Single-well low-pressure sulfur-containing natural gas recovery processing system

Abstract

The utility model discloses a single-well low-pressure sulfur-containing natural gas recovery processing system. The system comprises a filtering dehydration unit, an air recovery unit and an external transportation desulfurization unit, the filtering dehydration unit, the discharged air recovery unit and the output desulfurization unit are communicated in sequence; the vent gas recovery unit comprises a working nozzle, a receiving chamber, a mixing chamber and a diffusion chamber; the receiving chamber is communicated with the mixing chamber, and the mixing chamber is communicated with the diffusion chamber. The utility model belongs to a set of technology and complete equipment suitable for recycling single-well low-pressure sulfur-containing natural gas. The recovery processing capacity is actually designed according to working conditions, the requirement for single-well low-pressure sulfur-containing natural gas pressurization recovery is met, and environmental pollution caused by emission of the low-pressure sulfur-containing natural gas is avoided.

Description

Technical Field

[0001] The utility model relates to the field of natural gas recovery and processing, in particular to a single-well low-pressure sulfur-containing natural gas recovery and processing system. Background Art

[0002] At present, there is no mature low-pressure sour natural gas recovery and utilization technology in China. Low-pressure sour natural gas produced in a single well is generally discharged by flaring, which causes a large waste of natural gas energy, pollutes the environment, and harms the occupational health and safety of related personnel. At present, in the process of foreign natural gas development, the recovery and utilization of low-pressure sour natural gas all adopts the compressor boosting process. Its sour-resistant natural gas compressor consumes huge energy, has high maintenance costs, unstable gas volume, large investment, and high risks. At the same time, the boosting process is complex, the equipment is huge, and the system relies heavily, which is not very applicable. Therefore, it is urgent to develop a safe process technology and complete set of equipment suitable for single-well gas production of low-pressure sour natural gas. Finally, the high-sulfur gas single well reaches the process technology requirements of safe production and fully enclosed operation. At present, there is no actual successful application of single-well low-pressure sour gas. Utility Model Content

[0003] Therefore, in order to solve the above-mentioned shortcomings, the utility model provides a single-well low-pressure sour natural gas recovery and processing system; the present application belongs to a set of technologies and complete equipment suitable for the recovery and utilization of single-well low-pressure sour natural gas, and the recovery and processing capacity is designed according to the actual working conditions to meet the requirements of pressurized recovery of single-well low-pressure sour natural gas, so as to avoid environmental pollution caused by the emission of low-pressure sour natural gas.

[0004] The utility model is implemented in this way: a single-well low-pressure sulfur-containing natural gas recovery and processing system is constructed; the system comprises a filtering and dehydrating unit, a venting air recovery unit, and an external desulfurization unit; the filtering and dehydrating unit, the venting air recovery unit, and the external desulfurization unit are connected in sequence; the venting air recovery unit comprises a working nozzle, a receiving chamber, a mixing chamber, and a diffusion chamber; the receiving chamber and the mixing chamber are connected, and the mixing chamber and the diffusion chamber are connected.

[0005] Further, the receiving chamber and the mixing chamber correspond to the front end position of the air recovery unit.

[0006] Furthermore, the working nozzle corresponds to the front end of the receiving chamber, and the diffusion chamber corresponds to the tail end position of the exhaust air recovery unit.

[0007] Furthermore, the lower ends of the receiving chamber and the mixing chamber are the ejection fluid ends, the working nozzle corresponds to the working fluid inlet end, and the diffusion chamber corresponds to the compressed fluid outlet end.

[0008] Furthermore, the mixing chamber and the diffusion chamber are fixed by a flange.

[0009] The utility model has the following advantages: The application belongs to a set of technology and complete equipment suitable for the recovery and utilization of low-pressure sour natural gas in a single well. The recovery and processing capacity is designed according to the actual working conditions to meet the requirements of pressurized recovery of low-pressure sour natural gas in a single well, so as to avoid environmental pollution caused by the discharge of low-pressure sour natural gas. Technical advantages: 1. It can be applied to flash gas recovery of triethylene glycol unit. 2. Recovery of low-pressure natural gas in wellhead gas production wastewater tank. 3. During normal production, single wells and gas gathering stations realize fully enclosed operation, fully enclosed transportation of wastewater, and no external discharge and ignition of low-pressure natural gas, which reduces the pollution of the environment caused by the combustion of sour natural gas and the occupational injury of operating employees. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a block diagram of the system composition of this application;

[0011] Figure 2 It is an external schematic diagram of the exhaust air recovery unit (ejector for natural gas) in this application;

[0012] Figure 3 This is a diagram of the internal structure of the exhaust air recovery unit (natural gas ejector) in this application.

[0013] Among them: a filtering and dehydrating unit 10, an air recovery unit 20, a working nozzle 21, a receiving chamber 22, a mixing chamber 23, a diffusion chamber 24, and an external desulfurization unit 30. DETAILED DESCRIPTION

[0014] The following will be combined with the attached Figure 1-Figure 3 The utility model is described in detail, and the technical solutions in the embodiments of the utility model are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0015] The utility model provides a single well low-pressure sulfur-containing natural gas recovery and processing system, such as Figure 1 As shown; the system includes a filtration and dehydration unit 10, an air recovery unit 20, and an external desulfurization unit 30; the filtration and dehydration unit 10, the air recovery unit 20, and the external desulfurization unit 30 are connected in sequence.

[0016] In this application, an air recovery unit (ejector for natural gas) is placed, such as Figure 2-Figure 3 As shown; the air recovery unit 20 is composed of a working nozzle 21, a receiving chamber 22, a mixing chamber 23, and a diffusion chamber 24; the receiving chamber 22 and the mixing chamber 23 are connected, and the mixing chamber 23 and the diffusion chamber 24 are connected.

[0017] like Figure 2-Figure 3As shown; the receiving chamber 22 and the mixing chamber 23 correspond to the front end position of the air recovery unit.

[0018] like Figure 2-Figure 3 As shown; the working nozzle 21 corresponds to the front end of the receiving chamber 22, and the diffusion chamber 24 corresponds to the tail end position of the air recovery unit.

[0019] like Figure 2-Figure 3 As shown; the lower ends of the receiving chamber 22 and the mixing chamber 23 are the ejection fluid ends, the working nozzle 21 corresponds to the working fluid inlet end, and the diffusion chamber 24 corresponds to the compressed fluid outlet end.

[0020] like Figure 2-Figure 3 As shown; the mixing chamber 23 and the diffusion chamber 24 are fixed by a flange.

[0021] This application is a set of technology and complete equipment suitable for the recovery and utilization of low-pressure sour natural gas in a single well. The recovery and processing capacity is designed according to the actual working conditions, meeting the requirements of pressurized recovery of low-pressure sour natural gas in a single well, so as to avoid environmental pollution caused by the discharge of low-pressure sour natural gas.

[0022] The following is a detailed description of the ejector pressurization process of the exhaust air recovery unit (natural gas ejector) in this application;

[0023] Working nozzle process:

[0024] (1) After the working fluid enters the working nozzle, it goes through the following process;

[0025] A. Pressure reduction and acceleration process: The gas is depressurized and accelerated in the tapered nozzle flow channel. When the gas reaches the nozzle throat, the speed and pressure reach the critical value.

[0026] B. Diffusion and acceleration process: After the gas passes through the nozzle throat, it is further accelerated in the nozzle expansion section, causing the flow rate to exceed the critical value.

[0027] (2) Carrying and mixing stage: After the high-speed working fluid flowing out of the nozzle enters the receiving chamber, the dynamic pressure of the high-speed fluid at the nozzle outlet is lower than the static pressure of the ejected fluid entering the annular space of the receiving chamber. The working fluid carries the ejected fluid into the mixing chamber. In the mixing chamber, the ejected fluid is fully mixed under the impact of the high-speed working airflow.

[0028] (3) Diffusion and pressure recovery process: After being fully mixed, the high and low pressure fluids gradually decrease in the diffuser pipe and the pressure gradually recovers. Finally, the flow rate reaches the pipeline speed, and the pressure recovery is higher than the pressure of the ejector fluid (which increases the pressure of the ejector fluid) and lower than the pressure of the working fluid, and then enters the pipeline system.

[0029] Design of technical measures;

[0030] A. Install a one-way valve and a stop valve on the low-pressure sulfur-containing natural gas pipeline to prevent overpressure caused by shutting off the external gas transmission and reflux. Add a flow meter and a pressure gauge to measure the exhaust volume of the sewage tanker and observe the pressure change. The pressure level and material of the stop valve to the separator pipeline are the same. The pressure level and material of the stop valve to the sewage tank connection pipeline are the same as the sewage tank.

[0031] B. Stop valves shall be installed at the gas phase outlet of the sewage tank and the exhaust pipe of the sewage tank truck to prevent the exhaust gas of the sewage tank truck from entering the low-pressure gas of the sewage tank and causing safety accidents. The exhaust gas shall enter the venting torch.

[0032] C. The torch does not ignite in normal production status;

[0033] D. In an emergency situation, venting and ignition can be implemented by relying on the original process.

[0034] E. Venturi tube jet boost recovery, due to slight vibration due to flow velocity changes, a pipeline should be set to fix it.

[0035] F. The venturi tube jet booster flow expansion will produce temperature drop and pressure drop. The temperature and pressure of the natural gas at the outlet of the water jacket furnace should be appropriately adjusted.

[0036] Technical advantages: 1. It can be applied to flash gas recovery of triethylene glycol unit. 2. Low-pressure natural gas recovery in wellhead gas production wastewater tank. 3. Single well and gas gathering station realize fully enclosed operation during normal production, fully enclosed wastewater transportation, low-pressure natural gas is not discharged for ignition, and the combustion of sulfur-containing natural gas pollutes the environment and reduces the occupational injury of operating staff.

[0037] This application is an energy-saving project that is beneficial to safety, environmental protection, and occupational health. The "Low-pressure (sulfur-containing) natural gas recovery and boosting device" is used in the natural gas development and production industry.

[0038] Application prospects of the results:

[0039] 1. It can meet the national safety standards related to low-pressure recovery of sour natural gas.

[0040] 2. Low-pressure natural gas, biogas, coal-bed methane, etc. can be recycled and utilized in the later stage.

[0041] 3. Highly skid-mounted equipment can be quickly promoted and used on a large scale in the international and domestic markets.

[0042] Economic benefit forecast: Economic benefits for customers (well stations): Daily processing of sour natural gas within 500Nm3 / d, according to the current market situation, the sour natural gas fee is 0.8 yuan / standard cubic meter, and the daily income is 400 yuan / day. According to the annual operation of 330 days, the annual economic benefit is 132,000 yuan, and the investment is recovered in one and a half years. The low-pressure sour gas recovery system process has more significant economic benefits for projects with larger gas volume; considering that some detailed processes of well stations of different sizes need to be further improved in combination with on-site conditions, it is safer to control the gas volume at 500Nm3 / d for the initial (within half a year) test project.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-well low-pressure sour natural gas recovery and processing system, characterized in that: The system comprises a filtration and dehydration unit (10), a vented air recovery unit (20), and an external desulfurization unit (30); the filtration and dehydration unit (10), the vented air recovery unit (20), and the external desulfurization unit (30) are connected in sequence; the vented air recovery unit (20) comprises a working nozzle (21), a receiving chamber (22), a mixing chamber (23), and a diffusion chamber (24); the receiving chamber (22) and the mixing chamber (23) are connected, and the mixing chamber (23) and the diffusion chamber (24) are connected.

2. A single-well low-pressure sour natural gas recovery and processing system according to claim 1, characterized in that: The receiving chamber (22) and the mixing chamber (23) correspond to the front end position of the exhaust air recovery unit.

3. A single-well low-pressure sour natural gas recovery and processing system according to claim 1, characterized in that: The working nozzle (21) corresponds to the front end of the receiving chamber (22), and the diffusion chamber (24) corresponds to the rear end of the exhaust air recovery unit.

4. A single-well low-pressure sour natural gas recovery and processing system according to claim 1, characterized in that: The lower ends of the receiving chamber (22) and the mixing chamber (23) are fluid ejection ends, the working nozzle (21) corresponds to the working fluid inlet end, and the diffusion chamber (24) corresponds to the compressed fluid outlet end.

5. A single-well low-pressure sour natural gas recovery and processing system according to claim 1, characterized in that: The mixing chamber (23) and the diffusion chamber (24) are fixed via a flange.

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