CN118221300A - Oil exploitation wastewater treatment process - Google Patents

Abstract

The present invention relates to the technical field of high-difficulty wastewater treatment, and in particular to a process for treating wastewater from oil production. Technical problem: The process for treating wastewater from oil production is mainly aimed at solving the problems of great difficulty in treating fracturing flowback fluid under the existing technology, poor treatment effect, difficulty in long-term stable discharge and large-scale application. Technical solution: A process for treating wastewater from oil production, the steps of which are as follows: S1: preliminary oil-water separation treatment; S2: ozone nano-flotation system; S3: dosing reaction system; S4: biological filtration system; S5: ozone nano-flotation deep treatment again; S6: sand carbon filtration system; S7: ultrafiltration filtration system; S8: DTRO filtration system; S9: electrocatalytic oxidation system; S10: MVR evaporation system; S11: low-temperature scraper evaporation system; S12: anti-pollution membrane filtration system. The present invention utilizes processes such as ozone + nano-fine bubble flotation, biological filtration system, sand carbon filtration system, ultrafiltration filtration system, DTRO filtration system, electrocatalytic oxidation system and anti-pollution membrane filtration system to achieve multiple purification effects on wastewater.

Description

A process for treating wastewater from oil production

Technical Field

The invention relates to the technical field of high-difficulty wastewater treatment, and in particular to a process for treating oil production wastewater.

Background technique

The current process steps for treating oil production wastewater are relatively simple, and the filtering mechanism is relatively single. There is often a certain amount of residual wastewater that needs to be re-filtered during wastewater treatment. The treatment of concentrated water is very difficult, time-consuming and labor-intensive, and cannot achieve the effect of efficient and stable wastewater treatment. Therefore, there is an urgent need for an oil production wastewater treatment process that can quickly separate water from oil and perform multi-step efficient filtering treatment on wastewater, so as to improve the treatment speed of oil production wastewater, and thereby meet the needs of users for efficient and stable wastewater treatment and environmental protection.

Summary of the invention

In view of the shortcomings of the prior art, the purpose of the present invention is to provide a process for treating oil production wastewater, which is mainly aimed at solving the technical problems of the prior art that the treatment of fracturing return fluid is difficult, the treatment effect is poor, it is difficult to achieve long-term stable emission standards and large-scale application.

The technical solution of the present invention is: a process for treating oil production wastewater, the steps of which are as follows:

S1: Preliminary oil-water separation treatment: First, the wastewater generated during the oil extraction process is collected into the produced water collection pool, and then the wastewater is introduced into the nano-gas flotation oil separation equipment. Highly dispersed tiny bubbles are used as carriers to adhere to the suspended matter in the wastewater, especially the oil droplets, so that their buoyancy is increased and they are removed as the bubbles rise to the water surface. The separated oil enters the oil collection barrel and returns to the oil field for use;

S2: Deep oil-water separation and oxidation treatment: The water treated by nano-flotation oil separation in S1 is mixed with the fracturing fluid in the fracturing fluid collection pool and then enters the ozone nano-flotation equipment. Under the action of ozone + nano-fine bubbles, a large number of hydroxyl free radicals are generated, which non-selectively and rapidly oxidize various organic matter in the water body, quickly open the ring and break the bonds of organic matter, and quickly degrade pollution indicators such as COD. It can also float suspended matter and macromolecular organic matter in sewage to the surface, thereby separating and removing them:

S21: Scum treatment: The scum produced by ozone nano-flotation in S2 is put into the sludge tank for treatment;

S3: Dosing reaction system: introduce the water treated by ozone nano-flotation in S2 into the dosing reaction equipment, add PAC, softener, PAM and other agents into the dosing reaction equipment, so that it can be mixed with the wastewater for treatment;

S4: Biological filtration system; the wastewater treated by the dosing reaction system enters the biological filtration equipment to intercept and filter suspended matter, and utilizes the metabolism of microorganisms to degrade organic matter:

S5: Advanced wastewater treatment: The clean water treated by the biological filtration equipment in S4 enters the nano-ozone flotation equipment to remove organic matter and color that is difficult to biodegrade. At the same time, nano-flotation technology is used again to separate suspended matter:

S51: Sludge treatment: The scum water produced in the nano-ozone flotation equipment is introduced into the sludge pool, and the sludge in the biological filtration equipment in S4 is also introduced into the sludge pool for treatment;

S6: Sand-carbon filtration system: The clean water treated by the nano-ozone flotation equipment enters the sand-carbon filtration equipment, where sand particles are used to intercept suspended matter, and the adsorption of activated carbon is used to remove residual color and some organic matter;

S61: introducing the backwash water in the sand carbon filtration device into the nano ozone flotation device for recirculation treatment;

S7: Ultrafiltration system: The clean water treated in the sand-carbon filtration equipment enters the ultrafiltration equipment, and the wastewater is filtered using an ultrafiltration membrane, which can intercept substances with larger molecular weight and further purify the water quality;

S71: Concentrated water treatment: The concentrated water treated in the ultrafiltration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment to remove some inorganic and organic matter, chromaticity, etc. in the water.

S8: DTRO filtration system; the clean water produced by the ultrafiltration filtration equipment in S7 enters the DTRO filtration equipment, and the DTRO membrane elements are used to separate and remove most of the soluble salts, small molecular organic matter, etc. in the leachate, and the concentrated water of the membrane system is reduced. Under high pressure, the leachate passes through the DTRO membrane system and becomes pure produced water;

S81: Washing water treatment: the washing water treated in the DTRO filtration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment;

S9: Electrocatalytic oxidation system; The concentrated water treated in the DTRO filtration equipment enters the electrocatalytic oxidation equipment, and adopts high-frequency pulse electrocoagulation method, using electrochemical principles, with the help of external power supply to produce electrochemical reactions, converting electrical energy into chemical energy. In a specific ionization equipment process, the organic or inorganic pollutants in the wastewater are oxidized and reduced, and then condensed and separated from the water body. It has a good removal effect on emulsified oil, macromolecular organic matter, microorganisms, heavy metal ions, fluoride ions, turbidity and some colored substances, and can remove most COD and convert it into low-toxic or harmless substances;

S91: The fresh water treated in the DTRO filtration equipment enters the anti-pollution membrane filtration equipment for treatment;

S10: MVR evaporation system: The wastewater from the electrocatalytic oxidation device enters the MVR evaporation device, where the wastewater is heated to boiling, the water evaporates and condenses for recovery, while the pollutants remain in the concentrated liquid, i.e. the mother liquor. The remaining crystallized salt from evaporation can be outsourced for treatment;

S11: Low-temperature scraper evaporation system: The mother liquor remaining after evaporation can enter the low-temperature scraper evaporation equipment, and the remaining crystallized salt can be outsourced for treatment. The condensed water of the MVR evaporation equipment and the low-temperature scraper evaporation equipment in S10 can enter the anti-pollution membrane filtration equipment for treatment together;

S12: Anti-pollution membrane filtration system: The fresh water treated in the anti-pollution membrane filtration equipment can be reused or discharged, and the concentrated water re-enters the DTRO filtration equipment for circulation treatment.

Beneficial effects of the present invention: The present invention adopts nano-flotation oil separation and nano-ozone flotation processes to quickly separate suspended matter and oil droplets and degrade part of COD, and utilizes biological filtration system, sand carbon filtration system, ultrafiltration filtration system, DTRO filtration system, electrocatalytic oxidation system and anti-pollution membrane filtration system to achieve multiple filtration and purification effects on waste liquid, which can greatly improve the treatment speed of wastewater, further enable oil production wastewater to be quickly and efficiently treated, and facilitate later recycling and reuse or discharge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a process flow chart of oil production wastewater treatment according to the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Please refer to FIG1 , the present invention provides an embodiment: a process for treating oil production wastewater, the steps of which are as follows:

S1: Preliminary oil-water separation treatment: First, the wastewater generated during the oil extraction process is collected into the produced water collection pool, and then the wastewater is introduced into the nano-gas flotation oil separation equipment. Highly dispersed tiny bubbles are used as carriers to adhere to the suspended matter in the wastewater, especially the oil droplets, so that their buoyancy is increased and they are removed as the bubbles rise to the water surface. The separated oil enters the oil collection barrel and returns to the oil field for use;

S2: Deep oil-water separation and oxidation treatment: The water treated by nano-flotation oil separation in S1 is mixed with the fracturing fluid in the fracturing fluid collection pool and then enters the ozone nano-flotation equipment. Under the action of ozone + nano-fine bubbles, a large number of hydroxyl free radicals are generated, which non-selectively and rapidly oxidize various organic matter in the water body, quickly open the ring and break the bonds of organic matter, and quickly degrade pollution indicators such as COD. It can also float suspended matter and macromolecular organic matter in sewage to the water surface, thereby separating and removing them;

S21: Scum treatment: The scum produced by ozone nano-flotation in S2 is put into the sludge tank for treatment;

S3: Dosing reaction system: introduce the water treated by ozone nano-flotation in S2 into the dosing reaction equipment, add PAC, softener, PAM and other agents into the dosing reaction equipment, so that it can be mixed with the wastewater for treatment;

S4: Biological filtration system; the wastewater treated by the dosing reaction system enters the biological filtration equipment to intercept and filter suspended matter, and utilizes the metabolism of microorganisms to degrade organic matter:

S5: Advanced wastewater treatment: The clean water treated by the biological filtration equipment in S4 enters the nano-ozone flotation equipment to remove organic matter and color that is difficult to biodegrade. At the same time, nano-flotation technology is used again to separate suspended matter:

S51: Sludge treatment: The scum water produced in the nano-ozone flotation equipment is introduced into the sludge pool, and the sludge in the biological filtration equipment in S4 is also introduced into the sludge pool for treatment;

S6: Sand-carbon filtration system: The clean water treated by the nano-ozone flotation equipment enters the sand-carbon filtration equipment, where sand particles are used to intercept suspended matter, and the adsorption of activated carbon is used to remove residual color and some organic matter;

S61: introducing the backwash water in the sand carbon filtration device into the nano ozone flotation device for recirculation treatment;

S7: Ultrafiltration system: The clean water treated in the sand-carbon filtration equipment enters the ultrafiltration equipment, and the wastewater is filtered using an ultrafiltration membrane, which can intercept substances with larger molecular weight and further purify the water quality;

S71: Concentrated water treatment: The concentrated water treated in the ultrafiltration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment to remove some inorganic and organic matter, chromaticity, etc. in the water:

S8: DTRO filtration system; the clean water produced by the ultrafiltration filtration equipment in S7 enters the DTRO filtration equipment, and the DTRO membrane elements are used to separate and remove most of the soluble salts, small molecular organic matter, etc. in the leachate, and the concentrated water of the membrane system is reduced. Under high pressure, the leachate passes through the DTRO membrane system and becomes pure produced water;

S81: Washing water treatment: the washing water treated in the DTRO filtration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment;

S9: Electrocatalytic oxidation system; The concentrated water treated in the DTRO filtration equipment enters the electrocatalytic oxidation equipment, and adopts high-frequency pulse electrocoagulation method, using electrochemical principles, with the help of external power supply to produce electrochemical reactions, converting electrical energy into chemical energy. In a specific ionization equipment process, the organic or inorganic pollutants in the wastewater are oxidized and reduced, and then condensed and separated from the water body. It has a good removal effect on emulsified oil, macromolecular organic matter, microorganisms, heavy metal ions, fluoride ions, turbidity and some colored substances, and can remove most COD and convert it into low-toxic or harmless substances;

S91: The fresh water treated in the DTRO filtration equipment enters the anti-pollution membrane filtration equipment for treatment;

S10: MVR evaporation system: The wastewater from the electrocatalytic oxidation device enters the MVR evaporation device, where the wastewater is heated to boiling, the water evaporates and condenses for recovery, while the pollutants remain in the concentrated liquid, i.e. the mother liquor. The remaining crystallized salt from evaporation can be outsourced for treatment;

S11: Low-temperature scraper evaporation system: The mother liquor remaining after evaporation can enter the low-temperature scraper evaporation equipment, and the remaining crystallized salt can be outsourced for treatment. The condensed water of the MVR evaporation equipment and the low-temperature scraper evaporation equipment in S10 can enter the anti-pollution membrane filtration equipment for treatment together;

S12: Anti-pollution membrane filtration system: The fresh water treated in the anti-pollution membrane filtration equipment can be reused or discharged, and the concentrated water re-enters the DTRO filtration equipment for circulation treatment.

As a preferred method, S3 first conducts a detailed water quality analysis of the oil production wastewater, including indicators such as pH value, suspended solids (SS), turbidity, oil content, chemical oxygen demand (COD), biological oxygen demand (BOD), etc., and determines the optimal dosage of PAC, softener and PAM under different water quality conditions through small or pilot tests.

Preferably, the biological filtration equipment in S4 is usually composed of a plurality of biological filter tanks, each of which is filled with biological fillers to provide a growth environment for microorganisms.

Preferably, the sludge in the sludge tank in S51 is treated by a filter press, and finally the sludge is outsourced for treatment.

Preferably, in the sand-carbon filtration equipment of S6, the sand layer is located in the upper layer of the filter tank body for preliminary filtration and interception of larger particles of suspended solids, and the activated carbon layer is located below the sand layer for adsorbing organic matter, color and other pollutants.

Preferably, S6 also has a backwashing system, which includes a backwashing pipeline, a pump and a valve, and is used to regularly backwash the filter medium to remove trapped pollutants and restore the filtering performance.

As a preferred choice, the DTRO membrane in S8 has the characteristics of high pollution resistance and high concentration. It is a special membrane element dedicated to sewage treatment. When treating oilfield wastewater, it does not need to rely on pretreatment. Because its internal structure is an open flow channel design, it can efficiently treat wastewater containing more colloids, suspended solids, etc.

Preferably, the electrocatalytic oxidation in S9 utilizes electrochemical principles to generate electrochemical reactions with the help of an external power source, converting electrical energy into chemical energy, and oxidizing and reducing organic or inorganic pollutants in the wastewater in a specific ionization equipment process.

Preferably, the pH value, impurities and pollutants that may exist in the wastewater may affect the effect of electrocatalytic oxidation, so the wastewater needs to be properly pretreated.

When using the oil production wastewater treatment process of the present invention, the steps are as follows:

S1: Preliminary oil-water separation treatment: First, the wastewater generated during the oil extraction process is collected in the produced water collection pool, and then the wastewater is introduced into the nano-flotation oil separation equipment. Highly dispersed tiny bubbles are used as carriers to adhere to the suspended matter in the wastewater, especially the oil droplets, so that they rise to the water surface with the bubbles and are removed. The separated oil enters the oil collection barrel and returns to the oil field;

S2: Deep oil-water separation and oxidation treatment: The water treated by nano-flotation oil separation in S1 is mixed with the fracturing fluid in the fracturing fluid collection pool and then enters the ozone nano-flotation equipment. Under the action of ozone + nano-fine bubbles, a large number of hydroxyl free radicals are generated, which non-selectively and rapidly oxidize various organic matter in the water body, quickly open the ring and break the bonds of organic matter, and quickly degrade pollution indicators such as COD. It can also float suspended matter and macromolecular organic matter in sewage to the water surface, thereby separating and removing them;

S21: Scum treatment: The scum produced by ozone nano-flotation in S2 is put into the sludge tank for treatment;

S3: Dosing reaction system: introduce the water treated by ozone nano-flotation in S2 into the dosing reaction equipment, add PAC, softener, PAM and other agents into the dosing reaction equipment, so that it can be mixed with the wastewater for treatment;

S4: Biological filtration system; the wastewater treated by the dosing reaction system enters the biological filtration equipment to intercept and filter suspended matter, and utilizes the metabolism of microorganisms to degrade organic matter:

S5: Advanced wastewater treatment: The clean water treated by the biological filtration equipment in S4 enters the nano-ozone flotation equipment to remove organic matter and color that is difficult to biodegrade. At the same time, nano-flotation technology is used again to separate suspended matter:

S51: Sludge treatment: The scum water produced in the nano-ozone flotation equipment is introduced into the sludge pool, and the sludge in the biological filtration equipment in S4 is also introduced into the sludge pool for treatment;

S6: Sand-carbon filtration system: The clean water treated by the nano-ozone flotation equipment enters the sand-carbon filtration equipment, where sand particles are used to intercept suspended matter, and the adsorption of activated carbon is used to remove residual color and some organic matter;

S61: introducing the backwash water in the sand carbon filtration device into the nano ozone flotation device for recirculation treatment;

S7: Ultrafiltration system: The clean water treated in the sand-carbon filtration equipment enters the ultrafiltration equipment, and the wastewater is filtered using an ultrafiltration membrane, which can intercept substances with larger molecular weight and further purify the water quality;

S71: Concentrated water treatment: The concentrated water treated in the ultrafiltration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment to remove some inorganic and organic matter, chromaticity, etc. in the water:

S8: DTRO filtration system; the clean water produced by the ultrafiltration filtration equipment in S7 enters the DTRO filtration equipment, and the DTRO membrane elements are used to separate and remove most of the soluble salts, small molecular organic matter, etc. in the leachate, and the concentrated water of the membrane system is reduced. Under high pressure, the leachate passes through the DTRO membrane system and becomes pure produced water;

S81: Washing water treatment: the washing water treated in the DTRO filtration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment;

S9: Electrocatalytic oxidation system; The concentrated water treated in the DTRO filtration equipment enters the electrocatalytic oxidation equipment, and adopts high-frequency pulse electrocoagulation method, using electrochemical principles, with the help of external power supply to produce electrochemical reactions, converting electrical energy into chemical energy. In the specific ionization equipment process, the organic or inorganic pollutants in the wastewater are oxidized and reduced, and then condensed and separated from the water body. It has a good removal effect on emulsified oil, macromolecular organic matter, microorganisms, heavy metal ions, fluoride ions, turbidity and some colored substances, and can remove most COD and convert it into low-toxic or harmless substances; the pH value, impurities and pollutants that may exist in the wastewater will affect the effect of electrocatalytic oxidation, so the wastewater needs to be properly pretreated;

S91: The fresh water treated in the DTRO filtration equipment enters the anti-pollution membrane filtration equipment for treatment;

S10: MVR evaporation system: The wastewater from the electrocatalytic oxidation device enters the MVR evaporation device, where the wastewater is heated to boiling, the water evaporates and condenses for recovery, while the pollutants remain in the concentrated liquid, i.e. the mother liquor. The remaining crystallized salt from evaporation can be outsourced for treatment;

S11: Low-temperature scraper evaporation system: The mother liquor remaining after evaporation can enter the low-temperature scraper evaporation equipment, and the remaining crystallized salt can be outsourced for treatment. The condensed water of the MVR evaporation equipment and the low-temperature scraper evaporation equipment in S10 can enter the anti-pollution membrane filtration equipment for treatment together;

S12: Anti-pollution membrane filtration system: The fresh water treated in the anti-pollution membrane filtration equipment can be reused or discharged, and the concentrated water re-enters the DTRO filtration equipment for circulation treatment.

Through the above steps, the use of nano-flotation oil separation and nano-ozone flotation processes can quickly separate suspended matter and oil droplets and degrade some organic matter, while the use of biological filtration system, sand carbon filtration system, ultrafiltration filtration system, DTRO filtration system, electrocatalytic oxidation system and anti-pollution membrane filtration system can achieve multiple filtration and purification effects on waste liquid, which can greatly improve the treatment speed of wastewater, further enable oil production wastewater to be treated quickly and efficiently, and facilitate later recycling and reuse or discharge, so as to solve the technical problems that the treatment method under the existing technology is relatively single, there is often a certain amount of residual concentrated water in the filtration treatment of wastewater, the treatment is very difficult, the efficiency is low, the cost is high, the stability is poor, etc., thereby meeting the needs of users for efficient and stable treatment of wastewater and environmental protection.

The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention.

Claims (9)

1. A process for treating oil production wastewater; the steps are as follows: S1: Preliminary oil-water separation treatment: First, the wastewater generated during the oil extraction process is collected into the produced water collection pool, and then the wastewater is introduced into the nano-gas flotation oil separation equipment. Highly dispersed tiny bubbles are used as carriers to adhere to the suspended matter in the wastewater, especially the oil droplets, so that their buoyancy is increased and they are removed as the bubbles rise to the water surface. The separated oil enters the oil collection barrel and returns to the oil field for use; S2: Deep oil-water separation and oxidation treatment: The water treated by nano-flotation oil separation in S1 is mixed with the fracturing fluid in the fracturing fluid collection pool and then enters the ozone nano-flotation equipment. Under the action of ozone + nano-fine bubbles, a large number of hydroxyl free radicals are generated, which non-selectively and rapidly oxidize various organic matter in the water body, quickly open the ring and break the bonds of organic matter, and quickly degrade pollution indicators such as COD. It can also float suspended matter and macromolecular organic matter in sewage to the surface, thereby separating and removing them; S21: Scum treatment: The scum produced by ozone nano-flotation in S2 is put into the sludge tank for treatment; S3: Dosing reaction system: introduce the water treated by ozone nano-flotation in S2 into the dosing reaction equipment, add PAC, softener, PAM and other agents into the dosing reaction equipment, so that it can be mixed with the wastewater for treatment; S4: Biological filtration system; the wastewater treated by the dosing reaction system enters the biological filtration equipment to intercept and filter suspended matter, and utilizes the metabolism of microorganisms to degrade organic matter: S5: Advanced wastewater treatment: The clean water treated by the biological filtration equipment in S4 enters the nano-ozone flotation equipment to remove organic matter and color that is difficult to biodegrade. At the same time, nano-flotation technology is used again to separate suspended matter: S51: Sludge treatment: The scum water produced in the nano-ozone flotation equipment is introduced into the sludge pool, and the sludge in the biological filtration equipment in S4 is also introduced into the sludge pool for treatment; S6: Sand-carbon filtration system: The clean water treated by the nano-ozone flotation equipment enters the sand-carbon filtration equipment, where sand particles are used to intercept suspended matter, and the adsorption of activated carbon is used to remove residual color and some organic matter; S61: introducing the backwash water in the sand carbon filtration device into the nano ozone flotation device for recirculation treatment; S7: Ultrafiltration system: The clean water treated in the sand-carbon filtration equipment enters the ultrafiltration equipment, and the wastewater is filtered using an ultrafiltration membrane, which can intercept substances with larger molecular weight and further purify the water quality; S71: concentrated water treatment: the concentrated water treated in the ultrafiltration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment to remove some inorganic and organic substances, chromaticity, etc. in the water; S8: DTRO filtration system; the clean water produced by the ultrafiltration filtration equipment in S7 enters the DTRO filtration equipment, and the DTRO membrane elements are used to separate and remove most of the soluble salts, small molecular organic matter, etc. in the leachate, and the concentrated water of the membrane system is reduced. Under high pressure, the leachate passes through the DTRO membrane system and becomes pure produced water; S81: Washing water treatment: the washing water treated in the DTRO filtration equipment is introduced into the nano-ozone flotation equipment for recirculation treatment; S9: Electrocatalytic oxidation system; The concentrated water treated in the DTRO filtration equipment enters the electrocatalytic oxidation equipment, and adopts high-frequency pulse electrocoagulation method, using electrochemical principles, with the help of external power supply to produce electrochemical reactions, converting electrical energy into chemical energy. In a specific ionization equipment process, the organic or inorganic pollutants in the wastewater are oxidized and reduced, and then condensed and separated from the water body. It has a good removal effect on emulsified oil, macromolecular organic matter, microorganisms, heavy metal ions, fluoride ions, turbidity and some colored substances, and can remove most COD and convert it into low-toxic or harmless substances; S91: The fresh water treated in the DTRO filtration equipment enters the anti-pollution membrane filtration equipment for treatment; S10: MVR evaporation system: The wastewater from the electrocatalytic oxidation device enters the MVR evaporation device, where the wastewater is heated to boiling, the water evaporates and condenses for recovery, while the pollutants remain in the concentrated liquid, i.e. the mother liquor. The remaining crystallized salt from evaporation can be outsourced for treatment; S11: Low-temperature scraper evaporation system: The mother liquor remaining after evaporation can enter the low-temperature scraper evaporation equipment, and the remaining crystallized salt can be outsourced for treatment. The condensed water of the MVR evaporation equipment and the low-temperature scraper evaporation equipment in S10 can enter the anti-pollution membrane filtration equipment for treatment together; S12: Anti-pollution membrane filtration system: The fresh water treated in the anti-pollution membrane filtration equipment can be reused or discharged, and the concentrated water re-enters the DTRO filtration equipment for circulation treatment. 2. A process for treating oil production wastewater according to claim 1, characterized in that: in S3, a detailed water quality analysis of the oil production wastewater is first performed, including indicators such as pH value, suspended solids (SS), turbidity, oil content, chemical oxygen demand (COD), biological oxygen demand (BOD), etc., and the optimal dosage of PAC, softener and PAM under different water quality conditions is determined through small or pilot tests. 3. A process for treating oil production wastewater according to claim 1, characterized in that: the biological filtration equipment in S4 is usually composed of multiple biological filter tanks, each of which is filled with biological fillers to provide a growth environment for microorganisms. 4. The process for treating oil production wastewater according to claim 1, characterized in that the sludge in the sludge pool in S51 is treated by a filter press, and finally the sludge is outsourced for treatment. 5. A process for treating oil production wastewater according to claim 1, characterized in that: in the sand-carbon filtering equipment of S6, the sand layer is located in the upper layer of the filtering tank body, which is used for preliminary filtering and intercepting larger particles of suspended matter, and the activated carbon layer is located below the sand layer, which is used for adsorbing organic matter, chromaticity and other pollutants. 6. A process for treating oil production wastewater according to claim 1, characterized in that: S6 also has a backwashing system, which includes a backwashing pipeline, a pump and a valve, which is used to regularly backwash the filter medium to remove trapped pollutants and restore the filtering performance. 7. A process for treating oil production wastewater according to claim 1, characterized in that: the DTRO membrane in S8 has the characteristics of high pollution resistance and high concentration, and is a special membrane element dedicated to sewage treatment. When treating oil field wastewater, it does not need to rely on pretreatment. Because its internal structure is an open flow channel design, it can efficiently treat wastewater containing more colloids, suspended matter, etc. 8. A process for treating oil production wastewater according to claim 1, characterized in that: the electrocatalytic oxidation in S9 utilizes electrochemical principles, generates electrochemical reactions with the help of an external power source, converts electrical energy into chemical energy, and oxidizes and reduces organic or inorganic pollutants in the wastewater in a specific ionization equipment process. 9. A process for treating oil production wastewater according to claim 8, characterized in that the pH value, impurities and pollutants that may exist in the wastewater may affect the effect of electrocatalytic oxidation, so the wastewater needs to be properly pretreated.