Oil-gas-water on-site treatment integrated device

Abstract

The invention relates to the technical field of oil-gas-water treatment equipment, in particular to an oil-gas-water on-site treatment integrated device which comprises an oil-gas-water separator and a cyclone separator, and the oil-gas-water separator comprises a free water separation cavity, a produced water buffer cavity, a low-water-content oil buffer cavity, a first-stage air floatation cavity, a second-stage air floatation cavity, an inclined plate cavity, a floating oil cavity and a water purification cavity; the cyclone separator is communicated with the free water separation cavity; a low-water-content oil buffer cavity is arranged below the produced water buffer cavity; air flotation center cylinders are arranged in the first-stage air flotation cavity and the second-stage air flotation cavity; a floating oil cavity is arranged below the inclined plate cavity; the purified water cavity is connected with a purified water outlet pipe; the purified water outlet pipe is connected with the dissolved air pump, the dissolved air pump is further connected with the oil-gas-water separator and the bubble filter, the top of the bubble filter is communicated with the top of the oil-gas-water separator, and the side faces of the bubble filter are connected with the two dissolved air releasers respectively. According to the invention, a station is formed by one skid, oil-gas-water three-site treatment is realized, the technological process occupies a small area, intensification is realized, the auxiliary process is simplified, and the working efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas water treatment equipment, and particularly to an integrated device for on-site treatment of oil, gas and water. Background Art

[0002] With the continuous development of old oilfields, most old oilfields have entered the high water cut development stage. The water cut of the produced fluid from oil wells is increasing continuously. The water cut of some oil wells reaches more than 95%. This brings huge pressure to the existing gathering and transportation systems and produced water treatment systems, and causes serious energy consumption. In order to achieve on-site water separation, on-site treatment and on-site reinjection in high water cut oilfields, the present invention proposes an integrated device for on-site treatment of oil, gas and water. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the existing technology and propose to design an integrated device for on-site treatment of oil, gas and water, which integrates functions such as oil, gas and water separation and produced water treatment.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows: An integrated device for on-site treatment of oil, gas and water includes an oil-gas-water separator and a hydrocyclone separator. The oil-gas-water separator includes a free water separation chamber, a produced water buffer chamber, a low water cut oil buffer chamber, a primary flotation chamber, a secondary flotation chamber, an inclined plate chamber, a floating oil chamber and a purified water chamber. One side of the hydrocyclone separator is provided with an oil-gas-water mixture inlet. The top of the hydrocyclone separator is connected to the free water separation chamber through an associated gas pipe, and one side of the lower part is connected to the free water separation chamber through a liquid inlet pipe. The free water separation chamber is connected to the produced water buffer chamber through a water level regulator A. Below the produced water buffer chamber is the low water cut oil buffer chamber. A primary flotation central cylinder is arranged in the primary flotation chamber, and a secondary flotation central cylinder is arranged in the secondary flotation chamber. An inclined plate group is arranged in the inclined plate chamber, and below the inclined plate chamber is the floating oil chamber. The purified water chamber is connected to the inclined plate chamber through a water level regulator B, and the purified water chamber is connected to a purified water outlet pipe. The purified water outlet pipe is connected to the inlet pipe of a dissolved air pump through a dissolved air pump inlet water pipe. The inlet pipe of the dissolved air pump is also connected to the top of the oil-gas-water separator through an air flotation gas pipe. Water and air flotation gas are mixed in the inlet pipe of the dissolved air pump and then enter the dissolved air pump for pressurization to increase the solubility of gas in water. The outlet of the dissolved air pump is connected to a bubble sieve through a dissolved air pump outlet water pipe. The top of the bubble sieve is connected to the top of the oil-gas-water separator through a surplus gas return pipe, so that the surplus air flotation gas can return to the cavity of the oil-gas-water separator through the pipeline. The side of the bubble sieve is connected to two dissolved air release devices through dissolved air liquid pipes respectively. The inlet of one dissolved air release device is connected to the primary flotation chamber through a secondary flotation inlet water pipe, and the outlet is connected to the secondary flotation central cylinder. The inlet of the other dissolved air release device is connected to the produced water buffer chamber through a primary flotation inlet water pipe, and the outlet is connected to the primary flotation central cylinder. After the dissolved air liquid is released by the dissolved air release device, a large number of micron-sized bubbles are generated, so that impurities such as emulsions and fine suspended particles in the produced water adhere to the bubbles and float to the water surface together with the bubbles. During operation, the incoming liquid realizes the three-phase separation of oil, gas and water through the hydrocyclone separator and the free water separation chamber. The separated produced water is purified through the primary flotation chamber, the secondary flotation chamber and the inclined plate chamber. Natural gas and low water cut oil are transported out, and the produced water goes to the water injection system. One skid forms a station, realizing the on-site treatment of oil, gas and water. The process flow occupies a small area, is intensive, the auxiliary process is simplified, and the working efficiency of the whole process flow is high.

[0005] Further, a sand collection bag is arranged at the bottom of the free water separation chamber. The sand collection bag is connected to a sewage discharge pipe, and the sediment at the bottom of the free water separation chamber is discharged through the sewage discharge pipe.

[0006] Further, sewage outlets are arranged at the bottoms of the low water cut oil buffer chamber, the primary flotation chamber, the secondary flotation chamber, the floating oil chamber and the purified water chamber. The sewage outlets are all connected to the sewage discharge pipe. The sediment at the bottoms of the low water cut oil buffer chamber, the primary flotation chamber, the secondary flotation chamber, the floating oil chamber and the purified water chamber is discharged through the sewage discharge pipe.

[0007] Furthermore, the bottom of the low-water-content oil buffer chamber is connected to the low-water-content oil main outlet pipe through the low-water-content oil outlet pipe, and the low-water-content emulsified oil flows into the low-water-content oil main outlet through the low-water-content oil outlet.

[0008] Furthermore, the liquid inlet pipe is connected to the low-water-content oil main outlet pipe through a liquid inlet bypass pipe. The liquid inlet bypass pipe can adjust the water content fluctuation of the incoming liquid to cause the water content change of the externally transmitted water.

[0009] Furthermore, the bottom of the oil floating cavity is connected to the low-water oil main oil outlet pipe through the oil floating outlet pipe, and the oil floating enters the oil floating cavity and is discharged through the oil floating outlet.

[0010] Furthermore, a liquid separation bag is arranged on the top of the free water separation chamber, and a vent is arranged on one side of the liquid separation bag to meet the overpressure release requirement, and the top is connected to the low water content oil main outlet pipe through a gas outlet pipe. After being separated by the liquid separation bag, the associated gas is introduced into the low water content oil main outlet pipe through the gas outlet pipe, and mixed with the low water content oil and gas to be transported to the downstream processing station.

[0011] Furthermore, the first-stage air flotation chamber and the second-stage air flotation chamber are provided with oil collecting grooves, and the floating oil enters the floating oil chamber through the oil collecting grooves.

[0012] Furthermore, a free water separation chamber overflow weir is provided between the free water separation chamber and the produced water buffer chamber.

[0013] Technical effects of the present invention: Compared with the prior art, the present invention provides an integrated device for on-site treatment of oil, gas and water. The low-water oil separated after treatment is transported to the downstream joint station for treatment. The produced water can be reinjected on-site after reaching the water injection index to meet the needs of oil reservoir development. The produced water of the oil field is transformed from a "large cycle" to a "small cycle", and from a long process to a short process, which greatly reduces the energy consumption of round-trip transportation of produced water and reduces the load of the downstream produced water treatment station. The device is a station built on a skid, which realizes on-site treatment of oil, gas and water. The process occupies a small area, is intensive, has simplified auxiliary processes, and has a high removal efficiency for the entire process. It has good economic and environmental benefits for oil fields with high water content and ultra-high water content in the late stage of development. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structural principle of the integrated device for on-site treatment of oil, gas and water of the present invention.

[0015] Figure 2 It is a side view of the oil floating chamber of the present invention.

[0016] In the figure, 1 is the inlet of the oil-gas-water mixture; 2 is the hydrocyclone separator; 3 is the liquid inlet pipe; 4 is the associated gas pipe; 5 is the free water separation chamber; 6 is the produced water buffer chamber; 7 is the low water cut oil buffer chamber; 8 is the first-stage air flotation chamber; 9 is the second-stage air flotation chamber; 10 is the inclined plate chamber; 11 is the floating oil chamber; 12 is the clean water chamber; 13 is the first-stage air flotation central cylinder; 14 is the second-stage air flotation central cylinder; 15 is the inclined plate group; 16 is the water level regulator A; 17 is the water level regulator B; 18 is the overflow weir plate of the free water separation chamber; 19 is the oil collection tank; 20 is the low water cut oil outlet pipe; 21 is the liquid inlet bypass pipe; 22 is the total low water cut oil outlet pipe; 23 is the floating oil outlet pipe; 24 is the sewage discharge pipe; 25 is the dissolved air pump; 26 is the inlet pipe of the dissolved air pump; 27 is the outlet pipe of the dissolved air pump; 28 is the bubble sieve; 29 is the dissolved air liquid pipe; 30 is the inlet pipe of the first-stage air flotation; 31 is the inlet pipe of the second-stage air flotation; 32 is the dissolved air release device; 33 is the liquid separation package; 34 is the vent port; 35 is the air flotation gas pipe; 36 is the surplus gas return pipe; 37 is the gas outlet pipe; 38 is the sand collection package; 39 is the clean water outlet pipe. Detailed implementation mode

[0017] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the specification.

[0018] Embodiment 1: As Figure 1 shown, an integrated on-site treatment device for oil, gas and water involved in this embodiment includes an oil-gas-water separator and a hydrocyclone separator 2. The oil-gas-water separator includes a free water separation chamber 5, a produced water buffer chamber 6, a low water cut oil buffer chamber 7, a first-stage air flotation chamber 8, a second-stage air flotation chamber 9, an inclined plate chamber 10, a floating oil chamber 11 and a clean water chamber 12.

[0019] One side of the hydrocyclone separator 2 is provided with an inlet 1 of the oil-gas-water mixture. The top of the hydrocyclone separator 2 is connected to the free water separation chamber 5 through the associated gas pipe 4, and the lower part on one side is connected to the free water separation chamber 5 through the liquid inlet pipe 3. The incoming oil-gas-water mixture enters the hydrocyclone separator 2. The separated associated gas passes through the associated gas pipe 4, and the separated incoming liquid enters the free water separation chamber 5 through the liquid inlet pipe 3, and free water separation is carried out under the action of gravity.

[0020] A free water separation weir plate 18 is provided between the free water separation chamber 5 and the produced water buffer chamber 6. Below the produced water buffer chamber 6 is a low water cut oil buffer chamber 7. The bottom of the low water cut oil buffer chamber 7 is connected to the low water cut oil main outlet pipe 22 through a low water cut oil outlet pipe 20. The low water cut emulsified oil overflows to the low water cut oil buffer chamber 7 through the free water separation weir plate 18 and is collected into the low water cut oil main outlet pipe 22 through the low water cut oil outlet pipe 20. The free water separation chamber 5 and the produced water buffer chamber 6 are also connected through a water level regulator A16. A liquid separation package 33 is provided at the top of the free water separation chamber 5. An air vent 34 is provided on one side of the liquid separation package 33. The top of the liquid separation package 33 is connected to the low water cut oil main outlet pipe 22 through a gas outlet pipe 37. The associated gas is separated by the liquid separation package 33 and is collected into the low water cut oil main outlet pipe 22 through the gas outlet pipe 37.

[0021] A first-stage air flotation central cylinder 13 is provided in the first-stage air flotation chamber 8, and a second-stage air flotation central cylinder 14 is provided in the second-stage air flotation chamber 9. Oil collection troughs 19 are provided in the first-stage air flotation chamber 8 and the second-stage air flotation chamber 9. The generated floating oil enters the floating oil chamber 11 through the oil collection troughs 19.

[0022] The floating oil chamber 11 is located below the inclined plate chamber 10, and an inclined plate group 15 is provided in the inclined plate chamber 10; the purified water chamber 12 and the inclined plate chamber 10 are connected through a water level regulator B17. The purified water chamber 12 is connected to a purified water outlet pipe 39. The qualified treated produced water is discharged through the purified water outlet pipe 39 and sent to the water injection system.

[0023] The purified water outlet pipe 39 is connected to the inlet pipe of a dissolved air pump 25 through a dissolved air pump inlet pipe 26. The inlet pipe of the dissolved air pump 25 is also connected to the top of the oil-gas-water separator through an air flotation gas pipe 35. The outlet of the dissolved air pump 25 is connected to a bubble screening device 28 through a dissolved air pump outlet pipe 27. The top of the bubble screening device 28 is connected to the top of the oil-gas-water separator through a surplus gas return pipe 36. The side of the bubble screening device 28 is respectively connected to two dissolved air release devices 32 through a dissolved air liquid pipe 29; the inlet of one of the dissolved air release devices 32 is connected to the first-stage air flotation chamber 8 through a second-stage air flotation inlet pipe 31 and the outlet is connected to the second-stage air flotation central cylinder 14; the inlet of the other dissolved air release device 32 is connected to the produced water buffer chamber 6 through a first-stage air flotation inlet pipe 30 and the outlet is connected to the first-stage air flotation central cylinder 13.

[0024] A sand collection package 38 is provided at the bottom of the free water separation chamber 5. Drain ports are provided at the bottoms of the low water cut oil buffer chamber 7, the first-stage air flotation chamber 8, the second-stage air flotation chamber 9, the floating oil chamber 11 and the purified water chamber 12. The sand collection package 38 and all the drain ports are connected to a drain pipe 24.

[0025] The inlet pipe 3 is connected to the low water cut oil main outlet pipe 22 through a liquid inlet bypass pipe 21; the bottom of the floating oil chamber 11 is connected to the low water cut oil main outlet pipe 22 through a floating oil outlet pipe 23.

[0026] When the present invention is in use, the oil-gas-water mixed liquid enters the cyclone separator 2 through the oil-gas-water mixed liquid inlet 1, the associated gas separated by the cyclone separator 2 passes through the associated gas pipe 4, and the separated liquid enters the free water separation chamber 5 through the liquid inlet pipe 3, and the free water is separated under the action of gravity, and the low-water emulsified oil overflows to the low-water oil buffer chamber 7 through the overflow weir plate 18 of the free water separation chamber, and passes through the low-water oil outlet pipe 20, and is merged with the liquid inlet bypass pipe 21 to the low-water oil main outlet pipe 22. The function of the liquid inlet bypass pipe 21 is to adjust the water content fluctuation of the incoming liquid to cause the water content change of the external water. After the associated gas is separated by the liquid separation bag 33, it is merged into the low-water oil main outlet pipe 22 through the gas outlet pipe 37, and is mixed with the low-water oil and gas to the downstream processing station.

[0027] The produced water separated from the free water separation chamber 5 enters the produced water buffer chamber 6 through the water level regulator A16. The water in the produced water buffer chamber 6 enters the primary air flotation center tube 13 through the primary air flotation water inlet pipe 30, and is subjected to air flotation separation in the primary air flotation chamber 8. The generated floating oil enters the floating oil chamber 11 through the oil collecting tank 19 and is discharged through the floating oil outlet pipe 23. The produced water of the primary air flotation chamber 8 enters the secondary air flotation center tube 14 through the secondary air flotation water inlet pipe 31, and is subjected to air flotation separation in the secondary air flotation chamber 9. The generated floating oil enters the floating oil chamber 11 through the oil collecting tank 19. Specifically, as Figure 2 As shown, the floating oil enters the oil collecting tank 19 through the top of the oil collecting tank 19. The bottom of the oil collecting tank 19 slopes toward the floating oil chamber 11, so that the collected floating oil flows into the floating oil chamber 11 along the oil collecting tank 19. The secondary gas flotation water enters the inclined plate chamber 10 through the inclined plate group 15, and the inclined plate chamber 10 water enters the clean water chamber 12 after being regulated by the water level regulator B17. The treated qualified produced water is discharged to the water injection system through the clean water outlet pipe 39.

[0028] The water for flotation is taken from the treated water in the device. The inlet of the dissolved air pump 25 is provided with a flotation gas inlet pipe. The water in the dissolved air pump water inlet pipe 26 and the gas in the flotation gas pipe 35 are mixed in the flotation gas inlet pipe and then enter the dissolved air pump 25 for pressurization, and enter the bubble filter 28 through the dissolved air pump outlet pipe 27. The surplus flotation gas flows back to the flotation cavity through the surplus gas reflux pipe 36; the dissolved air liquid passes through the dissolved air liquid pipe 29 and is released by the dissolved air releaser 32, generating micron-level bubbles that fully contact with the incoming water in the central tube.

[0029] In order to meet the overpressure relief requirements of the entire container, a vent 34 is provided on the liquid separation package 33. When the pressure in the container exceeds the allowable pressure, the natural gas in the integrated device can be safely discharged to the venting system through the vent 34.

[0030] Each chamber of the entire oil-gas-water separator is provided with a sewage outlet, and a sand collecting bag 38 is provided at the bottom of the free water separation chamber 5, and regular sewage and sand removal can be achieved through the backwashing port and sewage outlet on the sand collecting bag 38. The flocculated sediments in the primary air flotation chamber 8, the secondary air flotation chamber 9, and the inclined plate chamber 10 are discharged through the sewage pipe 24.

[0031] The low-water-content oil buffer chamber 7 and the clean water chamber 12 are provided with liquid level gauges, and liquid level control is achieved through each outlet electric valve.

[0032] The present invention determines the cavity size in combination with actual production data. The incoming liquid is separated into gas and liquid by the vertical cyclone separator 2, and overflows to the low-water-content oil buffer chamber 7 after passing through the free water separation chamber 5. The separated associated gas is passed through the liquid separation bag 33 wire mesh mist collector and then merged into the low-water-content oil main outlet pipe 22. The produced water separated by the free water separation chamber 5 enters the produced water buffer chamber 6 after water level adjustment, and is further removed by the first-level flotation and second-level flotation oil removal and suspended matter removal, and then passes through the inclined plate chamber 10 to further remove small-sized oil droplets and suspended matter before entering the clean water chamber 12. The produced water is metered out of the skid. The present invention can realize the operations of low-water-content oil export and produced water purification in one cavity, relieves the pressure on the existing gathering and transportation system and produced water treatment system, reduces energy consumption, and can meet the needs of oil reservoir development.

[0033] The above-mentioned specific implementation modes are only specific cases of the present invention. The patent protection scope of the present invention includes but is not limited to the above-mentioned specific implementation modes. Any appropriate changes or modifications made thereto by any ordinary technician in the technical field in accordance with the claims of the present invention shall fall within the patent protection scope of the present invention.

Claims

1. An integrated device for on-site treatment of oil, gas and water, characterized in that It includes an oil-gas-water separator and a hydrocyclone separator. The oil-gas-water separator includes a free water separation chamber, a produced water buffer chamber, a low water cut oil buffer chamber, a primary air flotation chamber, a secondary air flotation chamber, an inclined plate chamber, a floating oil chamber and a clean water chamber. One side of the hydrocyclone separator is provided with an oil-gas-water mixture inlet. The top of the hydrocyclone separator is connected to the free water separation chamber through an associated gas pipe, and the lower part on one side is connected to the free water separation chamber through a liquid inlet pipe. The free water separation chamber is connected to the produced water buffer chamber through a water level regulator A. Below the produced water buffer chamber is the low water cut oil buffer chamber. A primary air flotation central cylinder is arranged in the primary air flotation chamber, and a secondary air flotation central cylinder is arranged in the secondary air flotation chamber. An inclined plate group is arranged in the inclined plate chamber, and below the inclined plate chamber is the floating oil chamber. The clean water chamber is connected to the inclined plate chamber through a water level regulator B, and the clean water chamber is connected to a clean water outlet pipe. The clean water outlet pipe is connected to the inlet pipe of a dissolved air pump through a dissolved air pump inlet pipe. The inlet pipe of the dissolved air pump is also connected to the top of the oil-gas-water separator through an air flotation gas pipe. The outlet of the dissolved air pump is connected to a bubble sieve through a dissolved air pump outlet pipe. The top of the bubble sieve is connected to the top of the oil-gas-water separator through a surplus gas return pipe. The side of the bubble sieve is respectively connected to two dissolved air release devices through dissolved air liquid pipes. The inlet of one dissolved air release device is connected to the primary air flotation chamber through a secondary air flotation inlet pipe and the outlet is connected to the secondary air flotation central cylinder. The inlet of the other dissolved air release device is connected to the produced water buffer chamber through a primary air flotation inlet pipe and the outlet is connected to the primary air flotation central cylinder.

2. The integrated on-site oil-gas-water treatment device according to claim 1, wherein A sand collection bag is arranged at the bottom of the free water separation chamber, and the sand collection bag is connected to a sewage discharge pipe.

3. The integrated on-site oil-gas-water treatment device according to claim 1, characterized in that Sewage discharge ports are arranged at the bottoms of the low water cut oil buffer chamber, the primary air flotation chamber, the secondary air flotation chamber, the floating oil chamber and the clean water chamber, and the sewage discharge ports are all connected to the sewage discharge pipe.

4. The integrated on-site oil-gas-water treatment device according to claim 1, characterized in that The bottom of the low water cut oil buffer chamber is connected to a low water cut oil total outlet pipe through a low water cut oil outlet pipe.

5. The integrated on-site oil-gas-water treatment device according to claim 1, characterized in that The liquid inlet pipe is connected to the low water cut oil total outlet pipe through a liquid inlet bypass pipe.

6. The integrated on-site oil-gas-water treatment device according to claim 1, wherein, The bottom of the floating oil chamber is connected to the low water cut oil total outlet pipe through a floating oil outlet pipe.

7. The integrated device for on-site treatment of oil, gas and water according to claim 1, characterized in that, A liquid separation bag is arranged at the top of the free water separation chamber. An air vent is arranged on one side of the liquid separation bag, and the top is connected to the low water cut oil total outlet pipe through a gas outlet pipe.

8. The integrated on-site oil-gas-water treatment device according to claim 1, characterized in that, Oil collection troughs are arranged in the primary air flotation chamber and the secondary air flotation chamber.

9. The integrated device for on-site treatment of oil, gas and water according to any one of claims 1-8, characterized in that, A free water separation chamber overflow weir plate is arranged between the free water separation chamber and the produced water buffer chamber.

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