CN211339121U - High-sulfur-content oil and gas field sewage treatment system - Google Patents

Abstract

The utility model discloses a high sulfur-containing oil and gas field sewage treatment system, which comprises the following steps that liquid phase (containing sulfur, oil, water and other substances) separated by a three-phase separator is introduced into a flash tank, a large amount of gas is flashed out from the liquid phase through depressurization, partial gas is discharged, the liquid is discharged into a tubular mixer I, an oxidant solution is added into a medicament adding port of the tubular mixer I to remove hydrogen sulfide in sewage to prepare desulfurized sewage, the desulfurized sewage is detected and then is introduced into a pressure oil remover to realize oil-water separation, oil and water are recycled, the liquid is sent into a flotation oil tank, oil sludge is recycled into a sludge recycling box by an electric valve at the top of the oil flotation tank, the process of the utility model is reasonable, hydrogen sulfide in the desulfurized sewage is removed by adopting the combination of the depressurization flash distillation and the chemical method, sulfide is changed into stable elemental sulfur, then, the elemental sulfur suspended in the sewage is recovered by utilizing an oil flotation process, so that the aims of sulfur removal and sewage purification are fulfilled.

Description

High-sulfur-content oil and gas field sewage treatment system

Technical Field

The utility model relates to an oil gas field sewage treatment field, in particular to high sulphur oil gas field sewage treatment system.

Background

In the process of producing oil gas in oil field and gas field, water with stratum is produced together. The produced oil and water form a mixture. The oil (crude oil and gas) and the high-salinity water of the stratum form an oil-water blending emulsified state due to physical changes of formation physicochemical reaction, pressure in the extraction process and the like. And after primary oil-water separation, the separated water-containing oil is conveyed to a joint station through a pipeline pump for deep oil-water separation. In the separation process, the oil field base station and the united station usually adopt a gravity settling deep separation mode to carry out deep separation, and a demulsifier is added for many times according to the demulsification degree under different conditions. After multiple times of sedimentation, a large amount of produced water is separated. The part of water is called produced water, and the produced water is treated until the produced water meets the reinjection requirement and is used for reinjecting the oil well to supplement the stratum water quantity. And the high-concentration sewage (including sewage for cleaning oil tank facilities regularly) which is remained after multiple times of settlement and is difficult to demulsify is poured into a sewage concentration field arranged in a base station or a united station for further settlement and concentration so as to form surface emulsifiable oil, middle high-oil-content sewage, bottom asphaltene settlement and layered distribution of sludge. Hereinafter, the concentrated water is collectively referred to as high oil content sewage.

Because the oil-gas field sewage contains higher proportion of oil and asphaltene, and the high-oil-content sewage contains high oil content, high concentration of chemical substances, high salinity and difficult oil globule emulsification, the traditional mode has no good solution effect on the oil-gas field sewage. In view of the above problems, a solution is proposed as follows.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a high sulphur oil gas field sewage treatment system has and can effectually handle the purification to oil gas field sewage to reach the advantage of purifying water quality.

The above technical purpose of the present invention can be achieved by the following technical solutions:

a high-sulfur-content oil and gas field sewage treatment system comprises a PID controller, a flash tank, a pressure oil remover, a buffer water tank, an oil flotation tank, a purification water tank, a dosing system, an above-ground recovery system and an underground recovery system, and is characterized in that one end of the flash tank is provided with a three-phase separator, the three-phase separator is provided with a first pipeline, the three-phase separator is connected with the flash tank through the first pipeline, the first pipeline is provided with a first valve group, one end of the flash tank is connected with a waste gas treatment system, one end of the flash tank is connected with a second pipeline, the second pipeline is provided with a blue filter tank, one side of the blue filter tank is provided with a water outlet regulating valve, the other end of the second pipeline is fixedly connected with one side of the pressure oil remover, the second pipeline is connected with a first tubular mixer, and one side of the second pipeline, the upper end of the pressure oil remover is fixedly provided with a first discharge pipe, the pressure oil remover is connected with an above-ground recovery system through the first discharge pipe, the above-ground recovery system comprises a dirty oil recovery box and a filter pressing system, one end of the dirty oil recovery box is connected with a second discharge pipe, the dirty oil recovery box is connected with the filter pressing system through the second discharge pipe, one end of the pressure oil remover is connected with a third pipeline, the pressure oil remover is connected with a buffer water tank through a third pipeline, one end of the buffer water tank is connected with a fourth pipeline, the buffer water tank is fixedly connected with an oil flotation tank through a fourth pipeline, the fourth pipeline is connected with a second tubular mixer and a third tubular mixer, one end of the oil flotation tank is connected with a fifth pipeline, the oil flotation tank is fixedly connected with a purified water tank through a fifth pipeline, the fifth pipeline is fixedly provided with a filtering system, and one side of the purified, and the sixth pipeline is connected with an external delivery pump, and the flash tank, the pressure oil remover, the buffer water tank, the oil flotation tank, the purification water tank and the overground recovery system are fixedly connected with the underground recovery system.

By adopting the technical scheme, the PID controller controls the first valve group to be opened, so that a liquid phase separated by the three-phase separator is introduced into the flash tank, a large amount of hydrogen sulfide and other combustible gases are flashed out from sewage, the valve is opened, part of gas is discharged into the waste gas treatment system to be treated, the liquid in the flash tank is sent into the first tubular mixer, after the medicine is added into the first tubular mixer, the liquid detected by the first detection system is sent into the pressure oil remover, the sewage is layered after standing, the upper-layer dirty oil is sent into the ground recovery system, then the sewage is sent into the buffer water tank through the back pressure valve, the buffer water tank, the water in the buffer water tank is sent into the second tubular mixer, the medicine is added into the second tubular mixer, the sewage is neutralized, then the sewage enters the third tubular mixer, and the medicine is added for treatment, the sewage is sent into an oil flotation tank, the oil sludge on the upper layer in the oil flotation tank is sent into a filter pressing system for filter pressing, the sewage in the oil flotation tank is discharged into a filtering system, the filtered and purified water is sent into a purification water tank, the water in the purification water tank is discharged into an evaporation tank through an external delivery pump to be evaporated or is conveyed to a reinjection system, and meanwhile, the water can also be used as the back washing water of a filter to finish the purification of the sewage.

As preferred, underground recovery system includes secret sewage recovery case and secret sump oil recovery case, the lower extreme of flash tank, pressure degreaser, buffer tank, oil flotation tank, purified water tank, sump oil recovery case all has set firmly the blowoff valve, the lower extreme of blowoff valve has set firmly the blow off pipe, the blow off pipe is connected with secret sewage recovery case, all be equipped with glass sight cup on the blow off pipe, all set firmly the receipts oil valve on oil flotation tank and the sump oil recovery case, be connected with oil recovery pipe on the receipts oil valve, oil recovery pipe and secret sump oil recovery case fixed connection.

Adopt above-mentioned technical scheme, open the blowoff valve, can with the water in each container, through the blow off pipe drain into underground sewage collection box in, convenient maintenance and the maintenance to the container, when the blow off water, can follow the liquid that glass sight glass locates to see through in the blow off pipe, when liquid becomes oil, close the blowoff valve, open and receive the oil valve, in the dirty oil income underground dirty oil collection box with the container, the completion is to the categorised collection of sewage and dirty oil.

As preferred, one side of secret sewage recovery case is connected with the drain pipe, be equipped with the sewage pump on the drain pipe, set firmly manometer one on the sewage pump, one side of secret sewage recovery case is connected with the oil drain pipe, be equipped with dirty oil pump on the oil drain pipe, manometer two has set firmly on the dirty oil pump, all be equipped with the level gauge in secret sewage recovery case and the secret dirty oil recovery case, all set firmly fire blocking cap on secret sewage recovery case and the secret dirty oil recovery case.

By adopting the technical scheme, the underground sewage recovery tank mainly collects sewage, overflow and backwash liquid of each tank body, the tank body is arranged below the ground, after a certain liquid level is collected, the tank body is lifted to a front pipeline of an inlet of the pressure oil remover through the sewage pump, and then the sewage treatment process is carried out, the first pressure gauge is used for checking and judging the pump lifting of an operator, the underground sewage recovery tank is mainly used for receiving recovered sewage oil and filtrate, the tank body is arranged below the ground, after the certain liquid level is collected, the sewage at the bottom is lifted to the front pipeline of the inlet of the pressure oil remover through the sewage oil pump, the sewage treatment process is carried out, the sewage oil is filled and lifted to the tank to ensure normal production and use, redundant recovered sewage oil is lifted to a designated place, and the.

Preferably, the first valve group comprises an ESD valve and an incoming water valve, the ESD valve is interlocked with the liquid phase of the three-phase separator, and the incoming water valve is electrically connected with the PID controller.

By adopting the technical scheme, the ESD valve is interlocked with the liquid level of the liquid phase of the three-phase separator, the ESD valve is automatically closed when the liquid level is lower than a set value so as to prevent gas phase from mixing, and meanwhile, the PID controller automatically adjusts the size of the water inlet valve according to the liquid level of the liquid phase of the three-phase separator so that the liquid phase can be stably transmitted.

Preferably, the detection system comprises a pressure gauge, a thermometer and a flowmeter, the waste gas treatment system comprises a recovery system and a low-pressure fire cabinet combustion system, and a safety valve is arranged on the waste gas treatment system.

Adopt above-mentioned technical scheme, the waste gas that the flash distillation came out lets in recovery system and retrieves, perhaps lets in to burn in the low pressure fire cabinet, realizes the processing to waste gas, prevents environmental pollution.

Preferably, the dosing system comprises a first dosing device, a second dosing device, a third dosing device and a fourth dosing device, the lower end of the first tubular mixer is connected with the first dosing device, the first dosing device comprises two oxidant dissolving tanks and an oxidant dosing pump, the oxidant dosing pump is fixedly connected with the first tubular mixer, the lower end of the second tubular mixer is connected with the second dosing device, the second dosing device comprises two sodium hydroxide dissolving tanks and a sodium hydroxide dosing pump, the sodium hydroxide dosing pump is fixedly connected with the second tubular mixer, the lower end of the third tubular mixer is connected with the third dosing device, the third dosing device comprises two coagulant dissolving tanks and a coagulant dosing pump, the coagulant dosing pump is fixedly connected with the third tubular mixer, the lower end of the oil flotation tank is connected with the fourth dosing device, the fourth dosing device comprises two flocculant dissolving tanks and a flocculant dosing pump, and the flocculating agent feeding pump is fixedly connected with the oil flotation tank.

By adopting the technical scheme, an oxidant solution is added into a first tubular mixer through an adding device, the oxidant solution and sulfur elements in sewage are oxidized, hydrogen sulfide in the sewage is removed, the sulfur-removed sewage is prepared, a second adding device adds a sodium hydroxide solution into the sewage, the pH value of the sewage is adjusted, a third adding device adds a coagulant into a third tubular mixer, the sewage is fed into an oil flotation tank after mixing, and a fourth adding device adds a flocculating agent into the oil flotation tank to layer the solution in the oil flotation tank.

Preferably, the dirty oil recovery box comprises a first three independent space, an electrically operated valve is arranged in each first independent space, each electrically operated valve is connected with a second discharge pipe, and a liquid level meter is arranged in each three independent space.

By adopting the technical scheme, three independent spaces work circularly, three electric valves at the top automatically switch according to the liquid level of each box body, when the liquid level of the first space reaches 75%, the first electric valve is closed to stop liquid feeding, and the like, and the three spaces are used in turn; when the liquid level of the second space reaches 75%, the liquid enters the third space, and at the moment, the first space blowdown valve is opened to discharge sewage to the sewage recovery tank below.

Preferably, one side of the dirty oil recovery tank is provided with an oil filling tank, one side of the oil filling tank is fixedly connected with one end of the oil discharge pipe, one side of the oil filling tank is provided with an oil filling pipe, the oil filling pipe is provided with two oil filling pumps, one end of the oil discharge pipe is connected with the fourth pipeline, one side of the oil discharge pipe, which is close to the fourth pipeline, is fixedly provided with a dispersion system, the dispersion system comprises two dispersion pumps, and one side of the dispersion pump is provided with a pressure gauge.

By adopting the technical scheme, the dirty oil is collected into the oil filling tank, the oil filling pump is started after the liquid level in the oil filling tank reaches a certain height, the oil in the oil filling tank is dispersed by the dispersion pump and then is added into the tubular mixer III, and the oil flotation work is facilitated.

Preferably, the filter pressing system comprises a sludge recovery tank and a filter press, wherein a second three independent space is arranged in the sludge recovery tank, the second three independent space is internally provided with a liquid level meter, the lower end of the second independent space is provided with a blow-down valve, one side of the second independent space is fixedly provided with three mud discharge valves, the mud discharge valves are connected with mud discharge pipes, the other ends of the mud discharge pipes are fixedly connected with the filter press, and an oil suction pipe on the oil flotation tank is connected with the second three independent space.

Adopt above-mentioned technical scheme, two independent work in three independent space, fatlute can the layering after static, and bottom sewage passes through the blowoff valve and arranges to the sewage recovery case below, and mud is then taken out to the filter-press in through the mud valve, and the filtrating flows to the dirty oil recovery case below certainly, and the dry mud is stacked to mud and is piled up the canopy.

Preferably, the filtering system comprises two filtering tanks, pressure gauges are arranged on the filtering tanks, and the outward conveying pump is connected with the pressure gauges.

Adopt above-mentioned technical scheme, two filter jars use and wash in turn, improve work efficiency, the manometer can monitor filter jar for judge whether the filter need wash and whether accomplish.

When the system is used for treating oil and gas field sewage, part of sulfide is gasified and discharged in a decompression flash evaporation mode, sulfur in the sewage is oxidized into elemental sulfur through oxidation reaction, the sulfur is purified, oil and water are separated through oil flotation, layering, filtering, filter pressing and other processes, and collection and utilization of the oil and purification of water quality are completed.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment;

FIG. 2 is a schematic diagram of a connection of an embodiment flash system;

FIG. 3 is a connection diagram of an embodiment above-ground recovery system;

FIG. 4 is a connection diagram of a buffer tank according to an embodiment;

FIG. 5 is a connection diagram of an embodiment refueling apparatus;

FIG. 6 is a schematic view showing the connection of a filter press apparatus according to the embodiment;

FIG. 7 is a schematic view of the connection of an underground sewage recovery tank according to an embodiment;

FIG. 8 is a schematic view of the connection of an underground sump oil recovery tank according to an embodiment;

FIG. 9 is a schematic diagram of the connection of the dosing system according to the embodiment;

FIG. 10 is a schematic diagram of the connection of an example oil flotation system;

FIG. 11 is a connection diagram of an embodiment filtration system;

FIG. 12 is a connection diagram of the purified water tank of the embodiment.

Reference numerals: 1. a flash tank; 2. a pressure oil remover; 3. a buffer water tank; 4. an oil flotation tank; 5. a purified water tank; 6. a three-phase separator; 7. an exhaust gas treatment system; 8. a first tubular mixer; 9. a dirty oil recovery tank; 10. a second tubular mixer; 11. a tubular mixer III; 12. an underground sewage recovery tank; 13. an underground sump oil recovery tank; 14. a sewage pump; 15. a sump oil pump; 16. an ESD valve; 17. an incoming water valve; 18. an oxidant dissolving box; 19. an oxidant dosing pump; 20. a sodium hydroxide dissolving box; 21. a sodium hydroxide feeding pump; 22. a coagulant dissolving box; 23. a coagulant adding pump; 24. dissolving a flocculant in a pesticide box; 25. a flocculating agent adding pump; 26. an oil tank; 27. a gasoline pump; 28. a dispersion pump; 29. a sludge recovery tank; 30. a filter press; 31. and (7) filtering the tank.

Detailed Description

The following description is only a preferred embodiment of the present invention, and the scope of protection is not limited to the embodiment, in which like parts are denoted by like reference numerals. It should be noted that as used in the following description, the terms "front," "back," "left," "right," "upper," and "lower" refer to directions in the drawings, and the terms "bottom" and "top," "inner," and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

As shown in fig. 1 and 2, the high-sulfur oil and gas field sewage treatment system comprises a PID controller, a flash tank 1, a pressure oil remover 2, a buffer water tank 3, an oil flotation tank 4, a purified water tank 5, an above-ground recovery system and an underground recovery system. One end of the flash tank 1 is connected with a first pipeline, and one end of the first pipeline, which is far away from the flash tank 1, is connected with a three-phase separator 6. An ESD valve 16(SDV101) is arranged on the first pipeline, the ESD valve 16 is interlocked with the liquid phase liquid level of the three-phase separator 6, and when the liquid level is lower than a set value, the ESD valve 16 is automatically closed to prevent gas phase from mixing. And a water inlet valve 17(LV102) is arranged on the first pipeline, and the PID controller adjusts the water inlet valve 17 according to the liquid phase liquid level of the three-phase separator 6.

The liquid phase separated by the three-phase separator 6 enters the flash tank 1, the pressure at the outlet of the three-phase separator 6 is 7-8.5Mpa, and the working pressure of the flash tank 1 is 0.25-0.35 Mpa. When entering the flash tank 1, the sewage boils. A large amount of hydrogen sulfide and other combustible gases in the wastewater are flashed off. And a regulating valve (PV101) is arranged on the flash tank 1, and the regulating valve can be automatically opened according to the pressure detection and the set value of the flash tank 1 to discharge part of gas into a recovery system or burn the gas into a torch of a low-pressure emptying system. One side of the regulating valve is provided with a safety valve, so that the waste gas cannot flow back into the flash tank 1 during treatment.

As shown in fig. 1 and 2, a second pipeline is arranged between the inside of the flash tank 1 and the first tubular mixer 8, a blue filter tank 31 is arranged on the second pipeline, and a water outlet regulating valve (LV101) is arranged on one side of the blue filter tank 31. The liquid in the flash tank 1 enters a second pipeline, is filtered by a blue filter and then enters a first tubular mixer 8. And starting the oxidant feeding pump 19, feeding an oxidant solution into the first tubular mixer 8, oxidizing the oxidant solution and sulfur elements in the sewage, and removing hydrogen sulfide in the sewage to obtain the desulfurized sewage.

As shown in fig. 1 and fig. 3, one side of the second pipeline is connected with a detection system, the first detection system comprises a pressure gauge, a thermometer and a flowmeter, and the pipeline pressure (PT201\ PG201), the temperature (TG201) and the flow rate (FG201) of the desulfurization wastewater are measured before the desulfurization wastewater enters the pressure oil remover 2. The other end of the pipeline II is fixedly connected with one side of the pressure oil remover 2, the sulfur-removed sewage is introduced into the pressure oil remover 2 after being detected, and the oil and the water can be separated in the pressure oil remover 2 due to the fact that the densities of the water and the oil are different. The top of the pressure oil remover 2 is provided with three electric valves (MV201, MV202 and MV203), the electric valves are automatically controlled at fixed time, and the time can be set according to the actual requirement. The three electric valves are sequentially started to recycle the sump oil gathered on the upper layer into the sump oil recycling tank 9. The oil-removing sewage enters the buffer water tank 3 through the back pressure valve.

As shown in fig. 1 and 3, a pressure gauge (PG202) is arranged on the top of the pressure oil remover 2, so that inspection personnel can conveniently observe and record. And three blow-down valves are arranged at the bottom of the pressure oil remover 2 and are communicated with an underground sewage recovery tank. When the pressure oil remover 2 needs to be overhauled, the three drain valves are opened in sequence, liquid in the tank body is discharged to the underground sewage recovery tank, and the pressure oil remover is convenient to overhaul.

As shown in fig. 1 and 3, three independent spaces one are provided in the dirty oil recovery tank 9, liquid level meters (LGT102A, LGT102B, LGT102C) are provided in the three independent spaces one, and electric valves (MV1002A, MV102B, MV102C) are provided above the three independent spaces one. Dirty oil firstly enters a first independent space, when the liquid level in the first independent space reaches 75%, an electric valve on the first independent space is closed, the dirty oil enters a second independent space, and the like.

When the dirty oil begins to enter the second independent space I, the dirty oil in the first independent space I begins to stand and stratify. And when the liquid level in the first independent space meets the requirement and the sump oil begins to enter the first independent space, the sump oil in the first independent space completes standing and layering. The lower end of each independent space I is provided with a blow-down valve, at the moment, the blow-down valve at the lower end of the first independent space I is opened, and sewage at the lower layer can pass through the blow-down valve and enters the underground sewage recovery tank 12 through the pipeline III.

As shown in fig. 1 and 3, an oil collection valve is provided on the side of the dirty oil recovery tank 9. And a glass viewing cup is arranged on the third pipeline, and liquid flowing through the third pipeline can be observed through the glass viewing cup. When dirty oil flows through the third pipeline, the drain valve is closed, and the oil collecting valve is opened to recover the dirty oil into the underground dirty oil recovery tank 13.

And the water in the buffer water tank 3 is sent into the second tubular mixer 10 through a lifting pump, and a sodium hydroxide solution is added into the second tubular mixer 10 to adjust the pH value of the sewage.

As shown in fig. 1 and 4, the buffer tank 3 is provided with a liquid level meter (LGT101), an upper limit meter (LS101) and a lower limit meter (LS102), the upper limit meter is used for alarming when the liquid level is exceeded, the lower limit meter is used as a necessary condition for starting the lift pump, and the lift pump automatically stops or cannot be started when the liquid level is lower than the lower limit.

Overflow pipeline is established at 3 tops of buffer tank, and the blowoff valve is established to 3 bottoms of buffer tank, when needs overhaul buffer tank 3, can empty liquid to secret sewage recovery case 12. The outlet of the lifting pump is provided with a pressure gauge (PT101\ PT102) which can display the outlet pressure of the lifting pump, so that inspection personnel can conveniently check and record the pressure. The lift pump is controlled according to the liquid level frequency conversion of the buffer water tank 3, the rotating speed is automatically adjusted while the normal working liquid level is ensured, and continuous and stable production is achieved.

As shown in fig. 5 and fig. 6, the recovered oil is sent to the third tubular mixer 11 by the refueling pump 27(P-1A \ P-1B) through the dispersion pump 28(P-2A \ P-2B), coagulant is added into the third tubular mixer 11, the liquid is sent to the oil flotation tank 4 after mixing, and flocculant is added into the oil flotation tank 4. And a flow meter (FG202) is arranged between the third tubular mixer 11 and the oil flotation tank 4, and the flow rate of liquid entering the oil flotation tank 4 is measured according to the flow meter, so that the frequency conversion control dosing pump can conveniently and accurately dose the liquid. The electric valve at the top of the oil flotation tank 4 recovers the sludge into the sludge recovery tank 29 and sends the purified water into the filter tank 31. The bottom of the oil flotation tank 4 is provided with a blow-down valve which is used for blow-down during maintenance and is reserved with a cleaning opening.

As shown in fig. 1 and 10, the outlet of the gasoline pump 27 is provided with a safety valve and a pressure gauge (PG211) for inspection and recording by an inspector. Pressure transmitters are arranged at the inlet end and the outlet end of the oil flotation tank 4, signals of the pressure transmitters (PT211\ PT212) enter a central control system, so that the pressure detection and monitoring of the inlet and the outlet of the oil flotation tank 4 are facilitated, and a pressure gauge (PG213\ PG214) is convenient for inspection personnel to check and record. The pressure gauge (PG215\ PG215) is used for adjusting a backpressure valve between 2 pressure gauges.

After standing and layering the oil sludge, discharging the sewage into an underground sewage recovery tank 12, wherein three independent spaces II are arranged in a sludge recovery tank 29, and liquid level meters (LT103A \ LT103B \ LT103C) and electric valves (MV101A \ MV101B \ MV101C) are arranged in the three independent spaces II. The three electric valves automatically control three spaces to be used alternately according to respective liquid levels.

The oil sludge enters the three independent spaces II respectively, and the bottom of each independent space II is provided with a drain valve and a mud valve. And when the oil sludge in the independent space II is settled, the oil sludge is layered, and the sewage at the bottom is discharged to a sewage recovery tank below through a drain valve. And discharging the sludge into a filter pressing system through a sludge discharge valve for filter pressing. And (3) enabling filtrate obtained by filter pressing to flow into an underground sump oil recovery tank 13, and stacking filter residues to a sludge piling shed.

As shown in fig. 1 and 11, the purified water purified by the oil flotation tank 4 enters the two filter tanks 31, and the two filter tanks 31 are alternately used and backwashed. The filter tank 31 is provided with a plurality of pressure gauges (PG242\ PG243\ PG244\ PG245\ PG246\ PG247) and a plurality of pressure transmitters (PT243\ PT241\ PT242\ PT244), wherein the pressure gauges (PG242\ PG245\ PG244\ PG247) are used for judging whether the filter needs to be cleaned and whether the cleaning is finished. And transmitting signals of the pressure transmitters (PT243\ PT241\ PT242\ PT244) to a central control room to remind an operator of corresponding work and recording real-time data in time. The pressure gauge (PG243\ PG246) is used for displaying the pressure of the two filters in time.

As shown in fig. 1 and 12, the purified water filtered by the filter tank 31 is discharged into the purified water tank 5, and a liquid level meter (LT102) for exciting and displaying the liquid level in the purified water tank 5 is provided in the purified water tank 5. An overflow pipeline is arranged at the top of the water purification tank 5, a blow-down valve is arranged at the bottom of the water purification tank 5, and when the water purification tank is overhauled, the blow-down valve is used for emptying liquid into the underground sewage recovery tank 12, so that the water purification tank is convenient to overhaul.

As shown in fig. 1 and 12, an external pump is arranged on one side in the purified water tank 5, and a pressure gauge (PT105\ PT106) is arranged at the outlet of the external pump. The manometer shows defeated pump outlet pressure outward, and the personnel of being convenient for patrol and examine look over and the record. The purified water is conveyed to an evaporation pool through an external conveying pump to be evaporated or conveyed to a reinjection system, and meanwhile, the purified water can also be used as filter backwashing water.

As shown in fig. 1 and 2, the underground sewage recycling tank 12 mainly collects the sewage, overflow and backwash liquid of each tank, the tank is arranged below the ground, a liquid level meter (LT105) is arranged, after a certain liquid level is collected, the tank is lifted to a front pipeline of an inlet of the pressure oil remover 2 through a sewage pump 14, and then the tank enters a sewage treatment process. The outlet pressure gauge (PG108) of the sewage pump 14 is used for the operator to check and judge the pump start.

As shown in fig. 7 and 8, the underground dirty oil recovery tank 13 is mainly used for receiving and recovering dirty oil and filtrate, the tank body is arranged below the ground, a liquid level meter (LT104) is arranged, after a certain liquid level is collected, bottom sewage is lifted to a pipeline in front of an inlet of the pressure oil remover 2 through the dirty oil pump 15, and then enters a sewage treatment process. The dirty oil is lifted to the oil filling tank 26 to ensure normal production and use; and lifting the redundant recovered sump oil to a designated place. The outlet pressure gauge (PG107) of the sump oil pump 15 is used for the check and judgment of the pump starting of an operator.

As shown in fig. 1 and 9, the dosing system adopts frequency conversion control, four sets of dosing devices are provided in total, each set of device is provided with 2 drug dissolving tanks for alternate use, each drug dissolving tank is provided with a liquid level meter (LT231\ LT232\ LT233\ LT234\ LT235\ LT236\ LT237\ LT238), each set of device is provided with a pressure gauge (PG231\ PG232\ PG233\ PG234) at the outlet of the dosing pump for detecting the outlet pressure, and a safety valve is provided for protecting the dosing pump; the four medicaments are sodium hydroxide, a flocculating agent, a coagulating agent and an oxidizing agent respectively.

The above-mentioned embodiments further explain in detail the technical problems, technical solutions and advantages solved by the present invention, and it should be understood that the above only is a specific embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A high-sulfur-content oil and gas field sewage treatment system comprises a PID controller, a flash tank (1), a pressure oil remover (2), a buffer water tank (3), an oil flotation tank (4), a purification water tank (5), a dosing system, an above-ground recovery system and an underground recovery system, and is characterized in that one end of the flash tank (1) is provided with a three-phase separator (6), the three-phase separator (6) is provided with a first pipeline, the three-phase separator (6) is connected with the flash tank (1) through the first pipeline, the first pipeline is provided with a first valve group, one end of the flash tank (1) is connected with a waste gas treatment system (7), one end of the flash tank (1) is connected with a second pipeline, the second pipeline is provided with a blue filter tank (31), one side of the blue filter tank (31) is provided with a water outlet regulating valve, and the other end of the second pipeline is fixedly connected with one side of the, the device comprises a pipeline II, a pipeline I (8) is connected to the pipeline II, a detection system I is connected to one side, close to a pressure oil remover (2), of the pipeline II, a discharge pipe I is fixedly arranged at the upper end of the pressure oil remover (2), the pressure oil remover (2) is connected with a ground recovery system through the discharge pipe I, the ground recovery system comprises a sump oil recovery tank (9) and a filter pressing system, one end of the sump oil recovery tank (9) is connected with the discharge pipe II, the sump oil recovery tank (9) is connected with the filter pressing system through the discharge pipe II, one end of the pressure oil remover (2) is connected with a pipeline III, the pressure oil remover (2) is connected with a buffer water tank (3) through the pipeline III, one end of the buffer water tank (3) is connected with a pipeline IV, the buffer water tank (3) is fixedly connected with an oil flotation tank (4) through the pipeline IV, and the pipeline IV is connected with a pipe mixer II (10) and a pipe, one end of the oil flotation tank (4) is connected with a pipeline five, the oil flotation tank (4) is fixedly connected with a purified water tank (5) through the pipeline five, a filtering system is fixedly arranged on the pipeline five, a pipeline six is fixedly arranged on one side of the purified water tank (5), an outward conveying pump is connected to the pipeline six, and the flash tank (1), the pressure oil remover (2), the buffer water tank (3), the oil flotation tank (4), the purified water tank (5) and the ground recovery system are fixedly connected with an underground recovery system.

2. The high-sulfur oil and gas field sewage treatment system according to claim 1, wherein the underground recovery system comprises an underground sewage recovery tank (12) and an underground dirty oil recovery tank (13), the lower ends of the flash tank (1), the pressure oil remover (2), the buffer water tank (3), the oil flotation tank (4), the purification water tank (5) and the dirty oil recovery tank (9) are respectively and fixedly provided with a blow-down valve, the lower end of the blow-down valve is respectively and fixedly provided with a blow-down pipe, the blow-down pipes are connected with the underground sewage recovery tank (12), the blow-down pipes are respectively provided with a glass sight cup, the oil flotation tank (4) and the dirty oil recovery tank (9) are respectively and fixedly provided with an oil collecting valve, the oil collecting valves are connected with oil collecting pipes, and the oil collecting pipes are fixedly connected with the underground dirty oil recovery tank (13).

3. The high-sulfur oil and gas field sewage treatment system according to claim 2, wherein one side of the underground sewage recovery tank (12) is connected with a drain pipe, a sewage pump (14) is arranged on the drain pipe, a first pressure gauge is fixedly arranged on the sewage pump (14), one side of the underground sewage recovery tank (12) is connected with an oil discharge pipe, a sewage pump (15) is arranged on the oil discharge pipe, a second pressure gauge is fixedly arranged on the sewage pump (15), liquid level gauges are respectively arranged in the underground sewage recovery tank (12) and the underground sewage recovery tank (13), and fire-blocking caps are respectively fixedly arranged on the underground sewage recovery tank (12) and the underground sewage recovery tank (13).

4. The high sulfur content oil and gas field sewage treatment system according to claim 1, wherein the first valve set comprises an ESD valve (16) and an incoming water valve (17), the ESD valve (16) is interlocked with the three-phase separator (6) in liquid phase, and the incoming water valve (17) is electrically connected with a PID controller.

5. The high-sulfur oil and gas field sewage treatment system according to claim 1, wherein the detection system comprises a pressure gauge, a temperature gauge and a flow meter, the waste gas treatment system (7) comprises a recovery system and a low-pressure fire box combustion system, and a safety valve is arranged on the waste gas treatment system (7).

6. The high-sulfur-content oil-gas field sewage treatment system according to claim 1, wherein the dosing system comprises a first dosing device, a second dosing device, a third dosing device and a fourth dosing device, the lower end of the first tubular mixer (8) is connected with the first dosing device, the first dosing device comprises two oxidant dissolving boxes (18) and an oxidant dosing pump (19), the oxidant dosing pump (19) is fixedly connected with the first tubular mixer (8), the lower end of the second tubular mixer (10) is connected with the second dosing device, the second dosing device comprises two sodium hydroxide dissolving boxes (20) and a sodium hydroxide dosing pump (21), the sodium hydroxide dosing pump (21) is fixedly connected with the second tubular mixer (10), the lower end of the third tubular mixer (11) is connected with the third dosing device, the third dosing device comprises two dissolving boxes (22) and a coagulant dosing pump (23), the coagulant adding pump (23) is fixedly connected with the tubular mixer III (11), the lower end of the oil flotation tank (4) is connected with an adding device IV, the adding device IV comprises two flocculant dissolving tank boxes (24) and a flocculant adding pump (25), and the flocculant adding pump (25) is fixedly connected with the oil flotation tank (4).

7. The high-sulfur oil and gas field sewage treatment system according to claim 1, wherein the dirty oil recovery tank (9) comprises three independent spaces I, each of the three independent spaces I is provided with an electric valve, each of the three electric valves is connected with the discharge pipe II, and each of the three independent spaces is provided with a liquid level meter.

8. The high-sulfur oil and gas field sewage treatment system according to claim 1, wherein an oil filling tank (26) is arranged on one side of the dirty oil recovery tank (9), one side of the oil filling tank (26) is fixedly connected with one end of the oil discharge pipe, an oil filling pipe is arranged on one side of the oil filling tank (26), two oil filling pumps (27) are arranged on the oil filling pipe, one end of the oil discharge pipe is connected with the fourth pipeline, a dispersion system is fixedly arranged on one side of the oil discharge pipe close to the fourth pipeline, the dispersion system comprises two dispersion pumps (28), and a pressure gauge is arranged on one side of the dispersion pump (28).

9. The high-sulfur oil and gas field sewage treatment system according to claim 8, wherein the filter pressing system comprises a sludge recovery tank (29) and a filter press (30), three independent spaces II are arranged in the sludge recovery tank (29), a liquid level meter is arranged in each independent space II, a blow-down valve is arranged at the lower end of each independent space II, three sludge discharge valves are fixedly arranged on one side of each independent space II, a sludge discharge pipe is connected to each sludge discharge valve, the other end of each sludge discharge pipe is fixedly connected with the filter press (30), and an oil suction pipe on the oil flotation tank (4) is connected with the three independent spaces II.

10. The high-sulfur oil and gas field sewage treatment system according to claim 1, wherein the filtration system comprises two filtration tanks (31), a pressure gauge is arranged on each filtration tank (31), and the output pump is connected with the pressure gauge.

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