A device for treating waste steam discharged from heavy oil thermal recovery

Abstract

The application relates to a thickened oil thermal recovery external exhaust steam prying and installing treatment device, which comprises a base, a detachable flash tank arranged on one side of the base, a first platform and a second platform arranged on the other side of the base and protruding from the base, and a detachable air cooler arranged on the second platform, a liquid inlet end of the flash tank is communicated with a liquid conveying pipe, an air guide pipe communicated with the inside of the flash tank is arranged on the upper surface of the flash tank, a condensing part with a cavity is arranged on the air guide pipe, a spraying pipe is arranged on the upper side in the condensing part, the spraying pipe is communicated with a water outlet end of the air cooler, the condensing part above the spraying pipe is communicated with a non-condensed gas guide pipe, a cofferdam is formed between the air guide pipe and the lower part of the condensing part, the bottom of the cofferdam is communicated with a water inlet end of the air cooler. The produced liquid flash cooler, the air cooler and the circulating pump are integrated in a standard prying block, the inefficiency of the scattered deployment is solved, a prying and installing treatment system shared by multiple stations is designed, and the exhaust steam treatment of multiple or single transfer stations is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield development, and particularly relates to a skid-mounted treatment device for waste steam discharged in heavy oil thermal recovery. BACKGROUND

[0002] In a heavy oil field, a steam huff and puff method is usually used for thermal recovery, and a two-stage distribution station open-type gathering and transportation process is used as a supporting process. The gas-liquid mixture at high temperature is separated in a buffer tank (usually a normal pressure dome tank) in a transfer station. In this process, the high-temperature produced liquid is flashed due to pressure reduction, and a large amount of waste steam containing oil, volatile organic compounds (VOCs), hydrogen sulfide (H2S) and other toxic, harmful and combustible components is generated. These waste steams are usually not treated, directly discharged into the atmosphere through the normal pressure tank breathing port without organization, causing serious environmental pollution, greenhouse gas (methane) emission, accumulation of combustible gas, safety hazards of toxicity and waste of light hydrocarbon resources. With the increasingly stringent requirements for pollutant disposal rate and resource utilization rate in environmental protection, the existing open process needs to be improved.

[0003] In the prior art, the treatment of oil-containing steam is mainly through a simple condensation + incineration method, which includes a buffer tank, a spray tower, an oil-water separator and an air cooler. The equipment is arranged in a split mode and connected through pipelines. The defects of this method mainly include: 1. Low equipment integration and large land occupation, which is difficult to meet the needs of small treatment scenarios; 2. Equipment migration and reuse need to be repeatedly disassembled, which significantly increases the secondary implementation cost and limits the flexibility of the system; 3. Since the whole system is arranged outdoors, the circulating water in the air cooler, the spray tower, the oil-water separator and the water circulation pipeline therebetween cannot be circulated in case of power failure or other emergencies in winter. If the maintenance personnel do not handle it in time, the circulating water is easy to freeze, causing equipment damage.

[0004] Therefore, it is necessary to design a skid-mounted treatment device for waste steam discharged in heavy oil thermal recovery, which has high integration degree, small land occupation, can be repeatedly disassembled and can be used in winter to avoid freezing of equipment. SUMMARY

[0005] The present application aims to provide a skid-mounted treatment device for waste steam discharged in heavy oil thermal recovery, which can be repeatedly disassembled and has high integration degree, thereby meeting the needs of small treatment scenarios.

[0006] The application is achieved as follows: a skid-mounted waste steam treatment device for thermal recovery of thick oil, comprising a base, a detachable flash tank arranged on one side of the base, a first-stage platform and a second-stage platform arranged on the other side of the base and higher than the base, and a detachable air cooler arranged on the second-stage platform; a liquid inlet of the flash tank is communicated with a liquid inlet pipe; an upper surface of the flash tank is provided with a gas guide pipe communicated with the inside of the flash tank; a condenser with a cavity is arranged on the gas guide pipe; a spray pipe is arranged on the upper side of the condenser; the spray pipe is communicated with a water outlet of the air cooler; the condenser above the spray pipe is communicated with a non-condensed gas guide pipe; a cofferdam is formed between the gas guide pipe and the lower part of the condenser; and a water inlet of the air cooler is communicated with the cofferdam.

[0007] A liquid outlet pipe is communicated with the bottom of the flash tank; the liquid outlet pipe is communicated with a liquid inlet of a lifting pump; a liquid outlet of the lifting pump is communicated with a liquid outlet guide pipe; and a control valve is arranged on the liquid outlet pipe.

[0008] A circulating pump is arranged on the first-stage platform; the circulating pump is used for pressurized delivery of high-temperature circulating water to the air cooler; the air cooler is used for cooling the high-temperature circulating water to below 55 DEG C to form low-temperature circulating water which is sprayed from the spray pipe to exchange heat with oil-containing steam and volatile organic compounds; a liquid inlet of the circulating pump is communicated with the bottom of the cofferdam through a water outlet pipe; and a liquid outlet of the circulating pump is communicated with a water inlet of the air cooler through a water return pipe.

[0009] Soft pipes are communicated with the water inlets and outlets of the air cooler; the two soft pipes are respectively communicated with a water supply pipe and a water return pipe through joints; and the water supply pipe is communicated with the spray pipe.

[0010] The second-stage platform is a platform with a changeable inclination angle; the inclination of the second-stage platform is changed so that the air cooler is arranged at an inclination angle of 5 DEG to 10 DEG; and the water outlet of the air cooler forms the lowest end.

[0011] The second-stage platform comprises a base plate; a reversible flap is rotatably connected to one end of the base plate; a push-pull device for pushing and pulling the flap to turn over is arranged on the other end of the base plate; an installation position surrounded by a limiting frame is arranged on the upper surface of the flap; and the air cooler is detachably installed in the installation position.

[0012] Symmetrical mounting seats are arranged on one end of the base plate; shaft holes are formed in the mounting seats; the two ends of a rotating shaft are rotatably connected to the shaft holes; one end of the flap is fixedly connected to the surface of the rotating shaft; and the other end of the flap is connected to the upper end of the push-pull device through a universal joint.

[0013] An extension plate lower than the base plate is fixedly connected to the rear side of the base plate; the base plate and the extension plate form a height difference; and the lower end of the push-pull device is connected to the base plate through a universal joint.

[0014] A liquid guide device is arranged above the gas guide pipe; the liquid guide device is used for guiding the condensed liquid into the cofferdam; the liquid guide device comprises a protruding part; and the periphery of the protruding part is located directly above the opening of the cofferdam.

[0015] The upper part of the condensing part between the spray pipe and the liquid guide device is provided with a sieve plate tray group, and the sieve plate tray group comprises at least two upper and lower sieve plates with sieve holes, and the sieve holes on the adjacent upper and lower sieve plates are oppositely staggered.

[0016] By implementing the technical scheme, the produced liquid flash cooler, the air cooler, and the circulating pump composed of the flash tank and the condensing part are integrated in a standard skid block, the inefficiency of scattered deployment is solved, a skid-mounted treatment system shared by multiple stations is designed, and waste gas treatment of multiple or single transfer stations is realized. The bottleneck of migration and reuse is broken through, the equipment can be hoisted and transported as a whole through modular design, the problem of high cost of secondary disassembly of traditional split equipment is solved. Unattended and high automation are realized: through frequency conversion control and interlocking logic of key parameters, stable, efficient and low labor intervention operation of the system is realized. The process system is designed according to the gravity difference of the inclination angle. In the event of an emergency (such as power failure), a small amount of circulating water in the air cooler can be automatically discharged into the condensing part by relying on the gravity difference, so as to avoid the influence of equipment freezing and blocking on production. BRIEF DESCRIPTION OF DRAWINGS

[0017] The specific structure of the present application is shown in the following drawings and examples:

[0018] Figure 1 is a structural schematic diagram of the present application;

[0019] Figure 2 is a structural schematic diagram of the secondary platform.

[0020] Legend: 1. Condensing part, 2. Spray pipe, 3. Liquid guide device, 4. Cofferdam, 5. Flash tank, 6. Liquid conveying pipe, 7. Base, 8. Liquid outlet pipe, 9. Water outlet pipe, 10. Booster pump, 11. Liquid outlet guide pipe, 12. Circulating pump, 13. Primary platform, 14. Secondary platform, 14-1. Limiting frame, 14-2. Flap, 14-3. Push-pull device, 14-4. Extension plate, 14-5. Bottom plate, 14-6. Shaft, 14-7. Mounting seat, 15. Water return pipe, 16. Air cooler, 17. Water conveying pipe, 18. Non-condensable gas guide pipe, 19. Sieve plate tray group, 20. Air guide pipe. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Example: Figure 1 As shown, a skid-mounted treatment device for waste gas from heavy oil thermal recovery includes a base 7. A detachable flash tank 5 is provided on one side of the base 7. A primary platform 13 and a secondary platform 14, which are higher than the base, are provided on the other side of the base 7. A detachable air cooler 16 is provided on the secondary platform 14. The liquid inlet of the flash tank 5 is connected to a liquid delivery pipe 6. A gas guide pipe 20, which is connected to the interior of the flash tank 5, is provided on the upper surface of the flash tank 5. A condenser section 1 with an internal cavity is covered by the gas guide pipe 20. A spray pipe 2 is provided on the upper side inside the condenser section 1. The spray pipe 2 is connected to the water outlet of the air cooler 16. The condenser section 1 above the spray pipe 2 is connected to a non-condensable gas outlet pipe 18. A dam 4 is formed between the gas guide pipe 20 and the lower part of the condenser section 1. The bottom of the dam 4 is connected to the water inlet of the air cooler 16.

[0024] Heavy oil thermal recovery produced fluid is fed into flash tank 5 through delivery pipe 6. The produced fluid changes from a high temperature and high pressure state to a low pressure environment, causing the liquid substances in the produced fluid to evaporate rapidly and transform into gaseous substances, which is called flash evaporation. During this process, a large amount of oil vapor and volatile organic compounds are generated. The oil vapor and volatile organic compounds enter the condenser section 1 through the gas guide pipe 20. After being cooled by spraying, most of the water vapor and some light oil vapor are condensed, and the resulting oil-water mixture falls into the dike 4. The light oil and some condensate on the upper layer of the dike 4 overflow back into flash tank 5 through the gas guide pipe 20. Non-condensable gas is discharged to the downstream processing system, such as a small pressure swing adsorption unit or a desulfurization + incineration unit, through non-condensable gas outlet pipe 18.

[0025] Furthermore, a liquid outlet pipe 8 is connected to the bottom of the flash tank 5, which is connected to the inlet of the booster pump 10. The outlet of the booster pump 10 is connected to the liquid outlet pipe 11, and a control valve is installed on the liquid outlet pipe 8. Part of the produced liquid, a small amount of condensed light oil, and condensate entering the flash tank 5 are transported to the downstream heavy oil processing station via the booster pump 10.

[0026] Further, the circulating pump 12 is arranged on the first platform 13, and is used to deliver high-temperature circulating water to the air cooler 16, and the air cooler 16 is used to cool the high-temperature circulating water to below 55℃ to form low-temperature circulating water which is sprayed from the spraying pipe 2 to exchange heat with the oil-containing steam and volatile organic compounds. The inlet of the circulating pump 12 is communicated with the bottom of the cofferdam 4 through the outlet pipe 9, and the outlet of the circulating pump 12 is communicated with the water inlet end of the air cooler 16 through the return pipe 15.

[0027] Further, the water inlet end and the water outlet end of the air cooler 16 are communicated with hoses, and the two hoses are respectively communicated with the water supply pipe 17 and the return pipe 15 through joints. The water supply pipe 17 is communicated with the spraying pipe 2.

[0028] Further, as shown in the figure, Figure 2 the second platform 14 is a platform with a changeable inclination angle. By changing the inclination of the second platform 14, the air cooler 16 can be arranged at an inclination of 5° to 10°, so that the water outlet end of the air cooler 16 is formed as the lowest end, and thus in the case of power failure or other emergency, the circulating water will not be retained in the air cooler 16, and damage can be avoided.

[0029] Further, the second platform includes a bottom plate 14-5, a reversible flap 14-2 is rotatably connected to one end of the bottom plate 14-5, and a push-pull device 14-3 for pushing and pulling the flap 14-2 to turn over is arranged at the other end of the bottom plate 14-5. The air cooler 16 is detachably mounted on the upper surface of the flap 14-2. The push-pull device 14-3 is a hydraulic arm, including a cylinder and a telescopic arm. The push-pull device 14-3 can also be other suitable push-pull devices with telescopic structure.

[0030] Further, symmetric mounting seats 14-7 are arranged at one end of the bottom plate 14-5, shaft holes are formed in the mounting seats 14-7, the two ends of the shaft 14-6 are rotatably connected to the shaft holes, one end of the flap 14-2 is fixedly connected to the surface of the shaft 14-6, and the other end of the flap 14-2 is connected to the upper end of the push-pull device 14-3 through a universal joint.

[0031] Further, an extension plate 14-4 lower than the bottom plate 14-5 is fixedly connected to the rear side of the bottom plate 14-5 (i.e. the same side direction as the water inlet end of the air cooler 16), and the bottom plate 14-5 and the extension plate 14-4 form a height difference. The lower end of the push-pull device 14-3 is connected to the bottom plate 14-5 through a universal joint. The space formed by the height difference between the bottom plate 14-5 and the extension plate 14-4 is used to install the push-pull device 14-3. When the push-pull device 14-3 is retracted to the lowest stroke, the flap 14-2 is in contact with the bottom plate 14-5.

[0032] Further, the universal joint comprises a cavity ball seat fixed on the lower surface of the turning plate 14-2 and the upper surface of the bottom plate 14-5, the cavity ball seat has a spherical cavity, and the surface of the cavity ball seat is provided with an opening in communication with the spherical cavity; the upper end of the push-pull device 14-3 is fixed with a ball head which is inserted into the spherical cavity, and the diameter of the ball head is smaller than the diameter of the spherical cavity and larger than the inner diameter of the opening.

[0033] [0031 Similarly, the universal joint comprises a cavity ball seat fixed on the upper surface of the extension plate 14-4, the cavity ball seat has a spherical cavity, and the surface of the cavity ball seat is provided with an opening in communication with the spherical cavity; the lower end of the push-pull device 14-3 is fixed with a ball head which is inserted into the spherical cavity, and the diameter of the ball head is smaller than the diameter of the spherical cavity and larger than the inner diameter of the opening.

[0034] Further, the left and right sides of the bottom plate 14-5 are respectively provided with a push-pull device 14-3, and the upper and lower ends of the push-pull device 14-3 are connected in the same way as described above. This way makes the turning plate 14-2 bear force on both sides, giving the turning plate 14-2 stable support.

[0035] Further, the upper surface of the turning plate 14-2 is provided with a mounting position surrounded by a limiting frame 14-1, and the air cooler 16 is detachably mounted in the mounting position. The limiting frame 14-1 can limit the air cooler 16, preventing the fixing screws for mounting the air cooler 16 from loosening or coming off and causing the air cooler 16 to slide.

[0036] Further, the liquid guide device 3 is arranged above the gas guide pipe 20, and is used to guide the condensed liquid into the cofferdam 4. The liquid guide device 3 comprises a protruding part, and the periphery of the protruding part is located directly above the opening of the cofferdam 4. After the oil-containing steam and volatile organic compounds are exchanged with the spray water, the oil-water mixture formed falls from the periphery of the liquid guide device 3 into the cofferdam 4, thereby avoiding the oil-water mixture from directly entering the flash tank 5 through the gas guide pipe 20.

[0037] Further, the upper part of the condensing part 1 between the spray pipe 2 and the liquid guide device 3 is provided with a sieve plate tray group 19, and the sieve plate tray group 19 comprises at least two upper and lower sieve plates with sieve holes, and the sieve holes on the adjacent upper and lower sieve plates are staggered. The oil-containing steam and volatile organic compounds rise from below the sieve plate tray group 19 and pass through the sieve holes; the spray water is sprayed from above to the sieve plate tray group 19 and flows horizontally on the sieve plate. The gas-liquid two-phase is in close contact on the sieve plate through bubbling, and the gas-liquid contact is sufficient, thereby realizing mass transfer and heat transfer, and most of the water vapor and part of the light oil vapor are condensed.

[0038] The pump speed can be dynamically adjusted by the frequency converter of the circulating pump 12 to maintain the liquid level in the cofferdam 4 below the condensate water overflow and evacuation, and when the liquid level in the cofferdam 4 is below 35%, the circulating pump 12 reduces the frequency, and when the liquid level is higher than 65%, the circulating pump 12 increases the frequency.

[0039] The air speed of the air cooler 16 is adjusted by the frequency converter of the fan to control the inlet temperature of the non-condensable gas discharge pipe 18 to be ≤55℃, and when the low-temperature circulating water temperature is higher than 58℃, the air cooler fan increases the frequency, and when the temperature is lower than 52℃, the fan reduces the frequency.

[0040] The present application achieves high integration and flexibility: the plug-in design highly integrates the core equipment, integrates the flash tank 5, the condensing part 1, the air cooler 16, the circulating pump 12, the control system, etc. in a single sled, and is suitable for large / small interface station scenarios; greatly reduces the site civil engineering, installation workload and time, and reduces the overall investment cost; supports overall hoisting migration, has low reuse cost, and completely solves the problems of low disassembly and assembly efficiency of split equipment and high secondary implementation cost.

[0041] The present application designs a platform with a changeable inclination angle through the secondary platform 14, changes the gravity difference by changing the inclination angle, and when a sudden power failure occurs, the circulating water in the air cooler 16 is automatically discharged into the condensing part 1 through the spray pipe, thereby eliminating the risk of freezing and blocking of the air cooler 16.

[0042] The present application can realize frequency control and interlocking logic of key parameters through frequency control and PLC / DCS system, and then realize adjustment of the working frequency of the circulating pump 12 and the air cooler 16, so as to realize full-automatic unattended operation, and manual intervention is reduced by more than 90%. The frequency control and PLC / DCS system are prior art, and are not the invention points of the present application, and are not described in detail here.

[0043] The above technical features constitute an embodiment of the present application, which has strong adaptability and implementation effect, and unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.

Claims

1. A skid-mounted device for treating exhaust steam in heavy oil thermal recovery, characterized in that: The base is provided with a detachable flash tank on one side, a first stage platform and a second stage platform higher than the base on the other side, and a detachable air cooler on the second stage platform. The liquid inlet of the flash tank is communicated with the liquid delivery pipe. The upper surface of the flash tank is provided with a gas guide pipe communicated with the inside of the flash tank. The gas guide pipe is covered with a cavity condenser. The upper side of the condenser is provided with a spray pipe communicated with the water outlet of the air cooler. The condenser above the spray pipe is communicated with the non-condensed gas outlet pipe. The gas guide pipe and the lower part of the condenser form a cofferdam. The bottom of the cofferdam is communicated with the water inlet of the air cooler. ​ The second stage platform is a platform with changeable inclination angle. The inclination change of the second stage platform enables the air cooler to be arranged at an inclination angle of 5°-10°. The liquid outlet of the air cooler forms the lowest end.

2. The device for treating exhaust steam of heavy oil thermal recovery according to claim 1, characterized in that: The bottom of the flash tank is communicated with a liquid outlet pipe. The liquid outlet pipe is communicated with the liquid inlet of the lifting pump. The liquid outlet of the lifting pump is communicated with the liquid outlet pipe. The liquid outlet pipe is provided with a control valve.

3. The device for treating exhaust steam of heavy oil thermal recovery according to claim 1, characterized in that: The first stage platform is provided with a circulating pump. The circulating pump is used to pressurize and deliver high temperature circulating water to the air cooler. The air cooler is used to cool the high temperature circulating water to below 55°C to form low temperature circulating water which is sprayed from the spray pipe to exchange heat with the oil-containing steam and volatile organic compounds. The liquid inlet of the circulating pump is communicated with the bottom of the cofferdam through a water outlet pipe. The liquid outlet of the circulating pump is communicated with the water inlet of the air cooler through a backwater pipe.

4. The device for treating exhaust steam of heavy oil thermal recovery according to claim 1 or 3, characterized in that: The water inlet and the water outlet of the air cooler are communicated with hoses. The two hoses are respectively communicated with the water delivery pipe and the backwater pipe through joints. The water delivery pipe is communicated with the spray pipe.

5. The device for treating exhaust steam of heavy oil thermal recovery according to claim 1, characterized in that: The second stage platform includes a bottom plate. A reversible flap is rotatably connected to one end of the bottom plate. A push-pull device for pushing and pulling the flap to turn over is arranged at the other end of the bottom plate. An installation position surrounded by a limiting frame is arranged on the upper surface of the flap. The air cooler is detachably installed in the installation position.

6. The device for treating exhaust steam of heavy oil thermal recovery according to claim 5, characterized in that: Symmetrical mounting seats are arranged at one end of the bottom plate. Shaft holes are formed in the mounting seats. The two ends of the shaft are rotatably connected to the shaft holes. One end of the flap is fixedly connected to the surface of the shaft. The other end of the flap is connected to the upper end of the push-pull device through a universal joint.

7. The device for treating exhaust steam of heavy oil thermal recovery according to claim 5, characterized in that: An extension plate lower than the bottom plate is fixedly connected to the rear side of the bottom plate. The bottom plate and the extension plate form a height difference. The lower end of the push-pull device is connected to the bottom plate through a universal joint.

8. The device for treating exhaust steam of heavy oil thermal recovery according to claim 1, characterized in that: A liquid guide device is arranged above the gas guide pipe. The liquid guide device is used to guide the condensed liquid into the cofferdam. The liquid guide device includes a protruding part. The periphery of the protruding part is located directly above the opening of the cofferdam.

9. The device for treating exhaust steam of heavy oil thermal recovery according to claim 8, characterized in that: A sieve plate tray group is arranged in the upper part of the condenser between the spray pipe and the liquid guide device. The sieve plate tray group includes at least two sieve plates arranged in an upper and lower manner and having sieve holes. The sieve holes on the adjacent upper and lower sieve plates are offset relative to each other.

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