Drilling hydraulic filtrate treatment system

Abstract

The utility model relates to a drilling hydraulic filtrate treatment system which comprises a softening and hardness-removing reaction tank, an ultrafiltration system and a special nanofiltration system, a water inlet of the softening and hardness-removing reaction tank is connected with a drilling hydraulic filtrate input pipeline, a water outlet of the softening and hardness-removing reaction tank is connected with a flocculation sedimentation tank, and a water outlet of the flocculation sedimentation tank is connected with the ultrafiltration system. A sludge outlet of the flocculation sedimentation tank is connected with a sludge concentration tank, an outlet of the sludge concentration tank is connected with a sludge dewatering machine, a water outlet of the sludge concentration tank flows back to the softening and hardness removal reaction tank through a pipeline, and a water outlet of the ultrafiltration system is connected with a special nanofiltration system; an air floatation device is arranged between the flocculation sedimentation tank and the ultrafiltration system, effluent of the flocculation sedimentation tank enters the air floatation device through a pipeline, and produced water of the air floatation device is lifted to the ultrafiltration system by a pump; according to the utility model, the effluent quality can stably reach the standard, the sewage treatment problem is solved, the water resource is favorably saved, and the risk problem that the effluent quality exceeds the standard due to poor treatment effect is avoided.

Description

[Technical field]

[0001] The utility model relates to the technical field of drilling fluid treatment, in particular to a drilling hydraulic filtrate treatment system. [Background Technology]

[0002] Drilling hydraulic filtrate is the liquid waste generated by the solid-liquid separation of drilling fluid. The main pollutants in the wastewater are SS, COD, oil, etc. It has the characteristics of high chroma, high suspended matter, and high salt content. Drilling hydraulic filtrate cannot be discharged directly and needs to be professionally treated. However, according to the on-site treatment situation, due to the limitations of the treatment conditions at the drilling construction site, the treatment effect is often not good.

[0003] In addition, the main treatment method for drilling hydraulic filtrate in China is to transport the on-site filtrate to a sewage treatment plant. The treatment cost is high, the treatment effect is poor, and there is a risk of the effluent quality exceeding the standard. [Contents of the utility model]

[0004] The purpose of the utility model is to solve the above-mentioned deficiencies and provide a drilling hydraulic filtrate treatment system, which can ensure that the effluent water quality is stable and meets the standards, solve the sewage treatment problem, is conducive to saving water resources, and avoids the risk of effluent water quality exceeding the standard due to poor treatment effect.

[0005] In order to achieve the above-mentioned purpose, a drilling hydraulic filtrate treatment system is designed, which includes a softening and hardness removal reaction tank 1, a flocculation sedimentation tank 2, a sludge concentration tank 3, a sludge dewatering machine 4, an ultrafiltration system 5 and a special nanofiltration system 6. The water inlet of the softening and hardness removal reaction tank 1 is connected to the drilling hydraulic filtrate input pipeline through a pipeline, the water outlet of the softening and hardness removal reaction tank 1 is connected to the flocculation sedimentation tank 2 through a pipeline, the water outlet of the flocculation sedimentation tank 2 is connected to the ultrafiltration system 5 through a pipeline, and the sludge outlet of the flocculation sedimentation tank 2 is connected to the ultrafiltration system 5 through a pipeline. A pipeline is connected to a sludge thickening tank 3, the outlet of the sludge thickening tank 3 is connected to a sludge dewatering machine 4, the water outlet of the sludge thickening tank 3 is returned to the softening and hardness removal reaction tank 1 through a pipeline, and the water outlet of the ultrafiltration system 5 is connected to a special nanofiltration system 6 through a pipeline; an air flotation device is arranged between the flocculation sedimentation tank 2 and the ultrafiltration system 5, and the air flotation device is used to remove oil substances, and the outlet water of the flocculation sedimentation tank 2 enters the air flotation device through a pipeline, and the produced water of the air flotation device is pumped to the ultrafiltration system 5.

[0006] Furthermore, the ultrafiltration system 5 includes an inlet pump 501, a self-cleaning filter 502, an ultrafiltration membrane 503, an ultrafiltration water production pool 504 and an ultrafiltration concentrated water pool 505. The water inlet of the inlet pump 501 is connected to the flocculation sedimentation tank 2 through a pipeline, the water outlet of the inlet pump 501 is connected to the self-cleaning filter 502 through a pipeline, the other end of the self-cleaning filter 502 is connected to the ultrafiltration membrane 503, and the feed liquid passing through the self-cleaning filter 502 directly enters the ultrafiltration membrane 503, the water production outlet of the ultrafiltration membrane 503 is connected to the ultrafiltration water production pool 504 through a pipeline, the concentrated water outlet of the ultrafiltration membrane 503 is connected to the ultrafiltration concentrated water pool 505 through a pipeline, and the ultrafiltration water production pool 504 is connected to the special nanofiltration system 6 through a pipeline.

[0007] Furthermore, the ultrafiltration membrane 503 adopts a vertical filter element, and the membrane elements of the ultrafiltration membrane 503 are arranged in parallel and horizontally installed on a bracket.

[0008] Furthermore, the ultrafiltration membrane 503 is a hollow fiber membrane, and the cutoff pore size of the hollow fiber membrane is 0.2-0.03 microns.

[0009] Furthermore, the special nanofiltration system 6 includes an inlet pump 601, a security filter 602, a high-pressure pump 603, a special nanofiltration membrane 605, a special nanofiltration membrane system water production pool 606 and a special nanofiltration membrane system concentrated water pool 607. The water inlet of the inlet pump 601 is connected to the ultrafiltration water production pool 504 of the ultrafiltration system 5 through a pipeline. The produced water of the ultrafiltration water production pool 504 is lifted to the security filter 602 by the inlet pump 601. The other end of the security filter 602 is connected to the high-pressure pump 603. The feed liquid passing through the security filter 602 enters the high-pressure pump 603. The water outlet of the high-pressure pump 603 is connected to the special nanofiltration membrane 605 through a pipeline. The permeate outlet of the special nanofiltration membrane 605 is connected to the special nanofiltration membrane system water production pool 606 through a pipeline, and the concentrated liquid outlet of the special nanofiltration membrane 605 is connected to the special nanofiltration membrane system concentrated water pool 607 through a pipeline.

[0010] Furthermore, it also includes a circulation pump 604, which is arranged on the pipeline between the high-pressure pump 603 and the special nanofiltration membrane 605. The special nanofiltration membrane 605 is provided with a reflux port, and the reflux port circulates back to the circulation pump 604 through the pipeline.

[0011] Furthermore, the special nanofiltration membrane 605 is a rolled membrane, and the membrane element of the special nanofiltration membrane 605 is provided with an open flow channel. The membrane element of the special nanofiltration membrane 605 is covered by a pressure vessel and two terminal flanges, and the flanges are used to provide connection between inlet water and concentrated water.

[0012] Furthermore, the water inlet and outlet ends of the safety filter 602 are respectively provided with pressure gauge 1 and pressure gauge 2, and the filter element thereof is replaced according to the pressure difference between pressure gauge 1 and pressure gauge 2.

[0013] Compared with the prior art, the utility model has a novel structure and a reasonable design. By adopting the system to treat wastewater, the wastewater can meet the standards and can be reused as drilling fluid, which can solve the problem of sewage treatment and is beneficial to saving water resources, especially in water-scarce areas. In addition, the utility model utilizes an ultrafiltration membrane and a special nanofiltration membrane combination to stably and effectively remove chroma and COD in the wastewater, which can ensure that the effluent water quality is stable and meets the standards, has a strong tolerance to water quality fluctuations, a high degree of automation, is more convenient to operate, and is more economical in the long run. [Drawings]

[0014] Figure 1 It is a principle block diagram of the utility model;

[0015] Figure 2 This is the principle block diagram of the ultrafiltration system of the utility model;

[0016] Figure 3 This is the principle block diagram of the special nanofiltration system of the utility model;

[0017] Figure 4 This is a schematic diagram of the structure of the rolling method of the special nanofiltration membrane of the utility model;

[0018] In the figure: 1, softening and hardness removal reaction tank 2, flocculation sedimentation tank 3, sludge thickening tank 4, sludge dewatering machine 5, ultrafiltration system 6, special nanofiltration system 501, water inlet pump 1 502, self-cleaning filter 503, ultrafiltration membrane 504, ultrafiltration water production tank 505, ultrafiltration concentrated water tank 601, water inlet pump 2 602, security filter 603, high-pressure pump 604, circulation pump 605, special nanofiltration membrane 606, special nanofiltration membrane system water production tank 607, special nanofiltration membrane system concentrated water tank. [Specific implementation method]

[0019] As attached Figure 1As shown, the utility model provides a drilling hydraulic filtrate treatment system, including a softening and hardness removal reaction tank 1, a flocculation sedimentation tank 2, a sludge thickening tank 3, a sludge dewatering machine 4, an ultrafiltration system 5 and a special nanofiltration system 6, the water inlet of the softening and hardness removal reaction tank 1 is connected to the drilling hydraulic filtrate input pipeline through a pipeline, the water outlet of the softening and hardness removal reaction tank 1 is connected to the flocculation sedimentation tank 2 through a pipeline, the water outlet of the flocculation sedimentation tank 2 is connected to the ultrafiltration system 5 through a pipeline, the sludge outlet of the flocculation sedimentation tank 2 is connected to the sludge thickening tank 3 through a pipeline, the outlet of the sludge thickening tank 3 is connected to the sludge dewatering machine 4, the water outlet of the sludge thickening tank 3 is refluxed to the softening and hardness removal reaction tank 1 through a pipeline, and the water outlet of the ultrafiltration system 5 is connected to the special nanofiltration system 6 through a pipeline; an air flotation device is arranged between the flocculation sedimentation tank 2 and the ultrafiltration system 5, the air flotation device is used to remove oil substances, the effluent of the flocculation sedimentation tank 2 enters the air flotation device through a pipeline, and the produced water of the air flotation device is pumped to the ultrafiltration system 5.

[0020] As attached Figure 2 As shown, the ultrafiltration system 5 includes an inlet pump 501, a self-cleaning filter 502, an ultrafiltration membrane 503, an ultrafiltration water production pool 504 and an ultrafiltration concentrated water pool 505. The water inlet of the inlet pump 501 is connected to the flocculation sedimentation tank 2 through a pipeline, and the water outlet of the inlet pump 501 is connected to the self-cleaning filter 502 through a pipeline. The other end of the self-cleaning filter 502 is connected to the ultrafiltration membrane 503. The feed liquid passing through the self-cleaning filter 502 directly enters the ultrafiltration membrane 503. The water production outlet of the filter membrane 503 is connected to the ultrafiltration water production pool 504 through a pipeline, the concentrated water outlet of the ultrafiltration membrane 503 is connected to the ultrafiltration concentrated water pool 505 through a pipeline, and the ultrafiltration water production pool 504 is connected to the special nanofiltration system 6 through a pipeline; the ultrafiltration membrane 503 adopts a vertical filter element, and the membrane elements of the ultrafiltration membrane 503 are arranged in parallel and horizontally installed on the bracket; the ultrafiltration membrane 503 adopts a hollow fiber membrane, and the retention pore size of the hollow fiber membrane is 0.2-0.03 microns.

[0021] As attached Figure 3As shown, the special nanofiltration system 6 includes a water inlet pump 601, a security filter 602, a high-pressure pump 603, a circulation pump 604, a special nanofiltration membrane 605, a special nanofiltration membrane system water production pool 606 and a special nanofiltration membrane system concentrated water pool 607. The water inlet of the water inlet pump 601 is connected to the ultrafiltration water production pool 504 of the ultrafiltration system 5 through a pipeline. The produced water of the ultrafiltration water production pool 504 is lifted to the security filter 602 through the water inlet pump 601. The other end of the security filter 602 is connected to the high-pressure pump 603. The feed liquid passing through the security filter 602 enters the high-pressure pump 603. The water outlet of the high-pressure pump 603 is connected to the special nanofiltration membrane 605 through a pipeline. The permeate outlet of the special nanofiltration membrane 605 is connected to the special nanofiltration membrane system 5 through a pipeline. The water production pool 606 and the concentrated liquid outlet of the special nanofiltration membrane 605 are connected to the special nanofiltration membrane system concentrated water pool 607 through a pipeline; the circulation pump 604 is arranged on the pipeline between the high-pressure pump 603 and the special nanofiltration membrane 605, and a reflux port is provided on the special nanofiltration membrane 605, and the reflux port circulates back to the circulation pump 604 through the pipeline; the special nanofiltration membrane 605 is a rolled membrane, and the membrane element of the special nanofiltration membrane 605 is provided with an open flow channel, and the membrane element of the special nanofiltration membrane 605 is covered by a pressure vessel and two terminal flanges, and the flanges are used to provide a connection between the inlet and the concentrated water; the inlet and outlet ends of the security filter 602 are respectively provided with pressure gauge 1 and pressure gauge 2, and its filter element is replaced according to the pressure difference between pressure gauge 1 and pressure gauge 2.

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0023] The utility model adopts softening and hardness removal + flocculation sedimentation + air flotation + ultrafiltration + special nanofiltration, wherein the effluent of the special nanofiltration is reused as drilling fluid after being qualified. Specifically, the drilling hydraulic filtrate first enters the softening and hardness removal reaction tank, in which the corresponding reagents are added according to the process requirements, and the pH value of the reaction is controlled. The reagents and the influent are completely mixed and reacted through sufficient mechanical stirring. The water containing sediments after the reaction overflows into the flocculation sedimentation tank; the effluent from the sedimentation tank enters the flotation device to remove oil substances; the flotation water is pumped to the ultrafiltration membrane assembly to remove suspended matter, bacteria, microorganisms and other impurities. The water after ultrafiltration is clear and transparent with a turbidity close to zero; the ultrafiltration effluent is pumped to the special nanofiltration membrane system by a pump, and a security filter is set at the back to prevent large particles of impurities from entering the membrane, providing the last guarantee for the special nanofiltration membrane; there are pressure meters at the inlet and outlet of the filter, and the filter element is replaced when the pressure difference exceeds 2.0 bar; the effluent of the security filter is further pressurized by a high-pressure pump to meet the filtration requirements of the special nanofiltration membrane; the effluent after the high-pressure pump enters the membrane assembly, and the membrane assembly adopts a special nanofiltration membrane column. In order to ensure sufficient flow and cross-flow velocity on the membrane surface and avoid membrane pollution, a circulation pump can also be set in front of the membrane module. The high-pressure and high-flow water discharged from the circulation pump directly enters the membrane column. The water discharged from the membrane module is divided into two parts: concentrate and permeate; there is a servo control valve at the concentrate end to control the pressure in the membrane group to produce the necessary water recovery rate. The permeate enters the water production tank and is finally reused; the concentrate is discharged into the concentrated water tank and finally transported for disposal.

[0024] The ultrafiltration system uses highly anti-pollution hollow fiber membrane elements, equipped with pipeline valves, self-cleaning units, dosing units and automatic control units, etc., to form a closed-loop continuous operating system, from which impurities such as bacteria, microorganisms and suspended matter are removed. The purified water is clear and transparent, and the turbidity is close to zero. Specifically, the water produced by the flocculation sedimentation system is pumped to the self-cleaning filter by the water inlet pump to preliminarily intercept and remove larger particles of suspended matter and some fine suspended matter in the raw water, such as baths, rust, mud, microorganisms, etc., to provide safety protection for subsequent membrane treatment equipment. The feed liquid passing through the self-cleaning filter is directly ultrafiltered by the membrane element. The ultrafiltration membrane assembly adopts a vertical filter element. The membrane element is arranged in parallel and installed horizontally on the bracket. There are complete pipes and corresponding indispensable valves (including automatic valves and valves connected to the inlet and outlet pipes of the cleaning liquid during cleaning) between the membrane shells to connect them into one. The wastewater enters the water production tank after being filtered by the ultrafiltration membrane. After ultrafiltration, the produced water meets the subsequent special nanofiltration membrane inlet requirements, and the concentrated water returns to the system reaction precipitation system for further treatment.

[0025] The ultrafiltration system described in the utility model has the following advantages:

[0026] High filtration accuracy: The ultrafiltration membrane uses a hollow fiber membrane with a retention pore size of 0.2-0.03 microns, which can remove most of the suspended particle impurities in the water.

[0027] High packing density: Among membrane elements per unit volume, hollow fiber membranes have the largest effective membrane area and the highest filtration and separation efficiency, thus reducing floor space, investment, and operating costs.

[0028] Low filtration pressure: The filtration equipment using hollow fiber separation membrane has an extremely low operating pressure, usually 0.05-0.08Mpa, which reduces energy consumption, investment and operating costs.

[0029] Easy to clean: Hollow fiber membranes can be backwashed and chemically cleaned; among the membrane cleaning methods, backwashing is undoubtedly the best membrane cleaning method, which can achieve the best cleaning effect and restore the membrane performance to the maximum extent, thereby extending the service life of the membrane, reducing the labor intensity of operation, and reducing operating costs.

[0030] Repairable: Hollow fiber membrane elements are assembled from thousands or tens of thousands of hollow fiber filaments. Once individual fiber filaments are damaged, they can be detected by certain methods and the membrane element can be repaired. The repaired membrane element can continue to be used without any impact on the separation effect.

[0031] The specific principle of the special nanofiltration system is that the water produced by the ultrafiltration system is lifted to the security filter by the water inlet pump to further remove suspended matter in the feed liquid; the feed liquid passing through the core filter directly enters the high-pressure pump; in order to ensure sufficient flow and cross-flow velocity on the membrane surface and avoid membrane pollution, a circulation pump is set in front of the membrane assembly, and the high-pressure and high-flow water flowing out of the circulation pump directly enters the special nanofiltration membrane; the special nanofiltration membrane produces water concentrate and permeate, and there is a servo control valve at the concentrate end to control the pressure in the membrane group to produce the necessary water recovery rate. The permeate enters the water production pool and is finally reused, and the concentrate is discharged into the concentrate pool, waiting for external transportation and treatment.

[0032] Special nanofiltration systems can also combine the advantages of open channels and roll membrane components to develop membrane elements with narrow and open channel designs. The effective components of special nanofiltration membrane components are membrane packages and spacers wrapped around pipe fittings. The entire membrane element is covered by a GRP pressure vessel and two terminal flanges, which provide connections between inlet water and concentrated water. Special nanofiltration membrane elements are roll membranes, but they are different from traditional roll membranes. The problem with traditional roll membranes is that their spacers are easily blocked and scaled, which restricts the inlet flow channel and increases the pressure difference. To address this problem, special nanofiltration membrane elements combine the advantages of open flow channels and roll element designs to obtain a membrane element with a narrow and open flow channel structure. This design greatly optimizes the effective area of ​​the inlet flow channel and the membrane, and alleviates the shortcomings of traditional roll membranes to a large extent.

[0033] In addition, if attached Figure 4 As shown in the figure, the special nanofiltration membrane can also be improved in the rolling method: shorten the blades and increase the number of blades. Its advantages are: ① shorten the length of the fresh water channel and reduce the pressure loss of the fresh water channel; ② so that the net driving pressure along the membrane tends to be the same; ③ try to keep the water flux at different places on the membrane surface equal; ④ reduce the degree of concentration polarization.

[0034] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. The standard parts used can be purchased from the market, and special-shaped parts can be customized according to the records in the specification and drawings. The specific connection methods of each part adopt mature conventional means such as bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0035] The present invention is not limited to the above-mentioned implementation modes, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be considered as equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A drilling hydraulic filtrate treatment system, characterized in that: The invention comprises a softening and hardness removal reaction tank (1), a flocculation sedimentation tank (2), a sludge thickening tank (3), a sludge dewatering machine (4), an ultrafiltration system (5) and a special nanofiltration system (6), wherein the water inlet of the softening and hardness removal reaction tank (1) is connected to a drilling hydraulic filtrate input pipeline via a pipeline, the water outlet of the softening and hardness removal reaction tank (1) is connected to a flocculation sedimentation tank (2) via a pipeline, the water outlet of the flocculation sedimentation tank (2) is connected to the ultrafiltration system (5) via a pipeline, and the sludge outlet of the flocculation sedimentation tank (2) is connected to a sludge thickening tank ( 3), the outlet of the sludge thickening tank (3) is connected to a sludge dewatering machine (4), the water outlet of the sludge thickening tank (3) is returned to the softening and de-hardening reaction tank (1) through a pipeline, and the water outlet of the ultrafiltration system (5) is connected to a special nanofiltration system (6) through a pipeline; an air flotation device is arranged between the flocculation sedimentation tank (2) and the ultrafiltration system (5), and the air flotation device is used to remove oil substances, and the effluent of the flocculation sedimentation tank (2) enters the air flotation device through a pipeline, and the water produced by the air flotation device is pumped to the ultrafiltration system (5).

2. The drilling hydraulic filtrate treatment system according to claim 1, characterized in that: The ultrafiltration system (5) comprises an inlet pump (501), a self-cleaning filter (502), an ultrafiltration membrane (503), an ultrafiltration water production pool (504) and an ultrafiltration concentrated water pool (505). The water inlet of the inlet pump (501) is connected to the flocculation sedimentation tank (2) via a pipeline, the water outlet of the inlet pump (501) is connected to the self-cleaning filter (502) via a pipeline, the other end of the self-cleaning filter (502) is connected to the ultrafiltration membrane (503), the feed liquid passing through the self-cleaning filter (502) directly enters the ultrafiltration membrane (503), the water production outlet of the ultrafiltration membrane (503) is connected to the ultrafiltration water production pool (504) via a pipeline, the concentrated water outlet of the ultrafiltration membrane (503) is connected to the ultrafiltration concentrated water pool (505) via a pipeline, and the ultrafiltration water production pool (504) is connected to the special nanofiltration system (6) via a pipeline.

3. The drilling hydraulic filtrate treatment system according to claim 2, characterized in that: The ultrafiltration membrane (503) adopts a vertical filter element, and the membrane elements of the ultrafiltration membrane (503) are arranged in parallel and installed horizontally on a bracket.

4. The drilling hydraulic filtrate treatment system according to claim 2, characterized in that: The ultrafiltration membrane (503) is a hollow fiber membrane, and the cutoff pore size of the hollow fiber membrane is 0.2-0.03 microns.

5. The drilling hydraulic filtrate treatment system according to claim 2, characterized in that: The special nanofiltration system (6) comprises a second water inlet pump (601), a security filter (602), a high-pressure pump (603), a special nanofiltration membrane (605), a special nanofiltration membrane system water production pool (606) and a special nanofiltration membrane system concentrated water pool (607). The water inlet of the second water inlet pump (601) is connected to the ultrafiltration water production pool (504) of the ultrafiltration system (5) through a pipeline. The water produced by the ultrafiltration water production pool (504) is lifted to the security filter (602) by the second water inlet pump (601). The other end of the security filter (602) is connected to a high-pressure pump (603), and the feed liquid passing through the security filter (602) enters the high-pressure pump (603). The water outlet of the high-pressure pump (603) is connected to a special nanofiltration membrane (605) through a pipeline, and the permeate outlet of the special nanofiltration membrane (605) is connected to a special nanofiltration membrane system water production pool (606) through a pipeline, and the concentrated liquid outlet of the special nanofiltration membrane (605) is connected to a special nanofiltration membrane system concentrated water pool (607) through a pipeline.

6. The drilling hydraulic filtrate treatment system according to claim 5, characterized in that: It also includes a circulation pump (604), which is arranged on a pipeline between the high-pressure pump (603) and the special nanofiltration membrane (605). The special nanofiltration membrane (605) is provided with a reflux port, and the reflux port circulates back to the circulation pump (604) through the pipeline.

7. The drilling hydraulic filtrate treatment system according to claim 5, characterized in that: The special nanofiltration membrane (605) is a rolled membrane, and the membrane element of the special nanofiltration membrane (605) is provided with an open flow channel. The membrane element of the special nanofiltration membrane (605) is covered by a pressure vessel and two terminal flanges, and the flanges are used to provide a connection between the inlet water and the concentrated water.

8. The drilling hydraulic filtrate treatment system according to claim 5, characterized in that: The water inlet and outlet ends of the safety filter (602) are respectively provided with a pressure meter 1 and a pressure meter 2, and the filter element is replaced according to the pressure difference between the pressure meter 1 and the pressure meter 2.

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