CN114212910A

CN114212910A - System for directly arrange outward after oil gas field water treatment

Info

Publication number: CN114212910A
Application number: CN202111356953.8A
Authority: CN
Inventors: 岳自恒; 王媛; 田昊; 李宁军; 史永峰
Original assignee: Shaanxi Haimo Oilfield Service Co ltd
Current assignee: Shaanxi Haimo Oilfield Service Co ltd
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2022-03-22

Abstract

The invention discloses a system for directly discharging water after oil and gas field water treatment, which comprises: the system comprises pretreatment equipment, solid-liquid separation equipment, fine treatment equipment, effluent monitoring equipment, sludge reduction equipment and resource utilization equipment; the pretreatment equipment, the solid-liquid separation equipment, the fine treatment equipment, the effluent monitoring equipment, the sludge reduction equipment and the resource utilization equipment are respectively provided with corresponding skid-mounted chassis. The system disclosed by the invention can be used for treating the wastewater of the oil and gas field, integrates the monitoring equipment and the resource utilization equipment, can be used for monitoring the effluent quality in real time, and can achieve the direct discharge standard after the wastewater of the oil and gas field is treated, so that the effluent is prevented from polluting the environment, and the environmental protection risk is effectively avoided. The generated concentrated solution is purified and recycled, so that the investment cost and the operation cost are reduced; each equipment sled dress is integrated, and the installation transportation is convenient, has expanded the adaptability of equipment, is fit for the waste water treatment of scattered well site.

Description

System for directly arrange outward after oil gas field water treatment

Technical Field

The invention belongs to the technical field of oil and gas field water treatment, and particularly relates to a system for directly discharging water after oil and gas field water treatment.

Background

In recent years, rapid increases in oil and gas field production have had an impact on the world's energy landscape. Oil and gas field development consists of 3 stages of drilling, fracturing completion and production. Drilling wastewater is generated in the drilling stage, the liquid which is firstly returned to the ground after the hydraulic fracturing operation is finished is called fracturing flow-back liquid, and the liquid which is returned from the production stage after the flow-back stage is finished is called produced water. Thus, drilling wastewater, frac flowback fluid, and produced water are the main components of oil and gas field wastewater.

Analysis of waste water quality of oil and gas field

As can be seen from the analysis of the water quality of the oil and gas field wastewater, the oil and gas field wastewater has the characteristics of high COD content, high SS content, high TDS (total dissolved solids) content, large water quality fluctuation and the like. The COD main components of the flowback fluid are organic matters in the stratum and chemical additives in the fracturing fluid; the SS comprises the main components of clay in the stratum and mechanical impurities generated in the drilling process; TDS mainly comprises ions such as sodium, chlorine, potassium, calcium and magnesium, and the high TDS content is mainly caused by erosion of the fracturing fluid to the stratum or mixing of the fracturing fluid and the stratum water; the reason why the quality fluctuation of the flowback fluid is large is that as the development time becomes longer, the retention time of the fracturing fluid in the stratum becomes longer, the COD content of the flowback fluid is reduced, and the TDS content is increased. In conclusion, the fracturing flow-back fluid of the oil and gas field is complex in composition and high in treatment difficulty, and is considered to be one of the most difficult-to-treat industrial sewage.

At present, the treatment modes of the waste water of the oil and gas field in China mainly comprise deep well reinjection, well field recycling and discharge technologies, and when the deep well is reinjected, the deep well is strictly selected, so that underground water is polluted, and the transportation cost is high; because the water source around the oil and gas field site is abundant, the clean water source is mainly adopted in the field production, the oil and gas field waste water is recycled, and in conclusion, the treatment systems for deep well reinjection and well site recycling have certain environmental risks and application limitations. With the rise of membrane technology, the direct drainage technology for treating the oil and gas field wastewater becomes a main direction for solving the problem of removing the oil and gas field wastewater, the oil and gas field wastewater after pretreatment-reverse osmosis treatment can meet the discharge requirement of landmark water, the oil and gas field wastewater can be directly discharged into rivers to supplement the consumption of water resources, and the membrane has long-term social benefit and economic benefit.

Through the investigation and research of the prior art, the process idea of high-temperature evaporation salt production of the generated concentrated solution is mainly adopted for treating the oil-gas field wastewater by advanced oxidation (ozone and Fenton), flocculation, water softening, filtration, ultrafiltration and reverse osmosis, and although the process can meet the discharge requirement, the water quality of the effluent cannot be monitored in real time, so that the environmental protection and safety risks are increased; meanwhile, the high-temperature evaporator has high energy consumption, and a large amount of generated salt is accumulated on the site and cannot be recycled. At present, the process equipment is mainly arranged in a combined station mode, long-distance pipeline transportation or a large number of automobile pulling transportation needs to be erected for water supply, the equipment is large in occupied area, high in investment cost and high in operation cost, and the process equipment is not suitable for the treatment requirements of scattered well sites in mountain areas.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a system for directly discharging water after oil and gas field water treatment. The technical problem to be solved by the invention is realized by the following technical scheme:

a system for directly discharging water in an oil and gas field after water treatment comprises: the system comprises pretreatment equipment, solid-liquid separation equipment, fine treatment equipment, effluent monitoring equipment, sludge reduction equipment and resource utilization equipment;

an outlet of the pretreatment equipment is communicated with an inlet of the solid-liquid separation equipment, an outlet of the solid-liquid separation equipment is communicated with an inlet of the fine treatment equipment, and an outlet of the fine treatment equipment is communicated with an inlet of the effluent monitoring equipment; the outlet of the pretreatment equipment is also communicated with the inlet of the sludge reduction equipment, and the outlet of the solid-liquid separation equipment is also communicated with the inlet of the sludge reduction equipment; the concentrated solution outlet of the fine treatment equipment is also communicated with the inlet of the resource utilization equipment; the filtrate port of the sludge reduction equipment is communicated with the inlet of the pretreatment equipment;

the pretreatment equipment, the solid-liquid separation equipment, the fine treatment equipment, the effluent monitoring equipment, the sludge reduction equipment and the resource utilization equipment are respectively provided with corresponding skid-mounted chassis.

In one embodiment of the present invention, the preprocessing apparatus includes: a sand removal tank, a pre-oxidation tank, an aeration device and a tail gas treatment device;

the bottom of the sand removing tank is provided with a slag discharge port;

the water outlet of the desanding tank is connected with the water inlet of the pre-oxidation tank, the gas outlet of the aeration device is connected with the gas inlet in the pre-oxidation tank, the gas inlet of the gas collecting hood of the tail gas treatment device is connected with the upper part of the pre-oxidation tank, the slag discharge port of the desanding tank is connected with the inlet of the sludge reduction device, and the water outlet of the pre-oxidation tank is communicated with the inlet of the solid-liquid separation device.

In one embodiment of the present invention, the solid-liquid separation apparatus comprises: the device comprises a primary lift pump, a water softening tank, a dosing device, a multifunctional solid-liquid separation tank, a secondary lift pump, a filter tank and a primary buffer water tank;

the water outlet of the pre-oxidation tank is communicated with the inlet of the primary lift pump;

the outlet of the primary lifting pump is connected with the inlet of the water softening tank, the outlet of the water softening tank is connected with the water inlet of the multifunctional solid-liquid separation tank, the outlet of the multifunctional solid-liquid separation tank is connected with the inlet of the secondary lifting pump, the slag outlet of the multifunctional solid-liquid separation tank is connected with the inlet of the sludge reduction equipment, the outlet of the secondary lifting pump is connected with the inlet of the filter tank, the outlet of the filter tank is connected with the inlet of the primary buffer water tank, and the outlet of the chemical feeding device is respectively connected with the water softening tank and the chemical inlet of the multifunctional solid-liquid separation tank;

and the outlet of the primary buffer water tank is communicated with the fine treatment equipment.

In one embodiment of the present invention, the fine processing apparatus includes: the device comprises a lift pump, a cartridge filter, a first-stage high-pressure reverse osmosis membrane component, a second-stage high-pressure reverse osmosis membrane component, a normal-pressure reverse osmosis membrane component and a stripping tower;

the outlet of the primary buffer water tank is communicated with the inlet of the lifting pump;

the outlet of the lifting pump is connected with the inlet of the safety filter, the outlet of the safety filter is connected with the inlet of the first-stage high-pressure reverse osmosis membrane module, the outlet of the first-stage high-pressure reverse osmosis membrane module is connected with the inlet of the normal-pressure reverse osmosis membrane module, and the water outlet of the normal-pressure reverse osmosis membrane module is connected with the water inlet of the stripping tower; the concentrated solution outlet of the first-stage high-pressure reverse osmosis membrane component and the concentrated solution outlet of the normal-pressure reverse osmosis membrane component are both connected with the inlet of the second-stage high-pressure reverse osmosis membrane component, and the water outlet of the second-stage high-pressure reverse osmosis membrane component is connected with the water inlet of the stripping tower;

and the water outlet of the stripping tower is communicated with the inlet of the water outlet monitoring equipment.

In one embodiment of the present invention, the effluent monitoring apparatus comprises: the system comprises a flow cell, a pH on-line monitor, a COD on-line monitor, an ammonia nitrogen on-line monitor, a chloride ion on-line monitor and a suspended matter on-line monitor;

the water outlet of the stripping tower is communicated with the water inlet of the flow cell;

the delivery port and the outer mouth of arranging of flow-through cell are connected, and the sample connection of pH on-line monitoring appearance, COD on-line monitoring appearance's sample connection, ammonia nitrogen on-line monitoring appearance's sample connection, chloride ion on-line monitoring appearance's sample connection and suspended solid on-line monitoring appearance all are located in the flow-through cell.

In one embodiment of the present invention, the sludge reducing apparatus includes: a sludge pump, a sludge tank and a sludge drying device;

the sludge discharging port of the pretreatment equipment and the slag discharging port of the solid-liquid separation equipment are connected with the inlet of the sludge pump, the outlet of the sludge pump is connected with the sludge inlet of the sludge tank, the sludge outlet of the sludge tank is connected with the feed inlet of the sludge drying device, and the filtrate generated by the filtrate port of the sludge drying device returns to the pretreatment equipment.

In an embodiment of the present invention, the resource utilization apparatus includes: a liquid storage tank and a booster pump;

and a concentrated solution outlet of the second-stage high-pressure reverse osmosis membrane component is connected with a solution inlet of the liquid storage tank, and a water outlet of the liquid storage tank is connected with a water inlet of the booster pump.

The invention has the beneficial effects that:

the system disclosed by the invention can be used for treating the wastewater of the oil and gas field, integrates the monitoring equipment and the resource utilization equipment, can be used for monitoring the effluent quality in real time, and can achieve the direct discharge standard after the wastewater of the oil and gas field is treated, so that the effluent is prevented from polluting the environment, and the environmental protection risk is effectively avoided. The generated concentrated solution is purified and recycled, so that the investment cost and the operation cost are reduced; each equipment sled dress is integrated, and the installation transportation is convenient, has expanded the adaptability of equipment, is fit for the waste water treatment of scattered well site.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic structural diagram of a system for directly discharging water after oil and gas field water treatment according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a pretreatment apparatus provided in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a solid-liquid separation apparatus provided in an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a fine processing apparatus provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an effluent monitoring apparatus provided in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a sludge reduction apparatus according to an embodiment of the present invention.

Description of reference numerals:

10-pretreatment equipment; 11-a sand removal tank; 12-a pre-oxidation tank; 13-an aeration device; 14-a tail gas treatment device; 20-a solid-liquid separation device; 21-first stage lift pump; 22-a water softening tank; 23-a dosing device; 24-a multifunctional solid-liquid separation tank; 25-a secondary lift pump; 26-a filtration tank; 27-a primary buffer water tank; 30-fine processing equipment; 31-a lift pump; 32-a cartridge filter; 33-first-stage high-pressure reverse osmosis membrane module; 34-a two-stage high-pressure reverse osmosis membrane module; 35-normal pressure reverse osmosis membrane module; 36-a stripping column; 40-effluent monitoring equipment; 41-a flow-through cell; 42-pH on-line monitor; 43-COD on-line monitor; 44-ammonia nitrogen on-line monitoring instrument; 45-chloride ion on-line monitor; 46-suspended matter on-line monitor; 50-sludge reduction equipment; 51-sludge pump; 52-a sludge tank; 53-sludge drying device; and 60-resource utilization equipment.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

Example one

Referring to fig. 1, a system for directly discharging water from an oil and gas field after water treatment comprises: the system comprises a pretreatment device 10, a solid-liquid separation device 20, a fine treatment device 30, an effluent monitoring device 40, a sludge reduction device 50 and a resource utilization device 60.

The outlet of the pretreatment device 10 is communicated with the inlet of the solid-liquid separation device 20, the outlet of the solid-liquid separation device 20 is communicated with the inlet of the fine treatment device 30, and the outlet of the fine treatment device 30 is communicated with the inlet of the effluent monitoring device 40; the outlet of the pretreatment device 10 is also communicated with the inlet of the sludge reduction device 50, and the outlet of the solid-liquid separation device 20 is also communicated with the inlet of the sludge reduction device 50; the concentrated solution outlet of the fine treatment device 30 is also communicated with the inlet of the resource utilization device 60. The filtrate port of the sludge reduction device 50 is communicated with the inlet of the pretreatment device 10. The pretreatment device 10 is integrally arranged on a skid-mounted chassis, the solid-liquid separation device 20 is integrally arranged on the skid-mounted chassis, the fine treatment device 30 is integrally arranged on the skid-mounted chassis, the effluent monitoring device 40 is integrally arranged on the skid-mounted chassis, the sludge reduction device 50 is integrally arranged on the skid-mounted chassis, the resource utilization device 60 is integrally arranged on the skid-mounted chassis, and all the devices are integrated on the respective skid-mounted chassis.

In the embodiment, the system integrates related equipment for wastewater treatment, effluent monitoring and concentrated solution purification, the functionality of the system is increased, the wastewater of the oil and gas well can be treated, the effluent quality can be monitored in real time, the wastewater of the oil and gas field can reach the direct discharge standard after being treated, the effluent is prevented from polluting the environment, the environmental protection risk is effectively avoided, the generated concentrated solution can be purified and recycled, and the investment cost and the operation cost are reduced; each equipment sled dress is integrated, and the installation transportation is convenient, has expanded the adaptability of equipment, is fit for the waste water treatment of scattered well site.

The oil and gas field wastewater comprises but is not limited to drilling wastewater, fracturing return water, well flushing wastewater, acidizing wastewater and produced water. The pretreatment device 10 is mainly used for removing organic impurities, sulfides, harmful gases, macromolecular organic matters, floating oil and other pollutants in wastewater.

The solid-liquid separation device 20 is mainly used for removing suspended matters, bacteria and main scale forming ions in the wastewater after adjusting the pH of the wastewater, and realizing solid-liquid separation.

The fine treatment device 30 is mainly used for removing chloride ions, ammonia nitrogen, COD and other pollutants in the wastewater.

The effluent monitoring equipment 40 is mainly used for monitoring the treated water quality on line and ensuring that the treated water quality meets the standard requirements.

The sludge reduction facility 50 is mainly used for reducing the amount of the generated sludge and performing appropriate harmless treatment.

The resource utilization equipment 60 is mainly used for purifying the generated concentrated solution, and after recovery and split charging, the concentrated solution is used as an oil-gas field drilling mud weighting agent, an additive needed in fracturing fluid and other resource utilization modes.

Further, as shown in fig. 2, the pretreatment device 10 includes: a sand removing tank 11, a pre-oxidation tank 12, an aeration device 13 and a tail gas treatment device 14. The bottom of the desanding tank 11 is provided with a slag discharge port.

The water outlet of the desanding tank 11 is connected with the water inlet of the pre-oxidation tank 12, the air outlet of the aeration device 13 is connected with the air inlet of the pre-oxidation tank 12, the air inlet of the gas collecting hood of the tail gas treatment device 14 is connected with the upper part of the pre-oxidation tank 12, the slag discharge port of the desanding tank 11 is connected with the inlet of the sludge reduction device 50, and the water outlet of the pre-oxidation tank 12 is communicated with the inlet of the solid-liquid separation device 20.

In this embodiment, oil gas field waste water gets into in the preprocessing equipment 10, when actual operation, for example oil gas field waste water can adopt gravity to subside or whirl form to separate the machine miscellaneous, the detritus of aquatic earlier through desanding jar 11, can be according to taking up an area of and containing the nimble selection of sand condition. The retention time of the gravity settling is 15-30 min.

The waste water after the treatment of the sand removing tank 11 enters the pre-oxidation tank 12 in a self-flowing mode, the waste water flows from the upper part to the lower part of the pre-oxidation tank 12 and then fully contacts and reacts with the nano gas generated by the aeration device 13, so that sulfide in the waste water is oxidized into sulfur simple substance to be separated out from the water, according to the Henry's law, hydrogen sulfide, methane and other gases overflow from the water, the overflowed gas is collected by the gas collecting hood in the tail gas treatment device 14, and the harmful gas is collected by the absorption liquid and then discharged to the atmosphere after reaching the standard. The effluent of the pre-oxidation tank 12 enters a solid-liquid separation device 20.

The oxidation method is a common oxidation method which is one of the main means for treating the oil-gas field wastewater and comprises the following steps: air oxidation, potassium permanganate oxidation, potassium persulfate oxidation, hypochlorite oxidation, Fenton oxidation, electrocatalytic oxidation, ozone oxidation and the like.

When treating oil field waste water, the air source can be changed into ozone, and the action of ozone oxidation is mainly to remove polymer viscosity reduction, COD and BOD, ammonia nitrogen, sterilization, decoloration and deodorization. The macromolecular organic matters in the water are oxidized into micromolecular organic matters, so that the load of rear-end equipment is reduced. The ozone oxidation has the characteristics of high oxidation efficiency, no need of adding medicaments, simple operation, no secondary pollution and the like.

When the gas field wastewater is treated, the treatment can be flexibly carried out according to the field condition, and when the COD in the water is lower than 1000mg/L or the sulfides are lower, an air source can be adopted to oxidize and remove the sulfides in the water, promote the growth and the propagation of living things, oxidize and decompose macromolecular organic matters, degrade the COD and achieve the purpose of reducing the viscosity; when one or more of COD (chemical oxygen demand) in water is more than 1000mg/L, sulfides are higher, viscosity is higher and the like, ozone can be used as a gas source, and the functions of removing sulfides, COD, ammonia nitrogen, viscosity and the like in water are mainly achieved.

In a feasible implementation mode, the aeration device 13 not only has the aeration and oxygenation functions of the conventional aeration device 13, but also can combine rotational flow water inflow with various combined steam-water cutting modes, so that after the steam-water mixture is cut for multiple times, the pre-oxidation tank 12 has the advantages of tiny bubbles (smaller than 10 microns), high gas utilization rate, high stirring capacity, large service area and the like, and the flexibility and wide applicability of equipment are greatly enhanced.

In a feasible implementation manner, the pre-oxidation tank 12 mainly comprises a tank body and a water distributor, and is used for oxidizing pollutants such as impurities, sulfides, harmful gases, viscosity, floating oil and the like in the wastewater to prevent corrosion to equipment and influence on the surrounding environment. The aeration device 13 comprises a fan, a pipeline and a nano aerator and is used for removing hydrogen sulfide and sulfide in the water through oxidation. The tail gas treatment device 14 mainly comprises a gas collecting hood, a pipeline, a fan, an absorption liquid storage tank and absorption liquid, and is used for absorbing harmful gas overflowing from the waste water to prevent the pollution to the surrounding environment.

Further, as shown in fig. 3, the solid-liquid separation apparatus 20 includes: a primary lift pump 21, a water softening tank 22, a dosing device 23, a multifunctional solid-liquid separation tank 24, a secondary lift pump 25, a filter tank 26 and a primary buffer water tank 27;

the water outlet of the pre-oxidation tank 12 is communicated with the inlet of the primary lift pump 21. The export of one-level elevator pump 21 and the access connection of water softening tank 22, the export of water softening tank 22 is connected with the water inlet of multi-functional solid-liquid separation jar 24, the export of multi-functional solid-liquid separation jar 24 and the access connection of second grade elevator pump 25, the slag notch of multi-functional solid-liquid separation jar 24 and the access connection of mud decrement equipment 50, the export of second grade elevator pump 25 and the access connection of filter tank 26, the export of filter tank 26 and the access connection of one-level buffer tank 27, charge device 23's export is connected with the medicine inlet of water softening tank 22 and multi-functional solid-liquid separation jar 24 respectively. The outlet of the primary buffer tank 27 communicates with the fine processing equipment 30.

In this embodiment, the first-stage lift pump 21 lifts the effluent from the pre-oxidation tank 12 to the water softening tank 22, and the chemical feeding device 23 adds a compound water softening agent to the water softening tank 22, so that the calcium, magnesium, iron, barium, and the like in the wastewater form a precipitate or complex, which is separated out from the water. The water quality softening tank 22 effluent overflows to a multifunctional solid-liquid separation tank 24, a pH regulator, a flocculating agent and a coagulating agent are added into the multifunctional separation tank through a dosing device 23, so that precipitates and suspended matters in wastewater flocculate, the high-efficiency separation zone realizes rapid solid-liquid separation, a solid phase is precipitated in a mud bucket, a liquid phase overflows to a buffer zone, and then is conveyed to a filter tank 26 through a secondary lift pump 25, and the finer suspended matters and bacteria in the water are removed and automatically flow to a primary buffer water tank 27.

In one possible implementation, the water softening tank 22 mainly includes a stirrer and a tank body, and is mainly used for removing scale formation of calcium, magnesium, iron and the like in water or ions corroding equipment.

The multifunctional solid-liquid separation tank 24 mainly comprises a tank body, a mixing reaction device (one or more components of a stirrer/pipeline mixer/folded plate/micro vortex reactor), a filler (inclined plate/inclined tube), a sludge concentration device and a buffer zone, and is mainly used for removing sediments, suspended matters and bacteria in water.

The multifunctional solid-liquid separation tank 24 has the functions of medicament mixing and reaction, inclined plate sedimentation, sludge collection, wastewater buffering and the like, and the micro-vortex reactor is adopted to strengthen the mixing reaction of the medicaments, so that the mixing reaction is more sufficient than the conventional stirring reaction; the bottom of the sludge bucket is provided with a concentrated sludge scraper, so that sludge at the bottom of the sludge bucket is not accumulated, and the sludge discharge efficiency is higher; the inclined plate module made of special materials is adopted, so that the problems of easy oxidation, difficult maintenance and easy collapse of the traditional inclined pipe are solved.

The dosing device 23 mainly comprises a dosing tank, a medicine storage tank, a stirrer, a dosing pump and a pipeline, and the mainly dosed medicines comprise a pH regulator (acid and alkali), an oxidant, a flocculating agent, a coagulant, an ion remover, a water quality stabilizer and the like.

The primary buffer tank 27 is mainly used to ensure the effective water amount of the pump operation, namely: the pumping amount of the pump in normal operation for 10-15 min is met.

The filtering tank 26 mainly comprises a tank body and a filler, and is mainly used for further filtering and removing suspended matters, sediments and bacteria in the wastewater.

The filler of the filter tank 26 can be different fillers according to different wastewater treatment, and when the oil field wastewater is treated, oleophylic hydrophobic materials such as walnut shells, nut shells, activated carbon and the like can be adopted to adsorb oil in water to the maximum extent; when the gas field wastewater is treated, hydrophilic and oleophobic materials such as quartz sand, active filter materials, magnetite, garnet and modified fiber bundles/spheres can be adopted to remove suspended matters in water to the maximum extent or carry out grading on concentrated fillers according to conditions.

Further, as shown in fig. 4, the fine processing apparatus 30 includes: a lift pump 31, a cartridge filter 32, a first-stage high-pressure reverse osmosis membrane component 33, a second-stage high-pressure reverse osmosis membrane component 34, a normal-pressure reverse osmosis membrane component 35 and a stripping tower 36. The outlet of the primary buffer tank 27 communicates with the inlet of a lift pump 31.

The outlet of the lift pump 31 is connected with the inlet of the security filter 32, the outlet of the security filter 32 is connected with the inlet of the first-stage high-pressure reverse osmosis membrane component 33, the outlet of the first-stage high-pressure reverse osmosis membrane component 33 is connected with the inlet of the normal-pressure reverse osmosis membrane component 35, and the water outlet of the normal-pressure reverse osmosis membrane component 35 is connected with the water inlet of the stripping tower 36; the concentrated solution outlet of the first-stage high-pressure reverse osmosis membrane component 33 and the concentrated solution outlet of the normal-pressure reverse osmosis membrane component 35 are both connected with the inlet of the second-stage high-pressure reverse osmosis membrane component 34, and the water outlet of the second-stage high-pressure reverse osmosis membrane component 34 is connected with the water inlet of the stripping tower 36. The water outlet of the stripping tower 36 is communicated with the inlet of the water outlet monitoring device 40. The concentrated solution outlet of the second-stage high-pressure reverse osmosis membrane component 34 is communicated with the solution inlet of the resource utilization equipment 60.

In this embodiment, the outlet water of the primary buffer water tank 27 is delivered to a security filter 32 through a lift pump 31, after filtering and intercepting finer suspended matters in the water, the outlet water enters a primary high-pressure reverse osmosis membrane module 33, and then 80% of COD, ammonia nitrogen, more than 95% of suspended matters, more than 92% of chloride ions and more than 99% of bacteria in the water are treated, the outlet water enters a normal-pressure reverse osmosis membrane module 35, so that pollutants required by emission standards such as COD, ammonia nitrogen and chloride ions are further removed until reaching standards, then the outlet water enters a stripping tower 36, organic gas which may cause fluctuation of COD and ammonia nitrogen indexes is stripped, concentrated solutions generated by the primary high-pressure reverse osmosis membrane module 33 and the normal-pressure reverse osmosis membrane module 35 enter a secondary high-pressure reverse osmosis membrane module 34, so as to be further concentrated and reduced, and the concentration ratio can reach 5:1 at most.

In a feasible implementation mode, the first-stage high-pressure reverse osmosis membrane module 33 and the second-stage high-pressure reverse osmosis membrane module 34 are disc-type membrane modules manufactured by international-level membrane materials, and through special structural design, turbulence is formed on the surface of a filter membrane, the permeation filtration rate and the self-cleaning effect of the membrane are enhanced, the phenomena of membrane blockage and extremely poor concentration are effectively avoided, the service life of the membrane is prolonged, and the membrane modules are suitable for wastewater treatment with high turbidity, high pollution and high salinity.

In one possible implementation, the cartridge filter 32 consists essentially of one or more of a stainless steel screen/pp cotton filter/high flux membrane, which is primarily designed to remove suspended matter from the water and prevent clogging of the back end membrane equipment.

The reverse osmosis membrane of the first-stage high-pressure reverse osmosis membrane module 33 is mainly composed of 90bar DTRO (disc type reverse osmosis membrane), and is mainly used for removing other pollutants such as COD (chemical oxygen demand), ammonia nitrogen, chloride ions and the like in water.

The reverse osmosis membrane of the normal pressure reverse osmosis membrane module 35 mainly comprises a STRO (pipe network reverse osmosis membrane), and mainly reduces COD, ammonia nitrogen and chloride ions;

the reverse osmosis membrane of the secondary high-pressure reverse osmosis membrane component 34 mainly consists of 160barDTRO, and is mainly used for further concentrating concentrated solution generated by the system and reducing the generation amount of wastewater;

the stripping tower 36 mainly comprises a tower body, a filler and a blower, and is mainly used for stripping organic waste gas in the waste water so as to further reduce COD.

Further, as shown in fig. 5, the effluent monitoring apparatus 40 includes: a flow cell 41, a pH on-line monitor 42, a COD on-line monitor 43, an ammonia nitrogen on-line monitor 44, a chloride ion on-line monitor 45 and a suspended matter on-line monitor 46.

The water outlet of the stripping tower 36 is communicated with the water inlet of the flow cell 41. The delivery port and the outer mouth of flow-through cell 41 are connected, and the sample connection of pH on-line monitoring appearance 42, the sample connection of COD on-line monitoring appearance 43, the sample connection of ammonia nitrogen on-line monitoring appearance 44, the sample connection of chloride ion on-line monitoring appearance 45 and the sample connection of suspended solid on-line monitoring appearance 46 all are located flow-through cell 41.

In this embodiment, the pH on-line monitor 42, the COD on-line monitor 43, the ammonia nitrogen on-line monitor 44, the chloride ion on-line monitor 45 and the suspended matter on-line monitor 46 mainly monitor pH, COD, ammonia nitrogen, chloride ion and suspended matter in the treated wastewater from time to time, ensure the normal operation of the treatment equipment, and meet the requirements of discharge standards. Sampling ports of a pH on-line monitor 42, a COD on-line monitor 43, an ammonia nitrogen on-line monitor 44, a chloride ion on-line monitor 45 and a suspended matter on-line monitor 46 are sequentially arranged on the upper part of the flow cell 41 in a parallel connection mode.

Specifically, the effluent of the stripping tower 36 enters the inlet of the flow cell 41, the upper part of the flow cell 41 is respectively provided with a sampling port of a pH online monitor 42, a COD online monitor 43, an ammonia nitrogen online monitor 44, a chloride ion online monitor 45 and a suspended matter online monitor 46, and the water outlet of the flow cell 41 is connected with an external discharge port. The online monitoring instrument is used for regularly and quantitatively extracting the wastewater sample for online analysis, so that the emission requirement attention index monitoring is achieved, and meanwhile, a basis is provided for the adjustment and optimization of the whole system and equipment process parameters, such as: when the water outlet is not up to the standard, the water outlet of the flow cell 41 is immediately closed, and the residual wastewater in the pipeline is discharged to the accident cell to prevent and treat environmental pollution. And the effluent discharged from the external discharge port enters an external discharge system for discharging.

Further, as shown in fig. 6, the sludge reducing apparatus 50 includes: a sludge pump 51, a sludge tank 52 and a sludge drying device 53. A slag discharge port of the pretreatment device 10 and a slag discharge port of the solid-liquid separation device 20 are connected with an inlet of a sludge pump 51, an outlet of the sludge pump 51 is connected with a sludge inlet of a sludge tank 52, a sludge outlet of the sludge tank 52 is connected with a feed inlet of a sludge drying device 53, and filtrate generated by a filtrate port of the sludge drying device 53 returns to the pretreatment device 10.

In this embodiment, specifically, sludge generated from the slag discharge port of the desanding tank 11 and the slag discharge port of the multifunctional solid-liquid separation tank 24 is injected into a sludge tank 52 by a sludge pump 51, the compactness and the floc diameter of floc sludge are increased by sludge conditioning measures (adding conditioning agents such as anionic flocculant and lime, and then slowly stirring), and then the sludge enters a sludge drying device 53 for drying and dewatering, the generated solid is bagged and subjected to harmless treatment, and the generated filtrate is circulated to the pre-oxidation tank 12 for treatment.

In one possible implementation, the sludge drying device 53 mainly includes one or more combinations of a plate-and-frame filter press, a laminated dehydrator, a centrifuge, and the like. The method is mainly characterized in that sludge and flocs generated by the whole device are subjected to dehydration and reduction treatment, so that the water content of the sludge is less than or equal to 80 percent.

Further, the resource utilization device 60 includes: a liquid storage tank and a booster pump;

the concentrated solution outlet of the second-stage high-pressure reverse osmosis membrane component 34 is connected with the solution inlet of the liquid storage tank, and the water outlet of the liquid storage tank is connected with the water inlet of the booster pump.

The liquid storage tank and the increasing pump are mainly used for purifying high-salt-content concentrated water, then the high-salt-content concentrated water is pumped to the liquid pulling vehicle through the increasing pump, and then the high-salt-content concentrated water is pulled and transported to the site to be used for preparing a mud weighting agent and a fracturing fluid additive for recycling.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. The utility model provides a system that directly arranges outward after oil and gas field water treatment which characterized in that includes: the system comprises a pretreatment device (10), a solid-liquid separation device (20), a fine treatment device (30), an effluent monitoring device (40), a sludge reduction device (50) and a resource utilization device (60);

an outlet of the pretreatment equipment (10) is communicated with an inlet of the solid-liquid separation equipment (20), an outlet of the solid-liquid separation equipment (20) is communicated with an inlet of the fine treatment equipment (30), and an outlet of the fine treatment equipment (30) is communicated with an inlet of the effluent monitoring equipment (40); the outlet of the pretreatment device (10) is also communicated with the inlet of the sludge reduction device (50), and the outlet of the solid-liquid separation device (20) is also communicated with the inlet of the sludge reduction device (50); a concentrated solution outlet of the fine treatment equipment (30) is also communicated with an inlet of the resource utilization equipment (60); the filtrate port of the sludge reduction equipment (50) is communicated with the inlet of the pretreatment equipment (10);

the pretreatment equipment (10), the solid-liquid separation equipment (20), the fine treatment equipment (30), the effluent monitoring equipment (40), the sludge reduction equipment (50) and the resource utilization equipment (60) are respectively provided with corresponding skid-mounted chassis.

2. The system for direct discharge after oil and gas field water treatment according to claim 1, characterized in that the pretreatment device (10) comprises: a sand removal tank (11), a pre-oxidation tank (12), an aeration device (13) and a tail gas treatment device (14);

a slag discharge port is arranged at the bottom of the sand removing tank (11);

the delivery port of desanding tank (11) is connected with the water inlet of pre-oxidation tank (12), the gas outlet of aeration equipment (13) with the air inlet in pre-oxidation tank (12) is connected, the gas inlet of the gas collecting channel of tail gas processing apparatus (14) with the upper portion of pre-oxidation tank (12) is connected, the deslagging port of desanding tank (11) with the access connection of mud decrement equipment (50), the delivery port of pre-oxidation tank (12) with the import intercommunication of solid-liquid separation equipment (20).

3. The system for direct discharge after oil and gas field water treatment according to claim 2, wherein the solid-liquid separation equipment (20) comprises: a primary lift pump (21), a water softening tank (22), a dosing device (23), a multifunctional solid-liquid separation tank (24), a secondary lift pump (25), a filtering tank (26) and a primary buffer water tank (27);

the water outlet of the pre-oxidation tank (12) is communicated with the inlet of the primary lift pump (21);

the outlet of the primary lifting pump (21) is connected with the inlet of the water softening tank (22), the outlet of the water softening tank (22) is connected with the water inlet of the multifunctional solid-liquid separation tank (24), the outlet of the multifunctional solid-liquid separation tank (24) is connected with the inlet of the secondary lifting pump (25), the slag outlet of the multifunctional solid-liquid separation tank (24) is connected with the inlet of the sludge reduction equipment (50), the outlet of the secondary lifting pump (25) is connected with the inlet of the filter tank (26), the outlet of the filter tank (26) is connected with the inlet of the primary buffer water tank (27), and the outlet of the chemical adding device (23) is respectively connected with the chemical inlet of the water softening tank (22) and the chemical inlet of the multifunctional solid-liquid separation tank (24);

the outlet of the primary buffer water tank (27) is communicated with the fine processing equipment (30).

4. The system for direct discharge after oil and gas field water treatment according to claim 3, wherein the fine treatment equipment (30) comprises: a lift pump (31), a cartridge filter (32), a first-stage high-pressure reverse osmosis membrane component (33), a second-stage high-pressure reverse osmosis membrane component (34), a normal-pressure reverse osmosis membrane component (35) and a stripping tower (36);

the outlet of the primary buffer water tank (27) is communicated with the inlet of the lifting pump (31);

an outlet of the lift pump (31) is connected with an inlet of the cartridge filter (32), an outlet of the cartridge filter (32) is connected with an inlet of the first-stage high-pressure reverse osmosis membrane module (33), an outlet of the first-stage high-pressure reverse osmosis membrane module (33) is connected with an inlet of the normal-pressure reverse osmosis membrane module (35), and a water outlet of the normal-pressure reverse osmosis membrane module (35) is connected with a water inlet of a stripping tower (36); a concentrated solution outlet of the first-stage high-pressure reverse osmosis membrane component (33) and a concentrated solution outlet of the normal-pressure reverse osmosis membrane component (35) are both connected with an inlet of the second-stage high-pressure reverse osmosis membrane component (34), and a water outlet of the second-stage high-pressure reverse osmosis membrane component (34) is connected with a water inlet of a stripping tower (36);

and the water outlet of the stripping tower (36) is communicated with the inlet of the water outlet monitoring equipment (40).

5. The system for direct discharge of treated water from oil and gas fields as claimed in claim 4, wherein the effluent monitoring device (40) comprises: a flow cell (41), a pH on-line monitor (42), a COD on-line monitor (43), an ammonia nitrogen on-line monitor (44), a chloride ion on-line monitor (45) and a suspended matter on-line monitor (46);

the water outlet of the stripping tower (36) is communicated with the water inlet of the flow cell (41);

the delivery port and the outer mouth of arranging of flow-through cell (41) are connected, and the sample connection of pH on-line monitoring appearance (42), the sample connection of COD on-line monitoring appearance (43), the sample connection of ammonia nitrogen on-line monitoring appearance (44), the sample connection of chloride ion on-line monitoring appearance (45) and the sample connection of suspended solid on-line monitoring appearance (46) all are located in flow-through cell (41).

6. The system for direct discharge after oil and gas field water treatment according to claim 5, wherein the sludge reduction device (50) comprises: a sludge pump (51), a sludge tank (52) and a sludge drying device (53);

the row's cinder notch of preliminary treatment equipment (10) with the slag notch of solid-liquid separation equipment (20) with the access connection of sludge pump (51), the export of sludge pump (51) with the mud mouth that advances of sludge tank (52) is connected, the mud mouth of sludge tank (52) with the feed inlet of sludge drying device (53) is connected, the filtrating that the filtrating mouth of sludge drying device (53) produced returns to preliminary treatment equipment (10).

7. The system for directly discharging the water after the oil and gas field water treatment according to claim 6, wherein the resource utilization device (60) comprises: a liquid storage tank and a booster pump;

and a concentrated solution outlet of the second-stage high-pressure reverse osmosis membrane component (34) is connected with a solution inlet of the liquid storage tank, and a water outlet of the liquid storage tank is connected with a water inlet of the booster pump.