CN112851001A - Method and device for quickly treating oily sewage in oil field - Google Patents

Abstract

The invention relates to a method and a device for quickly treating oily sewage in an oil field, belonging to the technical field of oily sewage treatment, and comprising a crude oil storage tank, a sewage storage tank, an inclined plate oil collecting sledge, a solid-liquid separation sledge, a dissolved air flotation sledge and a sludge dewatering sledge, wherein the inclined plate oil collecting sledge is provided with a raw material inlet, a sand-water outlet pipeline of the inclined plate oil collecting sledge is connected with the solid-liquid separation sledge, the solid-liquid separation sledge is provided with a mud-sand outlet, the crude oil outlet pipeline at the upper part of the inclined plate oil collecting sledge is connected with the crude oil storage tank, the sewage outlet pipeline of the inclined plate oil collecting sledge is connected with the sewage storage tank, the outlet of the sewage storage tank is connected with the dissolved air flotation sledge. The technology adopts the inclined plate oil collecting sledge to treat the early-stage sewage, and reduces the requirements on the oil content and the suspended matter content of the raw water; the terminal automatically discharges the low-water-content dry sludge, so that the transportation cost of sewage and sludge is reduced and eliminated; the online hardening and tempering process has high automation degree; the recovery of crude oil is completed at one time, and the treatment cost is low.

Description

Method and device for quickly treating oily sewage in oil field

Technical Field

The invention belongs to the technical field of oily sewage treatment, and particularly relates to a method and a device for quickly treating oily sewage in an oil field.

Background

In the oil field oil extraction ground process, the scale of an oil field produced water treatment system is huge, the process flow is complex, the operation management difficulty is high, some obvious problems exist in the sewage treatment process, and a plurality of problems are to be solved. Such as: the standard reaching rate of the water quality of part of oil fields needs to be further improved, the sterilization effect is poor, the pressure of produced water discharge is high, and the like.

The water quality of the oil field wastewater is greatly different due to different crude oil producing areas and different production processes. Aiming at the characteristics of different waste water in oil fields, the domestic treatment method is basically a physical method, a chemical method, a physicochemical method and a biological treatment method. The most adopted oily sewage treatment method is walnut shell filtration technology. The walnut shell filter is a separation device successfully developed by utilizing a filtering separation principle, adopts an oil-resistant filter material, namely a special walnut shell as a filter medium, and removes oil and suspended matters in water by utilizing the characteristics of large surface area, strong adsorption force and large pollutant interception capacity of the walnut shell. The device has two control modes of automation and manual operation. During filtering, water flows from top to bottom and passes through the water distributor, the filter material layer and the water collector to complete filtering. During backwashing, the stirrer overturns the filter material, and water flows from bottom to top, so that the filter material is thoroughly cleaned and regenerated. However, the walnut shell filtering process technology has the following defects: the water inlet process of the walnut shell filter has strict requirements, the oil content of raw water is required to be less than 100mg/l, the content of suspended matters is required to be less than 50 mg/l, and therefore, a coagulation and flocculation precipitation process is additionally arranged before sewage enters a filter tank; the replacement of the filter material has high labor intensity and generates secondary pollution; the back-flushing sewage is discharged into a sedimentation tank, and secondary pollution is generated; cleaning of the settling tank and settling tank (once a year) requires a large amount of labor cost and can generate secondary pollution; the high-water-content sludge after manual cleaning is hauled to a specified sludge treatment station of an oil field for treatment, so that high treatment cost is generated, and the sewage treated by the sludge treatment station is conveyed to the sewage treatment station for treatment again, so that part of sulfide component impurities are vicious circulated in an oil field ground treatment process system; there is no complete process scheme, and there is no effective means for separating the sludge and the crude oil in the waste liquid, which affects the long-period operation of the equipment.

Disclosure of Invention

The invention provides a method and a device for quickly treating oily sewage in an oil field for overcoming the defects of the prior art.

The invention relates to a device for quickly treating oily sewage in an oil field, which comprises a crude oil storage tank, a sewage storage tank, an inclined plate oil collecting sledge, a solid-liquid separation sledge, a dissolved air flotation sledge and a sludge dewatering sledge, wherein the inclined plate oil collecting sledge is provided with a raw material inlet, a sand water outlet pipeline of the inclined plate oil collecting sledge is connected with the solid-liquid separation sledge, the solid-liquid separation sledge is provided with a mud sand outlet, an upper crude oil outlet pipeline of the inclined plate oil collecting sledge is connected with the crude oil storage tank, a sewage outlet pipeline of the inclined plate oil collecting sledge is connected with the sewage storage tank, an outlet of the sewage storage tank is connected with the dissolved air flotation sledge, a scum outlet of the dissolved air flotation sledge is connected with the sludge dewatering sledge, a clear water outlet is.

As a further improvement of the invention, the inclined plate oil collecting sledge is characterized in that a box body is sequentially divided into a control chamber, a slow flow chamber and a crude oil collecting chamber from left to right by a partition plate, wherein a sand water output pump, a crude oil output pump and a sewage output pump are arranged in the control chamber; the left side upper portion of unhurried current room is equipped with the raw materials entry, the right side is equipped with and receives oil assembly to crude oil collection room, bottom at crude oil collection room and unhurried current room is equipped with the swash plate of downward sloping from the right side to the left side, its inclination is 3 ~ 8 degrees, interval is fixed with more than one settlement swash plate on the box inner wall of both sides in the unhurried current room, the lower part of settlement swash plate is equipped with the crude oil output pipeline of sewage output pipeline and crude oil collection room in the unhurried current room, sewage output pipeline passes through sewage discharge port entering sewage storage tank through sewage output pump, crude oil output pipeline passes through crude oil outlet entering crude oil storage tank through crude oil mouth through crude oil output pump, the sand water export of unhurried current room left.

As a further improvement of the invention, a sand baffle is fixed on an inclined plate at the rear section of the slow flow chamber, a crude oil output pipeline passes through the sand baffle, a drain pipe is arranged at the bottom of the slow flow chamber and passes through the sand baffle, an inlet of the drain pipe is arranged at the right side of the sand baffle, and an outlet of the drain pipe enters the solid-liquid separation sledge through a sand water outlet by a sand water output pump.

As a further improvement of the invention, the outlet of the sewage output pump is also respectively connected with a fine sand collecting flushing pipe, a sand discharging back flushing pipe and a sand flushing stirring pipe; the fine sand collecting flushing pipe is an L-shaped pipe and is arranged at the lower part of the sedimentation inclined plate, a bent pipe is longitudinally arranged at the left side of the sand baffle at the bottom of the slow flow chamber, and a spray head is arranged on the bent pipe; the outlet of the sand discharge backwashing pipe is communicated with a sand water outlet pipeline; the sand washing stirring pipe is longitudinally arranged above the left side of the slow flow chamber, and a spray head is arranged on the sand washing stirring pipe; a crude oil tank sewage inlet is arranged on the slow flow chamber.

As a further improvement of the invention, an oil receiving spray pump is also arranged in the control chamber, an oil receiving spray inlet pipe is arranged above the slow flow chamber and is connected with an oil receiving spray pump pipeline, an outlet of the oil receiving spray pump is connected with an oil receiving spray outlet spray pipe, and the oil receiving spray outlet spray pipe is longitudinally positioned above the left side of the slow flow chamber and is provided with a spray head.

As a further improvement of the invention, a liquid inlet I on the crude oil storage tank is connected with a crude oil outlet of the inclined plate oil collecting sledge, and a sewage outlet of the crude oil storage tank is connected with a crude oil tank sewage inlet on the inclined plate oil collecting sledge; the tank body is provided with a crude oil output port, an electric heater is arranged in the tank body, and a self-circulation heating pipeline is arranged in the tank body and connected with a circulating pump.

As a further improvement of the invention, the solid-liquid separation sledge is characterized in that a separation inclined bucket is fixed in a box body, a sand-water separator is arranged in the separation inclined bucket, a liquid inlet pipe of the separation inclined bucket is connected with a sand-water outlet of the inclined-plate oil collecting sledge, a liquid outlet of the liquid inlet pipe is arranged above the separation inclined bucket through a swirler, a sewage overflow port is arranged on the separation inclined bucket, and the sand-water separator is provided with a sand discharge outlet.

As a further improvement of the invention, the dissolved air floatation sledge is characterized in that a partition plate is arranged in a box body to divide the box body into a reaction chamber and a separation chamber, a sewage outlet pipeline of a sewage storage tank enters the reaction chamber through a liquid inlet II, a liquid inlet pump and a liquid inlet pipeline, releasers are arranged at the bottoms of the reaction chamber and the front section of the separation chamber and are connected with an outlet of a dissolved air tank through a pipeline, a scum collecting device is arranged at the top of the separation chamber, a scum box is arranged at the tail end of the separation chamber, a clear water outlet of the separation chamber arranged at the bottom of the scum box is discharged to a high-pressure pump room through a clear water discharge port through a clear water pump, a downward inclined slag receiving plate is arranged at an inlet of the scum box, and an outlet pipeline at the bottom of the scum box is.

As a further improvement of the invention, a scum outlet pipeline and a scum liquid inlet enter a scum stirring box of the sludge dewatering sledge, a stirring device and a heater are arranged on the scum stirring box, a liquid outlet pipeline at the bottom of the scum stirring box is connected to a liquid outlet pump, a water outlet of the liquid outlet pump is discharged to a slow flow chamber through an outlet pipe, a sludge outlet pipeline is connected to a screw stringing machine, and a liquid outlet and a sludge discharge port are arranged on the screw stringing machine.

The invention relates to a method for quickly treating oily sewage in an oil field, which comprises the following steps:

1. solid-liquid separation

Pouring oily sewage into an inlet of an inclined plate oil collecting sledge, and settling and discharging solid silt in the oily sewage to the bottom of the sledge through full diffusion of a settling inclined plate; collecting floating crude oil in the liquid phase to a crude oil storage tank through a scraper, and collecting and discharging sewage in the middle layer to a sewage storage tank; the inner bottom layer temperature of the inclined plate oil collecting sledge is 0-8 ℃, the liquid phase temperature is 50-80 ℃, the inclination angle of the sedimentation inclined plate is 30-60 degrees, and the number of plates is 2-8 grades;

2. air-float purification of sewage

Adding a flocculating agent, a coagulant and an oxidant into the sewage through a dissolved air floatation sledge, adhering fine impurities in the sewage into a suspended mass, and removing the suspended mass by using a chain scraper to prepare purified water;

3. sludge dewatering

And (3) pressurizing and filtering the sludge subjected to solid-liquid separation by using a plate-and-frame filter to prepare a sludge cake, discharging the sludge cake, and returning the filtered sewage to the dissolved air floatation sledge.

According to the method and the device for rapidly treating the oily sewage in the oil field, the inclined plate oil collecting sledge is adopted to treat the early-stage sewage, so that the requirements on the oil content and the suspended matter content of raw water are reduced, and the applicable range is wider; the filter material does not need to be replaced, and the labor intensity is reduced; the terminal automatically discharges the low-water-content dry sludge, so that the transportation cost of sewage and sludge is reduced and eliminated, and no secondary pollution is caused; the online hardening and tempering process has high automation degree; the recovery of crude oil is completed at one time, so that the economic benefit can be improved; the treatment cost is low, the standard treatment is realized at one time, and the vicious circle of the impurities of the sulfide components in the oil field ground treatment process system is avoided.

Drawings

FIG. 1 is a process flow diagram of the method for rapidly treating oily sewage in an oil field according to the present invention;

FIG. 2 is a longitudinal sectional view of the swash plate oil receiving skid;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a longitudinal cross-sectional view of a crude oil storage tank;

FIG. 5 is a top view of FIG. 4;

FIG. 6 is a longitudinal sectional view of the solid-liquid separation sled;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is a longitudinal cross-sectional view of the dissolved air skid;

FIG. 9 is a top view of FIG. 8;

FIG. 10 is a longitudinal sectional view of the sludge dewatering skid;

fig. 11 is a top view of fig. 10.

Detailed Description

The method and apparatus for rapidly treating oily sewage in oil field of the present invention will be further described with reference to the accompanying drawings.

The invention relates to a device for quickly treating oily sewage in an oil field, which comprises a crude oil storage tank 1 and a sewage storage tank 2, and further comprises an inclined plate oil collecting sledge 3, a solid-liquid separation sledge 4, a dissolved air flotation sledge 5 and a sludge dewatering sledge 6 as shown in figure 1, wherein the inclined plate oil collecting sledge 3 is provided with a raw material inlet 7, a sand-water outlet pipeline of the inclined plate oil collecting sledge is connected with the solid-liquid separation sledge 4, the solid-liquid separation sledge 4 is provided with a mud-sand outlet, the upper crude oil outlet pipeline of the inclined plate oil collecting sledge 3 is connected with the crude oil storage tank 1, the sewage outlet pipeline of the inclined plate oil collecting sledge 3 is connected with the sewage storage tank 2, the outlet of the sewage storage tank 2 is connected with the dissolved air flotation sledge 5, the scum outlet of the dissolved air flotation sledge 5 is connected with the sludge dewatering sledge 6, the.

The inclined plate oil receiving sledge 3 is characterized in that a box body is sequentially divided into a control chamber 9, a slow flow chamber 10 and a crude oil collecting chamber 11 from left to right by a partition plate 8, as shown in fig. 2 and 3, a sand water output pump 12, a crude oil output pump 13, a sewage output pump 14 and an oil receiving spray pump 15 are arranged in the control chamber 9; heaters are respectively arranged in the slow flow chamber 10 and the crude oil collecting chamber 11, and an operation hole is arranged at the upper part of the slow flow chamber 10.

The upper portion of the left side of the slow flow chamber 10 is provided with a raw material inlet 7, the right side is provided with an oil receiving assembly 30 to a crude oil collecting chamber 11, the bottom of the crude oil collecting chamber 11 and the slow flow chamber 10 is provided with an inclined plate 16 inclined downwards from right to left, the inclination angle of the inclined plate is 3-8 degrees, more than one sedimentation inclined plate 17 is fixed on the inner wall of the box body at the two sides in the slow flow chamber 10 at intervals, the sedimentation inclined plate 17 and the bottom wall have a certain gap, the lower part of the sedimentation inclined plate 17 is provided with a sewage output pipeline 18 in the slow flow chamber 10, a crude oil output pipeline 19 of the crude oil collecting chamber 11, the bottom of the slow flow chamber 10 is provided with a blow-.

A sand baffle plate 24 is fixed on the sloping plate 16 at the rear section of the slow flow chamber 10, the sewage output pipeline 18 and the fine sand collecting flushing pipe 25 are positioned at the front side of the sand baffle plate 24, the crude oil output pipeline 19 and the sewage discharge pipe 75 penetrate through the sand baffle plate 24, and the crude oil output pipeline 19 is connected with the bottom outlet of the crude oil collecting chamber 11; sewage in the slow flow chamber 10 enters the sewage storage tank 2 from the sewage output pipeline 18 through the sewage output pump 14 and the sewage outlet 20; a crude oil output pipeline 19 passes through a crude oil output pump 13 and enters the crude oil storage tank 1 through a crude oil port 21, meanwhile, a sewage outlet is also arranged on an output pipeline of the crude oil output pump 13, sewage at the bottom of a crude oil collecting chamber 11 is pumped out and conveyed to enter a buffer flow chamber, and then the crude oil at the upper part enters the crude oil storage tank 1 through the crude oil port 21 through the crude oil output pipeline under the control of a valve; because the bottom of the slow flow chamber 10 is of an inclined plate structure, materials with large sand specific gravity are accumulated on the left side, a sand water outlet 22 is arranged at the bottom of the left side, and enters the solid-liquid separation sledge 4 through the sand water outlet 23 via a sand water output pump 12, and meanwhile, the outlet of the drainage pipe 75 is also communicated with the sand water output pump 12 and enters the solid-liquid separation sledge 4 through the sand water outlet 23.

In order to facilitate the flowing of the upper dirty oil, an oil collecting spraying inlet pipe 31 is arranged above the slow flow chamber 10 and used for sucking the dirty water in the slow flow chamber and is connected with an oil collecting spraying pump 15 through a pipeline, an outlet of the oil collecting spraying pump 15 is connected with an oil collecting spraying outlet spray pipe 32, the oil collecting spraying outlet spray pipe 32 is longitudinally positioned above the left side of the slow flow chamber 10, a spray head is arranged on the oil collecting spraying outlet spray pipe 32, and the sucked dirty water is sprayed above the liquid level to promote the flowing of the dirty water.

The outlet of the sewage output pump 14 in the device is also respectively connected with a fine sand collecting flushing pipe 25, a sand discharging back flushing pipe 26 and a sand flushing stirring pipe 27; the fine sand collecting flushing pipe 25 is an L-shaped pipe and is arranged at the lower part of the sedimentation inclined plate 17, a bent pipe is longitudinally arranged at the left side of the bottom sand baffle 24 of the slow flow chamber 10, and the bent pipe is provided with a spray head 28, so that fine sand retained at the bottom of the inclined plate can be conveniently flushed and collected to the outlet 22 at the left side; the outlet of the sand discharge backwash pipe 26 is communicated with the pipeline of the sand water outlet 22 and is flushed when the pipeline of the sand water outlet 22 is blocked; the sand-washing stirring pipe 27 is longitudinally arranged above the left side of the flow buffering chamber 10, and is provided with a spray header which is used for stirring sand and stones accumulated at the sand water outlet 22 to enhance the fluidity and facilitate the output; the slow flow chamber 10 is provided with a crude oil tank sewage inlet 29.

During treatment, sewage is discharged into the plate oil collecting pry 3 through the raw material inlet 7 by the tank car, 4 sedimentation inclined plates flow in the tank car, massive impurities, large granular impurities and silt in incoming liquid are deposited at the bottom of the pry and are conveyed to the solid-liquid separation pry 4 through the sand water output pump 12, crude oil floating on the liquid level is cleaned and collected through the chain type scraper conveyor and is conveyed to the crude oil storage tank 1 through the centrifugal pump, the sewage is temporarily transferred into the liquid collecting tank at the rear end of the device through overflow, and finally the crude oil is conveyed into the liquid collecting tank at the 500m by the centrifugal pump³And the intermediate sewage storage tank is used for storing.

The electric heater and the liquid level meter are arranged in the flow slowing chamber 10 and the crude oil collecting chamber 11, so that the temperature in the prying chamber is guaranteed to be 0-8 ℃ all the time in winter, the recovery temperature of the crude oil on the upper layer is 50-80 ℃, automatic temperature control is realized, the liquid level meter is linked with the centrifugal pump to realize automatic control, and an ultrahigh liquid level early warning system is arranged.

As shown in fig. 4 and 5, the crude oil storage tank 1 is used for storing crude oil collected by the inclined plate oil collecting skid 3, a liquid inlet i 33 of the crude oil storage tank is connected with a crude oil outlet 21 of the inclined plate oil collecting skid 3, and a sewage outlet 34 of the crude oil storage tank is connected with a crude oil tank sewage inlet 29 on the inclined plate oil collecting skid 3; the tank body is provided with a crude oil output port 35, an electric heater 36 is arranged in the tank body to enhance the flow, and a self-circulation heating pipeline 37 is arranged in the tank body and connected with a circulating pump 38 to enable the tank body to be heated uniformly. Crude oil in the incoming liquid is collected to a crude oil storage tank of 50m3 in a unified way after separation and stored, the crude oil goes up and goes down, a water cutting backflow pipeline is arranged at the bottom of the tank, and bottom sewage is cut back to an inclined plate to recover an oil skid. An electric heater (capable of manually setting the temperature) is arranged in the device, so that the temperature in the tank in winter is ensured to be 20-80 ℃ all the time.

As shown in fig. 6 and 7, the solid-liquid separation skid 4 stores sand water discharged from a sand water outlet 22 of the inclined plate oil collecting skid 3 and a sewage discharge pipe 75, the solid-liquid separation skid 4 is formed by fixing a separation inclined bucket 39 in a box body, a sand-water separator 40 is installed in the separation inclined bucket 39, a heater and a temperature controller are installed in the separation inclined bucket 39, a liquid inlet pipe 41 of the separation inclined bucket is connected with the sand water outlet 23 of the inclined plate oil collecting skid 3, a liquid outlet of the liquid inlet pipe 41 is arranged above the separation inclined bucket 39 through a swirler 42, a sewage overflow port 43 is formed in the separation inclined bucket 39, and sewage discharged through the sewage overflow port 43 enters a buffer chamber of the inclined plate oil collecting skid 3. A sand discharge outlet 44 is provided in the sand-water separator 40. Utilize the swash plate principle of subsiding to realize the separation of silt and sewage, the silt that subsides dewaters through variable pitch strip seam screen cloth spiral dehydrator and with the silt particle arrange the device outside in the mud collecting tank, the sewage of separating shifts to the swash plate again and receives the oil sled. An electric heater is arranged in the device, so that the temperature in the pry in winter is always 0-8 ℃. The temperature is automatically controlled, the liquid level meter and the centrifugal pump are linked to realize automatic control, and an ultrahigh liquid level early warning system is arranged.

As shown in fig. 8 and 9, the inclined plate oil receiving sledge 3 is discharged from the sewage storage tank 2 and enters the dissolved air flotation sledge 5, the dissolved air flotation sledge 5 is internally provided with a partition plate 45 to divide the tank into a reaction chamber 46 and a separation chamber 47, both a bottom wall i 76 of the reaction chamber 46 and a bottom wall ii 77 of the separation chamber 47 are inclined bottoms, the inclination angle of the bottom wall i 76 is 15-20 degrees, and the inclination angle of the bottom wall ii 77 is 3-10 degrees. A sewage outlet pipeline of the sewage storage tank 2 enters the reaction chamber 46 through a liquid inlet II 48, a liquid inlet pump 49 and a liquid inlet pipeline 50, releasers 51 are arranged at the bottoms of the front sections of the reaction chamber 46 and the separation chamber 47, outlets of the releasers 51 and the steam dissolving tank 52 are connected through a pipeline 60, a scum collecting device 55 is arranged at the top of the separation chamber 47, a scum box 56 is arranged at the tail end, a clear water outlet 54 of the separation chamber 47 arranged at the bottom of the scum box 56 is discharged to a high-pressure pump room 63 through a clear water outlet 62 by a clear water pump 61, a downward-inclined slag facing plate 57 is arranged at the inlet of the scum box 56, and a bottom outlet pipeline of the scum box 56 is discharged to the sludge dewatering sledge 6 through a scum outlet 59 by a scum pump 58. The inlet pipeline of the steam dissolving tank 52 is connected with the clean water outlet 54 through a steam dissolving pump 53, and the liquid inlet pipeline 50 is provided with a medicine adding device 64 which is connected with a medicine adding tank 65 through a pipeline. A backup inlet 66 is provided in the inlet line 50. The sewage is purified by the dissolved air floatation pry, fine impurities and suspended matters in the sewage are adhered into clusters by adding a flocculating agent, a coagulant, a gel breaker, a degrading agent and the like, and meanwhile, the clustered impurities are wrapped on the surface in the process that nano-scale micro bubbles released by the dissolved air water rise to the liquid level, and the nano-scale micro bubbles quickly float and separate. And then, collecting scum on the liquid level to a scum box by using a chain scraper, and finally conveying the scum to a sludge dewatering sledge by using a centrifugal pump.

As shown in fig. 10 and 11, a scum outlet 59 pipeline and a scum inlet 67 of the dissolved air flotation sledge 5 enter a scum stirring box 68 of the sludge dewatering sledge 6, a stirring device 69 and a dosing device are arranged on the scum stirring box 68, a heater 70 is arranged in the scum stirring box, a liquid outlet 71 at the bottom of the scum stirring box is connected to a liquid outlet pump 72 through a pipeline, a water outlet of the liquid outlet pump 72 is discharged to the sewage tank 2 through an outlet 73 pipe, a sludge outlet pipeline is connected to a threading machine 74, and a liquid outlet and a sludge discharge port are arranged on the threading machine 73. And adding a flocculating agent and a coagulant into scum collected in the dissolved air floatation pry on line, dehydrating the sludge through a screw stringing machine, discharging dehydrated mud cakes, and returning filtrate to the dissolved air floatation pry.

The invention relates to a method for quickly treating oily sewage in an oil field, which comprises the following steps:

1. solid-liquid separation

Pouring oily sewage into an inlet of an inclined plate oil collecting sledge, and settling and discharging solid silt in the oily sewage to the bottom of the sledge through full diffusion of a settling inclined plate; collecting floating crude oil in the liquid phase to a crude oil storage tank through a scraper, and collecting and discharging sewage in the middle layer to a sewage storage tank; the inner bottom layer temperature of the inclined plate oil collecting sledge is 0-8 ℃, the liquid phase temperature is 50-80 ℃, the inclination angle of the sedimentation inclined plate is 30-60 degrees, and the number of plates is 2-8 grades;

2. air-float purification of sewage

Adding a flocculating agent, a coagulant and an oxidant into the sewage through a dissolved air floatation sledge, adhering fine impurities in the sewage into a suspended mass, and removing the suspended mass by using a chain scraper to prepare purified water;

3. sludge dewatering

And (3) pressurizing and filtering the sludge subjected to solid-liquid separation by using a plate-and-frame filter to prepare a sludge cake, discharging the sludge cake, and returning the filtered sewage to the dissolved air floatation sledge.

A complete set of 30m is designed by utilizing the device³Skid-mounted oil field comprehensive waste liquid treatment device with/h treatment capacity:

the field conditions are as follows:

a place: daqing oil field oil extraction six-factory comprehensive waste liquid deep injection station

The raw material sources are as follows: flushing fluid and workover fluid for oil extraction six-factory operation team

Production test time: 21/11/2019 to 30/12/2019

Heating source: 150kw electric heater

Clear water source: 0.15Mpa tap water

A compressed air source: 0.7MPa dry gas (supplied by on-site air compressor)

Power source: 380V,50HZ (provided by a 400Kw field transformer)

The oil field waste liquid treatment production test process:

1. tank car for drawing oil field waste liquid (liquid loading amount of each tank car is 10-20 m)³Left and right) liquid discharging pipe is aligned with a liquid discharging port of the inclined plate oil collecting pry to discharge liquid, and the liquid discharging amount is 150-200 m per day³Left and right;

2. the inner part of the inclined plate oil collecting pry is designed to be provided with a plate type gridThe sedimentation separation system of the grid deposits the blocky impurities and the silt in the incoming liquid at the bottom of the pry in a grid intercepting and precipitating mode, crude oil floats on the liquid surface and gathers, and the separated sewage enters 300-500 m³A storage tank;

3. after the liquid unloading work is finished, conveying the impurities deposited at the bottom of the prying machine to a solid-liquid separation pry through a slurry pump (for 3-5 minutes);

4. after the liquid unloading work is finished, the temperature of crude oil floating on the liquid surface reaches (40-60 ℃) through static heating of two submerged (10-20 kw) electric heaters, the crude oil is cleaned through a chain type oil scraper and is collected into a crude oil tank of an inclined plate oil collecting pry, and the crude oil is conveyed to a crude oil storage tank through a crude oil centrifugal pump after secondary heating (50-80 ℃);

5. the sewage is purified by the dissolved air floatation pry, a flocculating agent (0.01-0.05%), a coagulating agent (0.5-2%) and an oxidizing agent (0.5-1%) are added to adhere fine impurities and suspended matters in the sewage into clusters, and meanwhile, the clustered impurities are wrapped on the surface in the process that nano-scale microbubbles released by the dissolved air water rise to the liquid level and quickly float and separate. Then, scum on the liquid level is collected to a scum box by using a chain scraper, and finally the scum is conveyed to a sludge dewatering pry by using a centrifugal pump to achieve standard water output;

6. sewage containing silt and sand, which is beaten from the inclined plate oil receiving pry, is separated from the sewage in the solid-liquid separation pry by utilizing the inclined plate sedimentation principle, and is dewatered by the variable-pitch slotted screen spiral dehydrator and discharged with silt and sand, and the sewage is pumped into the inclined plate oil receiving pry;

7. the crude oil collected from the inclined plate oil collecting pry is uniformly collected to 50m³Storing the crude oil in a crude oil storage tank, wherein the crude oil is discharged from top to bottom, an electric heater is arranged at the bottom of the tank for heating dehydration (the power of the electric heater is 30-50 kw, the dehydration temperature is 60-90 ℃), the water cutting operation at the bottom of the tank is periodically operated, and the cut water flows back to an inclined plate oil recovery skid;

8. adding a flocculating agent (0.01-0.05%) and a coagulating agent (0.5-2%) into scum beaten by the dissolved air floatation pry, dehydrating the materials by using a sludge dehydration screw forming machine, discharging dehydrated mud cakes, and returning filtrate to the dissolved air floatation pry. A belt is arranged in the sludge dewatering pryStirring for 20-30 m³And the storage tank starts to operate when the materials are full.

And (3) test results:

7000 cubes of sewage is treated from 11 months, 21 days to 12 months, 30 days in 2019, and the water content in the treated mud is less than 70%; the water content in the silt separated by the variable-pitch slotted screen spiral dehydrator is less than 80 percent; the water content of the collected crude oil is less than 10 percent; the oil content in the treated water is less than 20 mg/l. (the oilfield polymer-containing sewage treatment standard is 20 mg/l); the content of suspended matters in water is less than 20 mg/l; tests show that the effect after treatment is better than the expected standard.

Claims (10)

1. Oil field oily sewage rapid treatment device, including crude oil storage tank (1) and sewage storage tank (2), its characterized in that still includes swash plate receipts oil sledge (3), solid-liquid separation sledge (4), dissolve gas air supporting sledge (5) and mud dehydration sledge (6), it has raw materials entry (7) to receive oil sledge (3) at the swash plate, its sand water outlet pipe connects solid-liquid separation sledge (4), be equipped with the silt sand discharge port on solid-liquid separation sledge (4), the upper portion crude oil outlet pipe connection crude oil storage tank (1) of oil sledge (3) is received to the swash plate, the sewage outlet pipe connection sewage storage tank (2) of oil sledge (3) is received to the swash plate, the exit linkage of sewage storage tank (2) dissolves gas air supporting sledge (5), the dross exit linkage mud dehydration sledge (6) of dissolving gas air supporting (5), the clear water discharge port is established to the lower part, the sledge end of mud dehydration sledge (6) discharges the dehydration mud cake.

2. The device for rapidly treating the oily sewage in the oil field as claimed in claim 2, wherein the inclined plate oil collecting sledge (3) is characterized in that a box body is sequentially divided into a control chamber (9), a slow flow chamber (10) and a crude oil collecting chamber (11) from left to right by a partition plate (8), and a sand water output pump (12), a crude oil output pump (13) and a sewage output pump (14) are arranged in the control chamber (9); the upper part of the left side of the slow flow chamber (10) is provided with a raw material inlet (7), the right side is provided with an oil collecting assembly (30) to a crude oil collecting chamber (11), a sloping plate (16) which inclines downwards is arranged at the bottom of the crude oil collecting chamber (11) and the buffer chamber (10) from right to left, more than one sedimentation sloping plate (17) is fixed on the inner walls of the box bodies at two sides in the slow flow chamber (10) at intervals, the lower part of the sedimentation sloping plate (17) is provided with a sewage output pipeline (18) in the slow flow chamber (10) and a crude oil output pipeline (19) of the crude oil collection chamber (11), the sewage output pipeline (18) enters the sewage storage tank (2) through a sewage discharge port (20) by a sewage output pump (14), the crude oil output pipeline (19) enters the crude oil storage tank (1) through a crude oil outlet (21) by a crude oil output pump (13), and a sand water outlet (22) at the bottom of the left side of the slow flow chamber (10) enters the solid-liquid separation sledge (4) through a sand water outlet (23) by a sand water output pump (12).

3. The device for rapidly treating the oily sewage in the oil field according to claim 2, which is characterized in that a sand baffle plate (24) is fixed on an inclined plate (16) at the rear section of the slow flow chamber (10), a crude oil output pipeline (19) penetrates through the sand baffle plate (24), a sewage discharge pipe (75) is arranged at the bottom of the slow flow chamber (10) and penetrates through the sand baffle plate (24), an inlet of the sewage discharge pipe is arranged at the right side of the sand baffle plate (24), and an outlet of the sewage discharge pipe enters the solid-liquid separation sledge (4) through a sand-water outlet (23) by a sand-water output pump (12).

4. The oil field oily sewage rapid treatment device according to claim 2, characterized in that the outlet of the sewage output pump (14) is respectively connected with a fine sand collecting flushing pipe (25), a sand discharging back flushing pipe (26) and a sand flushing stirring pipe (27); the fine sand collecting and flushing pipe (25) is an L-shaped pipe, is arranged at the lower part of the sedimentation inclined plate (17), is longitudinally arranged at the left side of the sand baffle plate (24) at the bottom of the slow flow chamber (10) by a bent pipe, and is provided with a spray head (28); the outlet of the sand discharge backwash pipe (26) is communicated with the pipeline of the sand water outlet (22); the sand washing stirring pipe (27) is longitudinally arranged above the left side of the flow buffering chamber (10), and a spray head is arranged on the sand washing stirring pipe; a crude oil tank sewage inlet (29) is arranged on the slow flow chamber (10).

5. The device for rapidly treating the oily sewage in the oil field as claimed in claim 2, wherein an oil receiving spraying pump (15) is further arranged in the control chamber (9), an oil receiving spraying inlet pipe (31) is arranged above the slow flow chamber (10) and is connected with the oil receiving spraying pump (15) through a pipeline, an outlet of the oil receiving spraying pump (15) is connected with an oil receiving spraying outlet spray pipe (32), and the oil receiving spraying outlet spray pipe (32) is longitudinally positioned above the left side of the slow flow chamber (10) and is provided with a spray head.

6. The oil field oily sewage rapid treatment device as claimed in claim 2, characterized in that a liquid inlet I (33) on the crude oil storage tank (1) is connected with a crude oil outlet (21) of the inclined plate oil receiving skid (3), and a sewage outlet (34) is connected with a crude oil tank sewage inlet (29) on the inclined plate oil receiving skid (3); the tank body is provided with a crude oil output port (35), an electric heater (36) is arranged in the tank body, and a self-circulation heating pipeline (37) is arranged in the tank body and connected with a circulating pump (38).

7. The oil field oily sewage rapid treatment device according to claim 2, characterized in that the solid-liquid separation sledge (4) is provided with a separation sloping bucket (39) in a box body, a sand-water separator (40) is arranged in the separation sloping bucket (39), a liquid inlet pipe (41) of the separation sloping bucket is connected with a sand-water outlet (23) of the sloping plate oil collecting sledge (3), a liquid outlet of the liquid inlet pipe (41) is arranged above the separation sloping bucket (39) through a swirler (42), a sewage overflow port (43) is arranged on the separation sloping bucket (39), and a sand-water outlet (44) is arranged on the sand-water separator (40).

8. The oil field oily sewage rapid treatment device according to claim 2, characterized in that the dissolved air floatation sledge (5) is provided with a partition plate (45) in the box body to divide the box body into a reaction chamber (46) and a separation chamber (47), a sewage outlet pipeline of the sewage storage tank (2) enters the reaction chamber (46) through a liquid inlet II (48), a liquid inlet pump (49) and a liquid inlet pipeline (50), releasers (51) are respectively arranged at the bottoms of the front sections of the reaction chamber (46) and the separation chamber (47), the releasers (51) are connected with an outlet of the dissolved steam tank (52) through a pipeline (60), a scum collecting device (55) is arranged at the top of the separation chamber (47), a scum box (56) is arranged at the tail end, a clear water outlet (54) of the scum box (56) is provided with the separation chamber (47) is discharged to a high-pressure pump room (63) through a clear water outlet (62) by a clear water pump (61), an inlet of the scum box (56) is provided with a slag receiving plate, the bottom outlet pipeline of the scum box (56) is discharged to the sludge dewatering sledge (6) through a scum outlet (59) by a scum pump (58).

9. The oil field oily sewage rapid treatment device according to claim 8, characterized in that a scum outlet (59) pipeline and a scum inlet (67) enter a scum stirring box (68) of the sludge dewatering skid (6), the scum stirring box (68) is provided with a stirring device (69) and an internal heater (70), a liquid outlet (71) at the bottom of the scum stirring box is connected to a liquid outlet pump (72) through a pipeline, a water outlet of the liquid outlet pump (72) is discharged to the slow flow chamber (10) through an outlet (73) pipe, a sludge outlet pipeline is connected to a threading machine (74), and the threading machine (73) is provided with a liquid outlet and a sludge discharge port.

10. The method for quickly treating the oily sewage of the oil field comprises the following steps:

(I) solid-liquid separation

Pouring oily sewage into an inlet of an inclined plate oil collecting sledge, and settling and discharging solid silt in the oily sewage to the bottom of the sledge through full diffusion of a settling inclined plate; collecting floating crude oil in the liquid phase to a crude oil storage tank through a scraper, and collecting and discharging sewage in the middle layer to a sewage storage tank; the inner bottom layer temperature of the inclined plate oil collecting sledge is 0-8 ℃, the liquid phase temperature is 50-80 ℃, the inclination angle of the sedimentation inclined plate is 30-60 degrees, and the number of plates is 2-8 grades;

(II) air-float purification of sewage

Adding a flocculating agent, a coagulant and an oxidant into the sewage through a dissolved air floatation sledge, adhering fine impurities in the sewage into a suspended mass, and removing the suspended mass by using a chain scraper to prepare purified water;

(III) sludge dewatering

And (3) pressurizing and filtering the sludge subjected to solid-liquid separation by using a plate-and-frame filter to prepare a sludge cake, discharging the sludge cake, and returning the filtered sewage to the dissolved air floatation sledge.

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