Methane monitoring system and method in oil field area

Abstract

The invention provides an oil field area methane monitoring system and method. The system comprises a pumping module, an optical signal measuring device and a data acquisition and processing module, the pumping module is communicated with the optical signal measuring device, and the optical signal measuring device is electrically connected with the data acquisition and processing module; the pumping module is used for collecting a gas sample and conveying the gas sample to the optical signal measuring device; the optical signal measuring device comprises a laser, a ring-down cavity and a detector; the laser is used for generating laser and emitting the laser into the ring-down cavity, so that the laser is repeatedly reflected in the ring-down cavity and penetrates through the gas sample, and the light intensity of the laser in the ring-down cavity is attenuated; the detector receives the emergent laser after light intensity attenuation and converts a light signal of the emergent laser into an electric signal; the data acquisition and processing module analyzes and calculates the methane concentration in the gas sample based on the electric signal so as to monitor the methane concentration. The sensitivity and the accuracy of methane monitoring are improved, and long-time online monitoring is realized.

Description

Technical Field

[0001] This invention belongs to the field of environmental monitoring technology, and specifically relates to a methane monitoring system and method for oilfield areas. Background Technology

[0002] During oilfield production, various processes and geological conditions lead to the volatilization of large amounts of flammable gases, especially methane and ethane, resulting in excessively high concentrations of flammable gases in localized areas. This phenomenon not only increases the risk of safety accidents such as fires and explosions but also pollutes the environment.

[0003] Traditional combustible gas monitoring methods, such as catalytic combustion, electrochemical, thermal conductivity, and semiconductor sensor methods, while meeting certain monitoring needs to some extent, generally suffer from several problems. These include: low detection sensitivity (these methods often struggle to achieve high-sensitivity monitoring); short lifespan (long-term exposure to harsh environments leads to performance degradation); and inability to perform long-term online monitoring (these methods cannot continuously monitor gas concentration changes, hindering the timely detection of potential safety hazards). Especially under complex atmospheric conditions and wind effects, these methods are susceptible to interference from other gases, leading to increased false alarm rates and unreliable monitoring results.

[0004] Furthermore, industrial facilities such as oil refineries often exist near oilfield production areas, and these facilities also produce flammable gases such as methane during their production processes. Driven by wind, these gases can diffuse into the oilfield production area, interfering with existing monitoring equipment and further complicating monitoring. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides an oilfield area methane monitoring system and method to solve or alleviate the problems existing in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution: In the first aspect of this application, an oilfield area methane monitoring system is provided, which includes: a pump suction module, an optical signal measuring device, and a data acquisition and processing module; The pump suction module is connected to the optical signal measuring device, and the optical signal measuring device is electrically connected to the data acquisition and processing module; The pump module is used to collect gas samples and deliver the gas samples to the optical signal measurement device; The optical signal measurement device includes a laser, a ring-down cavity, and a detector. The laser generates a laser of a preset wavelength and directs it into the ring-down cavity, causing the laser to be repeatedly reflected within the cavity. The ring-down cavity contains a gas sample, and the repeatedly reflected laser passes through the gas sample, causing methane molecules in the gas sample to absorb the laser energy, thus attenuating the intensity of the laser within the ring-down cavity. The detector is positioned on the light-emitting path of the ring-down cavity to receive the attenuated emitted laser light and convert the optical signal of the emitted laser light into an electrical signal. The data acquisition and processing module is electrically connected to the detector to analyze and calculate the methane concentration in the gas sample based on the electrical signal, so as to monitor the methane concentration.

[0007] Optionally, the monitoring system further includes: a gas flow direction prediction module; The gas flow direction prediction module includes an environmental information acquisition unit and a gas source tracing unit; The environmental information acquisition unit is used to collect environmental information in order to establish a gas flow model based on the environmental information; The gas tracing unit is used to analyze gas flow direction information based on the methane concentration data and the gas flow model to obtain the area where the methane gas leakage source is located.

[0008] Optionally, the monitoring system further includes an airflow analysis unit, which is used to build a gas flow model based on computer computing power; the establishment of the gas flow model includes constructing a gas flow and airflow direction gradient model based on environmental information; and processing the airflow direction gradient model based on error analysis algorithms and data optimization algorithms to improve the sensitivity and accuracy of the gas flow model.

[0009] Optionally, the monitoring system further includes: The alarm module is used to assess whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded, and the area where the methane gas leak source is located is obtained based on the gas tracing unit, and an abnormal concentration alarm is triggered.

[0010] Optionally, the concentration anomaly warning includes concentration anomaly warning within the oilfield area and concentration anomaly warning outside the oilfield area: The abnormal concentration alarm within the oilfield area is configured to trigger an alarm signal when a leak source is detected to be located inside the oilfield area, instructing personnel to stop operations and initiate the leak anomaly handling procedure. The abnormal concentration alarm outside the oilfield area is configured not to trigger an alarm signal when the leak source is detected to be outside the oilfield area. Instead, the leak source is marked to indicate its location, guiding subsequent dispatch of personnel to verify the abnormal leak situation.

[0011] Optionally, the monitoring system further includes a monitoring site configuration module, which includes: a sampling tower, a monitoring station building, and a tower location assessment module; The sampling tower is equipped with a sampling port and an environmental information acquisition unit. The sampling port is connected to the pump module and is used to collect gas samples. The environmental information acquisition unit is installed on the sampling tower to collect environmental information corresponding to the gas samples. The monitoring station is used to house the optical signal measurement device and the data acquisition and processing module. The tower location assessment module is used to perform one or a combination of the following methods to determine the construction location of the sampling tower and the monitoring station: Assess the interference between the sampling tower and monitoring station and other monitoring projects in the oilfield area to ensure that the sampling tower and monitoring station do not interfere with other monitoring projects, thereby determining the first construction location; Assess the safety impact of the sampling tower and monitoring station on other monitoring projects in the oilfield area, ensuring that the sampling tower and monitoring station meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determined the minimum distance between the sampling tower and the monitoring station building, based on monitoring only methane gas, to identify the location for the fourth construction site. Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location.

[0012] Optionally, the environmental information acquisition unit includes: An anemometer is used to collect wind speed and direction information; A thermometer and hygrometer are used to collect temperature and humidity information. A barometer is used to collect air pressure information; GPS positioning systems are used to obtain the geographic coordinates of the monitoring location in order to pinpoint the source of the gas leak.

[0013] Optionally, the pumping module includes multiple pumping units arranged along the height of the sampling tower; each pumping unit includes a sampling tube and a sampling pump; the sampling port is connected to the sampling tube in a one-to-one correspondence, and the sampling pump is connected to the optical signal measuring device to transport the gas sample collected at the sampling port to the optical signal measuring device for analysis through the sampling tube.

[0014] Optionally, the monitoring system further includes a calibration module, which includes a multi-port switching valve and multiple standard gas cylinders; The multi-port switching valve is used for inlet selection and instrument calibration, and it is equipped with multiple sample gas valve ports, multiple standard gas valve ports, and an outlet valve port. The plurality of sample gas valve ports are connected one-to-one with the plurality of pump suction units; The plurality of standard gas valve ports are connected to the plurality of standard gas cylinders, and the plurality of standard gas cylinders are respectively filled with low-concentration working standard gas, target standard gas, and high-concentration working standard gas; The air outlet valve is connected to the optical signal measuring device.

[0015] Optionally, the optical signal measuring device further includes a flow control device, whose inlet end is connected to the outlet valve and whose outlet end is connected to the optical signal measuring device, for controlling the flow rate of the gas sample entering the decay chamber within a preset range.

[0016] Optionally, the monitoring system further includes a temperature control module, which includes a PCB heating plate and a temperature control board, for maintaining the optical signal measuring device at a preset operating temperature.

[0017] Optionally, the monitoring system further includes a water removal device for removing water vapor from the gas sample.

[0018] Optionally, the water removal equipment includes a low-temperature cold trap device, which separates water vapor from the gas sample through low-temperature condensation.

[0019] Optionally, the laser is a DFB laser; In another aspect of this application, a method for monitoring methane in an oilfield area is provided, comprising the following steps: Gas samples are collected using a pump-suction module and then transported to the optical signal measurement device. A laser of a preset wavelength is generated by a laser and injected into the ring-down cavity of an optical signal measurement device, so that the laser is repeatedly reflected in the ring-down cavity; the repeatedly reflected laser passes through a gas sample in the ring-down cavity, so that the methane molecules in the gas sample absorb the laser energy, causing the intensity of the laser in the ring-down cavity to decrease. The detector receives the emitted laser light after the light intensity has attenuated and converts the optical signal of the emitted laser light into an electrical signal. The data acquisition and processing module analyzes and calculates the methane concentration in the gas sample based on the electrical signal to monitor the methane concentration.

[0020] Optionally, the monitoring method further includes: Environmental information is collected by an environmental information acquisition unit, and a gas flow model is established based on the environmental information. The gas tracing unit analyzes the gas flow direction information based on the methane concentration data and the gas flow model to determine the area where the methane gas leak source is located.

[0021] Optionally, the gas flow model established based on environmental information includes: building a gas flow model based on computer computing power; constructing a gas flow and airflow direction gradient model based on environmental information; and processing the airflow direction gradient model based on error analysis algorithms and data optimization algorithms to improve the sensitivity and accuracy of the gas flow model.

[0022] Optionally, the monitoring method further includes: The alarm module assesses whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded. Based on the gas tracing unit, the area where the methane gas leak source is located is obtained, and an abnormal concentration alarm is triggered.

[0023] Optionally, the concentration anomaly warning includes concentration anomaly warning within the oilfield area and concentration anomaly warning outside the oilfield area: When a leak source is detected to be located inside the oil field area, an alarm for abnormal concentration in the oil field area is triggered, and an alarm signal is issued to instruct personnel to stop operations and initiate the leak anomaly handling procedure. When a leak source is detected to be located outside the oilfield area, an alarm for abnormal concentration outside the oilfield area is triggered. Instead of issuing an alarm signal, the location of the leak source is indicated by marking the leak source, guiding subsequent dispatch of personnel to verify the abnormal leak situation.

[0024] Optionally, it also includes: Based on the tower location assessment module, one or a combination of the following methods are used to determine the construction locations of the sampling tower and the monitoring station: Assess the interference between the sampling tower and monitoring station and other monitoring projects in the oilfield area to ensure that the sampling tower and monitoring station do not interfere with other monitoring projects, thereby determining the first construction location; Assess the safety impact of the sampling tower and monitoring station on other monitoring projects in the oilfield area, ensuring that the sampling tower and monitoring station meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determined the minimum distance between the sampling tower and the monitoring station building, based on monitoring only methane gas, to identify the location for the fourth construction site. Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location; A sampling port is installed on the sampling tower, and a gas sample is collected through a pumping module connected to the sampling port. An environmental information acquisition unit is installed on the sampling tower to collect environmental information corresponding to the gas samples; A monitoring station is set up to house the optical signal measurement device and the data acquisition and processing module.

[0025] Optionally, the environmental information corresponding to the gas sample includes: Based on an anemometer, wind force and direction information is collected; Based on a thermometer and hygrometer, temperature and humidity information are collected; Based on a barometer, collect air pressure information; The GPS positioning system is used to obtain the geographic coordinates of the monitoring location in order to locate the source of the gas leak.

[0026] Optionally, the step of installing a sampling port on the sampling tower and collecting gas samples through a pumping module connected to the sampling port includes: Multiple pumping units are arranged along the height of the sampling tower, and each pumping unit includes a sampling tube and a sampling pump. Each sampling port is connected to a sampling tube in a one-to-one correspondence, and a gas sample is collected through each sampling port; Gas samples collected at each sampling port are transported through sampling tubes to an optical signal measurement device for analysis using a sampling pump.

[0027] Optionally, it also includes instrument calibration and intake selection steps: Set up a calibration module, including a multi-port switching valve and multiple standard gas cylinders; A multi-port switching valve is used for gas inlet selection and instrument calibration. It is equipped with multiple sample gas valve ports, low-concentration working standard gas valve ports, target standard gas valve ports, high-concentration working standard gas valve ports, and gas outlet valve ports. Connect the sample gas valve port to the pump suction unit one by one, connect the low concentration working standard gas valve port to the low concentration standard gas cylinder, connect the target standard gas valve port to the standard gas cylinder, connect the high concentration working standard gas valve port to the standard gas cylinder, and connect the gas outlet valve port to the optical signal measuring device. Instrument calibration can be performed by switching between different standard gas valve ports to select standard gases of different concentrations. Different sample gases can be selected for methane concentration detection by switching between different sample gas valve ports.

[0028] Optionally, it also includes: a flow control device installed in front of the optical signal measuring device, with its inlet end connected to the outlet valve and its outlet end connected to the optical signal measuring device, so as to control the flow control device to maintain the flow rate of the gas sample entering the decay chamber within a preset range.

[0029] Optionally, it also includes: a temperature control module, including a PCB heating plate and a temperature control board, for maintaining the optical signal measuring device within a preset operating temperature range.

[0030] Optionally, the monitoring method further includes: setting up a water removal device to remove water vapor from the gas sample.

[0031] Optionally, the step of setting up a water removal device to remove water vapor from the gas sample includes: setting up a low-temperature cold trap device to separate water vapor from the gas sample through the low-temperature condensation effect of the low-temperature cold trap device.

[0032] Optionally, the laser is a DFB laser.

[0033] This application provides a methane monitoring system for oilfield areas, comprising: a pumping module, an optical signal measuring device, and a data acquisition and processing module; the pumping module is connected to the optical signal measuring device, and the optical signal measuring device is electrically connected to the data acquisition and processing module; the pumping module is used to collect gas samples and transport the gas samples to the optical signal measuring device; the optical signal measuring device includes a laser, a ring-down cavity, and a detector; the laser is used to generate laser light of a preset wavelength and inject it into the ring-down cavity, so that the laser light is repeatedly reflected within the ring-down cavity; the ring-down cavity contains the gas sample, and the repeatedly reflected laser light passes through the gas sample, so that the methane molecules in the gas sample absorb the laser energy, causing the light intensity of the laser light in the ring-down cavity to attenuate; the detector is set on the light output path of the ring-down cavity to receive the emitted laser light after the light intensity has attenuated, and convert the optical signal of the emitted laser light into an electrical signal; the data acquisition and processing module is electrically connected to the detector to analyze and calculate the methane concentration in the gas sample in real time based on the electrical signal, thereby monitoring the methane concentration, improving the sensitivity and accuracy of methane monitoring, and realizing long-term online monitoring. Attached Figure Description

[0034] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of the accompanying drawings are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a schematic diagram of the monitoring system according to the embodiments of this application; Figure 2 This is a schematic diagram of the pump suction module according to an embodiment of this application; Figure 3 This is a schematic diagram of the monitoring station according to the embodiments of this application; Figure 4 This is a schematic diagram of the sampling tower according to an embodiment of this application; The labels in the diagram indicate: 1. Pump suction module; 11. Sampling port; 12. Sampling tube; 13. Water removal equipment; 14. Sampling pump; 15. Calibration module; 16. Semi-permeable membrane; 17. Pressure regulating device; 18. Flow control device; 2. Optical signal measuring device; 3. Data acquisition and processing module; 4. Monitoring station; 41. GPS positioning system; 5. Sampling tower; 51. Environmental information acquisition unit. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0036] It should be noted that the term "comprising" in the specification, claims, and accompanying drawings of this application is intended to cover non-exclusive inclusion. In this application, the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily used to better describe this application and its embodiments and are not intended to limit the indicated components to having a specific orientation. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Figure 1This is a schematic diagram of the monitoring system according to the embodiments of this application; Figure 2 This is a schematic diagram of the pump suction module according to an embodiment of this application; Figure 3 This is a schematic diagram of the monitoring station according to the embodiments of this application; Figure 4 This is a schematic diagram of the sampling tower according to an embodiment of this application; Exemplary System like Figure 1 - Figure 4 As shown in the embodiment of the methane monitoring system for an oilfield area provided in this application, the system includes: a pumping module 1, an optical signal measuring device 2, and a data acquisition and processing module 3; the pumping module 1 is connected to the optical signal measuring device 2, and the optical signal measuring device 2 is electrically connected to the data acquisition and processing module 3; the pumping module 1 is used to collect gas samples and transport the gas samples to the optical signal measuring device 2; the optical signal measuring device 2 includes a laser, a ring-down cavity, and a detector; the laser is used to generate laser light of a preset wavelength and inject it into the ring-down cavity so that the laser light is repeatedly reflected in the ring-down cavity; the ring-down cavity contains the gas sample, and the repeatedly reflected laser light passes through the gas sample so that the methane molecules in the gas sample absorb the laser energy, causing the light intensity of the laser light in the ring-down cavity to attenuate; the detector is set on the light output path of the ring-down cavity to receive the emitted laser light after the light intensity has attenuated, and convert the optical signal of the emitted laser light into an electrical signal; the data acquisition and processing module 3 is electrically connected to the detector to analyze and calculate the methane concentration in the gas sample based on the electrical signal, so as to monitor the methane concentration. This improved the sensitivity and accuracy of methane monitoring, enabling long-term online monitoring.

[0039] Optionally, the monitoring system further includes: a gas flow direction prediction module; The gas flow direction prediction module includes an environmental information acquisition unit 51 and a gas source tracing unit; The environmental information acquisition unit 51 is used to collect environmental information in order to establish a gas flow model based on the environmental information; The gas tracing unit is used to analyze gas flow direction information based on the methane concentration data and the gas flow model to obtain the area where the methane gas leakage source is located.

[0040] In this embodiment, the environmental information collected by the environmental information acquisition unit 51, such as wind direction, wind speed, temperature, and humidity, allows the system to construct an accurate gas flow model. Combined with the methane concentration data provided by the data acquisition and processing module 3, the gas source tracing unit can use complex algorithms to analyze the flow direction and speed of methane gas, thereby quickly locating the leak source. This is crucial for timely response measures to prevent the spread of methane leaks and safety accidents. Furthermore, after a methane leak is detected, traditional monitoring methods often require significant time and manpower to search for the leak source. However, a monitoring system equipped with a gas flow direction prediction module can quickly provide the location information of the leak source, enabling the emergency response team to quickly assemble and directly proceed to the leak point, greatly improving the efficiency of the emergency response. Simultaneously, in large-scale and complex environments such as oil fields, monitoring and responding to methane leaks requires reasonable resource allocation. Through the gas flow direction prediction module, the system can predict the range and trend of methane diffusion, providing the emergency response team with a scientific basis for decision-making and helping them to more rationally allocate human, material, and financial resources to achieve optimal resource allocation. Furthermore, the addition of the gas flow prediction module transforms the monitoring system from a simple data acquisition and analysis tool into a comprehensive platform with intelligent analysis and prediction capabilities. This enhanced intelligence not only improves the accuracy and reliability of the monitoring system but also makes it more adaptable to complex and ever-changing monitoring environments. Finally, methane leakage is a significant hidden danger in oilfield safety management. By introducing the gas flow prediction module, the monitoring system can quickly provide comprehensive information support when a methane leakage occurs, helping oilfield managers to fully understand the leakage situation and formulate effective response measures. This is of great significance for improving oilfield safety management, ensuring production safety, and protecting the environment.

[0041] Optionally, the monitoring system further includes an alarm module, used to assess whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded, and the area where the methane gas leakage source is located is obtained based on the gas tracing unit, and an abnormal concentration alarm is triggered.

[0042] Optionally, the concentration anomaly alarm includes concentration anomaly alarms within the oilfield area and concentration anomaly alarms outside the oilfield area: the concentration anomaly alarm within the oilfield area is configured to trigger an alarm signal when a leak source is detected within the oilfield area, instructing personnel to stop operations and initiate a leak anomaly handling procedure; the concentration anomaly alarm outside the oilfield area is configured not to trigger an alarm signal when a leak source is detected outside the oilfield area, but instead to indicate the location of the leak source by marking it, guiding subsequent dispatch of personnel to verify the leak anomaly.

[0043] In this embodiment, the alarm module can assess in real time whether the methane concentration exceeds a preset safety threshold. Once an exceedance is detected, the combustible gas concentration anomaly alarm mechanism is immediately triggered. This immediacy is crucial for preventing methane leaks from escalating into catastrophic consequences, providing valuable early warning time for oilfield workers and surrounding communities. Furthermore, while triggering the concentration anomaly alarm, the system not only records current methane concentration data and environmental information but also quickly locates the leak source area through the gas tracing unit, determining whether the leak source is located within or outside the oilfield area. This precise location capability allows the emergency response team to quickly pinpoint the source of the problem, enabling more effective implementation of countermeasures. Additionally, the system further categorizes concentration anomaly alarms into two scenarios: within and outside the oilfield area, and adopts different response strategies accordingly. For leaks within the oilfield area, an alarm signal is immediately triggered, instructing workers to stop operations and initiate leak anomaly handling procedures to prevent escalation. For leaks outside the area, the alarm status is maintained but not triggered; the leak source location is marked to guide subsequent verification, avoiding unnecessary waste of human resources and improving resource utilization efficiency. Furthermore, through pre-defined response procedures and clear division of responsibilities, the system ensures that relevant departments and personnel can respond quickly and take effective measures after an abnormal concentration alarm is triggered. This efficient emergency response mechanism helps reduce accident losses and protect personnel and environmental safety. Finally, the alarm module and its sub-functions not only supplement and improve the existing monitoring system but also optimize and enhance the entire oilfield safety management process. By introducing intelligent alarm and response mechanisms, the system can automatically identify potential risks, provide timely warnings, and guide effective responses, thereby improving the overall level of oilfield safety management.

[0044] Optionally, the monitoring system further includes a monitoring site configuration module, which includes: a sampling tower 5, a monitoring station 4, and a tower location assessment module; The sampling tower 5 is equipped with a sampling port 11 and an environmental information acquisition unit 51. The sampling port 11 is connected to the pump module 1 and is used to collect gas samples. The environmental information acquisition unit 51 is installed on the sampling tower 5 to collect environmental information corresponding to the gas samples. The monitoring station is used to house the optical signal measuring device 2 and the data acquisition and processing module 3; The tower location assessment module is used to perform one or a combination of the following methods to determine the construction location of the sampling tower 5 and the monitoring station 4: Assess the mutual interference between the sampling tower 5 and monitoring station 4 and other monitoring projects in the oilfield area, so that the sampling tower 5 and monitoring station 4 do not interfere with other monitoring projects, and determine the first construction location; Assess the safety impact of the sampling tower 5 and monitoring station 4 on other monitoring projects in the oilfield area, ensuring that the sampling tower 5 and monitoring station 4 meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determines the minimum distance between sampling tower 5 and monitoring station 4 when only methane gas is being monitored, in order to determine the location for the fourth construction site; Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location.

[0045] In this embodiment, the sampling port 11 installed on the sampling tower 5 is directly exposed to the atmosphere, effectively avoiding interference from ground obstacles on gas flow. Furthermore, the tower location assessment module provides a scientific basis for the construction location of the sampling tower 5 and the monitoring station 4 by comprehensively evaluating various factors such as interference, safety, sampling efficiency, and geographical location. This helps optimize the overall system layout, reduce unnecessary resource waste, and ensure harmonious coexistence between the monitoring system and other monitoring projects. Additionally, by assessing the interference and safety impact of the monitoring system on existing monitoring projects at the site, it can be ensured that the newly established methane monitoring system will not adversely affect other monitoring projects while meeting safety requirements, thus helping to maintain the overall stability and safety of the monitoring site and ensuring the smooth operation of monitoring work. Moreover, the gas sample residence time is assessed; the residence time is the time it takes for the gas sample to enter the cavity decay device from the sampling port 11. Ensuring that the residence time does not exceed 60 seconds helps reduce gas sample loss and changes during collection, improves sampling efficiency, and a shorter residence time also means that the system can respond more quickly to changes in methane concentration, improving the real-time performance of monitoring. Furthermore, by evaluating the minimum distance between sampling tower 5 and monitoring station 4, construction costs can be minimized while meeting monitoring requirements. Choosing the highest geographical location as the construction site helps reduce interference from ground obstacles to the monitoring equipment, lowering maintenance difficulty and costs. Finally, the tower location evaluation module considers a combination of various evaluation methods and factors, enabling the system to be flexibly adjusted and optimized according to the specific conditions and monitoring needs of different oilfield areas. This adaptability and scalability helps ensure that the monitoring system remains efficient, stable, and reliable during long-term operation.

[0046] Optionally, the sampling port 11 and the environmental information acquisition unit 51 are installed at the same height to ensure that the gas sample collected through the sampling port 11 corresponds to the environmental information collected through the environmental information acquisition unit 51, thereby improving the accuracy of the data.

[0047] Optionally, the environmental information acquisition unit 51 includes: An anemometer is used to collect wind speed and direction information; A thermometer and hygrometer are used to collect temperature and humidity information. A barometer is used to collect air pressure information; GPS positioning system 41 is used to obtain the geographic coordinates of the monitoring location in order to locate the source of the gas leak.

[0048] In this embodiment, the data provided by the anemometer is crucial for analyzing the flow direction and velocity of methane gas. Combined with data from the thermometer, hygrometer, and barometer, a more accurate gas flow model can be constructed, thereby improving the predictive ability of methane gas flow direction. This is significant for quickly locating gas leak sources, assessing leak risks, and developing emergency response strategies. Furthermore, by monitoring environmental parameters such as temperature, humidity, and air pressure in real time, the system can automatically adjust monitoring parameters and algorithms to adapt to monitoring needs under different environmental conditions. This environmental adaptability allows the monitoring system to maintain efficient and stable operation in various complex environments. Moreover, the GPS positioning system 41 not only provides the geographic coordinates of the monitoring location but also helps to accurately calculate the specific location of the gas leak source by combining the gas flow model and other environmental information. This precise positioning capability is crucial for timely response measures, preventing the spread of methane leaks, and reducing environmental pollution. Additionally, when a methane leak occurs, the real-time environmental information provided by the environmental information acquisition unit 51 provides important reference for the emergency response team. The team can quickly assess the leak risk and impact range based on changes in environmental parameters and develop effective emergency response plans, which helps to shorten response time and reduce accident losses. Furthermore, the accumulated environmental information data can be used for subsequent data analysis and research. In-depth mining and analysis of this data can reveal the correlation between methane leaks and environmental factors, providing a more scientific basis for environmental protection and safety management in oilfield areas. Finally, the introduction of the environmental information acquisition unit 51 enhances the monitoring system's intelligence capabilities. The system can automatically collect, process, and analyze environmental information, and make intelligent judgments and decisions based on this information. This increased intelligence helps reduce the possibility of human intervention and misjudgment, improving the accuracy and reliability of the monitoring system.

[0049] Optionally, a cavity mirror is provided inside the ring-down cavity, and the cavity mirror is used to repeatedly reflect the laser.

[0050] In this embodiment, the high-reflectivity cavity mirror within the ring-down cavity can repeatedly reflect the laser, significantly increasing the number of reflections within the cavity. This multiple reflection effect significantly extends the optical path of the laser within the cavity, thereby increasing the absorption opportunity of methane gas. Due to the increased absorption optical path, the system's detection sensitivity is correspondingly improved, enabling the detection of lower concentrations of methane gas. Furthermore, the ring-down time of the laser within the cavity is only related to the reflectivity of the cavity mirror and the absorption coefficient of the methane gas. This characteristic allows CRDS cavity ring-down spectroscopy to eliminate interference factors such as laser power fluctuations during detection, thereby improving detection accuracy and stability. By accurately measuring the ring-down time of the laser within the cavity, the concentration of methane gas can be accurately calculated. In addition, the use of the high-reflectivity cavity mirror makes the ring-down cavity a relatively closed environment, effectively isolating it from external environmental interference. This design reduces the impact of environmental noise, stray light, and other factors on the detection results, improving the system's anti-interference capability and stability. Furthermore, the introduction of cavity mirrors makes the ring-down cavity structure more compact and efficient. By rationally designing the reflectivity and shape of the cavity mirrors, the propagation path and mode of light within the cavity can be further optimized, improving the overall performance of the system. The material and manufacturing process of the cavity mirrors also have a significant impact on the system's performance. Using high-reflectivity lenses, such as those exceeding 99.99%, helps reduce light loss during reflection and improves the system's light utilization rate. In addition, cavity ring-down spectroscopy is not only applicable to the detection of methane gas but can also be extended to the detection of other gases. By adjusting the laser wavelength and selecting appropriate cavity mirror materials, simultaneous detection of multiple gases can be achieved. This multi-component detection capability provides a more comprehensive and efficient solution for environmental monitoring in oilfield areas.

[0051] Optionally, the monitoring system further includes: a data storage read / write module; The data storage read / write module is used to store and read monitoring data to ensure the integrity and traceability of the monitoring data.

[0052] In this embodiment, the data storage read / write module is responsible for the secure and reliable storage of data generated during the monitoring process, including methane concentration and environmental parameters. This centralized storage method avoids potential data loss, damage, or tampering during transmission or processing, thus ensuring the integrity and security of the monitoring data. Furthermore, through the data storage read / write module, users can easily access historical monitoring data. This traceability is crucial for data analysis, trend prediction, and accident investigation. For example, in the event of a methane leak, by reviewing historical data, the leak source can be quickly located, the extent of the leak and its impact can be assessed, providing strong support for emergency response and accident handling. In addition, the large amount of stored monitoring data provides abundant resources for data analysis and mining. By employing advanced data analysis techniques, valuable information and patterns can be extracted from massive amounts of data, providing a scientific basis for environmental protection, safety management, and production optimization in oilfield areas. Finally, the data storage read / write module typically possesses efficient data management and access mechanisms, enabling rapid response to data read / write requests based on actual needs. This optimized design helps reduce system resource waste and improves overall system performance and response speed.

[0053] Optionally, the pumping module 1 includes multiple pumping units arranged along the height of the sampling tower 5; each pumping unit includes a sampling tube 12 and a sampling pump 14; the sampling port 11 is connected to the sampling tube 12 in a one-to-one correspondence, and the sampling pump 14 is connected to the optical signal measuring device 2 to transport the gas sample collected at the sampling port 11 to the optical signal measuring device 2 for analysis through the sampling tube 12.

[0054] In this embodiment, multiple pump units are arranged along the height of the sampling tower 5, enabling precise collection of gas samples from different altitude layers. Since the distribution of gases such as methane in the air can be affected by various factors such as temperature, wind speed, and terrain, resulting in differences at different altitudes, this stratified sampling method can significantly improve the accuracy and coverage of monitoring, providing a more comprehensive reflection of the methane concentration distribution within the area. Furthermore, the simultaneous operation of multiple pump units allows for parallel collection of gas samples from multiple altitude layers, shortening the overall sampling time. This is particularly important for monitoring tasks requiring rapid response, ensuring sufficient monitoring data is obtained in a short time, providing strong support for subsequent data analysis and decision-making. Moreover, each pump unit includes an independent sampling tube 12 and sampling pump 14, allowing independent control of the sampling flow rate and sampling time, reducing cross-contamination and interference between samples from different altitude layers. Since the sampling port 11 is connected one-to-one with the sampling tube 12, it ensures that each sample comes from a specific sampling location, further reducing sampling errors. Furthermore, oilfield areas often have complex terrain and variable environments. Traditional single-point sampling methods may not be able to comprehensively reflect the methane concentration in the area. However, arranging multiple pump units along the height of sampling tower 5 allows for flexible adaptation to sampling needs at different heights and under varying terrain conditions, improving the adaptability and flexibility of the monitoring system. Moreover, the parallel operation of multiple pump units ensures that even if one or more units fail, the normal sampling operation of the others will not be affected. This redundancy design significantly enhances the reliability and stability of the monitoring system, ensuring continuous and stable operation in complex environments. Finally, since each pump unit collects gas samples from a specific altitude layer, these sample data can be categorized, stored, and analyzed. This stratified data provides a richer source of information for subsequent data analysis and mining, helping to discover the patterns, trends, and influencing factors of methane concentration changes at different altitude layers.

[0055] Optionally, the monitoring system further includes a calibration module 15, which includes a multi-port switching valve and multiple standard gas cylinders; The multi-port switching valve is used for inlet selection and instrument calibration, and it is equipped with multiple sample gas valve ports, multiple standard gas valve ports, and an outlet valve port. The plurality of sample gas valve ports are connected one-to-one with the plurality of pump suction units; The plurality of standard gas valve ports are connected to the plurality of standard gas cylinders, and the plurality of standard gas cylinders are respectively filled with low-concentration working standard gas, target standard gas, and high-concentration working standard gas; The air outlet valve is connected to the optical signal measuring device 2.

[0056] In this embodiment, the calibration module 15 provides standard gases of known concentrations, including low-concentration working standard gas, target standard gas, and high-concentration working standard gas, allowing for periodic or real-time calibration of the optical signal measuring device 2. This ensures that the monitoring instrument maintains high measurement accuracy even after prolonged operation, avoiding measurement errors caused by instrument drift or environmental factors. Furthermore, the multi-port switching valve design allows for easy switching from sampling mode to calibration mode without interrupting the monitoring task. This seamless switching capability guarantees the continuity and reliability of the monitoring system and reduces the risk of monitoring interruption due to calibration. Additionally, by connecting multiple standard gas cylinders to the multi-port switching valve and setting corresponding sample gas and standard gas valve ports, the calibration process becomes simpler and more efficient. Operators can quickly select the required standard gas for calibration without manually changing cylinders or adjusting connecting pipelines, thus saving time and labor costs. Moreover, multiple standard gas cylinders provide standard gases of different concentrations, supporting the implementation of various calibration strategies. For example, range calibration can be performed using low- and high-concentration working standard gases to ensure the instrument remains accurate throughout its measurement range; single-point calibration can be performed using target standard gases to verify the instrument's response accuracy to specific concentrations of methane. This flexibility helps meet calibration needs in different application scenarios. Meanwhile, calibration module 15 makes system maintenance and calibration more standardized and regulated. Regular calibration of the optical signal measuring device 2 allows for the timely detection and resolution of potential problems, such as sensor aging and optical component contamination, thereby extending the instrument's lifespan and reducing maintenance costs. Finally, regularly calibrated monitoring data is more reliable and trustworthy. This is particularly important for applications requiring high-precision methane concentration monitoring, such as oilfield leak detection and environmental monitoring. Reliable data support helps in making informed decisions and taking effective measures to address environmental issues such as methane leaks.

[0057] Optionally, the optical signal measuring device 2 further includes a pressure control device 17, which includes a regulating valve and a venting pipeline, and is used to regulate the pressure inside the sampling tube 12 so that the pressure inside the system meets the preset pressure conditions for the operation of the optical signal measuring device 2.

[0058] Optionally, the optical signal measuring device 2 further includes a flow control device 18, whose inlet end is connected to the outlet valve and whose outlet end is connected to the optical signal measuring device 2, for controlling the flow rate of the gas sample entering the decay chamber within a preset range.

[0059] In this embodiment, the flow control device 18 can monitor and control the flow rate of the gas sample entering the decay chamber in real time, ensuring it remains within a preset range. This is crucial for cavity decay spectroscopy, as the gas sample flow rate directly affects the measurement of decay time, and consequently, the accuracy of methane concentration calculation. Precise flow control reduces measurement errors caused by flow fluctuations, improving the accuracy of monitoring data. Furthermore, a stable flow input helps maintain the stability of the internal environment of the decay chamber, reducing adverse factors such as pressure and temperature fluctuations caused by flow changes. This stability is essential for maintaining the long-term, continuous, and accurate operation of the optical signal measurement device 2. In addition, precise control of the gas sample flow rate optimizes the response time of the optical signal measurement device 2. In monitoring scenarios requiring rapid response, such as monitoring sudden leaks, a fast and stable gas flow rate ensures that the monitoring system can quickly detect changes in methane concentration and issue timely alarms. Furthermore, the presence of the flow control device 18 helps reduce the risk of equipment damage or performance degradation due to abnormal flow. By promptly detecting and adjusting flow problems, unnecessary wear or damage to the attenuation cavity, optical components, etc., caused by excessive or insufficient flow can be avoided, thereby extending the service life of the equipment and reducing maintenance costs. For operators, the flow control device 18 provides an intuitive flow monitoring interface, allowing them to understand the flow status of the gas sample at any time. This real-time feedback mechanism helps operators better grasp the operating status of the monitoring system, promptly identify and resolve problems, thereby improving the overall user experience. Finally, due to the high flexibility and adjustability of the flow control device 18, it can adapt to the monitoring needs of different application scenarios. For example, in scenarios requiring high-precision measurement, the preset flow range can be further narrowed to improve measurement accuracy; in scenarios requiring rapid response, the flow control strategy can be optimized to shorten the response time.

[0060] Optionally, the sampling tube 12 is wrapped with anti-corrosion material to prevent the sampling tube 12 from being corroded and to extend the service life of the sampling tube 12.

[0061] Optionally, the monitoring system further includes a temperature control module, which includes a PCB heating plate and a temperature control board, for maintaining the optical signal measuring device 2 at a preset operating temperature.

[0062] In this embodiment, the performance and measurement results of the optical signal measuring device 2 are significantly affected by temperature fluctuations. The temperature control module precisely maintains the optical signal measuring device 2 within a preset operating temperature range, reducing measurement errors caused by temperature fluctuations and thus improving measurement accuracy and stability. In optical measurements, temperature fluctuations can increase thermal noise in optical components, affecting signal quality. The temperature control module helps reduce this thermal noise by stabilizing the temperature, improving the signal-to-noise ratio and measurement accuracy. Furthermore, optical components are temperature-sensitive; excessively high temperatures can lead to performance degradation or even damage. The temperature control module prevents overheating, protecting optical components from high-temperature damage and extending the device's lifespan. Moreover, temperature fluctuations can generate internal thermal stress, affecting structural stability and reliability. The temperature control module maintains stable internal temperatures, reducing thermal stress and improving device durability. Finally, the temperature control module enables the optical signal measuring device 2 to operate normally over a wider temperature range, in both cold and hot environments. This increases the device's adaptability and application range, allowing it to function in more diverse scenarios. In extreme environmental conditions, such as high humidity and high pollution, the temperature control module ensures stable internal temperatures, reducing performance degradation or malfunctions caused by environmental factors and improving overall system reliability. Simultaneously, by stabilizing the temperature, the module helps reduce equipment failures caused by temperature fluctuations, lowering maintenance costs. When maintenance is required, the module's design makes it easier for maintenance personnel to control the equipment temperature, simplifying maintenance procedures and improving efficiency. Finally, temperature control modules are typically equipped with temperature monitoring functions, displaying the equipment's operating temperature in real time. This allows operators to understand the equipment's temperature status at any time, promptly identifying and resolving problems. The module enables automated temperature control, maintaining the equipment within a preset operating temperature range without manual intervention. This increases system automation, reduces manual workload, and enhances the user experience.

[0063] Optionally, the optical signal measuring device 2 further includes a shock-absorbing spring, which is used to reduce the influence of external vibration on the optical signal measuring device 2 and maintain measurement stability.

[0064] Optionally, the monitoring system further includes a water removal device 13, which is used to remove water vapor from the gas sample.

[0065] In this embodiment, water vapor in the gas sample can interfere with the measurement process of the optical signal measuring device 2, leading to deviations in the measurement results. The introduction of the water removal device 13 can effectively remove water vapor from the gas sample, reducing its interference with the measurement results and thus improving the accuracy and reliability of the measurement. Furthermore, water vapor easily condenses into droplets or frost in optical systems, which can damage optical components and affect their light transmittance and stability. Removing water vapor through the water removal device 13 protects the optical components in the optical signal measuring device 2 from damage and extends their service life. Moreover, the presence of water vapor can lead to instability in the measurement signal, affecting the continuity and stability of the monitoring system. The water removal device 13 reduces this instability factor by removing water vapor, enhancing the overall stability of the system. Finally, in environments with high humidity, the water vapor content in the gas sample will increase significantly. The introduction of the water removal device 13 enables the monitoring system to operate normally in such environments, improving the system's adaptability and application range.

[0066] Optionally, the water removal device 13 includes a low-temperature cold trap device, which separates water vapor from the gas sample through low-temperature condensation.

[0067] In this embodiment, a cryogenic cold trap device is used to efficiently separate water vapor from the gas sample through low-temperature condensation. This water removal method is rapid and thorough, ensuring the dryness of the gas sample. Furthermore, the cryogenic cold trap device has a wide cooling temperature range, which can be adjusted according to actual needs. By selecting an appropriate cooling temperature, the water vapor removal effect can be precisely controlled to meet different monitoring requirements. In addition, compared with other water removal methods, the cryogenic cold trap device has certain advantages in terms of energy consumption. By optimizing the cooling temperature and cooling time, energy conservation and environmental impact can be achieved.

[0068] Optionally, the refrigeration temperature range of the cryogenic cold trap device is -70°C to -30°C, with a preset refrigeration temperature of -40°C, at which the corresponding water vapor concentration is 127 ppm.

[0069] In this embodiment, the cryogenic cold trap device can effectively remove water vapor from the gas sample at a cooling temperature of -40°C while maintaining low energy consumption. This temperature setting achieves a good balance between water removal efficiency and energy consumption. Furthermore, at the cooling temperature of -40°C, the corresponding water vapor concentration is 127 ppm, indicating that the water removal effect at this temperature is very significant, capable of reducing the water vapor content in the gas sample to an extremely low level.

[0070] Optionally, the dewatering device 13 further includes a semi-permeable membrane 16, which is installed in the flow path before the gas sample enters the optical signal measuring device 2, for drying the gas sample.

[0071] In this embodiment, the gas sample is dried using a semi-permeable membrane 16 before entering the optical signal measurement device 2. This provides a double guarantee for the dryness of the gas sample. Even if the cryogenic cold trap device fails to completely remove moisture, the semi-permeable membrane 16 can further reduce the moisture content. Furthermore, the semi-permeable membrane 16 not only dries the gas sample but also prevents other impurities from entering the optical signal measurement device 2 to a certain extent. This helps maintain the cleanliness of optical components and the stability of the optical system. In addition, the installation position of the semi-permeable membrane 16 is flexible and can be adjusted according to actual needs. This flexibility allows the monitoring system to better adapt to different monitoring scenarios and requirements.

[0072] Optionally, the water removal device 13 further includes a filtration device, which includes a hydrophobic filter screen and a filter element drying tank; The hydrophobic filter screen is made of polytetrafluoroethylene with a pore size of ≤10μm and is used to remove dust particles from the gas sample. The filter drying canister is used to remove water vapor and PM2.5 particulate pollution from the gas sample.

[0073] Optionally, the sampling tower 5 adopts a lattice structure to maintain ventilation performance without changing the gas flow direction, and the sampling tower 5 reaches a preset sampling height to cover the preset area monitoring requirements.

[0074] In this embodiment, the lattice structure design provides a large open space inside the sampling tower 5, facilitating free airflow. This structure effectively maintains ventilation performance, ensuring that gas samples can smoothly enter the sampling tower 5 during sampling, avoiding inaccurate sampling or blockages caused by airflow obstruction. The lattice structure also reduces wind resistance and minimizes interference with the surrounding environment. Furthermore, maintaining the stability of gas flow direction during sampling is crucial for obtaining accurate monitoring data. The lattice structure design ensures that the gas flow direction does not change significantly due to the structure itself as it passes through the sampling tower 5, helping to reduce errors caused by changes in flow direction and improving the reliability of monitoring data. Additionally, the sampling tower 5 reaches a preset sampling height to ensure coverage of the preset monitoring area. Different monitoring scenarios and targets may require different sampling heights. By adjusting the height of the sampling tower 5, different monitoring needs can be flexibly met, ensuring the comprehensiveness and accuracy of the monitoring data. A higher sampling height also helps reduce the impact of ground obstacles on the monitoring results. Furthermore, lattice structures typically possess high strength and stiffness, enabling them to withstand significant wind loads and other external forces. This structural form allows sampling tower 5 to maintain stable operation even under adverse weather conditions, reducing the likelihood of collapse or damage. The lattice structure also facilitates maintenance and repair, lowering long-term operating costs. Finally, through a rational design and layout of sampling tower 5, the location and number of sampling points can be optimized, improving monitoring efficiency.

[0075] In one possible design, the optical signal measuring device 2 of the monitoring system has at least two ring-down cavities to form a multi-cavity detection structure. The pump module 1 inputs the collected gas sample into the different ring-down cavities. The multi-cavity detection structure can monitor one of the methane, ethane, or other target gases in the gas sample.

[0076] In this embodiment, a multi-cavity detection structure is adopted, and different target gases can be detected in different optical signal measurement devices 2. The laser corresponding to each ring-down cavity has a laser wavelength set for the absorption peak of the target gas. Each ring-down cavity is equipped with a corresponding detector, which can simultaneously measure multiple target gases and ensure the consistency of measurement conditions, thereby improving detection efficiency.

[0077] Optionally, the sampling pump 14 is used to deliver the gas sample collected from the sampling port 11 to the optical signal measuring device 2 within a preset time, wherein the preset time is ≤1 minute, while ensuring stability and low noise characteristics during operation to reduce interference with the monitoring environment.

[0078] Optionally, the pump diaphragm material of the vacuum pump is pollution-free, leak-free, and free from methane gas adsorption and permeation.

[0079] In this embodiment, the time for the sample gas collected from sampling port 11 to reach the optical signal measuring device 2 is ≤1 minute. The sampling pump 14 is configured to deliver the sample gas collected from sampling port 11 to the optical signal measuring device 2 in a very short time. This rapid transmission reduces the time delay of the sample gas during transmission, which helps to monitor and respond quickly to environmental changes in real time, improving the timeliness and accuracy of monitoring. In addition, the sampling pump 14 exhibits high stability and low noise characteristics during operation. Stability ensures the continuity and consistency of sample gas transmission, avoiding abnormal monitoring data caused by pump failure or performance fluctuations, while low noise characteristics reduce interference with the monitoring environment. Furthermore, as a key component of the sampling pump 14, the choice of its material has a significant impact on the accuracy of the monitoring results. A pollution-free and leak-free pump membrane ensures that the sample gas is not affected by pollution or leakage during transmission; a pump membrane without methane gas adsorption and permeation effects can prevent the target gas in the sample gas from being adsorbed or permeated by the pump membrane during transmission, thereby ensuring the accuracy of the monitoring data.

[0080] Optionally, the sampling port 11 is installed in the prevailing wind direction at a sufficient height to avoid mutual interference and influence; The sampling tube 12 is installed on the side of the sampling tower 5, inside the protective tank and protective pipe to prevent water accumulation. The sampling tube 12 is made of polytetrafluoroethylene and wrapped with a layer of black aluminum-plastic tube to prevent corrosion.

[0081] In this embodiment, the sampling tube 12 is installed on the side of the sampling tower 5, located inside the protective trough and protective pipe. This design effectively prevents damage to the sampling tube 12 from external environmental factors, such as wind, rain, and animal bites. Furthermore, the protective trough and protective pipe prevent water accumulation in the sampling tube 12, avoiding corrosion or blockage caused by water accumulation and ensuring smooth sample gas transmission. In addition, the sampling tube 12 is made of polytetrafluoroethylene (PTFE). PTFE has excellent corrosion resistance, high-temperature resistance, and chemical stability, resisting the erosion of most chemicals and ensuring that the sample gas is not contaminated or deteriorated during transmission. Moreover, PTFE also has a low coefficient of friction and self-lubricating properties, helping to reduce resistance during sample gas transmission and improve transmission efficiency. Furthermore, the sampling tube 12 is wrapped with a layer of black aluminum-plastic composite tubing, which has good sun protection and heat insulation properties, preventing the sampling tube 12 from overheating due to exposure to high temperatures, thus affecting the properties of the sample gas. The black aluminum-plastic composite tubing also provides some mechanical protection, preventing damage to the sampling tube 12 from external impacts. At the same time, its black appearance can reduce heat absorption under direct sunlight, further reducing the surface temperature of the sampling tube 12.

[0082] Optionally, the sampling tower 5 is equipped with lightning protection facilities. The lightning protection facilities use disconnected metal lightning conductors. Before the sampling tube 12 enters the station building, the black plastic aluminum-plastic sampling tube 12 needs to be disconnected and connected to a polytetrafluoroethylene tube of the same diameter. The disconnection point is connected with a stainless steel tap to ensure that the airtightness meets the requirements and ensures the safe operation of the monitoring system.

[0083] In this embodiment, the black plastic aluminum-plastic sampling tube 12 is disconnected before entering the station building and connected to a polytetrafluoroethylene (PTFE) tube of the same diameter. This step aims to prevent lightning from being conducted into the station building through the sampling tube 12. Although the black plastic aluminum-plastic tube has properties such as sun protection and heat insulation, its metallic component may increase the risk of lightning conduction. Therefore, disconnecting and replacing it with a non-metallic PTFE tube is an effective measure to reduce the risk of lightning. In addition, a stainless steel tap is used for connection at the disconnection point, which ensures both the strength of the connection and the airtightness. Good airtightness is one of the keys to the normal operation of the monitoring system. It ensures that the sample gas will not be lost or contaminated due to leakage during transmission, thereby ensuring the accuracy and reliability of the monitoring data. Furthermore, through the above treatment, the sampling tube 12 has undergone dual protection against lightning and leakage before entering the station building, further improving the safety of the monitoring system. This not only protects the equipment from damage caused by lightning and leakage, but also ensures the safety of personnel and the environment during the monitoring process. Optionally, the gas flow model is a gas plume model. The gas plume model is based on the microstructure of gas flow, the influence of molecular collisions, the non-equilibrium effect of gas flow, and the molecular scale effect. It is built by algorithm fitting through a data processing computer on site. The algorithms used include, but are not limited to, molecular dynamics, Boltzmann equation, Monte Carlo algorithm, particle model, etc., to accurately describe and predict gas flow characteristics. It is suitable for simulation from multiple angles, including temperature, pressure, wind speed, and wind direction, thereby ensuring the high accuracy of the model.

[0084] In this embodiment, the gas plume model comprehensively considers the microstructure of gas flow, the effects of intermolecular collisions, non-equilibrium effects, and molecular-scale effects. These factors are often ignored or simplified in conventional fluid dynamics models. By meticulously simulating these microscopic processes, the model can more accurately predict the behavior of gas flow under different conditions, including complex temperature gradients, pressure changes, wind speed, and wind direction, thereby improving prediction accuracy. Furthermore, this model is not limited to simulating single parameters but can simultaneously consider and simulate the combined effects of multiple key environmental factors, such as temperature, pressure, wind speed, and wind direction, on gas flow. This multi-faceted simulation capability allows researchers and designers to more comprehensively understand and evaluate the performance of gas flow systems under different operating conditions, providing strong support for optimized design, improved efficiency, and enhanced safety. Additionally, by using on-site data processing computers for algorithm fitting, the model can be customized and optimized according to specific application scenarios and requirements. Whether in extreme environments with high temperature and pressure or in precise experimental conditions requiring highly accurate control, it can adapt by adjusting algorithm parameters and model structure, demonstrating strong adaptability and flexibility. Furthermore, this model and the algorithms it employs, such as molecular dynamics, the Boltzmann equation, the Monte Carlo algorithm, and particle models, have not only advanced fundamental research in the field of gas dynamics but also provided strong theoretical support for engineering applications. It enables researchers to explore the mechanisms of gas flow at the microscopic scale and helps engineers solve complex problems encountered in practical applications. At the same time, by accurately simulating and predicting gas flow characteristics, potential problems can be identified and optimized during the design phase, reducing the number of experiments and trial-and-error costs.

[0085] Optionally, the monitoring system further includes an airflow analysis unit, which is based on the Qt Toolkit language architecture and is used to build a gas flow model using computer computing power. The establishment of the gas flow model includes constructing a gas flow and airflow direction gradient model based on environmental information; and processing the airflow direction gradient model based on error analysis algorithms and data optimization algorithms to improve the sensitivity and accuracy of the gas flow model.

[0086] The environmental information includes: wind force and direction information, temperature and humidity information, air pressure information, geographical coordinates of the monitoring location, as well as methane concentration gradient information, concentration anomaly data information, and coordinates of the abnormal leak point obtained based on methane monitoring data.

[0087] Optionally, it also includes a power supply module for providing power to the laser.

[0088] Optionally, the environmental information collection unit 51 is installed in a “cross” shape around the operation area, and is used to collect environmental information such as wind direction, wind speed, temperature, and pressure, so as to accurately collect environmental information data and establish an air flow model for the oilfield area.

[0089] In this embodiment, the “cross” layout can ensure that the environmental information collection unit 51 captures data from multiple directions and angles, thereby achieving a full-range monitoring of the operation area environment. This layout effectively reduces data blind spots, improves the comprehensiveness and accuracy of environmental information data. For the accurate measurement of key environmental parameters such as wind direction, wind speed, temperature, and pressure, it helps to more precisely depict the meteorological conditions and air flow dynamics in the oilfield area, providing a reliable data basis for subsequent model establishment. In addition, based on the comprehensive and accurate environmental information data, a more refined and accurate air flow model for the oilfield area can be constructed. Such a model can more realistically reflect the movement laws of air flow in the oilfield area, including wind direction changes, wind speed distribution, temperature gradients, etc., providing strong support for the safety and efficiency of oilfield operations.

[0090] Optionally, the laser is a DFB laser; In the embodiment of the present application, a DFB (Distributed Feedback) laser can emit a very narrow laser linewidth, usually reaching the order of MHz or even kHz, which enables its output wavelength to precisely match the absorption peak of methane in a specific spectral region. Methane has an obvious absorption peak in the infrared spectral region, such as 1653.72 nm. By adjusting its output wavelength to near this absorption peak, the DFB laser can significantly improve the sensitivity and accuracy of methane detection. In addition, due to the high monochromaticity of the DFB laser, its output spectrum hardly contains light of other wavelengths, which helps to reduce background noise and interference from other gases during the detection process, thereby improving the signal-to-noise ratio of the detection signal. In addition, the DFB laser has a certain stability to temperature changes. By combining with a temperature control device, its temperature stability can be further improved to ensure the consistency of the output wavelength under different environmental conditions. Finally, the DFB laser has high long-term stability and can maintain stable output characteristics for a long time.

[0091] Exemplary method In an embodiment of the methane monitoring method for an oilfield area provided by the present application, the method includes the following steps: Collect a gas sample based on the pump suction module 1 and transport the gas sample to the optical signal measurement device 2; A laser of a preset wavelength is generated by a laser and injected into the ring-down cavity of the optical signal measuring device 2, so that the laser is repeatedly reflected in the ring-down cavity; the repeatedly reflected laser passes through the gas sample in the ring-down cavity, so that the methane molecules in the gas sample absorb the laser energy, thereby attenuating the light intensity of the laser in the ring-down cavity. The detector receives the emitted laser light after the light intensity has attenuated and converts the optical signal of the emitted laser light into an electrical signal. The data acquisition and processing module 3 analyzes and calculates the methane concentration in the gas sample based on the electrical signal to monitor the methane concentration.

[0092] Optionally, the monitoring method further includes: Environmental information is collected by the environmental information acquisition unit 51, and a gas flow model is established based on the environmental information. The gas tracing unit analyzes the gas flow direction information based on the methane concentration data and the gas flow model to determine the area where the methane gas leak source is located.

[0093] Optionally, the monitoring method further includes: The alarm module assesses whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded. Based on the gas tracing unit, the area where the methane gas leak source is located is obtained, and an abnormal concentration alarm is triggered.

[0094] Optionally, the concentration anomaly warning includes concentration anomaly warning within the oilfield area and concentration anomaly warning outside the oilfield area: When a leak source is detected to be located inside the oil field area, an alarm for abnormal concentration in the oil field area is triggered, and an alarm signal is issued to instruct personnel to stop operations and initiate the leak anomaly handling procedure. When a leak source is detected outside the oilfield area, an alarm for abnormal concentration outside the oilfield area is triggered. Instead of issuing an alarm signal, the location of the leak source is indicated by marking the leak source, guiding subsequent dispatch of personnel to verify the abnormal leak situation.

[0095] Optionally, it also includes: Based on the tower location assessment module, one or a combination of the following methods are used to determine the construction locations of sampling tower 5 and monitoring station 4: Assess the mutual interference between the sampling tower 5 and monitoring station 4 and other monitoring projects in the oilfield area, so that the sampling tower 5 and monitoring station 4 do not interfere with other monitoring projects, and determine the first construction location; Assess the safety impact of the sampling tower 5 and monitoring station 4 on other monitoring projects in the oilfield area, ensuring that the sampling tower 5 and monitoring station 4 meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determines the minimum distance between sampling tower 5 and monitoring station 4 when only methane gas is being monitored, in order to determine the location for the fourth construction site; Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location; A sampling port 11 is installed on the sampling tower 5, and a gas sample is collected through a pumping module 1 connected to the sampling port 11. An environmental information acquisition unit 51 is installed on the sampling tower 5 at the same height as the sampling port 11 to collect environmental information corresponding to the gas sample. A monitoring station 4 is set up to house the optical signal measurement device 2 and the data acquisition and processing module 3.

[0096] The sampling residence time is the time it takes for the gas sample to enter the cavity ringing device from the sampling port 11.

[0097] Optionally, the environmental information corresponding to the gas sample includes: Based on an anemometer, wind force and direction information is collected; Based on a thermometer and hygrometer, temperature and humidity information are collected; Based on a barometer, collect air pressure information; Based on the GPS positioning system 41, the geographic coordinates of the monitoring location are obtained to locate the gas leak source.

[0098] Optionally, a cavity mirror is provided in the decay cavity to re-reflect the laser.

[0099] Optionally, the monitoring method further includes: a data storage read / write module; The monitoring data is stored and retrieved using a data storage read / write module to ensure the integrity and traceability of the monitoring data.

[0100] Optionally, the step of installing a sampling port 11 on the sampling tower 5 and collecting gas samples through a pumping module 1 connected to the sampling port 11 includes: Multiple pumping units are arranged along the height of sampling tower 5, and each pumping unit includes a sampling pipe 12 and a sampling pump 14. The sampling port 11 is connected to the sampling tube 12 in a one-to-one correspondence, and gas samples are collected through each sampling port 11; Gas samples collected at each sampling port 11 are transported to the optical signal measuring device 2 for analysis via sampling tube 12 through sampling pump 14.

[0101] Optionally, it also includes instrument calibration and intake selection steps: The calibration module 15 includes a multi-port switching valve and multiple standard gas cylinders; A multi-port switching valve is used for gas inlet selection and instrument calibration. It is equipped with multiple sample gas valve ports, low-concentration working standard gas valve ports, target standard gas valve ports, high-concentration working standard gas valve ports, and gas outlet valve ports. Connect the sample gas valve port to the pump suction unit one by one, connect the low concentration working standard gas valve port to the low concentration standard gas cylinder, connect the target standard gas valve port to the standard gas cylinder, connect the high concentration working standard gas valve port to the standard gas cylinder, and connect the gas outlet valve port to the optical signal measuring device 2. Instrument calibration can be performed by switching between different standard gas valve ports to select standard gases of different concentrations. Different sample gases can be selected for methane concentration detection by switching between different sample gas valve ports.

[0102] Optionally, the system also includes adjusting the pressure inside the sampling tube 12 via a pressure control device 17, which includes a regulating valve and a venting line. The pressure adjustment ensures that the pressure inside the system meets the preset pressure conditions for the operation of the optical signal measuring device 2.

[0103] Optionally, it also includes: a flow control device 18 is provided in front of the optical signal measuring device 2, with its inlet end connected to the outlet valve and its outlet end connected to the optical signal measuring device 2, so as to control the flow control device 18 to maintain the flow rate of the gas sample entering the decay chamber within a preset range.

[0104] Optionally, it also includes wrapping the outside of the sampling tube 12 with anti-corrosion material to protect the sampling tube 12 from corrosion.

[0105] Optionally, it also includes: a temperature control module, including a PCB heating plate and a temperature control board, for maintaining the optical signal measuring device 2 within a preset operating temperature range.

[0106] Optionally, it also includes: installing shock-absorbing springs around the optical signal measuring device 2 to reduce the impact of external vibrations on measurement stability.

[0107] Optionally, the monitoring method further includes: setting up a water removal device 13 to remove water vapor from the gas sample.

[0108] Optionally, the step of setting the water removal device 13 to remove water vapor from the gas sample includes: setting a low-temperature cold trap device to separate water vapor from the gas sample through the low-temperature condensation effect of the low-temperature cold trap device.

[0109] Optionally, the refrigeration temperature range of the cryogenic cold trap device is -70°C to -30°C, with a preset refrigeration temperature of -40°C, at which the corresponding water vapor concentration is 127 ppm.

[0110] Optionally, it also includes: setting up a hydrophobic filter screen and a filter element drying tank to filter water vapor and particles; A hydrophobic filter made of polytetrafluoroethylene with a pore size ≤10μm is used to remove dust particles from the gas sample. A filter drying canister is installed to remove water vapor and PM2.5 particulate pollution from the gas sample.

[0111] Optionally, the removal of water vapor from the gas sample by the dehydration device 13 further includes installing a semi-permeable membrane 16 in the flow path of the gas sample before it enters the optical signal measuring device 2 to dry the gas sample.

[0112] Optionally, a lattice-structured sampling tower 5 is used to maintain ventilation performance without changing the gas flow direction. The sampling tower 5 reaches a preset sampling height to cover the preset area monitoring requirements.

[0113] Optionally, it also includes: setting the sampling pump 14 to deliver the gas sample from the sampling port 11 to the optical signal measuring device 2 in a time of ≤1 minute, while ensuring stability and low noise characteristics during operation to reduce interference with the monitoring environment; In one possible design, the optical signal measuring device 2 of the monitoring system has at least two ring-down cavities to form a multi-cavity detection structure. The pump module 1 inputs the collected gas sample into the different ring-down cavities. The multi-cavity detection structure can monitor one of the methane, ethane, or other target gases in the gas sample.

[0114] Optionally, the pump membrane material used for sampling is non-polluting, leak-free, and free from ethane gas adsorption and permeation.

[0115] Optionally, the sampling port 11 is installed in the prevailing wind direction of the sampling column, and the sampling port 11 has sufficient height to avoid mutual interference and influence when multiple sampling ports 11 are set. The sampling tube 12 is installed on the side of the sampling tower 5, inside the protective tank and protective pipe to prevent water accumulation. The sampling tube 12 is made of polytetrafluoroethylene and wrapped with a layer of black aluminum-plastic tube to prevent corrosion.

[0116] Optionally, it also includes installing lightning protection facilities on the sampling tower 5 to prevent lightning strikes. The lightning protection facilities use disconnected metal lightning conductors. Before the sampling tube 12 enters the station building, the black plastic aluminum-plastic sampling tube 12 needs to be disconnected and connected to a polytetrafluoroethylene tube of the same diameter. The disconnection point is connected with a stainless steel tap to ensure that the airtightness meets the requirements and ensures the safe operation of the monitoring method.

[0117] Optionally, the gas flow model is a gas plume model. The gas plume model is based on the microscopic structure of gas flow, the influence of molecular collisions, the non-equilibrium effect of gas flow, and the molecular scale effect, and is established by algorithm fitting through a data processing computer within the site. The algorithms used include, but are not limited to, molecular dynamics, Boltzmann equation, Monte Carlo algorithm, particle model, etc., to accurately describe and predict gas flow characteristics, and are applicable to simulations from multiple angles including temperature, pressure, wind speed, and wind direction, thus ensuring the high accuracy of the model.

[0118] Optionally, the monitoring method further includes an air flow analysis unit. The air flow analysis unit is based on the Qt Toolkit language architecture and is used to build a gas flow model using computer computing power. Establishing the gas flow model includes constructing a gas flow and air flow direction gradient model based on environmental information; processing the air flow direction gradient model using error analysis algorithms and data optimization algorithms to improve the sensitivity and accuracy of the gas flow model.

[0119] Optionally, environmental information collection units 51 are installed in a "rice" shape around the operation area to collect environmental information such as wind direction, wind speed, temperature, and pressure, to collect meteorological data and establish an air flow model for the oilfield area.

[0120] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A methane monitoring system for oilfield areas, characterized in that, include: Pump suction module, optical signal measurement device, data acquisition and processing module; The pump suction module is connected to the optical signal measuring device, and the optical signal measuring device is electrically connected to the data acquisition and processing module; The pump module is used to collect gas samples and deliver the gas samples to the optical signal measurement device; The optical signal measurement device includes a laser, a ring-down cavity, and a detector. The laser generates a laser of a preset wavelength and directs it into the ring-down cavity, causing the laser to be repeatedly reflected within the cavity. The ring-down cavity contains a gas sample, and the repeatedly reflected laser passes through the gas sample, causing methane molecules in the gas sample to absorb the laser energy, thus attenuating the intensity of the laser within the ring-down cavity. The detector is positioned on the light-emitting path of the ring-down cavity to receive the attenuated emitted laser light and convert the optical signal of the emitted laser light into an electrical signal. The data acquisition and processing module is electrically connected to the detector to analyze and calculate the methane concentration in the gas sample in real time based on the electrical signal, so as to monitor the methane concentration.

2. The methane monitoring system for oilfield areas according to claim 1, characterized in that, The monitoring system also includes: a gas flow direction prediction module; The gas flow direction prediction module includes an environmental information acquisition unit and a gas source tracing unit; The environmental information acquisition unit is used to collect environmental information in order to establish a gas flow model based on the environmental information; The gas tracing unit is used to analyze gas flow direction information based on the methane concentration data and the gas flow model to obtain the area where the methane gas leakage source is located.

3. The methane monitoring system for oilfield areas according to claim 2, characterized in that, The monitoring system also includes: The alarm module is used to assess whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded, and the area where the methane gas leak source is located is obtained based on the gas tracing unit, and an abnormal concentration alarm is triggered.

4. The methane monitoring system for oilfield areas according to claim 2, characterized in that, The monitoring system also includes a monitoring site configuration module, which includes: a sampling tower, a monitoring station building, and a tower location assessment module; The sampling tower is equipped with a sampling port and an environmental information acquisition unit. The sampling port is connected to the pump module and is used to collect gas samples. The environmental information acquisition unit is installed on the sampling tower to collect environmental information corresponding to the gas samples. The monitoring station is used to house the optical signal measurement device and the data acquisition and processing module. The tower location assessment module is used to perform one or a combination of the following methods to determine the construction location of the sampling tower and the monitoring station: Assess the interference between the sampling tower and monitoring station and other monitoring projects in the oilfield area to ensure that the sampling tower and monitoring station do not interfere with other monitoring projects, thereby determining the first construction location; Assess the safety impact of the sampling tower and monitoring station on other monitoring projects in the oilfield area, ensuring that the sampling tower and monitoring station meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determined the minimum distance between the sampling tower and the monitoring station building, based on monitoring only methane gas, to identify the location for the fourth construction site. Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location.

5. The methane monitoring system for oilfield areas according to claim 4, characterized in that, The pumping module includes multiple pumping units arranged along the height of the sampling tower; each pumping unit includes a sampling tube and a sampling pump; the sampling port is connected to the sampling tube in a one-to-one correspondence, and the sampling pump is connected to the optical signal measuring device to transport the gas sample collected at the sampling port to the optical signal measuring device for analysis through the sampling tube.

6. A method for monitoring methane in an oilfield area, comprising the following steps: Gas samples are collected using a pump-suction module and then transported to the optical signal measurement device. A laser of a preset wavelength is generated by a laser and injected into the ring-down cavity of an optical signal measurement device, so that the laser is repeatedly reflected in the ring-down cavity; the repeatedly reflected laser passes through a gas sample in the ring-down cavity, so that the methane molecules in the gas sample absorb the laser energy, causing the intensity of the laser in the ring-down cavity to decrease. The detector receives the emitted laser light after the light intensity has attenuated and converts the optical signal of the emitted laser light into an electrical signal. The data acquisition and processing module analyzes and calculates the methane concentration in the gas sample based on the electrical signal to monitor the methane concentration.

7. The method for monitoring methane in oilfield areas according to claim 6, characterized in that, The monitoring method also includes: Environmental information is collected by an environmental information acquisition unit, and a gas flow model is established based on the environmental information. The gas tracing unit analyzes the gas flow direction information based on the methane concentration data and the gas flow model to determine the area where the methane gas leak source is located.

8. The method for monitoring methane in oilfield areas according to claim 7, characterized in that, The monitoring method also includes: The alarm module assesses whether the methane concentration exceeds a set threshold. If the assessed methane concentration exceeds the threshold, the current methane concentration data and environmental information are recorded. Based on the gas tracing unit, the area where the methane gas leak source is located is obtained, and an abnormal concentration alarm is triggered.

9. The method for monitoring methane in oilfield areas according to claim 7, characterized in that, Also includes: Based on the tower location assessment module, one or a combination of the following methods are used to determine the construction locations of the sampling tower and the monitoring station: Assess the interference between the sampling tower and monitoring station and other monitoring projects in the oilfield area to ensure that the sampling tower and monitoring station do not interfere with other monitoring projects, thereby determining the first construction location; Assess the safety impact of the sampling tower and monitoring station on other monitoring projects in the oilfield area, ensuring that the sampling tower and monitoring station meet safety requirements compared to other monitoring projects, in order to determine the second construction location; The sampling residence time of the gas sample is evaluated to ensure that the sampling residence time is ≤60 seconds in order to determine the third construction location; The assessment determined the minimum distance between the sampling tower and the monitoring station building, based on monitoring only methane gas, to identify the location for the fourth construction site. Assess the relative elevation of the oilfield area's geographical location and select the highest point to determine the fifth construction location; A sampling port is installed on the sampling tower, and a gas sample is collected through a pumping module connected to the sampling port. An environmental information acquisition unit is installed on the sampling tower to collect environmental information corresponding to the gas samples; A monitoring station was set up to house the optical signal measurement device and the data acquisition and processing module.

10. The method for monitoring methane in an oilfield area according to claim 9, characterized in that, The step of installing a sampling port on a sampling tower and collecting gas samples through a pumping module connected to the sampling port includes: Multiple pumping units are arranged along the height of the sampling tower, and each pumping unit includes a sampling tube and a sampling pump. Each sampling port is connected to a corresponding sampling tube to collect gas samples through the sampling port; The gas sample collected at the sampling port is transported through a sampling tube to an optical signal measurement device for analysis by a sampling pump.

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