Skid-mounted dirty oil stabilizing treatment device and method

Abstract

The invention provides a skid-mounted sump oil stabilizing treatment device and method. In the skid-mounted dirty oil stabilizing treatment device, a three-phase separator, a stable gas separator, a dirty oil lifting pump, a dirty oil stabilizing tower, a stable oil air cooler, a stable gas air cooler and a heat exchanger are all mounted on a skid body, the dirty oil lifting pump is connected with an external dirty oil tank and connected with the dirty oil stabilizing tower, the dirty oil stabilizing tower is connected with the three-phase separator, and the three-phase separator is connected with the stable gas air cooler. The three-phase separator is connected with the heat exchanger, the heat exchanger is connected with the sump oil stabilizing tower, the sump oil stabilizing tower is connected with the heat exchanger, the heat exchanger is connected with one end of the stabilized oil air cooler, the other end of the stabilized oil air cooler is connected with an external sump oil storage tank, and the sump oil stabilizing tower is connected with the three-phase separator. The three-phase separator and the sump oil stabilizing tower are connected with one end of the stable gas air cooler, the other end of the stable gas air cooler is connected with the stable gas separator, and the stable gas separator is connected with external gas collecting equipment.

Description

Technical Field

[0001] The invention relates to the technical field of waste oil treatment after separation of produced water from oil and gas fields, and in particular to a skid-mounted waste oil stabilization treatment device and method. Background Art

[0002] As the development of gas fields enters the stable production stage, the oil content in gas field produced water increases. The volume ratio of oil in gas field produced water is about 8-32%. As a byproduct of gas field produced water, a large amount of hydrocarbon waste oil has a certain recycling value, but because this type of waste oil contains light components such as C1-C4, which are highly volatile and have high vapor pressure at room temperature, and some waste oil also contains H2S and CO2, in order to prevent environmental pollution caused by oil and gas evaporation loss and safety hazards during storage and transportation, it is necessary to stabilize the hydrocarbon waste oil, that is, to separate C1-C4 from the hydrocarbon waste oil, and at the same time reduce the content of H2S and CO2, and stipulate that the vapor pressure at the highest storage temperature after stabilization should not be greater than 0.7 times the local air pressure.

[0003] Considering environmental, safety and economic factors, when the mass fraction of C1-C4 in the waste oil is higher than 0.5%, stabilization treatment must be carried out. The purpose is to make the stabilized waste oil relatively stable under storage and transportation conditions, reduce evaporation loss, reduce environmental pollution, and improve development benefits. There is no device for stabilizing hydrocarbon waste oil in the prior art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a skid-mounted waste oil stabilization treatment device and method in view of the deficiencies in the prior art.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a skid-mounted waste oil stabilization treatment device, comprising: a skid body, a three-phase separator, a stable gas separator, a waste oil lifting pump, a waste oil stabilization tower, a stable oil air cooler, a stable gas air cooler and a heat exchanger for heat exchange between unstabilized oil and stabilized oil, the three-phase separator, the stable gas separator, the waste oil lifting pump, the waste oil stabilization tower, the stable oil air cooler, the stable gas air cooler and the heat exchanger are all installed on the skid body, one end of the waste oil lifting pump is connected to an external waste oil tank through a pipeline, the other end of the waste oil lifting pump is connected to a first end of the waste oil stabilization tower through a pipeline, the second end of the waste oil stabilization tower is connected to a first end of the three-phase separator through a pipeline, and the second end of the three-phase separator is connected to a The first end of the waste oil stabilization tower is connected to the first end of the heat exchanger through a pipeline, the second end of the heat exchanger is connected to the third end of the waste oil stabilization tower through a pipeline, the fourth end of the waste oil stabilization tower is connected to the third end of the heat exchanger through a pipeline, the fourth end of the heat exchanger is connected to one end of the stable oil air cooler through a pipeline, the other end of the stable oil air cooler is connected to an external waste oil storage tank through a pipeline, the fifth end of the waste oil stabilization tower is connected to the third end of the three-phase separator through a pipeline, the fourth end of the three-phase separator and the sixth end of the waste oil stabilization tower are connected to one end of the stable gas air cooler through a pipeline, the other end of the stable gas air cooler is connected to the first end of the stable gas separator through a pipeline, and the second end of the stable gas separator is connected to an external gas collecting device through a pipeline.

[0006] The beneficial effects of the technical solution of the present invention are as follows: the three-phase separator is used for the preliminary sedimentation separation of water-containing waste oil and volatile natural gas. The stable gas separator is used for gas-liquid separation. The heat exchanger is used to perform heat exchange between the oil phase after three-phase separation and the oil phase after distillation, and to heat and raise the temperature of the low-temperature oil phase after three-phase separation to reduce energy consumption, and to cool the stable oil phase after distillation to facilitate external discharge and storage. The waste oil in the oil and gas field is stabilized, and the vapor pressure of the treated oil phase at the highest storage temperature is not greater than 0.7 times the local air pressure, so that the stabilized waste oil remains relatively stable under storage and transportation conditions, reducing evaporation loss, while reducing environmental pollution, facilitating recycling, and preventing environmental pollution caused by oil and gas evaporation loss and safety hazards during storage and transportation.

[0007] Furthermore, the waste oil stabilization tower includes: a top heat exchanger, a middle and lower structured packing section and a bottom reboiler, the middle and lower structured packing section is installed above the bottom reboiler, the top heat exchanger is installed above the middle and lower structured packing section, the top heat exchanger is connected to the other end of the waste oil lifting pump and the first end of the three-phase separator through pipelines, the middle and lower structured packing section is connected to the second end of the heat exchanger through a pipeline, and the first end of the bottom reboiler is connected to the third end of the heat exchanger through a pipeline.

[0008] The beneficial effects of adopting the above further technical solution are: the arrangement of the tower top heat exchanger, the middle and lower structured packing section and the tower bottom reboiler facilitates the oil-gas separation and stabilization treatment of the waste oil. The tower bottom reboiler uses the on-site heat transfer oil for heating, rationally utilizes energy, and saves energy.

[0009] Furthermore, the second end of the tower bottom reboiler, the fifth end of the three-phase separator and the sixth end of the three-phase separator are connected to the external sewage discharge equipment through the drainage pipeline, the third end of the tower bottom reboiler and the fourth end of the tower bottom reboiler are connected to the heat transfer oil inlet pipe and the heat transfer oil return pipe one by one, the oil temperature of the heat transfer oil in the heat transfer oil inlet pipe is 200°C, the oil temperature of the heat transfer oil in the heat transfer oil return pipe is 160°C, the temperature control range of the tower bottom reboiler is 100-130°C, and the heating temperature range of the tower top heat exchanger is 40-60°C.

[0010] The beneficial effect of adopting the above further technical solution is that the tower bottom reboiler is heated by using the on-site heat transfer oil, which makes reasonable use of energy and saves energy. The three-phase separator and the tower bottom reboiler are provided with a drain port at the bottom, and the discharged liquid enters the manifold and is connected to the outside of the device (external). The reboiler heating heat source is the heat transfer oil, and the tower bottom reboiler is heated by using the on-site heat transfer oil, which makes reasonable use of energy and saves energy.

[0011] Furthermore, the seventh end of the three-phase separator, the sixth end of the waste oil stabilization tower and the third end of the stable gas separator are all connected to an external venting system through pipelines.

[0012] The beneficial effect of adopting the above further technical solution is that a safety venting system is set on the top of the three-phase separator, the dirty oil stabilization tower and the stabilized gas separator, and is connected to the outside of the device by a header.

[0013] Furthermore, a vertical safety filter is provided on the pipeline between the waste oil lifting pump and the external waste oil tank, and a sewage inspection port is provided at the bottom of the vertical safety filter.

[0014] The beneficial effect of adopting the above further technical solution is that the vertical safety filter is used to filter solid impurities in the dirty oil to ensure that the subsequent process is carried out safely and smoothly.

[0015] Furthermore, a water chamber and an oil chamber are provided in the three-phase separator, the internal pressure value range of the three-phase separator is 0.4-0.6MPa, and the boost range of the waste oil lift pump is 0.4-0.6MPa.

[0016] The beneficial effect of adopting the above further technical solution is: after the pressure is stabilized, the liquid levels of the water chamber and the oil chamber are established, and liquid level regulating valves are provided at the outlets of the water chamber and the oil chamber, which are controlled by the water chamber and oil chamber liquid level transmitters respectively.

[0017] Furthermore, a first valve is provided on the pipeline between the bottom reboiler and the sewage discharge equipment, a second valve and a third valve are provided on the pipeline between the three-phase separator and the sewage discharge equipment, the oil chamber is connected to the third valve through a pipeline, a fourth valve is provided on the pipeline between the third valve and the oil chamber, a fifth valve and a sixth valve are provided on the pipeline between the waste oil stabilization tower and the three-phase separator, a seventh valve is provided on the pipeline between the top heat exchanger and the stable gas air cooler, an eighth valve is provided on the pipeline between the stable gas separator and the waste oil tank, a first valve group is provided on the pipeline between the top heat exchanger and the venting system, and a second valve group is provided on the pipeline between the stable gas separator and the venting system.

[0018] The beneficial effect of adopting the above further technical solution is that sensors and regulating valves (valves) are used in various parts of the device to control operating parameters such as temperature, pressure, liquid level, flow, etc. to ensure the stable operation of the device. A regulating valve is set in the heating pipeline, and the opening of the regulating valve of the heat transfer oil pipeline is adjusted by the temperature parameter of the reboiler (tower bottom reboiler) to adjust the heat transfer oil flow, so that the temperature of the reboiler can be controlled to operate within the set range. A regulating valve is set in the exhaust pipeline of the top of the stabilization tower (dirty oil stabilization tower), and the opening of the regulating valve of the exhaust pipeline of the top of the stabilization tower is adjusted by the tower top pressure parameter to adjust the exhaust flow, so that the pressure of the stabilization tower (dirty oil stabilization tower) operates within the set range. A regulating valve is set in the exhaust pipeline of the three-phase separator, and the opening of the regulating valve of the exhaust pipeline of the three-phase separator is adjusted by the pressure parameter of the three-phase separator to adjust the exhaust flow, so that the pressure of the three-phase separator operates within the set range. A regulating valve is set on the oil discharge pipeline of the three-phase separator. The opening of the regulating valve of the three-phase separator oil discharge pipeline is adjusted by the liquid level parameters of the three-phase separator oil chamber to adjust the oil discharge flow rate so that the liquid level of the three-phase separator oil chamber operates within the set range. A regulating valve is set on the drainage pipeline of the three-phase separator. The opening of the regulating valve of the three-phase separator drainage pipeline is adjusted by the oil-water interface parameters of the three-phase separator water chamber to adjust the drainage flow rate and on-off so that the water level of the three-phase separator water chamber operates within the set range and ensures the separation time of oil and water in the three-phase separator. A regulating valve is set on the oil discharge pipeline of the reboiler (tower bottom reboiler). The opening of the regulating valve of the reboiler oil discharge pipeline is adjusted by the liquid level parameters of the reboiler to adjust the oil discharge flow rate and on-off so that the liquid level of the reboiler operates within the set range. A regulating valve is set on the discharge pipeline of the gas-liquid separator (stable gas separator). The opening of the regulating valve of the gas-liquid separator discharge pipeline is adjusted by the liquid level parameter of the gas-liquid separator to adjust the discharge flow and on-off, so that the liquid level of the gas-liquid separator operates within the set range. A regulating valve is set on the exhaust pipeline of the gas-liquid separator. The opening of the regulating valve of the gas-liquid separator exhaust pipeline is adjusted by the pressure parameter of the gas-liquid separator to adjust the exhaust flow and on-off, so that the pressure of the gas-liquid separator operates within the set range.

[0019] Furthermore, the skid body is a double-layer skid structure having an upper layer and a lower layer, a ladder is provided on the skid body, two ends of the ladder are connected to the upper layer and the lower layer in a one-to-one manner, the three-phase separator, the stable gas separator and the dirty oil lifting pump are installed on the lower layer, and the dirty oil stabilization tower, the stable oil air cooler, the stable gas air cooler and the heat exchanger are installed on the upper layer.

[0020] The beneficial effects of adopting the above further technical solution are: the overall layout is a double-layer skid, and the upper and lower layers can be accessed by the ladder on the skid. The overall double-layer skid-mounted integrated explosion-proof design is adopted. The safety of the device is improved, the layout is compact, the floor space is small, and the construction period is short.

[0021] In addition, the present invention also provides a skid-mounted waste oil stabilization treatment method, based on any one of the skid-mounted waste oil stabilization treatment devices described above, the skid-mounted waste oil stabilization treatment method comprises:

[0022] S1, the waste oil lifting pump pressurizes the waste oil in the external waste oil tank and transports the waste oil to the waste oil stabilization tower;

[0023] S2, the waste oil stabilization tower heats the waste oil;

[0024] S3, three-phase separator to separate the waste oil by sedimentation, and separate the gas phase waste oil;

[0025] S4, the heat exchanger heats up the waste oil;

[0026] S5, the waste oil stabilization tower separates the waste oil into oil and gas to form liquid phase waste oil and gas phase waste oil;

[0027] S6, heat exchanger and stabilized oil air cooler cool the liquid phase dirty oil to form stabilized oil;

[0028] S7, stabilized oil enters external dirty oil storage tank;

[0029] S8, the stable gas air cooler cools down the gas phase waste oil separated by the three-phase separator and the waste oil stabilization tower to form stable gas;

[0030] S9, a stable gas separator performs cyclone separation on the stable gas;

[0031] S10, the stable gas enters the external gas collection equipment.

[0032] The beneficial effects of the technical solution of the present invention are as follows: the three-phase separator is used for the preliminary sedimentation separation of water-containing waste oil and volatile natural gas. The stable gas separator is used for gas-liquid separation. The heat exchanger is used to perform heat exchange between the oil phase after three-phase separation and the oil phase after distillation, and to heat and raise the temperature of the low-temperature oil phase after three-phase separation to reduce energy consumption, and to cool the stable oil phase after distillation to facilitate external discharge and storage. The waste oil in the oil and gas field is stabilized, and the vapor pressure of the treated oil phase at the highest storage temperature is not greater than 0.7 times the local air pressure, so that the stabilized waste oil remains relatively stable under storage and transportation conditions, reducing evaporation loss, while reducing environmental pollution, facilitating recycling, and preventing environmental pollution caused by oil and gas evaporation loss and safety hazards during storage and transportation.

[0033] Furthermore, step S3 includes: the three-phase separator and the tower bottom reboiler discharge the liquid in the three-phase separator and the waste oil stabilization tower to an external sewage discharge device through a drainage pipeline.

[0034] The beneficial effect of adopting the above further technical solution is that: a liquid discharge port is provided at the bottom of the three-phase separator and the tower bottom reboiler, and the discharged liquid enters the manifold and is connected to the outside of the device (exterior).

[0035] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic structural diagram of a skid-mounted waste oil stabilization treatment device provided in an embodiment of the present invention.

[0037] Figure 2 A schematic diagram of process automatic control of a skid-mounted waste oil stabilization treatment device provided in an embodiment of the present invention.

[0038] Figure 3 for Figure 2 One of the partial enlarged views of the structure shown.

[0039] Figure 4 for Figure 2 The second partial enlarged view of the structure shown.

[0040] Figure 5 for Figure 2 The third partial enlarged view of the structure shown.

[0041] Figure 6 for Figure 2 The fourth partial enlarged view of the structure shown.

[0042] Figure 7 for Figure 2 The fifth partial enlarged view of the structure shown.

[0043] Figure 8 A schematic flow chart of a skid-mounted waste oil stabilization treatment method provided in an embodiment of the present invention.

[0044] Explanation of the accompanying drawings: 1. Three-phase separator; 2. Stabilized oil air cooler; 3. Heat exchanger; 4. Tower bottom reboiler; 5. Waste oil stabilization tower; 6. Tower top heat exchanger; 7. Stabilized gas air cooler; 9. Waste oil lifting pump; 10. Stabilized gas separator; 11. Vertical safety filter; 12. Waste oil tank; 13. Gas collecting equipment; 14. Middle and lower structured packing section; 15. Sewage discharge equipment; 16. Thermal oil inlet pipe; 17. Thermal oil return pipe; 18. Venting system; 20. Water chamber; 21. Oil chamber; 22. First valve; 23. Second valve; 24. Third valve; 25. Fourth valve; 26. Fifth valve; 27. Sixth valve; 28. Seventh valve; 29. ​​Eighth valve; 30. First valve group; 31. Second valve group. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0046] like Figures 1 to 7 As shown, an embodiment of the present invention provides a skid-mounted waste oil stabilization treatment device, comprising: a skid body, a three-phase separator 1, a stable gas separator 10, a waste oil lifting pump 9, a waste oil stabilization tower 5, a stable oil air cooler 2, a stable gas air cooler 7, and a heat exchanger 3 for heat exchange between unstabilized oil and stabilized oil, wherein the three-phase separator 1, the stable gas separator 10, the waste oil lifting pump 9, the waste oil stabilization tower 5, the stable oil air cooler 2, the stable gas air cooler 7, and the heat exchanger 3 are all installed on the skid body, one end of the waste oil lifting pump 9 is connected to an external waste oil tank 12 through a pipeline, the other end of the waste oil lifting pump 9 is connected to a first end of the waste oil stabilization tower 5 through a pipeline, and the second end of the waste oil stabilization tower 5 is connected to a first end of the three-phase separator 1 through a pipeline. The third end of the three-phase separator 1 is connected to the first end of the heat exchanger 3 through a pipeline, the second end of the heat exchanger 3 is connected to the third end of the waste oil stabilization tower 5 through a pipeline, the fourth end of the waste oil stabilization tower 5 is connected to the third end of the heat exchanger 3 through a pipeline, the fourth end of the heat exchanger 3 is connected to one end of the stable oil air cooler 2 through a pipeline, the other end of the stable oil air cooler is connected to an external waste oil storage tank through a pipeline, the fourth end of the three-phase separator 1 and the sixth end of the waste oil stabilization tower 5 are connected to one end of the stable gas air cooler 7 through a pipeline, the other end of the stable gas air cooler 7 is connected to the first end of the stable gas separator 10 through a pipeline, and the second end of the stable gas separator 10 is connected to an external gas collecting device 13 through a pipeline.

[0047] The beneficial effects of the technical solution of the present invention are as follows: the three-phase separator is used for the preliminary sedimentation separation of water-containing waste oil and volatile natural gas. The stable gas separator is used for gas-liquid separation. The heat exchanger is used to perform heat exchange between the oil phase after three-phase separation and the oil phase after distillation, and to heat and raise the temperature of the low-temperature oil phase after three-phase separation to reduce energy consumption, and to cool the stable oil phase after distillation to facilitate external discharge and storage. The waste oil in the oil and gas field is stabilized, and the vapor pressure of the treated oil phase at the highest storage temperature is not greater than 0.7 times the local air pressure, so that the stabilized waste oil remains relatively stable under storage and transportation conditions, reducing evaporation loss, while reducing environmental pollution, facilitating recycling, and preventing environmental pollution caused by oil and gas evaporation loss and safety hazards during storage and transportation.

[0048] Among them, For gate valve, It is a stop check valve. It is a high-sealing sampling stop valve. For ball valve, For safety valve, It is a throttling stop vent valve. It is a regulating valve. T is temperature, transmission, M is moisture, P is pressure, C is control, L is liquid level, I is display, A is analysis, alarm, V is valve, F is flow, Y is relay, S is switch or interlock, B is nozzle flame, Z is state, R is record, H is manual trigger, Q is integration, U is multivariable, multi-function, and N is fault. For monitoring system, For field instruments, is an electrical signal line, CO is stable dirty oil, NG is process gas, PD is sewage discharge, SO is unstabilized dirty oil, RG is venting, HOS is heat transfer oil, and HOR is heat transfer oil return. E-02 is a stable oil air cooler, E-04 is a heat exchanger, E-01 is a tower top heat exchanger, T-01 is a dirty oil stabilization tower, E-03 is a stable gas air cooler, P-01 / AB is a dirty oil lifting pump, F-01 is a vertical safety filter, and V-02 is a stable gas separator.

[0049] A skid-mounted waste oil stabilization treatment device provided in an embodiment of the present invention can be a skid-mounted waste oil stabilization treatment device for oil and gas fields, which is mainly composed of a three-phase separator, a stabilized gas separator, a tower bottom reboiler, a vertical security filter, a waste oil lifting pump, a waste oil stabilization tower, a tower top heat exchanger, a stabilized oil air cooler, a stabilized gas air cooler, an unstabilized oil / stabilized oil heat exchanger (heat exchanger), a skid seat, and pipeline instruments, etc., which can also be increased or decreased for use. The vapor pressure of the treated oil phase at the highest storage temperature is not greater than 0.7 times the local air pressure.

[0050] The skid seat is the base for installing all the components of the skid-mounted waste oil stabilization treatment device. It has high strength and can lift the skid-mounted waste oil stabilization treatment device as a whole.

[0051] The present invention processes the skid-mounted waste oil stabilization treatment device into a skid-mounted integrated waste oil stabilization treatment device, and the overall layout is a double-layer skid, and the upper and lower layers can be accessed back and forth through the ladder on the skid. The bottom layer (lower layer) equipment includes a three-phase separator, a stabilized gas separator, a tower bottom reboiler, a vertical security filter and a waste oil lifting pump. The upper layer equipment includes a waste oil stabilization tower, a tower top heat exchanger, a stabilized oil air cooler, a stabilized gas air cooler and an unstabilized oil / stabilized oil heat exchanger (heat exchanger). There are also skid seats and pipeline instruments.

[0052] The invention has reasonable overall layout, simple process, good treatment effect, simple operation and maintenance, can realize stable treatment of waste oil in oil and gas fields, and has good economic efficiency.

[0053] The main function of the vertical security filter is to filter solid impurities in the dirty oil. The filter mesh is 30 meshes to ensure the safety and stability of the subsequent process. The vertical security filter enters from the top and exits from the bottom. One end of the top pipeline is connected to the dirty oil to be treated, and the other end is connected to the top of the filter (vertical security filter); the side pipeline at the bottom of the filter is the filter outlet, which is connected to the inlet of the dirty oil lifting pump; there is a sewage inspection port at the bottom of the filter. The dirty oil to be treated enters the vertical security filter from the top through the pipeline, and the filtered dirty oil flows out from the bottom side pipeline.

[0054] The waste oil stabilization tower, also known as the distillation tower, is mainly composed of a top heat exchanger, a middle and lower structured packing section, and a bottom reboiler.

[0055] The three-phase separator is mainly used for the preliminary sedimentation and separation of water-containing waste oil and volatile natural gas. After the waste oil enters the three-phase separator, the pressure of the three-phase separator is about 0.4-0.6MPa (if there is less flash volatile gas in the waste oil, the device is equipped with an off-site fuel gas pressure replenishment process, that is, the three-phase separator is connected to an off-site fuel gas pressure replenishment system). After the pressure stabilizes, the liquid levels of the water chamber and the oil chamber are established. The outlets of the water chamber and the oil chamber are both equipped with liquid level regulating valves, which are controlled by the water chamber and oil chamber liquid level transmitters respectively.

[0056] The main function of the stable gas separator is gas-liquid separation. The gas phase separated from the three-phase separator and the volatile gas at the top of the dirty oil stabilization tower pass through the stable gas air cooler and then enter the stable gas separator for cyclone liquid separation. Finally, the stable gas is transported to the gas gathering equipment (external gas gathering area) through the top of the stable gas separator.

[0057] The main function of the stabilizing oil air cooler is to further cool the waste oil after it has been cooled by the stabilizing oil heat exchanger. After reaching about 40°C, it leaves the waste oil stabilization device (skid-mounted waste oil stabilization treatment device) and enters the waste oil tank.

[0058] The main function of the stable gas air cooler is to cool down the gas phase separated by the three-phase separator and the volatile gas at the top of the waste oil stabilization tower (to about 40°C), and then enter the stable gas separator.

[0059] The main function of the unstabilized oil / stabilized oil heat exchanger (heat exchanger) is to perform heat exchange between the oil phase after three-phase separation and the oil phase after distillation, to heat the low-temperature oil phase after three-phase separation to reduce energy consumption, and to cool down the stable oil phase after distillation to facilitate external discharge and storage.

[0060] like Figures 1 to 7As shown, further, the waste oil stabilization tower 5 includes: a top heat exchanger 6, a middle and lower structured packing section 14 and a bottom reboiler 4, the middle and lower structured packing section 14 is installed above the bottom reboiler 4, the top heat exchanger 6 is installed above the middle and lower structured packing section 14, the top heat exchanger 6 is connected to the other end of the waste oil lifting pump 9 and the first end of the three-phase separator 1 through pipelines, the middle and lower structured packing section 14 is connected to the second end of the heat exchanger 3 through a pipeline, and the first end of the bottom reboiler 4 is connected to the third end of the heat exchanger 3 through a pipeline.

[0061] The beneficial effects of adopting the above further technical solution are: the arrangement of the tower top heat exchanger, the middle and lower structured packing section and the tower bottom reboiler facilitates the oil-gas separation and stabilization treatment of the waste oil. The tower bottom reboiler uses the on-site heat transfer oil for heating, rationally utilizes energy, and saves energy.

[0062] like Figures 1 to 7 As shown, further, the second end of the tower bottom reboiler 4, the fifth end of the three-phase separator 1 and the sixth end of the three-phase separator 1 are connected to the external sewage discharge equipment 15 through a drainage pipeline, the third end of the tower bottom reboiler 4 and the fourth end of the tower bottom reboiler 4 are connected to the heat transfer oil inlet pipe 16 and the heat transfer oil return pipe 17 one by one, the oil temperature of the heat transfer oil in the heat transfer oil inlet pipe 16 is 200°C, the oil temperature of the heat transfer oil in the heat transfer oil return pipe 17 is 160°C, the temperature control range of the tower bottom reboiler 4 is 100-130°C, and the heating temperature range of the tower top heat exchanger 6 is 40-60°C.

[0063] The beneficial effect of adopting the above further technical solution is that the tower bottom reboiler is heated by using the on-site heat transfer oil, which makes reasonable use of energy and saves energy. The three-phase separator and the tower bottom reboiler are provided with a drain port at the bottom, and the discharged liquid enters the manifold and is connected to the outside of the device (external). The reboiler heating heat source is the heat transfer oil, and the tower bottom reboiler is heated by using the on-site heat transfer oil, which makes reasonable use of energy and saves energy.

[0064] like Figures 1 to 7 As shown, further, the seventh end of the three-phase separator 1, the sixth end of the waste oil stabilization tower 5 and the third end of the stable gas separator 10 are all connected to the external venting system 18 through pipelines.

[0065] The beneficial effect of adopting the above further technical solution is that a safety venting system is set on the top of the three-phase separator, the dirty oil stabilization tower and the stabilized gas separator, and is connected to the outside of the device by a header.

[0066] like Figures 1 to 7As shown, further, a vertical safety filter 11 is provided on the pipeline between the dirty oil lifting pump 9 and the external dirty oil tank 12, and a sewage inspection port is provided at the bottom of the vertical safety filter 11.

[0067] The beneficial effect of adopting the above further technical solution is that the vertical safety filter is used to filter solid impurities in the dirty oil to ensure that the subsequent process is carried out safely and smoothly.

[0068] like Figures 1 to 7 As shown, further, a water chamber 20 and an oil chamber 21 are provided in the three-phase separator 1, the internal pressure value range of the three-phase separator 1 is 0.4-0.6MPa, and the boost range of the waste oil lift pump 9 is 0.4-0.6MPa.

[0069] The beneficial effect of adopting the above further technical solution is: after the pressure is stabilized, the liquid levels of the water chamber and the oil chamber are established, and liquid level regulating valves are provided at the outlets of the water chamber and the oil chamber, which are controlled by the water chamber and oil chamber liquid level transmitters respectively.

[0070] like Figures 1 to 7 As shown, further, a first valve 22 is provided on the pipeline between the bottom reboiler 4 and the sewage discharge equipment 15, a second valve 23 and a third valve 24 are provided on the pipeline between the three-phase separator 1 and the sewage discharge equipment 15, the oil chamber 21 is connected to the third valve 24 through a pipeline, a fourth valve 25 is provided on the pipeline between the third valve 24 and the oil chamber 21, a fifth valve 26 and a sixth valve 27 are provided on the pipeline between the waste oil stabilization tower 5 and the three-phase separator 1, a seventh valve 28 is provided on the pipeline between the top heat exchanger 6 and the stable gas air cooler 7, an eighth valve 29 is provided on the pipeline between the stable gas separator 10 and the waste oil tank 12, a first valve group 30 is provided on the pipeline between the top heat exchanger 6 and the venting system 18, and a second valve group 31 is provided on the pipeline between the stable gas separator 10 and the venting system 18.

[0071] The beneficial effect of adopting the above further technical solution is that sensors and regulating valves (valves) are used in various parts of the device to control operating parameters such as temperature, pressure, liquid level, flow, etc. to ensure the stable operation of the device. A regulating valve is set in the heating pipeline, and the opening of the regulating valve of the heat transfer oil pipeline is adjusted by the temperature parameter of the reboiler (tower bottom reboiler) to adjust the heat transfer oil flow, so that the temperature of the reboiler can be controlled to operate within the set range. A regulating valve is set in the exhaust pipeline of the top of the stabilization tower (dirty oil stabilization tower), and the opening of the regulating valve of the exhaust pipeline of the top of the stabilization tower is adjusted by the tower top pressure parameter to adjust the exhaust flow, so that the pressure of the stabilization tower (dirty oil stabilization tower) operates within the set range. A regulating valve is set in the exhaust pipeline of the three-phase separator, and the opening of the regulating valve of the exhaust pipeline of the three-phase separator is adjusted by the pressure parameter of the three-phase separator to adjust the exhaust flow, so that the pressure of the three-phase separator operates within the set range. A regulating valve is set on the oil discharge pipeline of the three-phase separator. The opening of the regulating valve of the three-phase separator oil discharge pipeline is adjusted by the liquid level parameters of the three-phase separator oil chamber to adjust the oil discharge flow rate so that the liquid level of the three-phase separator oil chamber operates within the set range. A regulating valve is set on the drainage pipeline of the three-phase separator. The opening of the regulating valve of the three-phase separator drainage pipeline is adjusted by the oil-water interface parameters of the three-phase separator water chamber to adjust the drainage flow rate and on-off so that the water level of the three-phase separator water chamber operates within the set range and ensures the separation time of oil and water in the three-phase separator. A regulating valve is set on the oil discharge pipeline of the reboiler (tower bottom reboiler). The opening of the regulating valve of the reboiler oil discharge pipeline is adjusted by the liquid level parameters of the reboiler to adjust the oil discharge flow rate and on-off so that the liquid level of the reboiler operates within the set range. A regulating valve is set on the discharge pipeline of the gas-liquid separator (stable gas separator). The opening of the regulating valve of the gas-liquid separator discharge pipeline is adjusted by the liquid level parameter of the gas-liquid separator to adjust the discharge flow and on-off, so that the liquid level of the gas-liquid separator operates within the set range. A regulating valve is set on the exhaust pipeline of the gas-liquid separator. The opening of the regulating valve of the gas-liquid separator exhaust pipeline is adjusted by the pressure parameter of the gas-liquid separator to adjust the exhaust flow and on-off, so that the pressure of the gas-liquid separator operates within the set range.

[0072] Among them, the first valve group 30 includes: a first gate valve, a second gate valve, a first safety valve, and a first throttling stop vent valve. One end of the first gate valve is connected to the vent system, the other end of the first gate valve is connected to one end of the first safety valve, the other end of the first safety valve is connected to one end of the second gate valve, and the other end of the second gate valve is connected to the top heat exchanger 6. The two ends of the first throttling stop vent valve are connected to one end of the first gate valve and the other end of the second gate valve in a one-to-one correspondence.

[0073] The second valve group 31 includes: a second safety valve, a third gate valve, a fourth gate valve, and a second throttling stop vent valve, one end of the third gate valve is connected to the stable gas separator, the other end of the third gate valve is connected to one end of the second safety valve, the other end of the second safety valve is connected to one end of the fourth gate valve, the other end of the fourth gate valve is connected to the venting system, and the two ends of the second throttling stop vent valve are connected to one end of the third gate valve and the other end of the fourth gate valve in a one-to-one correspondence.

[0074] like Figures 1 to 7 As shown, further, the skid body is a double-layer skid structure with an upper layer and a lower layer, a ladder is provided on the skid body, and the two ends of the ladder are connected to the upper layer and the lower layer one by one, the three-phase separator 1, the stable gas separator 10 and the dirty oil lifting pump 9 are installed on the lower layer, and the dirty oil stabilization tower 5, the stable oil air cooler 2, the stable gas air cooler 7 and the heat exchanger 3 are installed on the upper layer.

[0075] The beneficial effects of adopting the above further technical solution are: the overall layout is a double-layer skid, and the upper and lower layers can be accessed by the ladder on the skid. The overall double-layer skid-mounted integrated explosion-proof design is adopted. The safety of the device is improved, the layout is compact, the floor space is small, and the construction period is short.

[0076] like Figure 8 As shown, in addition, the present invention also provides a skid-mounted waste oil stabilization treatment method, based on a skid-mounted waste oil stabilization treatment device described in any one of the above, the skid-mounted waste oil stabilization treatment method comprises:

[0077] S1, the waste oil lifting pump pressurizes the waste oil in the external waste oil tank and transports the waste oil to the waste oil stabilization tower;

[0078] S2, the waste oil stabilization tower heats the waste oil;

[0079] S3, three-phase separator to separate the waste oil by sedimentation, and separate the gas phase waste oil;

[0080] S4, the heat exchanger heats up the waste oil;

[0081] S5, the waste oil stabilization tower separates the waste oil into oil and gas to form liquid phase waste oil and gas phase waste oil;

[0082] S6, heat exchanger and stabilized oil air cooler cool the liquid phase dirty oil to form stabilized oil;

[0083] S7, stabilized oil enters external dirty oil storage tank;

[0084] S8, the stable gas air cooler cools down the gas phase waste oil separated by the three-phase separator and the waste oil stabilization tower to form stable gas;

[0085] S9, a stable gas separator performs cyclone separation on the stable gas;

[0086] S10, the stable gas enters the external gas collection equipment.

[0087] The beneficial effects of the technical solution of the present invention are as follows: the three-phase separator is used for the preliminary sedimentation separation of water-containing waste oil and volatile natural gas. The stable gas separator is used for gas-liquid separation. The heat exchanger is used to perform heat exchange between the oil phase after three-phase separation and the oil phase after distillation, and to heat and raise the temperature of the low-temperature oil phase after three-phase separation to reduce energy consumption, and to cool the stable oil phase after distillation to facilitate external discharge and storage. The waste oil in the oil and gas field is stabilized, and the vapor pressure of the treated oil phase at the highest storage temperature is not greater than 0.7 times the local air pressure, so that the stabilized waste oil remains relatively stable under storage and transportation conditions, reducing evaporation loss, while reducing environmental pollution, facilitating recycling, and preventing environmental pollution caused by oil and gas evaporation loss and safety hazards during storage and transportation.

[0088] Furthermore, step S3 includes: the three-phase separator and the tower bottom reboiler discharge the liquid in the three-phase separator and the waste oil stabilization tower to an external sewage discharge device through a drainage pipeline.

[0089] The beneficial effect of adopting the above further technical solution is that: a liquid discharge port is provided at the bottom of the three-phase separator and the tower bottom reboiler, and the discharged liquid enters the manifold and is connected to the outside of the device (exterior).

[0090] The process flow is divided into two main lines, the waste oil treatment line and the gas treatment line, as well as sewage and venting lines.

[0091] Waste oil treatment line: The unstabilized waste oil (0-50℃, 0.1-0.3MPa) to be treated first enters the vertical safety filter to filter out impurities in the waste oil. The filtered waste oil passes through the lifting pump (waste oil lifting pump), and is pressurized to 0.4-0.6MPa by the shielded pump (waste oil lifting pump, used to provide operating pressure for the entire device), and then enters the waste oil stabilization tower top heat exchange coil (tower top heat exchanger) to be heated to about 40-60℃, and then enters the three-phase separator for sedimentation separation.

[0092] The separated waste oil enters the unstable oil / stable oil heat exchanger (heat exchanger) from the outlet of the oil chamber of the three-phase separator. After heating to about 60-75°C, it enters the waste oil stabilization tower from the middle part (middle and lower structured packing section), that is, the top of the packing. It meets the hot gas phase flowing up from below in the packing (middle and lower structured packing section) of the waste oil stabilization tower, absorbs the heat of the gas phase, heats up the original liquid phase, and cools down the original gas phase. The components with smaller molecular weight and lighter weight in the original liquid phase absorb heat and become gas phase and move upward; at the same time, the components with larger molecular weight and heavier weight in the original gas phase are liquefied and continue to flow downward. After such a complex mass transfer and heat transfer process, a mass transfer process in a temperature range is completed, and a temperature gradient with low temperature at the top and high temperature at the bottom is formed in the packing. At the same time, the component distribution of small molecules at the top and large molecules at the bottom is formed to separate the gas in the waste oil. The temperature control range of the bottom of the tower reboiler is 100-130°C.

[0093] The stabilized liquid waste oil flows out from the reboiler at the bottom of the tower, and is cooled to about 100 degrees Celsius through the waste oil-stabilized oil heat exchanger (heat exchanger), and then continues to be cooled to about 40 degrees Celsius through the waste oil air cooler (stabilized oil air cooler) before leaving the device.

[0094] Gas treatment line: The waste oil heated to about 40-60℃ by the heat exchange coil (tower top heat exchanger) at the top of the waste oil stabilization tower enters the three-phase separator for sedimentation separation. The separated gas phase and the volatile gas at the top of the waste oil stabilization tower are treated by the stabilized gas air cooler (cooled to about 40℃) and then enter the stabilized gas separator. After cyclone separation, the stabilized gas is transported to the gas collection equipment through the top of the stabilized gas separator.

[0095] Drainage: There are drain ports at the bottom of the three-phase separator and the tower bottom reboiler. The discharged liquid enters the manifold and is connected to the outside of the device.

[0096] Among them, the outside of the device refers to the outside of the skid-mounted waste oil stabilization treatment device as a whole, or is called the outside. The dotted box in the figure represents the boundary. The inside of the boundary is the various components of the skid-mounted waste oil stabilization treatment device, and the outside of the boundary is the outside of the skid-mounted waste oil stabilization treatment device as a whole. The skid-mounted waste oil stabilization treatment device is all installed on a skid seat. The outside of the skid is the outside of the device, that is, the outside of the device, or is called the outside or the outside.

[0097] Venting: A safety venting system (venting system) is installed on the top of the three-phase separator, the waste oil stabilization tower and the stabilized gas separator in the device (skid-mounted waste oil stabilization treatment device), and is connected to the outside of the device by a header.

[0098] Bottom reboiler heating: The heat source for the bottom reboiler is heat transfer oil, the incoming oil temperature is 200℃, and the return oil temperature is about 160℃.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A skid-mounted waste oil stabilization treatment device, characterized in that: include: A skid, a three-phase separator, a stable gas separator, a dirty oil lifting pump, a dirty oil stabilizing tower, a stable oil air cooler, a stable gas air cooler, and a heat exchanger for exchanging heat between unstabilized oil and stabilized oil. The three-phase separator, the stable gas separator, the dirty oil lifting pump, the dirty oil stabilizing tower, the stable oil air cooler, the stable gas air cooler, and the heat exchanger are all installed on the skid. One end of the dirty oil lifting pump is connected to an external dirty oil tank through a pipeline, and the other end of the dirty oil lifting pump is connected to a first end of the dirty oil stabilizing tower through a pipeline. The second end of the dirty oil stabilizing tower is connected to the first end of the three-phase separator through a pipeline, and the second end of the three-phase separator is connected to the first end of the heat exchanger through a pipeline. The second end of the heat exchanger is connected to the third end of the waste oil stabilization tower through a pipeline, the fourth end of the waste oil stabilization tower is connected to the third end of the heat exchanger through a pipeline, the fourth end of the heat exchanger is connected to one end of the stable oil air cooler through a pipeline, the other end of the stable oil air cooler is connected to an external waste oil storage tank through a pipeline, the fifth end of the waste oil stabilization tower is connected to the third end of the three-phase separator through a pipeline, the fourth end of the three-phase separator and the sixth end of the waste oil stabilization tower are connected to one end of the stable gas air cooler through a pipeline, the other end of the stable gas air cooler is connected to the first end of the stable gas separator through a pipeline, and the second end of the stable gas separator is connected to an external gas collection device through a pipeline.

2. A skid-mounted waste oil stabilization treatment device according to claim 1, characterized in that: The waste oil stabilization tower includes: a top heat exchanger, a middle and lower structured packing section and a bottom reboiler. The middle and lower structured packing section is installed above the bottom reboiler, and the top heat exchanger is installed above the middle and lower structured packing section. The top heat exchanger is connected to the other end of the waste oil lifting pump and the first end of the three-phase separator through pipelines, respectively, the middle and lower structured packing section is connected to the second end of the heat exchanger through a pipeline, and the first end of the bottom reboiler is connected to the third end of the heat exchanger through a pipeline.

3. A skid-mounted waste oil stabilization treatment device according to claim 2, characterized in that: The second end of the tower bottom reboiler, the fifth end of the three-phase separator and the sixth end of the three-phase separator are connected to the external sewage discharge equipment through the drainage pipeline; the third end of the tower bottom reboiler and the fourth end of the tower bottom reboiler are connected to the heat transfer oil inlet pipe and the heat transfer oil return pipe one by one, the oil temperature of the heat transfer oil in the heat transfer oil inlet pipe is 200°C, the oil temperature of the heat transfer oil in the heat transfer oil return pipe is 160°C, the temperature control range of the tower bottom reboiler is 100-130°C, and the heating temperature range of the tower top heat exchanger is 40-60°C.

4. A skid-mounted waste oil stabilization treatment device according to claim 3, characterized in that: The seventh end of the three-phase separator, the sixth end of the waste oil stabilization tower and the third end of the stable gas separator are all connected to an external venting system through pipelines.

5. A skid-mounted waste oil stabilization treatment device according to claim 4, characterized in that: A vertical safety filter is arranged on the pipeline between the waste oil lifting pump and the external waste oil tank, and a sewage discharge inspection port is arranged at the bottom of the vertical safety filter.

6. The skid-mounted waste oil stabilization treatment device according to claim 5 is characterized in that: The three-phase separator is provided with a water chamber and an oil chamber. The internal pressure value range of the three-phase separator is 0.4-0.6MPa, and the boost range of the waste oil lifting pump is 0.4-0.6MPa.

7. The skid-mounted waste oil stabilization treatment device according to claim 6 is characterized in that: A first valve is provided on the pipeline between the bottom reboiler and the sewage discharge equipment, a second valve and a third valve are provided on the pipeline between the three-phase separator and the sewage discharge equipment, the oil chamber is connected to the third valve through a pipeline, a fourth valve is provided on the pipeline between the third valve and the oil chamber, a fifth valve and a sixth valve are provided on the pipeline between the waste oil stabilization tower and the three-phase separator, a seventh valve is provided on the pipeline between the top heat exchanger and the stable gas air cooler, an eighth valve is provided on the pipeline between the stable gas separator and the waste oil tank, a first valve group is provided on the pipeline between the top heat exchanger and the venting system, and a second valve group is provided on the pipeline between the stable gas separator and the venting system.

8. The skid-mounted waste oil stabilization treatment device according to claim 1 is characterized in that: The skid body is a double-layer skid structure with an upper layer and a lower layer. A ladder is provided on the skid body, and the two ends of the ladder are connected to the upper layer and the lower layer in a one-to-one manner. The three-phase separator, the stable gas separator and the dirty oil lifting pump are installed on the lower layer, and the dirty oil stabilization tower, the stable oil air cooler, the stable gas air cooler and the heat exchanger are installed on the upper layer.

9. A skid-mounted waste oil stabilization treatment method, characterized in that: Based on the skid-mounted waste oil stabilization treatment device according to any one of claims 1 to 8 above, the skid-mounted waste oil stabilization treatment method comprises: S1, the waste oil lifting pump pressurizes the waste oil in the external waste oil tank and transports the waste oil to the waste oil stabilization tower; S2, the waste oil stabilization tower heats the waste oil; S3, three-phase separator to separate the waste oil by sedimentation, and separate the gas phase waste oil; S4, the heat exchanger heats up the waste oil; S5, the waste oil stabilization tower separates the waste oil into oil and gas to form liquid phase waste oil and gas phase waste oil; S6, heat exchanger and stabilized oil air cooler cool the liquid phase dirty oil to form stabilized oil; S7, stabilized oil enters external dirty oil storage tank; S8, the stable gas air cooler cools down the gas phase waste oil separated by the three-phase separator and the waste oil stabilization tower to form stable gas; S9, a stable gas separator performs cyclone separation on the stable gas; S10, the stable gas enters the external gas collection equipment.

10. A skid-mounted waste oil stabilization treatment method according to claim 9, characterized in that: Step S3 includes: the three-phase separator and the tower bottom reboiler discharge the liquid in the three-phase separator and the waste oil stabilization tower to an external sewage discharge device through a drainage pipeline.

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