pipeline G5. The outlet of the bypass pipeline G5 is connected to the inlet of the second-stage lifting pump B2. A first bypass valve V7 is provided on the bypass pipeline G5 between the first bypass pipe G2 and the second bypass pipe G3. A second bypass valve V8 is provided on the bypass pipeline G5 between the second bypass pipe G3 and the third bypass pipe G4. A third bypass valve V9 is provided on the bypass pipeline G5 between the third bypass pipe G4 and the inlet of the second-stage lifting pump B2.

[0037] The pre-oxidation tank 2 is separated into a chemical dosing area and an aeration area by a vertical partition. The lower part of the chemical dosing area is connected to the aeration area through a notch below the vertical partition. An oxidation chemical tank 1 is installed at the head end of the skid-mounted base. The outlet of the oxidation chemical tank 1 is connected to the inlet of the chemical dosing area through an oxidant metering pump B3. A plurality of oxidation tank aeration components are evenly distributed at the bottom of the aeration area. Each oxidation tank aeration component is respectively connected to the outlet of the blower through an air supply pipeline. An overflow trough of the pre-oxidation tank is provided in the outlet area of the aeration area, and water overflows evenly through each sawtooth trough.

[0038] The biochemical pond 3 is evenly equipped with combined fillers for microorganisms to attach. Multiple biochemical pond aeration components are evenly distributed at the bottom of the biochemical pond 3, and each biochemical pond aeration component is respectively connected to the outlet of the blower through an air supply pipeline. A vertical partition is provided in the biochemical pond 3 to divide the biochemical pond 3 into a first biochemical pond and a second biochemical pond. The upper part of the first biochemical pond overflows and enters the bottom of the second biochemical pond through a diversion pipe; the bottoms of the first biochemical pond and the second biochemical pond can also be connected through the lower notch of the vertical partition. The biochemical pond aeration components of the first biochemical pond and the second biochemical pond are each provided with an aeration control valve to facilitate the zonal control of the aeration volume. A biochemical pond overflow trough is provided at the water outlet of the second biochemical pond, and the water overflows evenly through each serrated trough.

[0039] The flocculation sedimentation pond 4 includes a flocculation reaction pond and a sedimentation pond with a connected bottom. A mechanical stirring paddle is provided in the flocculation reaction pond, and a flocculant preparation pond 5 is provided above the flocculation reaction pond for adding flocculants. In the sedimentation pond, the sedimentation speed of the flocs is greater than the rising speed of the clear liquid, so as to realize the separation of the sediment; inclined plates are evenly arranged in the middle of the sedimentation pond to improve the sedimentation efficiency.

[0040] The post-filtration clarifying pond 7 is installed at the end of the skid-mounted base. The lower outlet of the sand filter tank 6 is connected to the upper inlet of the post-filtration clarifying pond 7, and the overflow port of the post-filtration clarifying pond 7 is connected to the treated drain pipe G7. The outlet of the treated drain pipe G7 is connected to the sewage drain pipe G6, and a total discharge valve V17 is installed at the outlet of the sewage drain pipe G6.

[0041] The lower outlet of the post-filtration clarifying pond 7 is connected to the inlet of the backwashing pump B5. The outlet of the backwashing pump B5 is connected to the lower outlet of the sand filter tank 6 through a backwashing inlet valve V10. The top outlet of the sand filter tank 6 is connected to the sewage drain pipe G6 through a backwashing drain pipe G8 and a backwashing drain valve V11.

[0042] Upper and lower limit alarms and interlock protections are set for the outlet pressure of each pump, and fault self-diagnosis is provided to ensure the stable, reliable and safe operation of the device; the equipment is integrally equipped with a liquid level transmitter, a pointer pressure gauge, a bimetallic thermometer, etc. to observe and adjust the inlet water temperature, pressure and flow rate; all sensors and instruments are explosion-proof type. It is powered by DC24V, the installation position is dust-proof, waterproof, shock-resistant and easy to replace and maintain, and is connected to the on-site distribution box or the PLC input port through an RVVP shielded cable.

[0043] The working principles of each treatment unit are as follows:

[0044] 1. Pre-oxidation

[0045] The sewage is lifted by the primary lift pump B1, and after flow regulation, it enters the pre-oxidation tank 2. The pre-oxidation tank 2 is equipped with a chemical dosing device, and oxidation chemicals are added through the chemical dosing device to oxidize and degrade the pollutants that are difficult to degrade in the sewage. An aeration component is arranged in the pre-oxidation tank 2, and oxygen is supplied by the air provided by the blower for oxygenation aeration to provide the necessary oxygen for the oxidation reaction to improve the efficiency of the oxidation reaction.

[0046] 2. Sewage biochemical treatment

[0047] The effluent from the pre-oxidation tank flows by gravity into the biochemical tank 3 for biochemical treatment. The biochemical tank 3 is equipped with a combined filler for microorganisms to attach to. A blower is equipped to supply oxygen to the biochemical tank 3. The operation of the biochemical tank 3 includes two modes: First, in the initial stage, petroleum hydrocarbon-degrading bacteria are added for acclimation and cultivation. The microorganisms multiply in large numbers in the tank and on the filler, and through their own metabolism, the emulsified oil and other organic substances in the water are removed, thus achieving sewage purification. Second, since the shale oil produced water contains a large amount of polymers, resulting in difficult destabilization of the sewage, to improve the sewage treatment efficiency, polyacrylamide-degrading bacteria are added in the initial stage to reduce the polymer content in the sewage.

[0048] 3. Flocculation and sedimentation

[0049] The effluent from the biochemical tank flows by gravity into the flocculation and sedimentation tank 4. Above the flocculation reaction tank of the flocculation and sedimentation tank 4, there is a flocculant preparation tank 5. A flocculant metering pump B4 is used to add flocculant to the flocculation reaction tank. At the same time, the flocculation reaction tank is equipped with a mechanical stirring paddle. The medicine and water are mechanically stirred in the flocculation reaction tank, increasing the velocity gradient of the medicine-water reaction, ensuring the required GT value for the reaction, and enabling the medicine and water to be evenly mixed. The coagulation and flocculation reactions are stable, and uniform flocs are generated. The sewage containing flocs enters the sedimentation tank, and after natural sedimentation, the clarified liquid rises to the overflow trough and is discharged.

[0050] 4. Filtration and filter media cleaning

[0051] The overflow effluent from the flocculation and sedimentation tank 4 is pressurized by the secondary lift pump B2 and pumped into the sand filter tank 6 for filtration. The sand filter tank 6 uses modified quartz sand as the filter media. The modified quartz sand does not stick to oil, is pollution-resistant, has a high filtration efficiency, and can intercept most of the suspended solids and part of the oil in the sewage, making the effluent further clarified;

[0052] The backwashing and regeneration of the filter media are carried out once per shift or adjusted appropriately according to the water quality of the effluent. Manual control of the backwashing pump B5 and the corresponding valves is used for backwashing. During backwashing, the sand filter effluent valve V6 and the outlet valve of the secondary lift pump B2 are closed, the backwashing inlet valve V10 and the backwashing drain valve V11 are opened, the backwashing pump B5 is started, and the clear water in the post-filtration clarifying tank 7 is used to clean the sand filter tank 6. The clear water in the post-filtration clarifying tank 7 is sent out by the backwashing pump B5, enters the bottom of the sand filter tank 6 through the backwashing inlet valve V10, flows upward and flushes the modified quartz sand filter media, flushes out the dirt, and is discharged through the backwashing drain pipe G8 and the backwashing drain valve V11 and enters the sewage pipe G6 for discharge.

[0053] 5. Sewage Discharge

[0054] The floating oil or floating scum on the top of the liquid level in the pre-oxidation tank 2, biochemical tank 3, and flocculation sedimentation tank 4 is discharged through the oil drain valve or manually removed. The bottom of the pre-oxidation tank 2 is connected to the sewage pipe G6 through the oxidation tank sewage discharge valve V12, the bottom of the biochemical tank 3 is connected to the sewage pipe G6 through the biochemical tank sewage discharge valve V13, the bottom of the flocculation sedimentation tank 4 is connected to the sewage pipe G6 through the sedimentation tank sewage discharge valve V14, the bottom of the sand filter tank 6 is connected to the sewage pipe G6 through the sand filter tank sewage discharge valve V15, and the bottom of the post-filtration clarifying tank 7 is connected to the sewage pipe G6 through the post-filtration tank sewage discharge valve V16. The sludge and sediment settled at the bottom of each tank are manually discharged through each sewage discharge valve.

[0055] 6. Adjust the Water Treatment Process Combination

[0056] Through the switching of valves, this device can select different combinations of water treatment units according to different water qualities, so as to select the optimal and most suitable treatment process configuration. The four units of pre-oxidation, biochemical, flocculation, and filtration can operate separately or in series with different combinations, and can also operate in series throughout the process. Through different combinations of treatment processes, targeted treatment of shale oil produced water is achieved.

[0057] The first process flow is as follows: The shale oil produced water from the oily sewage feed pipe G1 is sent out by the primary lift pump B1, metered by the rotameter, and then enters the pre-oxidation tank 2. After oxidation and degradation, the wastewater flows out from the pre-oxidation tank effluent valve V1 and then enters the biochemical tank 3 through the biochemical tank inlet valve V2. After biochemical degradation, the wastewater is discharged from the biochemical tank effluent valve V3 and then enters the flocculation sedimentation tank 4 through the flocculation reaction inlet valve V4. The overflow effluent after flocculation and sedimentation flows out from the sedimentation tank effluent valve V5, is sent into the sand filter tank 6 by the secondary lift pump B2 for filtration. The filtered clear liquid enters the post-filtration clarifying tank 7 through the sand filter effluent valve V6 for sedimentation and separation again, and the clarified liquid flows out through the treated drain pipe G7.

[0058] The second process flow is as follows: The shale oil produced water from the oil-containing sewage supply pipe G1 is sent out by the first-stage lift pump B1. After being metered by the rotor flowmeter, it enters the biochemical pool 3 through the first bypass pipe G2, the first bypass valve V7, the second bypass pipe G3 and the biochemical pool inlet valve V2. The wastewater after biochemical degradation is discharged from the biochemical pool outlet valve V3, and then enters the flocculation sedimentation tank 4 through the flocculation reaction inlet valve V4. The overflow water after flocculation sedimentation flows out from the sedimentation tank outlet valve V5, and is sent into the sand filter tank 6 by the second-stage lift pump B2 for filtration. The filtered clear liquid enters the post-filtration clarification tank 7 through the sand filter outlet valve V6 for sedimentation separation again, and the clarified liquid flows out through the treated drain pipe G7.

[0059] The third process flow is as follows: The shale oil produced water from the oil-containing sewage supply pipe G1 is sent out by the first-stage lift pump B1. After being metered by the rotor flowmeter, it enters the pre-oxidation tank 2. The wastewater after oxidation degradation flows out from the pre-oxidation tank outlet valve V1, and then enters the flocculation sedimentation tank 4 through the second bypass pipe G3, the second bypass valve V8, the third bypass pipe G4 and the flocculation reaction inlet valve V4. The overflow water after flocculation sedimentation flows out from the sedimentation tank outlet valve V5, and is sent into the sand filter tank 6 by the second-stage lift pump B2 for filtration. The filtered clear liquid enters the post-filtration clarification tank 7 through the sand filter outlet valve V6 for sedimentation separation again, and the clarified liquid flows out through the treated drain pipe G7.

[0060] The fourth process flow is as follows: The shale oil produced water from the oil-containing sewage supply pipe G1 is sent out by the first-stage lift pump B1. After being metered by the rotor flowmeter, it enters the pre-oxidation tank 2. The wastewater after oxidation degradation flows out from the pre-oxidation tank outlet valve V1, and then enters the biochemical pool 3 through the biochemical pool inlet valve V2. The wastewater after biochemical degradation is discharged from the biochemical pool outlet valve V3, and then enters the inlet of the second-stage lift pump B2 through the third bypass pipe G4 and the third bypass valve V9. It is sent into the sand filter tank 6 by the second-stage lift pump B2 for filtration. The filtered clear liquid enters the post-filtration clarification tank 7 through the sand filter outlet valve V6 for sedimentation separation again, and the clarified liquid flows out through the treated drain pipe G7.

[0061] The above is only the preferred and feasible embodiment of the present utility model, which shows and describes the basic principles, main features and advantages of the present utility model. It is not intended to limit the patent protection scope of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. Except for the above embodiments, without departing from the spirit and scope of the present utility model, the present utility model can also have other implementation manners. The present utility model will also have various changes and improvements. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present utility model. The protection scope required by the present utility model is defined by the appended claims and their equivalents. The technical features not described in the present utility model can be realized by or adopted the existing technologies, and will not be elaborated here.

Claims

1. An evaluation device for shale oil produced water treatment, comprising a skid-mounted base, characterized in that: The skid-mounted base is successively installed with a pre-oxidation tank, a biochemical tank, a flocculation sedimentation tank and a sand filter tank. The outlet of the oily sewage inlet pipe is connected to the inlet of the first lift pump. The outlet of the first lift pump is connected to the inlet of the pre-oxidation tank through a flow meter. The outlet of the pre-oxidation tank is connected to the inlet of the biochemical tank. The outlet of the biochemical tank is connected to the inlet of the flocculation sedimentation tank. The outlet of the flocculation sedimentation tank is connected to the upper inlet of the sand filter tank through a second lift pump; The outlet of the flow meter is also connected to a first bypass pipe. The outlet of the pre-oxidation tank is also connected to a second bypass pipe. The outlet of the biochemical tank is also connected to a third bypass pipe. The outlets of the first, second and third bypass pipes are respectively connected to a bypass pipeline. The outlet of the bypass pipeline is connected to the inlet of the second lift pump.

2. The shale oil produced water treatment evaluation device according to claim 1, wherein: The pre-oxidation tank is separated into a chemical dosing area and an aeration area by a vertical partition board. The lower part of the chemical dosing area is communicated with the aeration area through a notch under the vertical partition board. An oxidation chemical tank is installed at the head end of the skid-mounted base. The outlet of the oxidation chemical tank is connected to the inlet of the chemical dosing area through an oxidant metering pump; A plurality of oxidation tank aeration components are evenly distributed at the bottom of the aeration area. Each oxidation tank aeration component is respectively connected to the outlet of a blower through an air supply pipeline.

3. The shale oil produced water treatment evaluation device according to claim 1, characterized in that: Combined fillers for microorganisms to attach are evenly arranged in the biochemical tank. A plurality of biochemical tank aeration components are evenly distributed at the bottom of the biochemical tank. Each biochemical tank aeration component is respectively connected to the outlet of a blower through an air supply pipeline.

4. The shale oil produced water treatment evaluation device according to claim 1, wherein: The flocculation sedimentation tank includes a flocculation reaction tank and a sedimentation tank with a communicating bottom. A mechanical stirring paddle is arranged in the flocculation reaction tank. A flocculant preparation tank is arranged above the flocculation reaction tank. The bottom of the flocculant preparation tank is connected to the inlet of the flocculation reaction tank through a flocculant metering pump. Uniformly arranged inclined plates are arranged in the middle of the sedimentation tank.

5. The shale oil produced water treatment evaluation device according to claim 1, characterized in that: The bottoms of the pre-oxidation tank, the biochemical tank, the flocculation sedimentation tank and the sand filter tank are respectively connected to a sewage discharge pipe through sewage discharge valves.

6. The shale oil produced water treatment evaluation device according to claim 5, wherein: A post-filtration clarifying tank is also installed at the end of the skid-mounted base. The lower outlet of the sand filter tank is connected to the upper inlet of the post-filtration clarifying tank. The overflow outlet of the post-filtration clarifying tank is connected to a treated sewage discharge pipe.

7. The shale oil produced water treatment evaluation device according to claim 6, characterized in that: The bottom outlet of the post-filtration clarifying tank is connected to the sewage discharge pipe through a sewage discharge valve. The lower outlet of the post-filtration clarifying tank is connected to the inlet of a backwashing pump. The outlet of the backwashing pump is connected to the lower outlet of the sand filter tank through a backwashing inlet valve. The top outlet of the sand filter tank is connected to the sewage discharge pipe through a backwashing drain pipe and a backwashing drain valve.

8. The shale oil produced water treatment evaluation device according to claim 7, wherein: The outlet of the treated sewage discharge pipe is connected to the sewage discharge pipe. A main discharge valve is installed at the outlet of the sewage discharge pipe.

9. The shale oil produced water treatment evaluation device according to claim 1, wherein: A first bypass valve is installed on the bypass pipeline between the first bypass pipe and the second bypass pipe. A second bypass valve is installed on the bypass pipeline between the second bypass pipe and the third bypass pipe. A third bypass valve is installed on the bypass pipeline between the third bypass pipe and the inlet of the second lift pump.

10. The shale oil produced water treatment evaluation device according to claim 1, wherein: The biochemical pool is provided with a vertical partition plate to divide the biochemical pool into a first biochemical pool and a second biochemical pool. The overflow outlet of the first biochemical pool is connected to the lower part of the second biochemical pool through a vertical diversion pipe. The biochemical pool aeration components of the first biochemical pool and the second biochemical pool are each provided with an aeration control valve.

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