A gas-liquid two-phase flow wide gas-liquid ratio and wide range metering system

Abstract

The utility model discloses a kind of gas-liquid two-phase flow wide gas-liquid ratio and wide-range measurement system, belong to oil-gas field multiphase flow measurement technical field, including flow computer, separation component, fluid inlet pipeline and fluid outlet pipeline, the separation component is communicated with fluid inlet pipeline, liquid level meter and inlet pressure gauge are equipped on the separation component, gas phase pipeline and liquid phase pipeline respectively communicated with its inside are equipped on the separation component, liquid level control mechanism is equipped in the separation component, the liquid level control mechanism is used to close separation component and gas phase pipeline passage when liquid level in separation component rises, the one end of gas phase pipeline and liquid phase pipeline away from separation component is communicated with fluid outlet pipeline, gas phase flowmeter is equipped on the gas phase pipeline, liquid phase flowmeter and liquid path valve are equipped on the liquid phase pipeline.The utility model can select different measurement mode according to different working conditions, ensure the accuracy of measurement.

Description

Technical Field

[0001] This utility model belongs to the field of multiphase flow metering technology in oil and gas fields, specifically relating to a wide gas-liquid ratio and wide range metering system for gas-liquid two-phase flow. Background Technology

[0002] In natural gas development, the production of some high-pressure, high-yield natural gas wells varies greatly, especially the liquid volume. Conventional non-separated multiphase flow meters are simply unable to meet the metering requirements. Mature separator metering equipment requires larger and more expensive metering separators due to the large flow fluctuations and the resulting extremely large instantaneous flow. This increases the metering and management costs for enterprises. Therefore, there is an urgent need for a high-performance metering device that can adapt to the wide range and wide gas-liquid ratio of natural gas wells. Utility Model Content

[0003] The technical problem to be solved by this utility model is to address the shortcomings of the prior art by providing a gas-liquid two-phase flow metering system with a wide gas-liquid ratio and wide measurement range. Different metering modes can be selected according to different working conditions to ensure the accuracy of the measurement.

[0004] The technical solution adopted in this utility model is: a gas-liquid two-phase flow wide gas-liquid ratio and wide range metering system, including a flow computer, a separation component, a fluid inlet pipe, and a fluid outlet pipe. The separation component is connected to the fluid inlet pipe and is equipped with a level gauge and an inlet pressure gauge. The separation component is also equipped with a gas phase pipe and a liquid phase pipe, which are respectively connected to its interior. A level control mechanism is provided inside the separation component. This level control mechanism is used to close the channel between the separation component and the gas phase pipe when the liquid level inside the separation component rises. The gas phase pipeline and the liquid phase pipeline are connected to the fluid outlet pipeline at the ends away from the separation component. A gas phase flow meter is installed on the gas phase pipeline. A liquid phase flow meter and a liquid valve are installed sequentially from the end near the separation component to the end away from the separation component. The liquid phase pipeline is also provided with a liquid pressure regulating pipeline at both ends, which are respectively connected to the liquid phase pipeline and the fluid outlet pipeline. A liquid pressure regulating and throttling device is installed on the liquid pressure regulating pipeline. The level gauge, inlet pressure gauge, gas phase flow meter, liquid phase flow meter and liquid valve are all connected to the flow computer.

[0005] In one embodiment, the separation assembly includes a pre-separation tube and at least one main separation tube, which are connected sequentially by a connecting tube. The inlet pressure gauge is installed on the pre-separation tube, and the level gauge is installed on one of the main separation tubes. When there are multiple main separation tubes, a level control mechanism is installed in at least one of the main separation tubes.

[0006] In one embodiment, the gas flow meter and the liquid flow meter are variable cross-sectional area throttling flow meters, and the gas flow meter and the liquid flow meter are provided with a throttling element, the throttling element being a spindle shape.

[0007] In one embodiment, a gas pressure regulating pipeline is provided on the main separation pipe near the fluid outlet pipeline. The two ends of the gas pressure regulating pipeline are connected to the main separation pipe and the gas phase pipeline, respectively. A gas valve is provided on the gas pressure regulating pipeline, and the gas valve is connected to the flow computer.

[0008] In one embodiment, the fluid outlet pipeline is provided with a cleaning pipeline at both ends, which are respectively connected to the liquid phase pipeline and the fluid outlet pipeline. The cleaning pipeline is provided with a cleaning valve, which is connected to the flow computer.

[0009] In one embodiment, an outlet pressure gauge is provided on the fluid outlet pipeline, and the outlet pressure gauge is connected to a flow computer.

[0010] The beneficial effects of this utility model are as follows: 1. Different metering modes can be selected according to different working conditions to ensure the accuracy of metering. For simple working conditions, the system can be designed without electric valves to improve the reliability of the device actuator and eliminate maintenance. For natural gas wells with complex working conditions and large gas-liquid variation range, the device can be designed with electric valves to automatically adjust the opening of the liquid circuit valve according to relevant working condition information, adapt to working conditions in different gas-liquid ranges, ensure the separation efficiency of the separation components, ensure metering accuracy, and reduce labor costs. 2. The variable cross-sectional area throttling flow meter has a wider range ratio. The throttling element is designed as a spindle shape, which has a self-cleaning function. It can effectively avoid the accumulation of liquid phase impurities at the front end of the flow meter, which will affect the measurement accuracy. It also reduces the workload of replacing the throttling element and reduces the difficulty of using and operating the equipment. 3. For complex operating conditions such as blockage and intermittent liquid production in natural gas well sections, the device is equipped with a liquid level control mechanism and a liquid circuit pressure regulating and throttling device to prevent system pressure buildup. It can replace traditional large separators and greatly reduce the metering cost in the oil and gas industry. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model.

[0012] In the diagram: 1. Flow computer; 2. Separation assembly; 3. Fluid inlet pipe; 4. Fluid outlet pipe; 5. Level gauge; 6. Inlet pressure gauge; 7. Gas phase pipe; 8. Liquid phase pipe; 9. Gas phase flow meter; 10. Liquid phase flow meter; 11. Liquid valve; 12. Liquid pressure regulating pipe; 13. Liquid pressure regulating and throttling device; 14. Gas pressure regulating pipe; 15. Gas valve; 16. Cleaning pipe; 17. Cleaning valve; 18. Outlet pressure gauge; 201. Pre-separation pipe; 202. Main separation pipe; 203. Connecting pipe. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] like Figure 1 As shown, this utility model discloses a wide gas-liquid ratio and wide range metering system for gas-liquid two-phase flow, including a flow computer 1, a separation component 2, a fluid inlet pipe 3, and a fluid outlet pipe 4. The separation component 2 is connected to the fluid inlet pipe 3. The separation component 2 is equipped with a level gauge 5 and an inlet pressure gauge 6. The separation component 2 is provided with a gas phase pipe 7 and a liquid phase pipe 8, which are respectively connected to its interior. The separation component 2 is equipped with a level control mechanism, which is used to close the channel between the separation component 2 and the gas phase pipe 7 when the liquid level in the separation component 2 rises. The end of the pipeline 8 furthest from the separation component 2 is connected to the fluid outlet pipeline 4. A gas phase flow meter 9 is installed on the gas phase pipeline 7. A liquid phase flow meter 10 and a liquid valve 11 are installed sequentially from the end closest to the separation component 2 to the end furthest from the separation component 2 on the liquid phase pipeline 8. A liquid pressure regulating pipeline 12 is also provided on the liquid phase pipeline 8, with its two ends connected to the liquid phase pipeline 8 and the fluid outlet pipeline 4 respectively. A liquid pressure regulating and throttling device 13 is installed on the liquid pressure regulating pipeline 12. The level gauge 5, the inlet pressure gauge 6, the gas phase flow meter 9, the liquid phase flow meter 10, and the liquid valve 11 are all connected to the flow computer 1.

[0015] In one embodiment, the separation component 2 includes a pre-separation pipe 201 and at least one main separation pipe 202, which are connected in sequence by a connecting pipe 203. The inlet pressure gauge 6 is disposed on the pre-separation pipe 201, and the level gauge 5 is disposed on one of the main separation pipes 202. When there are multiple main separation pipes 202, a level control mechanism is disposed in at least one main separation pipe 202.

[0016] In this embodiment, the gas flow meter 9 and the liquid flow meter 10 are variable cross-sectional area throttling flow meters. The gas flow meter 9 and the liquid flow meter 10 are provided with throttling elements, and the throttling element baffle is a spindle body.

[0017] In this embodiment, a gas pressure regulating pipeline 14 is provided on the main separation pipe 202 near the fluid outlet pipeline 4. The two ends of the gas pressure regulating pipeline 14 are connected to the main separation pipe 202 and the gas phase pipeline 7, respectively. A gas valve 15 is provided on the gas pressure regulating pipeline 14, and the gas valve 15 is connected to the flow computer 1.

[0018] In this embodiment, the fluid outlet pipeline 4 is provided with a cleaning pipeline 16 with both ends connected to the liquid phase pipeline 8 and the fluid outlet pipeline 4 respectively. The cleaning pipeline 16 is provided with a cleaning valve 17, which is connected to the flow computer 1.

[0019] In this embodiment, an outlet pressure gauge 18 is provided on the fluid outlet pipeline 4, and the outlet pressure gauge 18 is connected to the flow computer 1.

[0020] The gas-liquid two-phase flow wide gas-liquid ratio and wide range metering system of this utility model can be used for metering the gas-liquid ratio and wide range of gas-liquid two-phase flow. It includes a gas-liquid two-phase flow wide gas-liquid ratio and wide range metering method, which includes the following steps: Step 1: Turn on the system, the flow computer 1 controls the liquid circuit valve 11 to close, set the metering mode switching pressure value and the metering mode switching liquid level change rate value, and proceed to Step 2. Step 2: The collected medium enters the separation component 2 through the fluid inlet pipe 3. It is separated into gas phase and liquid phase in the separation component 2. The gas phase enters the gas phase pipe 7 and proceeds to Step 3. The liquid phase remains in the separation component 2. The level gauge 5 and the inlet pressure gauge 6 collect the liquid level data and pressure data in the separation component 2 in real time and output the collected liquid level data and pressure data to the flow computer 1. The flow computer 1 calculates the liquid level change rate in real time based on the acquired liquid level data. If neither the collected pressure data nor the calculated liquid level change rate reaches the set metering mode switching pressure value or metering mode switching liquid level change rate value, the system enters the small flow metering mode and proceeds to Step 4. If either the collected pressure data or the calculated liquid level change rate reaches the set metering mode switching pressure value or metering mode switching liquid level change rate value, the system enters the large flow metering mode and proceeds to Step 9. If the liquid level in the separation component 2 reaches the liquid level at which the liquid level control mechanism opens, the system enters the mechanical liquid level control mode and proceeds to Step 11. Step 3: The gas phase passes through the gas phase flow meter 9, which measures the gas phase flow in real time and outputs the recorded gas phase flow data to the flow computer 1. The measured gas phase enters the fluid outlet pipe 4 and is discharged from the fluid outlet pipe 4. Step 4: The flow computer 1 sets the lower limit and upper limit of the metering liquid level of the separation component 2, and then proceeds to step 5; Step 5: The liquid phase remaining in the separation component 2 continues to increase. When the liquid phase in the separation component 2 reaches the lower limit of the metering liquid level, the level gauge 5 records the lower limit differential pressure value and the lower limit time, and outputs the recorded lower limit differential pressure value and the lower limit time data to the flow computer 1. When the liquid phase in the separation component 2 reaches the upper limit of the metering liquid level, the level gauge 5 records the upper limit differential pressure value and the upper limit time, and outputs the recorded upper limit differential pressure value and the upper limit time data to the flow computer 1, and proceeds to step 6. Step 6: Calculate the liquid phase mass flow rate; Step 7: The flow computer 1 controls the liquid circuit valve 11 to open, and the liquid phase enters the liquid phase pipeline 8, enters the fluid outlet pipeline 4 through the liquid phase pipeline 8, and is discharged from the fluid outlet pipeline 4. Step 8: The flow computer 1 calculates the flow rate of the mixed fluid, which is the sum of the gas flow rate measured in real time by the gas flow meter 9 in step 3 and the liquid mass flow rate calculated in step 6. Step 9: The flow computer 1 controls the liquid valve 11 to open, the liquid phase enters the liquid phase pipeline 8, the liquid phase passes through the liquid phase flow meter 10, the liquid phase flow meter 10 measures the liquid phase flow in real time and outputs the recorded liquid phase flow data to the flow computer 1, the measured liquid phase enters the fluid outlet pipeline 4 and is discharged from the fluid outlet pipeline 4, proceed to step 10. Step 10: The flow computer 1 calculates the flow rate of the mixed fluid. The flow rate of the mixed fluid is the sum of the gas flow rate measured in real time by the gas flow meter 9 in step 3 and the liquid flow rate measured in real time by the liquid flow meter 10 in step 9. Step 11: The liquid level control mechanism closes the separation component 2 and the gas phase pipeline 7. The extracted medium enters the liquid phase pipeline 8 through the separation component 2. If the extracted medium reaches the pressure that reaches the opening pressure of the liquid circuit pressure regulating and throttling device 13, the liquid circuit pressure regulating and throttling device 13 is opened, and part of the extracted medium enters the liquid circuit pressure regulating pipeline 12 and is discharged from the fluid outlet pipeline 4. When the liquid level in the separation component 2 reaches the closing condition of the liquid level control mechanism, the liquid level control mechanism opens the separation component 2 and the gas phase pipeline 7, and proceeds to step 2.

[0021] It also includes steps for adjusting the separation efficiency of the high-flow metering mode, as follows: The flow calculation unit 1 adjusts the opening of the liquid circuit valve 11 based on the liquid level data of the separation component, and controls the liquid level in the separation component 2 to be within a stable range.

[0022] It also includes a gas phase pressure regulation step, as detailed below: When an abnormal pressure value is set, the flow computer 1 acquires the pressure data collected by the inlet pressure gauge 6 in real time. When the acquired pressure data reaches the abnormal pressure value, the flow computer 1 controls the gas valve 15 to open, and part of the gas phase enters the gas pressure regulating pipeline 14, enters the fluid outlet pipeline 4 after passing through the gas phase pipeline 7, and is discharged from the fluid outlet pipeline 4. If the acquired pressure data is lower than the abnormal pressure value, the flow computer 1 controls the gas valve 15 to close.

[0023] It also includes system cleaning steps, as detailed below: The cleaning valve 17 is opened manually or controlled by the flow computer 1. The flow computer 1 controls the metering system to stop working in metering mode. The sampled medium enters through the fluid inlet pipe 3 and enters the separation component 2 to clean the dirt inside the separation component 2. After cleaning, the cleaning valve 17 is closed manually or controlled by the flow computer 1. The flow computer 1 controls the metering system to start working in metering mode, and the system cleaning step is completed.

[0024] In this system, separation component 2 separates components via swirling flow. Level gauge 5 is a differential pressure level gauge. The level control mechanism is a float valve or similar device that automatically closes the gas phase pipeline 7 based on a rise in liquid level. Gas phase flow meter 9 and liquid phase flow meter 10 are variable cross-sectional area throttling flow meters, which have a wider range ratio; simultaneously, their throttling element is designed as a spindle shape, possessing a self-cleaning function, effectively preventing the accumulation of liquid phase impurities at the flow meter's inlet, thus avoiding issues affecting measurement accuracy. The liquid circuit pressure regulating and throttling device 13 is a self-closing pressure regulating valve or similar device or mechanism that automatically opens when the liquid phase pressure is too high. The outlet pressure gauge 18 is installed to monitor the system outlet pressure value in real time, facilitating accurate judgment of the system's operating conditions.

[0025] In this system, the gas flow meter 9, liquid flow meter 10, and liquid flow regulating and throttling device 13 are designed as variable cross-sectional area throttling elements. The baffle of each throttling element is designed as a spindle shape. When the pressure difference between the front and rear ends of the baffle reaches a certain value, the baffle opens. The pressure difference before the baffle opens will affect the flow meter measurement. Therefore, the baffles of the gas flow meter 9 and liquid flow meter 10 are perforated in the center, providing an initial opening for the throttling element to avoid the aforementioned effect. The baffle of the liquid flow regulating and throttling device 13 is a sealed design to prevent liquid flow leakage from affecting the measurement when the production well produces pure gas.

[0026] In this system, the gas flow meter 9 and the liquid flow meter 10 are designed using the noise-based two-phase flow metering principle. When the system's liquid circuit pressure regulating and throttling device is damaged or the liquid level control mechanism in the separation pipe is damaged, metering can still be completed with reduced accuracy, thus improving equipment reliability and metering efficiency.

[0027] In step 2, the rate of liquid level change is calculated by the flow computer 1, which is obtained by dividing the change in liquid level height by the time taken for the change to occur. The change in liquid level is acquired by the level gauge 5. In the high-flow-rate metering mode separation efficiency adjustment step, the opening degree of the liquid circuit valve 11 is determined according to the operating conditions to maintain the liquid level in the separation component 2 within a stable range, thus ensuring the separation efficiency of the separation component 2. In the system cleaning step, the separation of the separation component 2 proceeds normally, but the metering mode of the metering system is stopped to prevent inaccurate metering caused by cleaning.

[0028] The embodiments described above merely illustrate specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A gas-liquid two-phase flow metering system with wide gas-liquid ratio and wide measurement range, characterized in that, The system includes a flow computer, a separation component, a fluid inlet pipe, and a fluid outlet pipe. The separation component is connected to the fluid inlet pipe and is equipped with a level gauge and an inlet pressure gauge. The separation component also has a gas phase pipe and a liquid phase pipe, which are respectively connected to its interior. A level control mechanism is installed inside the separation component to close the connection between the separation component and the gas phase pipe when the liquid level inside the separation component rises. The ends of the gas phase pipe and the liquid phase pipe furthest from the separation component are connected to the fluid outlet pipe. A gas phase flow meter is installed on the gas phase pipe. A liquid phase flow meter and a liquid valve are sequentially installed on the liquid phase pipe from the end closest to the separation component to the end furthest from the separation component. The liquid phase pipe also has a liquid pressure regulating pipe with both ends connected to the liquid phase pipe and the fluid outlet pipe, respectively. A liquid pressure regulating and throttling device is installed on the liquid pressure regulating pipe. The level gauge, inlet pressure gauge, gas phase flow meter, liquid phase flow meter, and liquid valve are all connected to the flow computer.

2. The gas-liquid two-phase flow wide gas-liquid ratio and wide measurement range metering system according to claim 1, characterized in that, The separation assembly includes a pre-separation tube and at least one main separation tube, which are connected sequentially by a connecting tube. The inlet pressure gauge is installed on the pre-separation tube, and the level gauge is installed on one of the main separation tubes. When there are multiple main separation tubes, a level control mechanism is installed in at least one of the main separation tubes.

3. The gas-liquid two-phase flow wide gas-liquid ratio and wide measurement range metering system according to claim 1, characterized in that, The gas flow meter and liquid flow meter are variable cross-sectional area throttling flow meters, and the gas flow meter and liquid flow meter are equipped with throttling elements, the throttling element baffles being spindle-shaped.

4. A wide gas-liquid ratio and wide measurement range metering system for gas-liquid two-phase flow according to claim 2, characterized in that, A gas pressure regulating pipeline is provided on the main separation pipe near the fluid outlet pipeline. The two ends of the gas pressure regulating pipeline are connected to the main separation pipe and the gas phase pipeline, respectively. A gas valve is provided on the gas pressure regulating pipeline, and the gas valve is connected to the flow computer.

5. A wide gas-liquid ratio and wide measurement range metering system for gas-liquid two-phase flow according to claim 1, characterized in that, The fluid outlet pipeline is provided with a cleaning pipeline at both ends, which are respectively connected to the liquid phase pipeline and the fluid outlet pipeline. The cleaning pipeline is equipped with a cleaning valve, which is connected to the flow computer.

6. A wide gas-liquid ratio and wide measurement range metering system for gas-liquid two-phase flow according to claim 1, characterized in that, An outlet pressure gauge is installed on the fluid outlet pipeline, and the outlet pressure gauge is connected to a flow computer.

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