CN212025045U

CN212025045U - Oil field low oil-containing sewage treatment pry

Info

Publication number: CN212025045U
Application number: CN202020699247.8U
Authority: CN
Inventors: 李�和; 梁鲜; 刘志孝; 谢伟永
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-11-27
Anticipated expiration: 2030-04-30

Abstract

The utility model discloses an oil field oily sewage handles sled solves the low oily sewage treatment problem in oil field, wholly sled dress, filter jar, end sled including cyclone, oil storage tank, water storage tank, first filtration jar, electrolysis jar, second. The cyclone separator and the oil storage tank are sequentially connected according to the flow direction of the crude oil; the cyclone separator, the water storage tank, the first filtering tank, the electrolysis tank and the second filtering tank are connected according to the sewage flow direction; the cyclone separator realizes the cyclone separation of crude oil and sewage, the first filtering tank and the second filtering tank realize the filtration of impurities and crude oil, and the electrolytic tank realizes the electrolytic sterilization and the flocculation and sedimentation of suspended matters. The filtering device comprises a water inlet, a water inlet pipe, a sealing cap, a drain pipe and a sealing flange, wherein a coarse-pore filter element, a medium-pore filter element, a fine-pore filter element and a support ring are arranged in the filtering device, impurities and crude oil in sewage are filtered according to different physical permeability, and are blocked and sealed in a closed cavity formed by the filtering device, and the filtering device can be integrally disassembled and assembled.

Description

Oil field low oil-containing sewage treatment pry

Technical Field

The utility model relates to an oil field low oily sewage handles sled, especially relates to a sled dress equipment that is arranged in the low oily sewage treatment that produces in the oil field production process.

Background

In the later period of oil field exploitation, the water content of the produced crude oil is above 80%, and the water content of part of crude oil is up to above 90%. The water-containing crude oil generates a large amount of oil-containing sewage after being subjected to three-phase separator, primary sedimentation separation and secondary sedimentation separation. According to the difference of oil content, the method can be divided into low oil-containing sewage and high oil-containing sewage, the treatment process of the high oil-containing sewage is complex, and in contrast, the treatment process of the low oil-containing sewage is simple. Common oily sewage treatment processes comprise oil-water separation, medicament demulsification, flocculation sedimentation, crude oil filtration and the like. The oily sewage is conveyed to the combined station, the sewage treatment station and other places through the gathering and transportation pipeline for centralized treatment and then reinjection, and the devices such as a filter, an air flotation machine and the like are used, so that the flow and the devices have large occupied area, complex process and high early investment. And small oily sewage treatment equipment with small occupied area and ideal treatment effect is sometimes needed in places such as oil field single wells, sewage measurement rooms and the like.

The single oily sewage treatment process and equipment have the limitations of the process and the equipment, and in the actual treatment process, the ideal treatment effect can be obtained only by combining and using a plurality of treatment processes. In the conventional oily sewage treatment of the oil field, the high oily sewage and the low oily sewage are not treated separately, but treated as the same type of oily sewage to be treated uniformly, so that the low oily sewage is treated in a targeted manner, the treatment cost and the equipment investment can be saved, and the treatment efficiency is improved.

Disclosure of Invention

To the oil field not with the production current situation that low oily sewage, high oily sewage handled respectively to and oil field individual well, measurement room etc. place to the demand of miniaturized low oily sewage treatment facility, the utility model provides a possess the low oily sewage treatment sled of functions such as water oil separating, crude oil filtration, electrolysis disinfect simultaneously.

The utility model discloses the technical problem that will solve adopts following technical scheme to realize:

the utility model provides an oil field low oiliness sewage treatment sled, wholly adopts sled dress structure, includes end sled, cyclone, oil storage tank, water storage tank, first filtration jar, electrolysis jar, second filtration jar. The cyclone separator, the oil storage tank, the water storage tank, the first filter tank, the electrolysis tank and the second filter tank are respectively arranged on the bottom pry through foundation bolts, and the cyclone separator and the oil storage tank are sequentially connected through a pipeline and a valve according to the flow direction of crude oil; the cyclone separator, the water storage tank, the first filtering tank, the electrolysis tank and the second filtering tank are sequentially connected through a pipeline and a valve according to the sewage flow direction.

The cyclone separator comprises an upper section cylinder, a middle section cone and a lower section cone, the upper section cylinder, the middle section cone and the lower section cone are connected through flanges respectively, the left end of the upper section cylinder is tangential to a separator liquid inlet, the top end of the upper section cylinder is provided with a separator oil overflow port, and the bottom end of the lower section cone is provided with a separator water outlet. The cyclone separator realizes cyclone separation of crude oil and sewage in the low oil-containing sewage by using a cyclone separation principle, separates out most of the crude oil in the low oil-containing sewage, and the crude oil after cyclone separation enters an oil storage tank through an oil overflow port of the separator; the separated sewage enters the water storage tank through the water outlet of the separator.

The oil storage tank add the tube structure for standard oval head, realize cyclone separation back crude oil storage function, oil storage tank barrel left end sets up the oil storage tank oil inlet, oil storage tank barrel front end sets up oil storage tank double flange level gauge mouth for the installation double flange level gauge shows the interior crude oil liquid level of oil storage tank, oil storage tank barrel bottom sets up the oil storage tank oil-out.

The water storage tank be standard oval head with the barrel structure, mainly realize sewage storage, buffer function behind the cyclone, water storage tank barrel left end sets up the water storage tank water inlet, water storage tank barrel front end sets up water storage tank double flange level gauge mouth for the double flange level gauge of installation shows the interior sewage liquid level of water storage tank, water storage tank barrel top sets up the water storage tank delivery port, water storage tank barrel bottom sets up the water storage tank drain.

The first filtering tank and the second filtering tank have the same structure. The first filtering tank realizes the filtering function of crude oil and impurities in the low-oil-content sewage after cyclone separation. The first filtering tank mainly comprises a filtering tank cylinder body, and a filtering device mounting opening is formed in the top end of the filtering tank cylinder body and used for mounting a filtering device. The front end of the filtering tank barrel is provided with a double-flange liquid level meter port of a filtering device for installing the double-flange liquid level meter and displaying the liquid level of sewage in the filtering tank, the left end of the filtering tank barrel is provided with a water outlet of the filtering tank, and the bottom end of the filtering tank is provided with a sewage discharge port of the filtering tank.

The filtering device consists of a water inlet, a water inlet pipe, a sealing cap, a drain pipe and a sealing flange. The water inlet pipe penetrates through the sealing flange and is welded on the two sides; the drain pipe is welded with the bottom end of the sealing flange in a single-side welding way; the sealing cap is provided with external threads, the bottom of the drain pipe is provided with internal threads, and the sealing cap is connected with the drain pipe in an internal and external thread mode; the sealing flange, the water inlet pipe, the water outlet pipe and the sealing cap form a circular cylinder closed cavity inside the filtering device. The sealing flange of the filtering device is connected with the filtering device mounting port at the top end of the filtering tank cylinder body in a flange mode, the sealing flange extends into the filtering tank cylinder body, and the filtering device can be integrally mounted and dismounted. The periphery of the water inlet pipe and the periphery of the water outlet pipe of the filtering device are respectively provided with a first circular small hole and a second circular small hole, the aperture of each small hole is phi 1 and phi 2, phi 2 is less than phi 1, a cylindrical coarse-pore filter core is arranged close to the outer wall of the water inlet pipe, a middle-pore filter core is arranged at a certain interval, a fine-pore filter core is arranged close to the inner wall of the water outlet pipe, and support rings are respectively arranged among the cylindrical coarse-pore filter core, the middle-pore filter core and the fine-pore filter core to realize the fixed support effect of.

The electrolytic tank mainly comprises an electrolytic tank barrel, the top of the electrolytic tank barrel is sequentially provided with an electrolytic tank water inlet, an electrode plate group and an electrolytic tank water outlet from right to left, the front end of the electrolytic tank barrel is provided with an electrolytic tank double-flange liquid level meter port for displaying the liquid level in the electrolytic tank, the bottom of the electrolytic tank barrel is provided with an electrolytic tank sewage outlet, the electrolytic tank water inlet and the electrolytic tank water outlet are all larger than the electrode plate group, the liquid level in the electrolytic tank is ensured to always not cover the electrode plate group, the phenomenon that the electrode plate group is dried due to too low liquid level is effectively avoided, the electrode plate group is connected with the electrolytic tank barrel in a flange mode, and the electrolytic tank mainly realizes the functions of low oily sewage electrolytic sterilization and flocculation.

When the cyclone separator is used, low-oil-content sewage tangentially enters the cyclone separator from the liquid inlet of the separator, most of crude oil in the low-oil-content sewage is separated by cyclone separation, and the separated crude oil enters the oil storage tank through the overflow port of the separator and the oil inlet of the oil storage tank and is discharged through the oil outlet of the oil storage tank. The sewage that is separated passes through the separator delivery port, get into the water storage tank through the water storage tank water inlet, discharge by the water storage tank delivery port, get into through the water inlet of filter equipment, through the first aperture around the inlet tube pipe wall, from interior to exterior passes the coarse pore and crosses the filter core in proper order, the mesopore filters the core, the pore filters the core, utilize different pores to filter the core to low oily sewage in impurity, the different physics permeability of crude oil, realize low oily sewage filtering capability, and with the low oily sewage in impurity, crude oil blocks, seal the closed cavity that forms in the annular space between the filter core of three-layer and filter equipment self structure, ensure can not flow the sewage after filter equipment secondary pollution passes through filter equipment. The sewage continuously enters the filtering tank cylinder through the second small holes on the periphery of the pipe wall of the drain pipe; the water is discharged from the water outlet of the filter tank, enters the electrolytic tank from the water inlet of the electrolytic tank, is electrolyzed by the electrode plate group, on one hand, bacteria and microorganisms in the low oily sewage are killed by electrolysis, the water quality is purified, on the other hand, some suspended substances in the sewage are flocculated and settled by electrolysis, the electrolyzed low oily sewage is discharged from the water outlet of the electrolytic tank, enters the second filter tank to be filtered in the same filtering process as the first filter tank, and further filters the flocculated and settled matters, impurities and crude oil generated by electrolysis of the electrolytic tank.

After the equipment is used for a period of time, the sewage quality discharged from the water outlet of the filter tank is sampled and tested, and whether the corresponding filter device needs to be replaced and cleaned is judged. When the filter device needs to be cleaned or replaced, the whole filter device is taken out, the sealing cap is opened, crude oil and solid impurities in the annular space between the three layers of filter elements are removed, the coarse-pore filter element, the medium-pore filter element, the fine-pore filter element and the support ring are taken out, the filter elements, the first small hole and the second small hole are cleaned by high-pressure steam, the filter elements are replaced when necessary, and after the cleaning or replacement is completed, the filter elements and the support ring are installed back in the original sequence.

The utility model has the advantages that: the utility model provides a skid-mounted device suitable for low oil-containing sewage treatment in small-sized places such as oil field single wells, sewage measurement rooms and the like, which has the advantages of integrated skid mounting, small occupied area, simple flow, and convenient installation, transportation and lifting; the device has the advantages that the cyclone separator, the filter tank, the electrolytic tank and other equipment are used in a combined mode, and meanwhile, the device has the functions of oil-water cyclone separation, crude oil and impurity filtration, electrolytic sterilization and suspended matter flocculation and sedimentation, the cyclone separator mature in the prior art is adopted to realize oil-water cyclone separation, the separation efficiency is high, the crude oil content in the low oil-containing sewage to be filtered is reduced, the replacement period of a filter device in a first filter and a second filter is prolonged, the low oil-containing sewage is subjected to primary filtration treatment before electrolysis, the quality of the low oil-containing sewage during electrolysis is improved, and the situations that the surface of an electrode plate group is scaled, the electrode plate group is punctured and the like due to the over-poor; but filter equipment unit integrated package, dismantle, through the physics filtering action of crossing the filter core, avoid using traditional filter materials such as quartz sand, walnut shell, thereby simplify flows such as loading and unloading, washing, screening of traditional low oily sewage filter material, reduce intensity of labour, filter equipment's airtight cavity structures and the annular space that the three-layer filter core formed, seal magazine and crude oil inside filter equipment, prevent that impurity and crude oil from producing secondary pollution to the low oily sewage after filtering, each layer crosses the filter core and is the cylinder structure, and filter area is big, and it is convenient to change and wash. The utility model discloses a combination of many equipment, many sets of technology is used, the low oily sewage treatment problem of solution that can the pertinence.

Drawings

FIG. 1 is a schematic view of a skid for treating oil field low oil-containing sewage

FIG. 2 is a schematic view of the flow connection of oil field low oil content sewage treatment prying

FIG. 3 is a schematic view of the flow connection of oil field low oil content sewage treatment prying

FIG. 4 is a schematic view of a cyclone separator

FIG. 5 is a schematic view of an oil storage tank

FIG. 6 is a schematic view of a water storage tank

FIG. 7 is a schematic view of a canister

FIG. 8 is a schematic view of a filter device

FIG. 9 is a schematic view showing the installation of a coarse filter element, a medium filter element and a fine filter element

FIG. 10 is a schematic view of an electrolytic tank

In the figure, 1, a cyclone separator, 2, an oil storage tank, 3, a water storage tank, 4, a first filter tank, 5, an electrolytic tank, 6, a second filter tank, 7, a bottom pry, 8, a separator oil overflow port, 9, a separator liquid inlet, 10, an upper section cylinder, 11, a middle section cone, 12, a lower section cone, 13, a separator water outlet, 14, an oil storage tank double-flange liquid level meter port, 15, an oil storage tank oil inlet, 16, an oil storage tank cylinder, 17, an oil storage tank oil outlet, 18, a water storage tank water outlet, 19, a water storage tank double-flange liquid level meter port, 20, a water storage tank cylinder, 21, a water storage tank water inlet, 22, a water storage tank sewage outlet, 23, a filter device, 24, a filter device mounting port, 25, a filter tank double-flange liquid level meter port, 26, a filter tank water outlet, 27, a filter tank cylinder, 28, a filter tank sewage outlet, 29, a water inlet, 30, a water inlet pipe, 32. the electrolytic tank comprises a second small hole, a drain pipe, a first small hole, a sealing cap, a thick-hole filter element, a middle-hole filter element, a thin-hole filter element, a support ring, a water inlet of the electrolytic tank, an electrode plate group, an electrolytic tank water outlet, an electrolytic tank double-flange liquid level meter port, an electrolytic tank sewage outlet, an electrolytic tank cylinder body and an electrolytic tank discharge port, wherein the second small hole is 33, the drain pipe is 34, the first small hole is 35, the sealing cap is 36, the thick-hole filter element is 37, the middle.

Detailed Description

The utility model provides an oil field low oiliness sewage treatment sled, wholly adopts sled dress structure, includes cyclone 1, oil storage tank 2, water storage tank 3, first filtration jar 4, electrolysis jar 5, second filtration jar 6, end sled 7 of crossing. The cyclone separator 1, the oil storage tank 2, the water storage tank 3, the first filter tank 4, the electrolytic tank 5 and the second filter tank 6 are respectively installed and fixed on the bottom pry 7 in a foundation bolt mode, and the cyclone separator 1 and the oil storage tank 2 are sequentially connected through a pipeline and a valve according to the flowing direction of crude oil; the cyclone separator 1, the water storage tank 3, the first filtering tank 4, the electrolysis tank 5 and the second filtering tank 6 are sequentially connected through a pipeline and a valve according to the sewage flow direction, as shown in fig. 1, 2 and 3.

The cyclone separator 1 comprises an upper section cylinder 10, a middle section cone 11 and a lower section cone 12, wherein the upper section cylinder 10, the middle section cone 11 and the lower section cone 12 are connected in a flange mode respectively, a separator liquid inlet 9 is arranged in the tangential direction of the left end of the upper section cylinder 10, a separator oil spilling port 8 is arranged at the top end, and a separator water outlet 13 is arranged at the bottom end of the lower section cone 12. The cyclone separator realizes cyclone separation of crude oil and sewage in the low oil-containing sewage by using a cyclone separation principle, and separates out most of crude oil in the low oil-containing sewage. The crude oil after cyclone separation enters the oil storage tank 2 through the oil overflow port of the separator, and the sewage enters the water storage tank 3 through the water outlet 13 of the separator, as shown in fig. 4.

Oil storage tank 2 add the tube structure for the oval head of standard, the primary structure is oil storage tank barrel 16, the 16 left ends of oil storage tank barrel set up oil storage tank oil inlet 15, the 16 front ends of oil storage tank barrel set up oil storage tank double flange level gauge mouth 14, be used for installing the double flange level gauge, show crude oil liquid level in the oil storage tank 2, when the liquid level is higher, oil storage tank oil-out 17 through the 16 bottom settings of oil storage tank barrel discharges crude oil, crude oil storage function after the cyclone separation is mainly realized to oil storage tank 2, as shown in fig. 5.

Water storage tank 3 add the tube structure for the oval head of standard, the primary structure is water

storage tank barrel

20, 20 left ends of water storage tank barrel set up water storage

tank water inlet

21, 20 front ends of water storage tank barrel set up water storage tank double flange level gauge mouth 19, be used for installing the double flange level gauge, show sewage liquid level in the

water storage tank

3, 18 discharge sewage through the water storage tank delivery port that 20 tops of water storage tank barrel set up, 20 bottoms of water storage tank barrel set up water storage tank drain 22, be used for 3 periodic blowdown of water storage tank, the water storage tank mainly realizes that cyclone back sewage is stored, buffer function, as shown in FIG. 6.

The first filtration jar with the second filter jar structure identical completely, the first filtration jar mainly comprises filtering a jar barrel 27, filter a jar barrel 27 top and set up filter equipment installing port 24, be used for installing filter equipment 23, filter equipment barrel 27 front end sets up filter equipment double flange level gauge mouth 25, be used for installing double flange level gauge, show 4 sewage liquid levels in the first filtration jar, filter a jar barrel 27 left end and set up filtration jar delivery port 26, filter a jar barrel 27 bottom and set up filtration jar drain 28, be used for filtering 4 periodic blowdown of jar, filter jar and mainly realize the filtration of low oily aquatic crude oil, impurity of containing oil after cyclone separation, as shown in figure 7.

The filtering device 23 is composed of a water inlet 29, a water inlet pipe 30, a sealing flange 31, a water outlet pipe 33 and a sealing cap 35. The water inlet pipe 30 penetrates through the sealing flange 31 and is welded on two sides; the drain pipe 33 is welded with the bottom end of the sealing flange 31 in a single-side welding way; the sealing cap 35 is provided with external threads, the bottom of the drain pipe 33 is provided with internal threads, and the sealing cap 35 is connected with the drain pipe 33 in an internal and external thread mode; the inlet pipe 30, the sealing flange 31, the drain pipe 33 and the sealing cap 35 together form a cylindrical closed cavity inside the filter device 23. The sealing flange 31 of the filtering device 23 is connected with the filtering device mounting port 24 at the top end of the filtering tank cylinder 27 in a flange mode, and extends into the filtering tank cylinder 27, so that the filtering device 23 can be integrally mounted and dismounted. The periphery of the pipe walls of the water inlet pipe 30 and the water outlet pipe 33 are respectively provided with a first circular small hole 34 and a second circular small hole 32, the aperture is phi 1 and phi 2, phi 2 is less than phi 1, a cylindrical coarse-pore filter element 36 is arranged close to the outer wall of the water inlet pipe 30, a middle-pore filter element 37 is arranged at a certain interval, a fine-pore filter element 38 is arranged close to the inner wall of the water outlet pipe 33, and support rings 39 are respectively arranged among the cylindrical coarse-pore filter element 36, the middle-pore filter element 37 and the fine-pore filter element 38 to realize the fixed support function of the filter elements, as shown in.

Electrolytic tank 5 mainly include electrolytic tank barrel 45, electrolytic tank barrel 45 top sets gradually electrolytic tank water inlet 40 from a left side from the right side, electrode plate group 41, electrolytic tank delivery port 42, electrolytic tank barrel 45 front end sets up electrolytic tank double flange level gauge mouth 43, show liquid level in the electrolytic tank, electrolytic tank barrel 45 bottom sets up electrolytic tank drain 44, electrolytic tank water inlet 40, electrolytic tank delivery port 42 highly all is greater than electrode plate group 41 height, guarantee that the liquid level does not have electrode plate group 41 in the electrolytic tank 5 all the time, effectively avoid the liquid level to hang down to lead to electrode plate group 41 dry combustion condition to take place, electrode plate group 41 and electrolytic tank barrel 45 pass through the flange mode and be connected, electrolytic tank 4 mainly realizes low oily sewage electrolysis and disinfects, the flocculation settlement function, as shown in figure 10.

When in use, the low oil-containing sewage tangentially enters the cyclone separator 1 from the liquid inlet 9 of the separator, most of crude oil in the low oil-containing sewage is separated by using the cyclone separation principle, the crude oil separated by the cyclone enters the oil storage tank 2 through the oil overflow port 8 of the separator and the oil inlet 15 of the oil storage tank, and then is discharged through the oil outlet 17 of the oil storage tank; the low oil-containing sewage after cyclone separation enters a water storage tank 3 for storage and buffering through a water outlet 13 of the separator and a water inlet 21 of the water storage tank, is discharged through a water outlet 18 of the water storage tank, enters from a water inlet 29 of a filtering device 23, passes through first small holes 34 on the periphery of the pipe wall of a water inlet pipe 30, sequentially passes through a coarse-hole filtering core 36, a medium-hole filtering core 37 and a fine-hole filtering core 38 from inside to outside, realizes the filtering function of the low oil-containing sewage after cyclone separation by utilizing different physical permeability of the filtering cores to impurities and crude oil in the low oil-containing sewage, and blocks and seals the filtered impurities and crude oil in an annular space between the three layers of filtering cores and a closed cavity formed by the structure of the filtering device, so that the sewage filtered by the filtering device 23 cannot flow out for secondary pollution; the sewage enters the filtering tank cylinder body 27 through the second small holes 32 on the periphery of the pipe wall of the drain pipe 33, is discharged through the filtering tank water outlet 26, enters the electrolytic tank 5 through the electrolytic tank water inlet 40, the low oil-containing sewage is electrolyzed by the electrode plate group 41, on one hand, bacteria and microorganisms in the low oil-containing sewage are killed through electrolysis, the water quality is purified, on the other hand, some suspended substances in the sewage are flocculated and settled through electrolysis, the electrolyzed low oil-containing sewage is discharged through the electrolytic tank water outlet 42, the electrolyzed low oil-containing sewage enters the second filtering tank 6 to be filtered in the same process as the first filtering tank 4, and therefore the flocculated sediments, impurities and crude oil generated by the electrolysis of the electrolytic tank 5 are further filtered.

After the equipment is used for a period of time, the quality of the sewage discharged from the water outlet 26 of the filter tank is sampled and tested, and whether the corresponding filter device needs to be replaced and cleaned is judged. When the filter device needs to be cleaned or replaced, the whole filter device is taken out, the sealing cap 35 is opened, crude oil and solid impurities in the annular space between the three layers of filter elements are removed, the coarse filter element 36, the medium filter element 37, the fine filter element 38 and the support ring 39 are taken out, the filter elements, the first small hole 34 and the second small hole 32 are cleaned by high-pressure steam, each layer of filter element is replaced if necessary, and after the cleaning or replacement is completed, each layer of filter element and the support ring 39 are installed back according to the original sequence.

Claims

1. The utility model provides a low oily sewage treatment sled in oil field wholly adopts sled dress structure, includes cyclone, oil storage tank, water storage tank, first filtration jar, electrolysis jar, second electrolysis jar, end sled, its characterized in that: the cyclone separator, the oil storage tank, the water storage tank, the first filter tank, the electrolytic tank and the second filter tank are respectively installed and fixed on the bottom pry in a foundation bolt mode, the cyclone separator and the oil storage tank are sequentially connected through a pipeline and a valve according to the flowing direction of crude oil, the cyclone separator, the water storage tank, the first filter tank, the electrolytic tank and the second filter tank are sequentially connected through a pipeline and a valve according to the flowing direction of sewage, the cyclone separator realizes the cyclone separation function of crude oil and sewage, the first filter tank and the second filter tank realize the filtering function of sewage, the electrolytic tank realizes the electrolytic sterilization and flocculation sedimentation functions of sewage, and the treatment function of low-oil-content sewage is realized through the combined use mode of the cyclone separator, the oil storage tank, the water storage tank, the first filter tank, the second filter tank, the electrolytic tank and the bottom pry; the first filtering tank and the second filtering tank are completely the same in structure, the first filtering tank is mainly composed of a filtering tank barrel, the top end of the first filtering tank is provided with a filtering device mounting port, the front end of the first filtering tank is provided with a filtering device double-flange liquid level meter port, the bottom end of the first filtering tank is provided with a filtering tank sewage outlet, the filtering device is connected with the filtering device mounting port in a flange mode and extends into the filtering tank barrel, the filtering device is composed of a water inlet, a water inlet pipe, a sealing flange, a drain pipe and a sealing cap, the water inlet pipe penetrates through the sealing flange and is welded on the two sides, the drain pipe is welded on the bottom side of the sealing flange in a single-side mode, the sealing cap is provided with an external thread, the bottom end of the drain pipe is provided with an internal thread, the sealing cap is connected with the external thread in the, The second small hole has the pore diameters of phi 1 and phi 2 respectively, wherein phi 2 is less than phi 1, a cylindrical coarse hole filter element is arranged close to the outer wall of the water inlet pipe, a middle hole filter element is arranged at a certain distance, a fine hole filter element is arranged close to the inner wall of the water drain pipe, support rings are respectively arranged among the cylindrical coarse hole filter element, the middle hole filter element and the fine hole filter element to realize the fixed supporting function of the filter elements, the filtration is realized by utilizing the different physical permeability of the different hole filter elements on impurities and crude oil, and the filtered impurities and crude oil are sealed in an annular space between the three layers of filter elements and a cylindrical closed cavity of the filter device.

2. The oilfield low oil-containing sewage treatment skid as defined in claim 1, wherein: the cyclone separator comprises an upper section cylinder body, a middle section cone body and a lower section cone body, wherein the upper section cylinder body, the middle section cone body and the lower section cone body are connected in a flange mode respectively, a separator liquid inlet is arranged at the left end of the upper section cylinder body in the tangential direction, a separator oil overflow port is arranged at the top end of the upper section cylinder body, and a separator water outlet is arranged at the bottom end of the lower section cone body.

3. The oilfield low oil-containing sewage treatment skid as defined in claim 1, wherein: the oil storage tank be standard oval head with tube structure, the primary structure is the oil storage tank barrel, oil storage tank barrel left end sets up the oil storage tank oil inlet, oil storage tank barrel front end sets up the oil storage tank double flange level gauge mouth, oil storage tank barrel bottom sets up the oil storage tank oil-out.

4. The oilfield low oil-containing sewage treatment skid as defined in claim 1, wherein: the water storage tank be standard oval head with tube structure, the primary structure is the water storage tank barrel, water storage tank barrel left end sets up the water storage tank water inlet, water storage tank barrel front end sets up water storage tank double flange level gauge mouth, water storage tank barrel top sets up the water storage tank delivery port, water storage tank barrel bottom sets up the water storage tank drain.

5. The oilfield low oil-containing sewage treatment skid as defined in claim 1, wherein: the electrolytic tank mainly comprises an electrolytic tank barrel, an electrolytic tank water inlet, an electrode plate group and an electrolytic tank water outlet are sequentially arranged at the top end of the electrolytic tank barrel from the right side to the left side, an electrolytic tank double-flange liquid level meter port is arranged at the front end of the electrolytic tank barrel, an electrolytic tank drain outlet is arranged at the bottom end of the electrolytic tank barrel, the height of the electrolytic tank water inlet and the height of the electrolytic tank water outlet are always larger than the height of the electrode plate group, the water level is prevented from being too low through the mode, the electrode plate group is dried, and the electrode plate group is connected with the electrolytic tank barrel through a flange.