A wellhead single elemental sulfur collection system

Abstract

The application provides a wellhead single sulfur trapping system, and relates to the technical field of sulfur-containing gas reservoir development.The wellhead single sulfur trapping system comprises a pipeline directly connected with a gas production tree, and the pipeline is sequentially connected in series from upstream to downstream with an inlet end pressure sensor, an inlet end valve, a mechanical filter, a sulfur dissolving tank and a gas flow meter.A filter element for trapping single sulfur and capable of being taken out from the shell is arranged in the mechanical filter, and a sulfur dissolving agent for trapping single sulfur is arranged in the sulfur dissolving tank.A pressure control valve is connected between the mechanical filter and the sulfur dissolving tank and between the sulfur dissolving tank and the gas flow meter.The opening degree of the inlet end valve can be adjusted according to the wellhead pressure parameter measured by the inlet end pressure sensor, so that the mechanical filter and the sulfur dissolving tank can continuously operate in a set pressure range, and the production gas sampling and single sulfur trapping under long-period and large-gas-volume conditions are realized, the randomness of the sulfur content determination result caused by small sampling volume is avoided, and the sulfur content determination error is reduced.

Description

Technical Field

[0001] This invention relates to the field of sulfur-bearing gas reservoir development technology, and in particular to a wellhead elemental sulfur capture system. Background Technology

[0002] In sulfur-bearing gas reservoirs, elemental sulfur dissolves in large quantities in gaseous form within the natural gas under the high temperature and pressure environment of the reservoir. When the extracted sulfur-bearing natural gas enters the gathering and transportation system, as the temperature and pressure of the pipelines decrease, the supersaturated sulfur gradually precipitates out to form solid elemental sulfur. This sulfur deposits form on the pipelines, valves, elbows, and processing equipment of the gathering and transportation system. In severe cases, this can lead to blockages in the gathering and transportation system or cause serious corrosion to the pipelines at the sulfur deposit sites, affecting the efficient development and transportation of natural gas.

[0003] To this end, Chinese invention patent CN113984578B discloses a separation device and method for determining the sulfur content of sulfur-containing produced gas. This method involves setting up a single-element sulfur trap at the wellhead and measuring the sulfur content in the natural gas at the wellhead to guide downstream sulfur deposition prevention in the gathering and transportation system. The separation device (equivalent to a single-element sulfur trap) includes a gas production box, a first separator, a second separator, and a gas collector connected in sequence. The first separator contains a particulate filter (equivalent to a filter element) for separating sulfur-containing solids, and the second separator contains a liquid filter membrane for separating sulfur-containing liquids. The first separator is connected to the gas production tree of the sulfur-containing gas well through the gas production box, and a pressure-reducing and cooling pipeline connects the first separator and the gas production box. When the above-mentioned separation device measures the sulfur content, it collects and samples the sulfur-containing produced gas through the gas sampling box, then promotes the precipitation of elemental sulfur through the depressurization and cooling pipeline, and uses the first separator to separate and weigh the precipitated elemental sulfur. The sulfur content in the produced gas is calculated by the weight of the weighed elemental sulfur and the weight of the produced gas in the gas sampling box.

[0004] In the above technical solution, due to the limited volume of the gas sampling box, the amount of sulfur-containing produced gas sampled is limited, and the results of sulfur content determination are somewhat random and have a large error, which cannot truly reflect the sulfur content in the produced gas. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a wellhead elemental sulfur capture system to solve the technical problem of large errors in sulfur content measurement results caused by small sample sizes in existing separation devices.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A wellhead elemental sulfur capture system includes a pipeline for direct connection to the wellhead tree. From upstream to downstream, the pipeline is connected in series an inlet pressure sensor for measuring wellhead pressure, an inlet valve for regulating pipeline pressure based on pressure measurement parameters, a mechanical filter for capturing elemental sulfur, a sulfur dissolving tank, and a gas flow meter. The mechanical filter housing contains a filter element for capturing elemental sulfur that can be removed from the housing. The sulfur dissolving tank contains a sulfur dissolving agent for capturing elemental sulfur. Pressure control valves for pressure regulation are connected between the mechanical filter and the sulfur dissolving tank, and between the sulfur dissolving tank and the gas flow meter.

[0007] This invention is a pioneering invention with the following advantages: By connecting an inlet pressure sensor and an inlet valve upstream of the pipeline, the inlet valve adjusts its opening based on the wellhead pressure parameters measured by the inlet pressure sensor, thereby achieving pressure regulation of the pipeline downstream of the inlet valve; it enables the mechanical filter and sulfur dissolving tank to connect with the gas production tree, enabling direct sampling of production gas; it allows the mechanical filter and sulfur dissolving tank to continuously perform long-term, high-volume production gas sampling and elemental sulfur capture within a set pressure range, avoiding randomness in sulfur content measurement results due to small sample sizes, reducing sulfur content measurement errors, and providing reliable data support for guiding surface process elemental sulfur deposition simulation and preventing sulfur deposition downstream of natural gas gathering and transportation pipelines.

[0008] Preferably, the housing is a horizontal cylindrical shape, and a quick-opening blind flange is connected to the end of the housing that is away from the gas inlet of the mechanical filter.

[0009] Preferably, a drain port is provided at the bottom of the end of the housing that is away from the gas inlet of the mechanical filter.

[0010] Preferably, the gas inlet and gas outlet on the tank are respectively connected to hydrogen sulfide sensors.

[0011] Preferably, the tank has a vertical structure, and the height of the gas inlet on the tank is lower than the height of the gas outlet on the tank.

[0012] Preferably, a liquid baffle is provided inside the tank between the sulfur dissolving agent liquid surface and the gas outlet to separate the sulfur dissolving agent carried in the gas.

[0013] Preferably, the wellhead elemental sulfur capture system also includes a control module, the inlet valve is an electrically controlled valve, and the inlet pressure sensor, the inlet valve, the hydrogen sulfide sensor, and the gas flow meter are all communicatively connected to the control module to adjust the inlet valve according to the parameters of the inlet pressure sensor, the hydrogen sulfide sensor, and the gas flow meter.

[0014] Preferably, the tank body is provided with an inlet and an outlet for the sulfur dissolving agent to flow in and out. Both the inlet and outlet are connected to a metering tank containing the sulfur dissolving agent, and a circulation pump is connected between the inlet and the metering tank.

[0015] Preferably, the pipeline outlet is connected to an exhaust gas treatment device.

[0016] Preferably, the outlet of the pipeline is connected to an outlet pressure sensor. Attached Figure Description

[0017] Figure 1 This is an overall connection diagram of an embodiment of the wellhead elemental sulfur capture device of the present invention; Figure 2 yes Figure 1 A schematic diagram of the mechanical filter in the diagram; Figure 3 yes Figure 1 A schematic diagram of the sulfur dissolving tank in the middle; Figure 4 yes Figure 1 A schematic diagram of the metering tank.

[0018] Explanation of reference numerals in the attached figures: 1. Inlet pressure sensor; 2. Inlet valve; 3. Mechanical filter; 3-1. Housing; 3-2. First gas inlet; 3-3. First gas outlet; 3-4. Quick-opening blind flange; 3-5. Filter element; 3-6. Support frame; 3-7. First drain port; 3-8. Support leg; 4. Nitrogen purging and replacement device; 5. Pressure regulating valve; 6. First hydrogen sulfide sensor; 7. Sulfur dissolving tank; 7-1. Sulfur dissolving tank body; 7-2. Second gas inlet; 7-3. Second gas outlet; 8. Sulfur dissolving agent filling device; 8-1 8-1-1 Metering tank; 8-1-2 Third drain port; 8-1-3 Top cover; 8-1-4 Breathing valve; 8-1-5 Dosing port; 8-1-6 Support feet; 9 Cleaning device; 10 Second hydrogen sulfide sensor; 11 Back pressure valve; 12 Gas flow meter; 13 Process valve; 14 Outlet pressure sensor; 15 Tail gas treatment device; 16 Data acquisition submodule; 17 Data processing submodule; 18 Safety control submodule; 19 Circulation pump. Detailed Implementation

[0019] In order to solve the technical problems in the prior art, the basic technical concept of the present invention is to measure and control the pressure of the produced gas entering the elemental sulfur capture device at the wellhead, so that the elemental sulfur capture system can perform long-term, large-volume production gas sampling and elemental sulfur capture, thereby avoiding the error in sulfur content measurement caused by small sample volume.

[0020] Based on the above concept, the present invention will be further described below with reference to different embodiments.

[0021] Specific embodiments of the wellhead elemental sulfur capture system of the present invention: As a basic embodiment, a wellhead elemental sulfur capture system, such as Figure 1 As shown, the system includes a pipeline for direct connection to the wellhead. From upstream to downstream, the pipeline is connected in series with an inlet pressure sensor 1 for measuring wellhead pressure, an inlet valve 2 for regulating pipeline pressure based on pressure measurement parameters, a mechanical filter 3 for capturing elemental sulfur, a sulfur dissolving tank 7, and a gas flow meter 12. The mechanical filter 3 has a filter element 3-5 inside its housing 3-1 for capturing elemental sulfur, which can be removed from the housing 3-1. The sulfur dissolving tank 7 has a tank body 7-1 containing a sulfur dissolving agent for capturing elemental sulfur. A pressure regulating valve 5 connects the mechanical filter 3 and the sulfur dissolving tank 7, and a back pressure valve 11 connects the sulfur dissolving tank 7 and the gas flow meter 12. Both the pressure regulating valve 5 and the back pressure valve 11 are used for pressure regulation.

[0022] Specifically, the inlet pressure sensor 1 is connected to the non-production wing of the wellhead's gas production tree to measure the pressure parameters of the produced gas. The inlet valve 2 adjusts its opening based on the measured pressure parameters, thereby controlling the pressure of the subsequent pipe section. Therefore, the pipe section containing the inlet pressure sensor 1 and the inlet valve 2 constitutes the pressure control section. When the pressure parameters measured by the inlet pressure sensor 1 exceed the pressure-bearing range of the mechanical filter 3 and the sulfur dissolving tank 7, the opening of the inlet valve 2 is adjusted to prevent the mechanical filter 3 and the sulfur dissolving tank 7 from communicating with the gas production tree. When the measured pressure parameters are within the pressure-bearing range of the mechanical filter 3 and the sulfur dissolving tank 7, the opening of the inlet valve 2 is adjusted to allow the sulfur-containing natural gas to slowly and sequentially enter the mechanical filter 3 and the sulfur dissolving tank 7, thereby capturing the elemental sulfur in the sulfur-containing natural gas. The natural gas flow is then statistically analyzed by the gas flow meter 12.

[0023] Furthermore, the mechanical filter 3 and the sulfur dissolving tank 7 are connected in series on the pipeline. The mechanical filter 3 includes a housing 3-1 with a gas inlet and a gas outlet, and the sulfur dissolving tank 7 has a tank body 7-1 with a gas inlet and a gas outlet. The gas outlet of the housing 3-1 is connected to a pressure regulating valve 5, and the gas outlet of the sulfur dissolving tank 7-1 is connected to a back pressure valve 11. For ease of description, the gas inlet of the mechanical filter 3 is defined as the first gas inlet 3-2, and the gas outlet of the mechanical filter 3 is defined as the first gas outlet 3-3; the gas inlet of the sulfur dissolving tank 7 is defined as the second gas inlet 7-2, and the gas outlet of the sulfur dissolving tank 7 is defined as the second gas outlet 7-3. Specifically, the first gas inlet 3-2 of the mechanical filter 3 is connected to the outlet of the inlet valve 2, the first gas outlet 3-3 is connected to the second gas inlet 7-2 by a pressure regulating valve 5, and the second gas outlet 7-3 is connected to the gas flow meter 12 by a back pressure valve 11.

[0024] Furthermore, the housing 3-1 is equipped with a filter element 3-5 for capturing elemental sulfur and which can be removed from the housing 3-1. The filter element 3-5 is coaxial with the housing 3-1 through a support frame 3-6, and the end of the filter element 3-5 near the first gas inlet 3-2 is sealed to the housing 3-1. The bottom of the housing 3-1 is connected to a support leg 3-8. The sulfur dissolving tank 7-1 is equipped with a sulfur dissolving agent for capturing elemental sulfur. When the produced gas enters the downstream of the pipeline through the pressure control section, as the pipeline temperature, pressure, and produced gas flow rate decrease, it passes through the filter element 3-5 of the mechanical filter 3 and the sulfur dissolving agent of the sulfur dissolving tank 7, causing elemental sulfur particles in the produced gas to precipitate and be collected for sulfur content determination.

[0025] In this embodiment, the mechanical filter 3 uses filter elements 3-5 to filter and collect elemental sulfur particles in the form of large particles, while the sulfur dissolving tank 7 uses a physical sulfur dissolving agent to absorb and collect elemental sulfur particles in the form of small particles. The mechanical filter 3 has a pressure resistance of 30 MPa and is suitable for gas wells with large volumes of gas and severe sulfur deposition. The filter elements 3-5 are configured as two nested elements, both made of polyester fiber, which is corrosion-resistant and water-resistant, and is used to remove elemental sulfur particles larger than 0.3 micrometers. The sulfur dissolving tank 7 has a pressure resistance of 30 MPa, and the sulfur dissolving agent is a physical sulfur dissolving agent, specifically carbon disulfide solution. Carbon disulfide solution can be thoroughly mixed with the produced gas, and has a fast sulfur dissolving rate and low cost, used to further remove small elemental sulfur particles from the produced gas. In other embodiments, the mechanical filter 3 may be in the form of a mechanical molecular sieve, and the physical sulfur dissolving agent may be cycloalkanes, toluene, or aromatics.

[0026] Furthermore, the pressure regulating valve 5 and the back pressure valve 11 are used for pressure regulation of the mechanical filter 3 and the sulfur dissolving tank 7, respectively, to ensure the full release of elemental sulfur from the produced gas and to allow the produced gas to reside for a certain period of time while passing through the mechanical filter 3 and the sulfur dissolving tank 7 for the capture or absorption of elemental sulfur. Specifically, the pressure regulating valve 5 controls the pressure in the mechanical filter 3, and the back pressure valve 11 controls the pressure in the sulfur dissolving tank 7. When the pressure in the mechanical filter 3 exceeds the rated working pressure, the pressure regulating valve 5 opens to release pressure; when the pressure in the sulfur dissolving tank 7 exceeds its rated working pressure, the back pressure valve 11 opens to release pressure. In other embodiments, it is not excluded that pressure regulating valve 5 or back pressure valve 11, or shut-off valves or other pressure control valves are used between the mechanical filter 3 and the sulfur dissolving tank 7, and between the sulfur dissolving tank 7 and the gas flow meter 12. As long as the mechanical filter 3 and the sulfur dissolving tank 7 are within their rated working pressure ranges, it is acceptable as long as the produced gas can reside for a certain period of time while passing through them.

[0027] When determining the elemental sulfur content, the captured elemental sulfur is separated and weighed, and the sulfur content is determined based on the flow rate recorded by the gas flow meter 12. In this embodiment, to facilitate the separation of elemental sulfur for sulfur content determination, both the mechanical filter 3 and the sulfur dissolving tank 7 employ physical collection methods; the inlet valve 2 is a shut-off valve. In other embodiments, the inlet pressure sensor 1 may be a temperature and pressure sensor or a pressure gauge, and the inlet valve 2 may be a pressure control valve or other valve switch.

[0028] Compared with existing technologies, the mechanical filter 3 and the sulfur dissolving tank 7 are connected to the gas production tree via pipelines. The opening of the inlet valve 2 is adjusted according to the wellhead pressure parameters measured by the inlet pressure sensor 1, thereby controlling the pressure of the subsequent pipelines. This allows the mechanical filter 3 and the sulfur dissolving tank 7 to operate continuously within the set pressure range. This avoids the steps of collecting, storing, and then separating elemental sulfur from the produced gas using a gas production box. It enables production gas sampling and elemental sulfur capture under long-term, large-volume conditions, avoiding randomness in sulfur content measurement results due to small sample sizes and reducing sulfur content measurement errors.

[0029] Based on the above embodiments, as a preferred embodiment, such as... Figure 1 , Figure 2 As shown, to facilitate the capture of elemental sulfur in the produced gas and the determination of its sulfur content, and to facilitate the installation and removal of the filter element 3-5, the housing 3-1 is designed as a horizontal cylindrical shape, and a quick-opening blind flange 3-4 is connected to the end of the housing 3-1 facing away from the first gas inlet 3-2 of the mechanical filter 3. Specifically, the first gas inlet 3-2 is located at one end of the housing 3-1, the first gas outlet 3-3 is located on the circumferential surface of the housing 3-1 near the other end, and the other end of the housing 3-1 is connected to the quick-opening blind flange 3-4. The first gas inlet 3-2 is used to connect to the outlet of the pressure control section, the first gas outlet 3-3 is used to connect to the sulfur dissolving tank 7, and the quick-opening blind flange 3-4 is used for the quick installation and removal of the filter element 3-5.

[0030] In other embodiments, the mechanical filter 3 may be a vertical cylindrical structure, with multiple layers of solid filter screens detachably connected from top to bottom inside the housing 3-1. The first gas inlet 3-2 is located at the top of the housing 3-1, and the first gas outlet 3-3 is located on the side wall near the bottom of the housing 3-1. A quick-opening blind flange 3-4 is provided at the bottom of the housing 3-1, allowing multiple solid filter screens to be removed sequentially. The multiple layers of solid filter screens can be individually connected to the inner wall of the mechanical filter 3, or they can be sequentially threaded and fixed onto a single mounting shaft for simultaneous inflow and outflow. In some other embodiments, the first gas inlet 3-2 and the first gas outlet 3-3 may be located at opposite ends of the housing 3-1. After the filter element 3-5 is installed inside the housing 3-1, flanges connect both ends of the housing 3-1 to the outlet of the pressure control pipe section and the second gas inlet 7-2 of the sulfur dissolving tank 7, respectively. When the filter element 3-5 needs to be removed, the flange connection at one end of the mechanical filter 3 can be opened.

[0031] Based on the above embodiments, as a preferred embodiment, such as... Figure 1 , Figure 2 As shown, since the produced gas inevitably carries downhole liquid when it enters the mechanical filter 3, in order to prevent the liquid from depositing in the housing 3-1 of the mechanical filter 3, a drain port 3-7 is provided at the bottom of the end of the housing 3-1 away from the first gas inlet 3-2 for draining the liquid after a period of collection or at the end of collection.

[0032] In addition, to ensure the safety of removing filter element 3-5, drain port 3-7 is also used to connect to nitrogen purging device 4. Drain port 3-7 is connected to nitrogen purging device 4 via a valve switch. During elemental sulfur collection, the valve switch is closed to prevent leakage. After elemental sulfur collection is complete, the valve switch is opened, and the residual gas inside housing 3-1 is purged using nitrogen purging device 4. After successful purging, the operator, wearing an air respirator and a hydrogen sulfide alarm, removes filter element 3-5 using a high-powered blower for strong purging. In other embodiments, it is also possible to have a separate purging port at the end of housing 3-1 near the first gas inlet 3-2. In this case, nitrogen purging device 4 can be directly connected to the purging port via a valve switch.

[0033] Based on the above embodiments, as a preferred embodiment, such as... Figure 1 , Figure 3As shown, hydrogen sulfide can react chemically with a sulfur solvent (carbon disulfide) under specific conditions to generate elemental sulfur. To reduce the error in measuring the elemental sulfur content in the produced gas, hydrogen sulfide sensors are connected to the second gas inlet 7-2 and the second gas outlet 7-3, respectively. The difference in hydrogen sulfide concentration at the second gas inlet 7-2 and the second gas outlet 7-3 of the sulfur dissolving tank 7 is used to determine whether hydrogen sulfide has reacted chemically to precipitate elemental sulfur within the tank 7. For ease of description, the hydrogen sulfide sensor at the second gas inlet 7-2 is defined as the first hydrogen sulfide sensor 6, and the hydrogen sulfide sensor at the second gas outlet 7-3 is defined as the second hydrogen sulfide sensor 10. By comparing the hydrogen sulfide concentration parameters measured by the first hydrogen sulfide sensor 6 and the second hydrogen sulfide sensor 10, it is determined whether hydrogen sulfide is leaking. When the hydrogen sulfide concentration changes, the passage is cut off through the inlet valve 2 on the pipeline. In other embodiments, the sulfur dissolving tank 7-1 may adopt the structure of the second separator disclosed in the invention patent with authorization announcement number CN113984578B in the background art.

[0034] In addition, to ensure the safe operation of the wellhead elemental sulfur capture system, a hydrogen sulfide sensor monitors the hydrogen sulfide concentration in the produced gas to control the opening and closing of inlet valve 2. When the hydrogen sulfide concentration exceeds a set value, the passage is cut off through inlet valve 2 on the pipeline. In other embodiments, other detection methods may be used for safety control.

[0035] Based on any of the above embodiments, as a preferred embodiment, such as Figure 1 , Figure 3 As shown, to ensure that elemental sulfur is fully absorbed by the sulfur dissolving agent in the sulfur dissolving tank 7, the sulfur dissolving tank 7-1 is designed as a vertical conical shape, and the height of the second gas inlet 7-2 on the sulfur dissolving tank 7-1 is lower than the height of the second gas outlet 7-3. The produced gas enters from the bottom of the sulfur dissolving tank 7-1 and exits from the top of the sulfur dissolving tank 7-1, increasing the residence time of the produced gas in the sulfur dissolving agent to ensure sufficient contact between the produced gas and the sulfur dissolving agent, thereby ensuring the absorption effect of the sulfur dissolving agent.

[0036] Based on the above embodiments, as a preferred embodiment, since the produced gas carries a portion of the sulfur-dissolving agent when it is discharged from the second gas outlet 7-3, a liquid screen is installed inside the sulfur dissolving tank 7-1 to separate the sulfur-dissolving agent carried in the gas, in order to improve the efficiency of the sulfur dissolving agent. The liquid screen is located between the sulfur dissolving agent liquid surface and the second gas outlet 7-3. The liquid screen can retain the liquid sulfur dissolving agent, thereby improving the removal efficiency of elemental sulfur by the sulfur dissolving agent. In other embodiments, it is not excluded that a liquid filter membrane or a hydrophobic valve, as disclosed in the invention patent with authorization publication number CN113984578B in the background art, may be used inside the sulfur dissolving tank 7-1 for sulfur dissolving agent separation.

[0037] Based on any of the above embodiments, as a preferred embodiment, such as Figure 1 As shown, to achieve automated control of the elemental sulfur capture system, the wellhead elemental sulfur capture system also includes a control module. The inlet valve 2 of the pressure control section is an electrically controlled valve, and the inlet pressure sensor 1, inlet valve 2, hydrogen sulfide sensor, and gas flow meter 12 are all communicatively connected to the control module to adjust the inlet valve 2 according to the parameters of the inlet pressure sensor 1, hydrogen sulfide sensor, and gas flow meter 12. Specifically, the control module includes a data acquisition submodule 16, a data processing submodule 17, and a safety control submodule 18 connected in series. The data acquisition submodule 16 is connected to the inlet pressure sensor 1, gas flow meter 12, first hydrogen sulfide sensor 6, and second hydrogen sulfide sensor 10, respectively. The safety control submodule 18 is connected to the inlet valve 2. Preferably, the inlet valve 2 is an electrically operated shut-off valve.

[0038] Specifically, the data acquisition submodule 16 is used for data acquisition and transmission; the data processing submodule 17 is used to display the acquired pressure, flow rate, and hydrogen sulfide concentration on a graphical interface, and to realize intelligent data acquisition, storage, analysis, processing, and remote transmission; the safety control submodule 18 realizes the linkage control between the hydrogen sulfide concentration and the inlet valve 2 through PLC program software. When the hydrogen sulfide concentration is within the safety set value range, the wellhead elemental sulfur capture system operates normally; when the hydrogen sulfide concentration exceeds the safety set value, the safety control submodule 18 sends a closing command to the control terminal of the inlet valve 2, automatically closing the inlet valve 2.

[0039] In other embodiments, the safety control system 18 can link the inlet pressure sensor 1, the gas flow meter 12, and each hydrogen sulfide sensor with the inlet valve 2 for coordinated control.

[0040] Based on any of the above embodiments, as a preferred embodiment, such as Figure 1 , Figure 4 As shown, in order to facilitate the measurement of the amount of sulfur dissolving agent and the measurement and weighing of elemental sulfur in the sulfur dissolving tank 7, the sulfur dissolving tank 7-1 is provided with an inlet and an outlet for the sulfur dissolving agent to flow in and out. Both the inlet and the outlet are connected to the metering tank 8-1 which stores the sulfur dissolving agent, and a circulation pump 19 is connected between the inlet and the metering tank 8-1.

[0041] Specifically, the metering tank 8-1 and the circulating pump 19 together constitute the sulfur dissolving agent injection device 8. The metering tank 8-1 includes a metering tank body 8-1-1 with a dosing port 8-1-5 and a drain port. The metering tank body 8-1-1 is cylindrical, and a breather valve 8-1-4 is connected to the upper cover plate 8-1-3 of the metering tank body 8-1-1. The bottom of the metering tank body 8-1-1 is provided with support feet 8-1-6. The circulating pump 19 replenishes the sulfur dissolving agent in the metering tank 8-1 to the sulfur dissolving tank 7 in a timely manner for the absorption of elemental sulfur in the produced gas. For ease of description and to distinguish it from the drain port of the mechanical filter 3 and the outlet of the sulfur dissolving tank 7, the drain port of the mechanical filter 3 is defined as the first drain port 3-7, the outlet of the sulfur dissolving tank 7 is defined as the second drain port, and the drain port of the metering tank 8-1 is defined as the third drain port 8-1-2.

[0042] In other embodiments, the sulfur dissolving tank 7 is also connected to a cleaning device 9, which includes a circulation pump 19 and a storage tank storing sulfur dissolving agent. The storage tank injects sulfur dissolving agent into the sulfur dissolving tank 7 through the circulation pump 19 to further rinse the residual elemental sulfur on the inner wall of the sulfur dissolving tank 7, and discharges the rinsed mixture into the metering tank 8-1 through the second drain port of the sulfur dissolving tank 7.

[0043] Based on any of the above embodiments, as a preferred embodiment, such as Figure 1 As shown, the pipeline outlet is connected to a tail gas treatment device 15. Furthermore, a flow valve 13 for controlling pipeline opening and closing is installed between the gas flow meter 12 and the tail gas treatment device 15. The tail gas treatment device 15 uses conventional techniques; for example, it can first undergo desulfurization via an alcohol amine method, using MEDA (N-methyldiethanolamine) to absorb hydrogen sulfide and carbon dioxide, then incinerate the remaining gas, and finally use an alkaline absorption tower for wet desulfurization of the flue gas. In addition, to facilitate the measurement of sulfur content in different gas reservoirs and the installation and relocation of the wellhead elemental sulfur capture system, it is designed as a skid-mounted structure.

[0044] Based on any of the above embodiments, as a preferred embodiment, such as Figure 1 As shown, an outlet pressure sensor 14 is connected to the pipeline outlet. Specifically, the outlet pressure sensor 14 is connected between the gas flow meter 12 and the tail gas treatment device 15. After connecting the wellhead elemental sulfur capture system to the gas production tree, before opening the inlet valve 2 on the pipeline, the process valve 13 is opened first to depressurize the wellhead elemental sulfur capture system, and the pressure inside the wellhead elemental sulfur capture system is observed through the outlet pressure sensor 14. When the pressure is within acceptable limits, the inlet valve 2 is then opened. In other embodiments, the gas flow rate inside the wellhead elemental sulfur capture system can be observed through the gas flow meter 12, and the inlet valve 2 is opened only when the gas flow rate approaches zero.

[0045] When used for sulfur content determination, this invention includes the following steps: 1) Open the quick-opening blind plate 3-4 of the mechanical filter 3, install the filter element 3-5 on the support frame 3-6, and make the inner end of the filter element 3-5 abut against the air inlet of the mechanical filter 3, and then close the quick-opening blind plate 3-4; 2) Turn on the circulation pump 19, inject the predetermined volume of physical sulfur dissolving agent into the sulfur dissolving tank 7 through the dosing port 8-1-5 of the metering tank 8-1 and the liquid inlet of the sulfur dissolving tank 7, and then turn off the circulation pump 19. 3) Check the airtightness of the elemental sulfur capture system, ensure that the inlet valve 2 of the pressure control section is closed, connect the elemental sulfur capture system to the non-production wing of the gas production tree, open the process valve 13, and release the pressure to zero. 4) Open the data acquisition submodule 16, data processing submodule 17 and safety control submodule 18 of the elemental sulfur capture system, and press the alarm buttons of inlet pressure sensor 1, hydrogen sulfide sensor 16 and hydrogen sulfide sensor 20. 5) Open the wellhead valve of the gas production tree. After the wellhead pressure stabilizes, close the wellhead valve. Then manually open the inlet valve 2 to slowly fill the mechanical filter 3 with the closed gas. After stabilization, open the pressure regulating valve 5 and the produced gas enters the sulfur dissolving tank 7. Open the back pressure valve 11 and the gas slowly passes through the sulfur dissolving tank 7. The physical sulfur dissolving agent is in a steady-state absorption process. After the gas is consumed, close the inlet valve 2. 6) Repeat step 5), repeat the trapping experiment and ventilation test until the cumulative gas volume reaches the required target value. Before the cumulative gas volume reaches the target value, observe the change of hydrogen sulfide concentration before and after the sulfur dissolving tank 7 at regular intervals. 7) When the hydrogen sulfide concentration changes, the test ends, the inlet valve 2 is closed, and the nitrogen purging device 4 is started to purge the pipeline after the mechanical filter 3 until the purging is qualified; 8) After the replacement is qualified and the pressure measured at the outlet pressure sensor 214 returns to zero, the operator puts on the air respirator and hydrogen sulfide alarm, and under the condition of strong purging with a high-power fan, opens the quick-opening blind plate 3-4 cover of the mechanical filter 3, takes out the filter element 3-5 and soaks the filter element 3-5 in the physical sulfur dissolving agent. 9) Discharge the physical sulfur dissolving agent solution in the sulfur dissolving tank 7 into the metering tank 8-1, and use the cleaning system 9 to flush the sulfur dissolving tank 7. The flushed physical sulfur dissolving agent solution is also discharged into the metering tank 8-1 to allow the physical sulfur dissolving agent solution in the metering tank 8-1 to settle fully. 10) The solution soaked in filter element 3-5 and the solution in metering tank 8-1 are dried by distillation, and then weighed using an analytical balance to determine the content of elemental sulfur in the cumulative gas volume of the sulfur-containing gas reservoir.

[0046] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wellhead elemental sulfur capture system, characterized in that, It includes a pipeline for direct connection to the wellhead, with an inlet pressure sensor for measuring wellhead pressure, an inlet valve for regulating pipeline pressure based on pressure measurement parameters, a mechanical filter and a sulfur dissolving tank for capturing elemental sulfur, and a gas flow meter connected in series from upstream to downstream. The mechanical filter has a filter element for capturing elemental sulfur that can be removed from the housing, and the sulfur dissolving tank contains a sulfur dissolving agent for capturing elemental sulfur. Pressure control valves for pressure regulation are connected between the mechanical filter and the sulfur dissolving tank, and between the sulfur dissolving tank and the gas flow meter.

2. The wellhead elemental sulfur capture system according to claim 1, characterized in that, The housing is a horizontal cylindrical shape, and a quick-opening blind flange is connected to the end of the housing that is away from the gas inlet of the mechanical filter.

3. The wellhead elemental sulfur capture system according to claim 1, characterized in that, A drain port is provided at the bottom of the end of the housing that is away from the gas inlet of the mechanical filter.

4. The wellhead elemental sulfur capture system according to claim 1, characterized in that, The gas inlet and gas outlet of the tank are respectively connected to hydrogen sulfide sensors.

5. The wellhead elemental sulfur capture system according to any one of claims 1-4, characterized in that, The tank has a vertical structure, and the height of the gas inlet on the tank is lower than the height of the gas outlet on the tank.

6. The wellhead elemental sulfur capture system according to claim 5, characterized in that, A liquid baffle is installed inside the tank between the sulfur dissolving agent liquid surface and the gas outlet to separate the sulfur dissolving agent carried in the gas.

7. The wellhead elemental sulfur capture system according to any one of claims 1-4, characterized in that, The wellhead elemental sulfur capture system also includes a control module. The inlet valve is an electrically controlled valve, and the inlet pressure sensor, the inlet valve, the hydrogen sulfide sensor, and the gas flow meter are all connected to the control module to adjust the inlet valve according to the parameters of the inlet pressure sensor, the hydrogen sulfide sensor, and the gas flow meter.

8. The wellhead elemental sulfur capture system according to any one of claims 1-4, characterized in that, The tank is equipped with an inlet and an outlet for the sulfur dissolving agent to flow in and out, respectively. Both the inlet and outlet are connected to a metering tank containing the sulfur dissolving agent, and a circulation pump is connected between the inlet and the metering tank.

9. The wellhead elemental sulfur capture system according to any one of claims 1-4, characterized in that, The pipeline outlet is connected to an exhaust gas treatment device.

10. The wellhead elemental sulfur capture system according to any one of claims 1-4, characterized in that, The pipeline outlet connection is equipped with an outlet pressure sensor.

Images