A device and method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields

Abstract

The present invention relates to a device and method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields, comprising a pretreatment system and a hydrogen sulfide removal system; the pretreatment system is connected to the sulfur-containing produced water; the pretreatment system comprises a gravity sedimentation tank, a mixing tank, a flotation separator, a filter and a buffer tank connected in sequence, and the sulfur-containing produced water is connected to the gravity sedimentation tank; the hydrogen sulfide removal system comprises a hollow fiber supported liquid membrane assembly, a water purification tank and a receiving phase liquid tank connected in sequence; the hollow fiber supported liquid membrane assembly comprises a membrane shell and a hollow fiber supported liquid membrane bundle tube arranged from outside to inside; sealing baffles are respectively arranged on the two side ports of the membrane shell, the shell side is provided with a shell side inlet and a shell side outlet, and the tube side is provided with a tube side inlet and a tube side outlet; the tube side inlet is connected to the buffer tank, and the tube side outlet is connected to the water purification tank; the shell side outlet and the shell side inlet are connected through the receiving phase liquid tank. The present invention can make the extraction and stripping processes proceed simultaneously.

Description

Technical Field

[0001] The invention relates to the technical field of removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields, and in particular to a device and method for removing hydrogen sulfide from sulfur-containing produced water based on a hollow fiber supported liquid membrane method. Background Art

[0002] Oil and gas field produced water is the formation water discharged during the oil and gas production process. In sulfur-containing oil and gas fields, the formation produces a large amount of hydrogen sulfide gas due to biological or thermochemical causes, so the sulfide content in produced water is relatively high. For high-sulfur oil and gas fields, the sulfide content in produced water can even reach more than 500 mg / L. Sulfides in produced water can cause serious corrosion to underground and surface pipelines and equipment; in addition, under acidic conditions, sulfides escape in the form of hydrogen sulfide gas, which greatly endangers the health and life safety of personnel.

[0003] Common methods for treating sulfur-containing wastewater include chemical oxidation, chemical precipitation, absorption, and steam stripping. Among them, steam stripping requires large equipment and high investment, so it is mostly used for treating sulfur-containing wastewater in large refineries; the absorption method often requires the use of a large amount of absorbent, which has high reagent costs. The commonly used methods for removing sulfur from produced water in oil and gas fields are precipitation and oxidation. However, the above two methods require a large amount of chemical reagents, which have huge reagent costs, causing huge economic costs for oil and gas field production, and will produce a large amount of sludge, causing secondary pollution.

[0004] Liquid membrane separation technology is a new separation technology that emerged in the 1970s. Due to its advantages of fast mass transfer, high separation efficiency, low energy consumption, small equipment footprint and wide application, it has attracted the attention of experts and scholars at home and abroad, and has carried out extensive basic research and applied research. Famous Chinese scientists, Professor Li Nianzhi and Professor He Wenshou, both academicians of the American Academy of Engineering, have conducted long-term research on the mass transfer mechanism and industrial application of liquid membranes. The development of liquid membranes has gone through the stages of emulsified liquid membranes and supported liquid membranes. The earliest research was on emulsified liquid membranes. Dalian University of Technology and Zhengzhou University and other units jointly carried out research on the removal of H2S from wastewater using emulsified liquid membranes, indicating that the removal rate can reach 96~99%, which is an efficient means of removing hydrogen sulfide. However, the emulsified liquid membrane process requires operations such as emulsification, separation, and demulsification, which is cumbersome and difficult to operate; in addition, the stability is poor. The supported liquid membrane does not require emulsification and demulsification, which greatly simplifies the operation of the liquid membrane separation process. However, there is no report on the removal of hydrogen sulfide from sulfur-containing produced water using supported liquid membranes. Summary of the invention

[0005] The present invention aims to solve the above problems and proposes a device and method for removing hydrogen sulfide from sulfur-containing produced water based on a hollow fiber supported liquid membrane method.

[0006] The technical solution of the present invention is:

[0007] (I) The present invention provides a device for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields.

[0008] A device for removing hydrogen sulfide from sulfur-containing produced water in an oil and gas field, comprising a pretreatment system and a hydrogen sulfide removal system connected in sequence; wherein the pretreatment system is connected to the sulfur-containing produced water; the pretreatment system comprises a gravity sedimentation tank, a mixing tank, a flotation separator, a filter and a buffer tank connected in sequence, and the sulfur-containing produced water is connected to the gravity sedimentation tank; the hydrogen sulfide removal system comprises a hollow fiber supported liquid membrane assembly, a clean water tank and a receiving phase liquid tank connected in sequence; the hollow fiber supported liquid membrane assembly comprises a membrane shell and a hollow fiber supported liquid membrane bundle tube arranged from outside to inside; sealing baffles are respectively arranged on the two side ports of the membrane shell, the shell side is provided with a shell side inlet and a shell side outlet, and the tube side is provided with a tube side inlet and a tube side outlet; the tube side inlet is connected to the buffer tank, and the tube side outlet is connected to the clean water tank; the shell side outlet and the shell side inlet are connected through the receiving phase liquid tank.

[0009] Preferably, the mixing tank is connected to an inorganic flocculant dosing tank via a first dosing pump, is connected to an organic flocculant dosing tank via a second dosing pump, and is connected to a first pH adjuster dosing tank via a third dosing pump.

[0010] The buffer tank is connected to a second pH adjuster dosing tank via a fourth dosing pump.

[0011] A water inlet pump is provided between the sulfur-containing produced water and the gravity sedimentation tank, a pressure pump is provided between the flotation separator and the filter, a first metering pump is provided between the buffer tank and the tube side inlet, and a second metering pump is provided between the shell side outlet and the shell side inlet.

[0012] The air flotation separator is an air flotation tank.

[0013] The filter is a multi-media filter.

[0014] The membrane pore diameter of the hollow fiber supported liquid membrane bundle tube is 250-450 μm, and the wall thickness of the membrane bundle tube is 50-100 μm.

[0015] A stirring device is arranged in the receiving phase liquid tank.

[0016] (ii) The present invention provides a method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields.

[0017] A method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields, using the above-mentioned device for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields, the method is as follows:

[0018] (1) Pretreatment: At room temperature, the sulfur-containing produced water enters the gravity settling tank for oil-water separation. The water phase after oil-water separation enters the mixing tank and is fully mixed with the reagent before entering the flotation separator for aeration flotation solid-liquid separation. The water phase after flotation separation enters the filter for further filtration. The filtered water phase enters the buffer tank to adjust the pH of the water phase to acidic.

[0019] (2) Hydrogen sulfide removal: hydrogen sulfide is removed by cross-flow liquid membrane process;

[0020] A receiving phase solution is built into the receiving phase liquid tank, and the receiving phase solution is a mixture of an extractant and a stripping agent, and the mixed volume ratio of the stripping agent to the extractant is (5-20):1;

[0021] At room temperature, the receiving phase solution in the receiving phase liquid tank is pumped into the shell side of the hollow fiber supported liquid membrane assembly, the hollow fiber supported liquid membrane bundle tube is immersed in the receiving phase solution, and the extractant in the receiving phase solution will be adsorbed in the hydrophobic hollow fiber supported liquid membrane voids; the pretreated sulfur-containing produced water in the buffer tank is pumped into the hollow fiber supported liquid membrane bundle tube in the tube side of the hollow fiber supported liquid membrane assembly, and the hydrogen sulfide molecules in the sulfur-containing produced water in the tube side are complexed with the extractant in the receiving phase solution in the voids of the hollow fiber supported liquid membrane to form a complex, which is mass transferred to the shell side by the hollow fiber supported liquid membrane, and then the complex is decomplexed by the stripping agent in the receiving phase solution in the shell side to achieve stripping; after the extraction and stripping process is completed, the water phase flows from the tube side outlet to the clean water tank to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back from the shell side outlet to the receiving phase liquid tank to achieve the circulation of the receiving phase solution.

[0022] Preferably, the sulfide content in the sulfur-containing produced water is 5-700 mg / L;

[0023] The reagent includes an inorganic flocculant, an organic flocculant and a first pH regulator;

[0024] The inorganic flocculant is a polyaluminium chloride solution, and the dosage is 300-1000ppm;

[0025] The organic flocculant is a polyacrylamide solution, and the dosage is 250-750ppm;

[0026] The air-water ratio of the air flotation separator is 6-10;

[0027] The buffer tank adjusts the pH of the water phase to 6-7;

[0028] The extractant is a kerosene organic phase in which EDA is dissolved, wherein the content of EDA is 2%-5%;

[0029] The stripping agent is a NaOH aqueous solution, wherein the NaOH concentration is 0.5-3.0 mol / L.

[0030] Among them, the flow rate of sulfur-containing produced water in the hollow fiber supported liquid membrane bundle tube is 200-500 mL / min;

[0031] The flow rate of the receiving phase solution in the shell side is 200-500 ml / min.

[0032] The technical effects of the present invention are:

[0033] (1) The hollow fiber supported liquid membrane cross-flow process proposed in the present invention can make the extraction and stripping processes proceed simultaneously. The process is greatly simplified compared with the extraction process. The equipment is simple and occupies a small area. The fixed investment is small and can be operated continuously. The hollow fiber supported liquid membrane technology breaks the chemical balance of the traditional extraction method, has a greater mass transfer driving force, and has a high separation efficiency.

[0034] (2) Compared with the drawback of the fixed carrier liquid membrane method in which the organic extraction phase is fixed in the membrane pores and the extractant is easily lost, the extractant in the present invention can be continuously circulated in the receiving phase liquid tank and the shell side of the hollow fiber supported liquid membrane module, making the hollow fiber supported liquid membrane more stable;

[0035] (3) Compared with the flat plate supported liquid membrane method in which the organic extraction phase exists in the extraction chamber between two flat plate liquid membranes, the extractant and the stripping agent phase in the present invention exist in the shell side of the hollow fiber supported liquid membrane module in a mixed form, so the mass transfer distance is small, the mass transfer resistance is small, the mass transfer driving force is large, and the mass transfer effect is good;

[0036] (4) The mobile phase in the shell side of the present invention is a receiving phase solution, that is, an extraction phase and a stripping solution mixed in a certain proportion. Therefore, the extraction and stripping processes can be simultaneously realized in the hollow fiber supported liquid membrane module without the need for additional stripping equipment, and the extractant can be directly recycled in the shell side. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the present invention.

[0038] Figure numerals: 1. Gravity sedimentation tank; 2. Mixing tank; 3. Flotation separator; 4. Multi-media filter; 5. Buffer tank; 6. Hollow fiber supported liquid membrane assembly; 7. Water purification tank; 8. Receiving phase liquid tank; 9. Inorganic flocculant dosing tank; 10. Organic flocculant dosing tank; 11. First pH adjuster dosing tank; 12. Second pH adjuster dosing tank; 13. Water inlet pump; 14. Booster pump; 15. Left sealing baffle; 16. Right sealing baffle; 17. Tube side inlet; 18. Tube side outlet; 19. Shell side inlet; 20. Shell side outlet. DETAILED DESCRIPTION

[0039] Example 1

[0040] A device for removing hydrogen sulfide from sulfur-containing produced water in an oil and gas field, comprising a pretreatment system and a hydrogen sulfide removal system connected in sequence; wherein the pretreatment system is connected to the sulfur-containing produced water; the pretreatment system comprises a gravity sedimentation tank 1, a mixing tank 2, a flotation separator 3, a filter and a buffer tank 5 connected in sequence, and the sulfur-containing produced water is connected to the gravity sedimentation tank 1; the hydrogen sulfide removal system comprises a hollow fiber supported liquid membrane assembly 6, a clean water tank 7 and a receiving phase liquid tank 8 connected in sequence; the hollow fiber supported liquid membrane assembly 6 comprises a membrane shell and a hollow fiber supported liquid membrane bundle tube arranged from outside to inside; sealing baffles are respectively arranged on the two side ports of the membrane shell, a shell side inlet 19 and a shell side outlet 20 are provided on the shell side, and a tube side inlet 17 and a tube side outlet 18 are provided on the tube side; the tube side inlet 17 is connected to the buffer tank 5, and the tube side outlet 18 is connected to the clean water tank 7; the shell side outlet 20 is connected to the shell side inlet 19 through the receiving phase liquid tank 8.

[0041] The specific implementation process of this embodiment is as follows:

[0042] (1) Pretreatment: At room temperature, the sulfur-containing produced water enters the gravity settling tank 1 for oil-water separation. The water phase after oil-water separation enters the mixing tank 2 and is fully mixed with the reagent before entering the flotation separator 3 for aeration flotation solid-liquid separation. The water phase after flotation separation enters the filter for further filtration. The filtered water phase enters the buffer tank 5 to adjust the pH of the water phase to acidic.

[0043] (2) Hydrogen sulfide removal: hydrogen sulfide is removed by cross-flow liquid membrane process;

[0044] The receiving phase liquid tank 8 contains a receiving phase solution, which is a mixture of an extractant and a stripping agent, and the mixed volume ratio of the stripping agent to the extractant is (5-20):1;

[0045] At room temperature, the receiving phase solution in the receiving phase liquid tank 8 is pumped into the shell side of the hollow fiber supported liquid membrane assembly 6, the hollow fiber supported liquid membrane bundle tube is immersed in the receiving phase solution, and the extractant in the receiving phase solution will be adsorbed in the hydrophobic hollow fiber supported liquid membrane gap; the pretreated sulfur-containing produced water in the buffer tank 5 is pumped into the hollow fiber supported liquid membrane bundle tube in the tube side of the hollow fiber supported liquid membrane assembly 6, and the hydrogen sulfide molecules in the sulfur-containing produced water in the tube side are complexed with the extractant in the receiving phase solution in the gap of the hollow fiber supported liquid membrane to form a complex, which is mass transferred to the shell side by the hollow fiber supported liquid membrane, and then the complex is decomplexed by the stripping agent in the receiving phase solution in the shell side to achieve stripping; after the extraction and stripping process is completed, the water phase flows from the tube side outlet 18 to the clean water tank 7 to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back to the receiving phase liquid tank 8 from the shell side outlet 20 to achieve the circulation of the receiving phase solution.

[0046] Wherein, preferably, the sulfide content in the sulfur-containing produced water is 5-700 mg / L; the reagent includes an inorganic flocculant, an organic flocculant and a first pH regulator; the inorganic flocculant is a polyaluminium chloride solution, and the dosage is 300-1000ppm; the organic flocculant is a polyacrylamide solution, and the dosage is 250-750ppm; the gas-water ratio of the flotation separator 3 is 6-10; the buffer tank 5 adjusts the pH of the water phase to 6-7; the extractant is a kerosene organic phase dissolved with EDA, wherein the content of EDA is 2%-5%; the stripping agent is a NaOH aqueous solution, wherein the NaOH concentration is 0.5-3.0 mol / L. Wherein, the flow rate of the sulfur-containing produced water in the hollow fiber supported liquid membrane bundle tube is 200-500 mL / min; the flow rate of the receiving phase solution in the shell side is 200-500 ml / min.

[0047] Example 2

[0048] On the basis of Example 1, it also includes:

[0049] The mixing tank 2 is connected to an inorganic flocculant dosing tank 9 through a first dosing pump, to an organic flocculant dosing tank 10 through a second dosing pump, and to a first pH adjuster dosing tank 11 through a third dosing pump. The buffer tank 5 is connected to a second pH adjuster dosing tank 12 through a fourth dosing pump. An inlet pump 13 is provided between the sulfur-containing produced water and the gravity sedimentation tank 1, a booster pump 14 is provided between the flotation separator 3 and the filter, a first metering pump is provided between the buffer tank 5 and the tube side inlet 17, and a second metering pump is provided between the shell side outlet 20 and the shell side inlet 19. The flotation separator 3 is an air flotation tank. The filter is a multi-media filter 4. The membrane pore size of the hollow fiber supported liquid membrane bundle tube is 250-450μm, and the wall thickness of the membrane bundle tube is 50-100μm; a left sealing baffle 15 is provided at the left port of the membrane shell, and a right sealing baffle 16 is provided at the right port of the membrane shell; a stirring device is provided in the receiving phase liquid tank 8.

[0050] Specific Experimental Example 1

[0051] At room temperature, the sulfur-containing produced water with a concentration of 10 mg / L and a pH of 6 enters the gravity sedimentation tank 1 through the water inlet pump 13 for gravity sedimentation oil-water separation and enters the mixing tank 2. The 500 mg / L PAC solution, the 250 mg / L PAM solution, and the 5% NaOH solution are respectively pumped into the mixing tank 2 through the dosing pump to be fully mixed with the produced water after oil removal to form mixed water. The mixed water enters the flotation tank for flocculation reaction and aeration flotation solid-liquid separation. The water after flotation separation enters the multi-media filter 4 through the pressure pump 14; the effluent of the multi-media filter 4 enters the buffer tank 5 through the pipeline, and the 5% HCl solution is pumped into the buffer tank 5 through the dosing pump, the pH is adjusted to 6, and the cross-flow liquid membrane process is used to remove hydrogen sulfide;

[0052] The extractant is a kerosene organic solution containing 2% EDA, and the stripping agent is an aqueous solution containing 0.5 mol / L NaOH. The stripping agent and the extractant are mixed in a ratio of 5:1 to form a receiving phase solution; the receiving phase solution is pumped into the shell side of the hollow fiber supported liquid membrane assembly 6 through the second metering pump and the shell side inlet 19, with a flow rate of 500 ml / min; the pretreated water in the buffer tank 5 is pumped into the hollow fiber supported liquid membrane bundle tube of the tube side of the hollow fiber supported liquid membrane assembly 6 through the tube side inlet 17 through the first metering pump, with a flow rate of 400 ml / min; after the extraction and stripping process is completed, the water flows from the tube side outlet 18 into the clean water tank 7 to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back from the shell side outlet 20 to the receiving phase liquid tank 8 to achieve the circulation of the receiving phase solution;

[0053] The sulfide content of the purified water in the water purification tank 7 was tested, and the sulfide content was 0.1 mg / L, and the sulfide removal rate reached 99%.

[0054] Specific Experimental Example 2

[0055] At room temperature, the sulfur-containing produced water with a concentration of 300 mg / L and a pH of 7 enters the gravity sedimentation tank 1 through the water inlet pump 13 for gravity sedimentation oil-water separation and enters the mixing tank 2. The 500 mg / L PAC solution, the 250 mg / L PAM solution, and the 5% NaOH solution are respectively pumped into the mixing tank 2 through the dosing pump to be fully mixed with the produced water after oil removal to form mixed water. The mixed water enters the flotation tank for flocculation reaction and aeration flotation solid-liquid separation. The water after flotation separation enters the multi-media filter 4 through the pressure pump 14; the effluent of the multi-media filter 4 enters the buffer tank 5 through the pipeline, and the 5% HCl solution is pumped into the buffer tank 5 through the dosing pump, the pH is adjusted to 6.5, and the cross-flow liquid membrane process is used to remove hydrogen sulfide;

[0056] The extractant is a kerosene organic solution containing 2% EDA, and the stripping agent is an aqueous solution containing 3 mol / L NaOH. The stripping agent and the extractant are mixed at a ratio of 20:1 to form a receiving phase solution; the receiving phase solution is pumped into the shell side of the hollow fiber supported liquid membrane assembly 6 through the second metering pump and the shell side inlet 19, with a flow rate of 200 ml / min; the pretreated water in the buffer tank 5 is pumped into the hollow fiber supported liquid membrane bundle tube of the tube side of the hollow fiber supported liquid membrane assembly 6 through the tube side inlet 17 through the first metering pump, with a flow rate of 200 ml / min; after the extraction and stripping process is completed, the water flows from the tube side outlet 18 into the clean water tank 7 to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back from the shell side outlet 20 to the receiving phase liquid tank 8 to achieve the circulation of the receiving phase solution;

[0057] The sulfide content of the purified water in the water purification tank 7 was tested, and the sulfide content was 5 mg / L. The sulfide removal rate reached 98.33%.

[0058] Specific Experimental Example 3

[0059] At room temperature, the sulfur-containing produced water with a concentration of 150 mg / L and a pH of 6.5 enters the gravity sedimentation tank 1 through the water inlet pump 13 for gravity sedimentation oil-water separation and enters the mixing tank 2. The 500 mg / L PAC solution, the 250 mg / L PAM solution, and the 5% NaOH solution are respectively pumped into the mixing tank 2 through the dosing pump to be fully mixed with the produced water after oil removal to form mixed water. The mixed water enters the flotation tank for flocculation reaction and aeration flotation solid-liquid separation. The water after flotation separation enters the multi-media filter 4 through the pressure pump 14; the effluent of the multi-media filter 4 enters the buffer tank 5 through the pipeline, and the 5% HCl solution is pumped into the buffer tank 5 through the dosing pump, the pH is adjusted to 6, and the cross-flow liquid membrane process is used to remove hydrogen sulfide;

[0060] The extractant is a kerosene organic solution containing 2% EDA, and the stripping agent is an aqueous solution containing 1.5 mol / L NaOH. The stripping agent and the extractant are mixed at a ratio of 10:1 to form a receiving phase solution; the receiving phase solution is pumped into the shell side of the hollow fiber supported liquid membrane assembly 6 through the second metering pump and the shell side inlet 19, with a flow rate of 300 ml / min; the pretreated water in the buffer tank 5 is pumped into the hollow fiber supported liquid membrane bundle tube of the tube side of the hollow fiber supported liquid membrane assembly 6 through the tube side inlet 17 through the first metering pump, with a flow rate of 250 ml / min; after the extraction and stripping process is completed, the water flows from the tube side outlet 18 into the clean water tank 7 to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back from the shell side outlet 20 to the receiving phase liquid tank 8 to achieve the circulation of the receiving phase solution;

[0061] The sulfide content of the purified water in the water purification tank 7 was tested, and the sulfide content was 1.3 mg / L. The sulfide removal rate reached 99.63%.

Claims

1. A method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields, characterized in that: A hydrogen sulfide removal device for sulfur-containing produced water from an oil and gas field is used, and the hydrogen sulfide removal device for sulfur-containing produced water from an oil and gas field comprises a pretreatment system and a hydrogen sulfide removal system connected in sequence; wherein the pretreatment system is connected to the sulfur-containing produced water; the pretreatment system comprises a gravity sedimentation tank (1), a mixing tank (2), an air flotation separator (3), a filter and a buffer tank (5) connected in sequence, and the sulfur-containing produced water is connected to the gravity sedimentation tank (1); the hydrogen sulfide removal system comprises a hollow fiber supported liquid membrane module (6), a water purification tank (7) and a receiving tank connected in sequence Phase liquid tank (8); the hollow fiber supported liquid membrane assembly (6) comprises a membrane shell and a hollow fiber supported liquid membrane bundle tube arranged from outside to inside; sealing baffles are respectively arranged on the two side ports of the membrane shell, the shell side is provided with a shell side inlet (19) and a shell side outlet (20), and the tube side is provided with a tube side inlet (17) and a tube side outlet (18); the tube side inlet (17) is connected to the buffer tank (5), and the tube side outlet (18) is connected to the clean water tank (7); the shell side outlet (20) and the shell side inlet (19) are connected through a receiving phase liquid tank (8); The removal method is as follows: (1) Pretreatment: At room temperature, the sulfur-containing produced water enters the gravity settling tank (1) for oil-water separation. The water phase after oil-water separation enters the mixing tank (2) and is fully mixed with the reagent before entering the flotation separator (3) for aeration flotation solid-liquid separation. The water phase after flotation separation enters the filter for further filtration. The filtered water phase enters the buffer tank (5) to adjust the pH of the water phase to acidic. (2) Hydrogen sulfide removal: hydrogen sulfide is removed by cross-flow liquid membrane process; A receiving phase solution is built into the receiving phase liquid tank (8), wherein the receiving phase solution is a mixture of an extractant and a stripping agent, and the mixed volume ratio of the stripping agent to the extractant is (5-20):1; At room temperature, the receiving phase solution in the receiving phase liquid tank (8) is pumped into the shell side of the hollow fiber supported liquid membrane assembly (6), the hollow fiber supported liquid membrane bundle tube is immersed in the receiving phase solution, and the extractant in the receiving phase solution is adsorbed in the hydrophobic hollow fiber supported liquid membrane voids; the sulfur-containing produced water in the buffer tank (5) that has been pretreated is pumped into the hollow fiber supported liquid membrane bundle tube in the tube side of the hollow fiber supported liquid membrane assembly (6), the hydrogen sulfide molecules in the sulfur-containing produced water in the tube side are complexed with the extractant in the receiving phase solution in the voids of the hollow fiber supported liquid membrane to form a complex, which is mass-transferred to the shell side by the hollow fiber supported liquid membrane, and then the complex is decomplexed by the stripping agent in the receiving phase solution in the shell side to achieve stripping; after the extraction and stripping process is completed, the water phase flows from the tube side outlet (18) into the clean water tank (7) to achieve the removal of hydrogen sulfide in the water; the receiving phase solution flows back from the shell side outlet (20) to the receiving phase liquid tank (8) to achieve the circulation of the receiving phase solution.

2. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 1, characterized in that: The mixing tank (2) is connected to an inorganic flocculant dosing tank (9) via a first dosing pump, is connected to an organic flocculant dosing tank (10) via a second dosing pump, and is connected to a first pH adjuster dosing tank (11) via a third dosing pump.

3. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 2, characterized in that: The buffer tank (5) is connected to a second pH adjuster dosing tank (12) via a fourth dosing pump.

4. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 3, characterized in that: A water inlet pump (13) is provided between the sulfur-containing produced water and the gravity settling tank (1), a pressure pump (14) is provided between the flotation separator (3) and the filter, a first metering pump is provided between the buffer tank (5) and the tube side inlet (17), and a second metering pump is provided between the shell side outlet (20) and the shell side inlet (19).

5. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 4, characterized in that: The air flotation separator (3) is an air flotation tank.

6. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 5, characterized in that: The filter is a multi-media filter (4).

7. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 6, characterized in that: The membrane pore diameter of the hollow fiber supported liquid membrane bundle tube is 250-450 μm, and the wall thickness of the membrane bundle tube is 50-100 μm.

8. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 7, characterized in that: The receiving phase liquid tank (8) is provided with a stirring device.

9. The method for removing hydrogen sulfide from sulfur-containing produced water in oil and gas fields according to claim 8, characterized in that: The sulfide content in the sulfur-containing produced water is 5-700 mg / L; The reagent includes an inorganic flocculant, an organic flocculant and a first pH regulator; The inorganic flocculant is a polyaluminium chloride solution, and the dosage is 300-1000ppm; The organic flocculant is a polyacrylamide solution, and the dosage is 250-750ppm; The air-water ratio of the air flotation separator (3) is 6-10; The buffer tank (5) adjusts the pH of the aqueous phase to 6-7; The extractant is a kerosene organic phase in which EDA is dissolved, wherein the content of EDA is 2%-5%; The stripping agent is a NaOH aqueous solution, wherein the NaOH concentration is 0.5-3.0 mol / L.

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