Intelligent protection method and device for wellhead of natural gas well

Abstract

The invention relates to an intelligent protection method and device for a wellhead of a natural gas well, and belongs to the technical field of wellhead intelligent medicament filling control. According to the method, the gas well output liquid is firstly collected, all indexes of the gas well output liquid are monitored, then all index data are transmitted to the control system, the control system conducts judgment according to the received index data, and when the indexes of the gas well output liquid are larger than or equal to a set threshold value, the chemical adding system is controlled to add corresponding chemicals to a gas well mouth. The control system intelligently diagnoses the corrosion and scaling conditions of the gas well according to the monitoring result, judges whether the gas well needs to be filled with the corrosion and scale inhibitor or not, and controls the automatic dosing device to fill the required medicament, so that intelligent filling of the corrosion inhibitor and the scale inhibitor is realized. According to the system, the pertinence and timeliness of dosing are improved to a great extent, the corrosion prevention and scale inhibition effects of the gas well can be enhanced on the premise that the labor intensity of workers is reduced, and the service cycle of a gas well tubular column is prolonged.

Description

Technical Field

[0001] The invention relates to a natural gas wellhead intelligent protection method and device, belonging to the technical field of wellhead intelligent injection agent control. Background Art

[0002] Natural gas is an important energy source. It is produced from oil and gas layers to the surface through oil pipes. However, during the production process, due to certain components in the fluid produced by the gas well, corrosion and scaling may occur in the gas well. Therefore, it is necessary to add corrosion inhibitors and scale inhibitors to the gas well to protect the gas well pipe column.

[0003] At present, the method of adding chemicals to natural gas wells is mainly to use remote control system for automatic filling, and the automatic filling system at the wellhead and the remote control system are used to achieve the timed and quantitative filling of chemicals. Although this method can achieve the addition of corrosion and scale inhibitors, the filling of chemicals is somewhat blind, resulting in unsatisfactory corrosion and scale inhibition effects. Summary of the invention

[0004] The purpose of the present invention is to provide a natural gas wellhead intelligent protection method and device to solve the problem of unsatisfactory corrosion and scale inhibition effects in the current protection process.

[0005] In order to solve the above technical problems, the present invention provides a natural gas wellhead intelligent protection method, which comprises the following steps:

[0006] 1) Collect gas well production fluid and dilute it;

[0007] 2) Monitor the indicators of the diluted gas well output fluid;

[0008] 3) Determine the corrosion and scaling conditions of gas wells based on the monitored indicator data;

[0009] 4) When the index data monitored in the gas well output fluid is greater than or equal to the corresponding set threshold, the dosing system is controlled to add the corresponding reagent into the gas well.

[0010] The present invention first collects the gas well output fluid and monitors its various indicators, and then makes judgments based on the monitored indicator data. When the indicator of the gas well output fluid is greater than or equal to the corresponding set threshold, the dosing system is controlled to add the corresponding agent to the gas well wellhead. Based on the monitoring results, the present invention intelligently diagnoses the corrosion and scaling of the gas well, determines whether the gas well needs to be injected with corrosion inhibitors and scale inhibitors, and controls the automated dosing system to inject the required agents, thereby realizing the intelligent injection of corrosion inhibitors and scale inhibitors. This system greatly improves the pertinence and timeliness of dosing, and can enhance the anti-corrosion and scale inhibition effect of the gas well and extend the service life of the gas well pipe string while reducing the intensity of manual labor.

[0011] Furthermore, the indicators in the gas well production fluid include calcium ion concentration and iron ion concentration.

[0012] Furthermore, the chemicals in the dosing system include corrosion inhibitors and scale inhibitors.

[0013] A natural gas wellhead intelligent protection device comprises a control system, a dosing system and an ion monitoring system. The ion monitoring system is used to connect with a gas production pipeline, collect gas well output fluid, dilute it, monitor various indicators in the diluted liquid, and transmit the monitored indicator data to the control system; the control system is used to judge the corrosion and scaling of the gas well according to the indicator data transmitted by the ion monitoring system, and when the indicator data in the gas well output fluid is greater than or equal to the corresponding set threshold value, send a control signal to the dosing system to control the dosing system to add the corresponding agent into the gas well; after receiving the control signal, the dosing system adds the corresponding agent into the gas well.

[0014] The present invention first collects the gas well output fluid and monitors its various indicators, and then makes judgments based on the monitored indicator data. When the indicator of the gas well output fluid is greater than or equal to the corresponding set threshold, the dosing system is controlled to add the corresponding agent to the gas well wellhead. Based on the monitoring results, the present invention intelligently diagnoses the corrosion and scaling of the gas well, determines whether the gas well needs to be injected with corrosion and scale inhibitors, and controls the automated dosing system to inject the required agents, thereby realizing the intelligent injection of corrosion inhibitors and scale inhibitors. This system greatly improves the pertinence and timeliness of dosing, and can enhance the anti-corrosion and scale inhibition effect of the gas well and extend the service life of the gas well pipe string while reducing the intensity of manual labor.

[0015] Furthermore, the ion monitoring system includes a water separation bag, a distilled water tank, a pump, a calcium ion detector and an iron ion detector; the water separation bag inlet is used to connect to the gas production pipeline to retain the gas output liquid, the water separation bag outlet is connected to the pump, and when monitoring is required, the gas output liquid is transferred to the calcium ion monitor and the iron ion monitor through the pump, and the distilled water tank outlet is connected to the pump to dilute the gas output liquid.

[0016] Furthermore, the ion monitoring system also includes a filter, which is arranged between the water separation bag and the pump and is used to filter impurities in the gas well production fluid.

[0017] The filter can filter out impurities in the produced fluid of the gas well, making the ion monitoring results more accurate.

[0018] Furthermore, it also includes a waste liquid collecting device, which is connected to the outlets of the calcium ion detector and the iron ion detector and is used to collect waste liquid after detection.

[0019] Furthermore, a liquid level sensor is provided in the waste liquid collection device, and the liquid level sensor is connected to the control system signal. When the amount of waste liquid in the waste liquid collection device is greater than or equal to a set threshold, the control system sends an alarm signal.

[0020] The monitored waste liquid is promptly processed and sent to the waste liquid collection device to prevent waste liquid pollution. When the amount of waste liquid is greater than or equal to the set threshold, an alarm signal is issued to remind manual transportation for treatment.

[0021] Furthermore, a liquid level sensor is provided in the distilled water tank, and the liquid level sensor is connected to the control system signal. When the water volume in the distilled water tank is less than or equal to a set threshold, the control system sends an alarm signal.

[0022] When the water volume is less than or equal to the set threshold, an alarm signal is issued to promptly remind humans to perform fluid replenishment operations.

[0023] Furthermore, valves are provided at the outlet of the water distribution bag and the outlet of the distilled water tank, and the valves are connected to the control system signal and are used to receive the control system signal to perform switch operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the intelligent protection device for a natural gas wellhead of the present invention;

[0025] In the figure: 1. Gas wellhead; 2. Gas production pipeline; 3. Water distribution bag; 4. Output liquid water tank; 5. Distilled water tank; 6. Filter; 7. Metering pump; 8. Calcium ion detector; 9. Iron ion detector; 10. Waste liquid collection box; 11. Control system; 12. Corrosion inhibitor box; 13. Scale inhibitor box; 14. Multi-way valve; 15. Dosing pump; 16. Check valve. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0027] Embodiment of the intelligent protection device for the wellhead of a natural gas well

[0028] The present invention includes a control system 11, a dosing system and an ion monitoring system. The dosing system and the ion monitoring system are connected to the control system 11 by signal. The ion monitoring system is connected to the gas production pipeline 2, and is used to collect gas well output fluid for filtering and dilution treatment, and monitor various indicators in the liquid after filtering and dilution treatment, and transmit the monitored indicator data to the control system 11. The control system 11 is used to judge the corrosion and scaling of the gas well according to the indicator data transmitted by the ion monitoring system, and when the indicator data in the gas well output fluid is greater than or equal to the corresponding set threshold, a control signal is sent to the dosing system to control the dosing system to add the corresponding agent to the gas wellhead. The dosing system is connected to the gas production wellhead, and after receiving the control signal, the dosing system adds the corresponding agent to the well through the gas production wellhead 1. The implementation principle of this system is as follows: Figure 1 As shown, the following is explained with reference to specific examples.

[0029] The ion monitoring system includes a water separation bag 3, an output liquid water tank 4, a distilled water tank 5, a filter 6, a metering pump 7, a calcium ion detector 8 and an iron ion detector 9; the outlet of the water separation bag 3 is connected to the inlet of the output liquid water tank 4, the inlet of the distilled water tank 5 is connected to the water adding device, the outlet of the output liquid water tank 4, the outlet of the distilled water tank 5 and the inlet of the filter 6 are connected, the outlet of the filter 6 is connected to the inlet of the metering pump 7, the outlet of the metering pump 7 is connected to the inlets of the calcium ion detector 8 and the iron ion detector 9 respectively, and the outlets of the calcium ion detector 8 and the iron ion detector 9 are connected to the waste liquid collection device 10.

[0030] The dosing system includes a dosing pump 15, a multi-way valve 14 and a medicine box. The dosing pump 15 is connected to the multi-way valve 14, and the multi-way valve 14 is connected to the medicine box. The medicine box is divided into a corrosion inhibitor box 12 and a scale inhibitor box 13, which store gas well corrosion inhibitor and scale inhibitor solutions respectively. The dosing pump 15 is connected to the gas wellhead through a one-way valve 16.

[0031] The gas wellhead 1 is connected with the gas production pipeline 2, and the gas well output liquid and natural gas are transported to the gas gathering station. The gas production pipeline 2 is connected with the water-dividing bag 3 in the ion monitoring system. During the gas well production process, the gas flow takes the liquid in the well out. After passing through the water-dividing bag, part of the liquid remains in the water-dividing bag. When it is necessary to monitor the ion concentration, the control system 11 controls the valve of the water-dividing bag 3 to open, and the liquid is transported to the output liquid water tank 4 due to gravity, and the valve is closed after the delivery is completed. After the liquid in the output liquid water tank 4 is filtered by the filter 6, the required liquid is extracted by the metering pump 7, and the calcium ion detection device and the iron ion detection device are respectively injected. Then the metering pump 7 extracts the distilled water in the distilled water tank 5 as required, and the calcium ion detection device and the iron ion detection device are respectively injected to dilute the gas well output liquid. After filtering and diluting, the calcium ion detection device and the iron ion detection device start to detect, and after the detection is completed, the detection result is transmitted to the control system 11, and the detected liquid is discharged to the waste liquid collection box 10 at the same time. After that, the metering pump 7 draws distilled water from the distilled water tank to clean the detection device, and the cleaning liquid is also discharged to the waste liquid collection tank 10. When the water volume of the distilled water tank 5 is less than or equal to the threshold value set for the water volume of the distilled water tank, the control system 11 sends an alarm signal to prompt manual refilling operation. When the amount of waste liquid in the waste liquid collection tank 10 is greater than or equal to the threshold value set for the waste liquid in the waste liquid collection tank, the control system 11 sends an alarm signal to prompt manual transportation operation to transport the waste liquid in the waste liquid collection tank to the purification plant for purification treatment.

[0032] The control system intelligently diagnoses the corrosion and scaling of the gas well according to the ion monitoring results. When the calcium ion concentration in the gas well output fluid is greater than or equal to the threshold value set for the calcium ion concentration, the control system opens the outlet valve of the scale inhibitor box 13, and then the control system starts the dosing pump to add scale inhibitor to the wellhead of the gas well; when the total iron ion concentration in the gas well output fluid is greater than or equal to the threshold value set for the total iron ion concentration, the control system opens the outlet valve of the corrosion inhibitor box 12, and then the control system starts the dosing pump to add corrosion inhibitor to the wellhead of the gas well, so that the indicators in the gas well output fluid meet the standards.

[0033] The above-mentioned embodiments are described in a relatively specific and detailed manner, and are only used to illustrate the technical solution of the present invention rather than to limit it. The output liquid water tank, filter, and waste liquid collection box in the embodiments are further improvements to the present invention, and are not necessary devices. As other implementations, one or more of the output liquid water tank, filter, and waste liquid collection box can be removed according to needs.

[0034] Embodiment of the intelligent protection method for natural gas wellhead

[0035] The present invention first collects gas well output liquid through the water separation bag 3, filters and dilutes the gas well output liquid, then detects the filtered and diluted gas well output liquid, and transmits the detection results to the control system 11. The control system 11 intelligently diagnoses the corrosion and scaling of the gas well according to the ion detection results. When the calcium ion concentration in the gas well output liquid is greater than or equal to the threshold value set by the calcium ion concentration, the control system 11 opens the outlet valve of the scale inhibitor medicine box 13, and then the control system 11 starts the dosing pump to add scale inhibitor to the gas wellhead; when the total iron ion concentration in the gas well output liquid is greater than or equal to the threshold value set by the total iron ion concentration, the control system 11 opens the outlet valve of the corrosion inhibitor medicine box 12, and then the control system 11 starts the dosing pump to add corrosion inhibitor to the gas wellhead, so that the indicators in the gas well output liquid meet the standards. The specific implementation method of the protection method has been described in detail in the embodiment of the natural gas wellhead intelligent protection system, which will not be repeated here.

Claims

1. A natural gas wellhead intelligent protection method, characterized in that: The protection method includes the following steps: 1) Collect gas well production fluid and dilute it; 2) Monitor the indicators of the diluted gas well output fluid; 3) Determine the corrosion and scaling conditions of gas wells based on the monitored indicator data; 4) When the index data monitored in the gas well output fluid is greater than or equal to the corresponding set threshold, the dosing system is controlled to add the corresponding reagent into the gas well.

2. The natural gas wellhead intelligent protection method according to claim 1, characterized in that: The indicators in the gas well production fluid include calcium ion concentration and iron ion concentration.

3. The natural gas wellhead intelligent protection method according to claim 1 or 2, characterized in that: The chemicals in the dosing system include corrosion inhibitors and scale inhibitors.

4. A natural gas wellhead intelligent protection device, including a control system and a dosing system, characterized in that: It also includes an ion monitoring system, which is used to connect with the gas production pipeline, collect gas well output fluid, and dilute it, monitor various indicators in the diluted liquid, and transmit the monitored indicator data to the control system; the control system is used to judge the corrosion and scaling of the gas well according to the indicator data transmitted by the ion monitoring system, and when the indicator data in the gas well output fluid is greater than or equal to the corresponding set threshold, send a control signal to the dosing system to control the dosing system to add the corresponding agent into the gas well; After receiving the control signal, the dosing system adds the corresponding reagent into the gas well.

5. The natural gas wellhead intelligent protection device according to claim 4 is characterized in that: The ion monitoring system includes a water separation bag, a distilled water tank, a pump, a calcium ion monitor and an iron ion monitor; the water separation bag inlet is used to connect to the gas production pipeline to retain the gas output liquid, the water separation bag outlet is connected to the pump, and when monitoring is required, the gas well output liquid is transferred to the calcium ion detector and the iron ion detector through the pump, and the distilled water tank outlet is connected to the pump to dilute the gas well output liquid.

6. The natural gas wellhead intelligent protection device according to claim 5, characterized in that: The ion monitoring system also includes a filter, which is arranged between the water separation bag and the pump and is used to filter impurities in the gas well output fluid.

7. The natural gas wellhead intelligent protection device according to claim 4 is characterized in that: It also includes a waste liquid collecting device, which is connected to the outlets of the calcium ion detector and the iron ion detector and is used to collect waste liquid after detection.

8. The natural gas wellhead intelligent protection device according to claim 7, characterized in that: The waste liquid collection device is provided with a liquid level sensor, which is connected to the control system signal. When the amount of waste liquid in the waste liquid collection device is greater than or equal to a set threshold, the control system sends an alarm signal.

9. The natural gas wellhead intelligent protection device according to claim 5, characterized in that: A liquid level sensor is arranged in the distilled water tank, and the liquid level sensor is connected with the control system signal. When the water volume in the distilled water tank is less than or equal to a set threshold value, the control system sends out an alarm signal.

10. The natural gas wellhead intelligent protection device according to claim 5, characterized in that: Valves are provided at the outlet of the water distribution bag and the outlet of the distilled water tank. The valves are connected to the control system signal and are used to receive the control system signal for switch operation.

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