A gas lift production control method and system

Abstract

The present application relates to the field of oil extraction, in particular to a gas lift oil extraction control method and system, the gas lift oil extraction control method and system can monitor key parameters in real time, accurately control the oil extraction process, and improve the oil extraction efficiency; the preset algorithm is adopted to realize the automatic control of the system, reduce the manual intervention, and reduce the operation cost; through the real-time feedback result, the controller can quickly respond to the abnormal situation of the system, take emergency measures in time, and protect the safe and effective operation of the equipment; the system has simple structure and convenient operation, and can flexibly adapt to different oil extraction scenes and demands.

Description

Technical Field

[0001] This invention relates to the field of oilfield production, specifically to a gas lift oil production control method and system. Background Technology

[0002] Intermittent gas lift is a primary method for draining fluid from low-yield natural gas wells. It involves intermittently injecting high-pressure gas into the annulus, which then passes through a gas lift valve or tubing foot into the tubing. This carries away the liquid accumulated in the wellbore (typically condensate or formation water), restoring the well's production capacity. Without other auxiliary measures, gas lift requires the injected gas flow rate to exceed the well's critical fluid-carrying capacity to lift the bottomhole fluid to the surface. Furthermore, due to the density difference between gas and liquid, the slippage pressure loss in the wellbore leads to reduced gas lift efficiency and higher lift pressure. Using plunger-assisted intermittent gas lift eliminates the fluid slippage problem through the physical barrier of the plunger, significantly improving gas lift efficiency, reducing production costs, and enhancing the profitability of low-yield, fluid-bearing wells. Currently, the automation and intelligence levels of plunger-assisted intermittent gas lift are low. Well shut-in recovery, gas lift production, and self-flowing production times are generally determined by oilfield engineers based on experience, and operation is typically manual. Summary of the Invention

[0003] The purpose of this invention is to provide a gas lift oil production control method and system to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a gas lift oil recovery control method, comprising the following steps:

[0005] Step S1: Monitor key parameters in the gas lift oil production process in real time using sensors;

[0006] Step S2: The controller acquires key parameter data of the gas lift oil production process from the sensors, specifically gas flow rate, liquid flow rate, pressure, and temperature;

[0007] Step S3: Preprocess the collected raw data. Preprocessing includes filtering, noise reduction, and compensation operations to obtain more accurate and reliable data.

[0008] Step S4: Extract features from the preprocessed data;

[0009] Step S5: Based on the extracted features, perform data analysis to determine the state and performance of the oil production process, specifically calculate the ratio of gas flow rate to liquid flow rate, and determine the liquid production situation of the gas lift oil production process.

[0010] Step S6: Based on the data analysis results, make judgments and decisions on the oil production process, determine the adjustment needs of liquid input based on the trend of liquid level change, and determine the control strategy for gas emission based on pressure changes.

[0011] Step S7: Based on the data analysis results and oil production requirements, generate corresponding control strategies;

[0012] Step S8: Convert the generated control strategy into control commands and send them to the actuator to control the input, discharge and pressure of liquids and gases.

[0013] Preferably, in step S4, features are extracted from the preprocessed data. Specifically, the extracted features include: average liquid flow rate: the average value of the liquid flow rate over a period of time is calculated, and the liquid transport status during the oil recovery process is determined by monitoring the average value of the liquid flow rate changes; liquid flow rate variance: the variance of the liquid flow rate over a period of time is calculated, and the variance reflects the fluctuation of the liquid flow rate.

[0014] Preferably, the step S5, which calculates the ratio of gas flow rate to liquid flow rate to determine the liquid production status of the gas lift oil recovery process, specifically includes:

[0015] Step S51, Data Collection: First, acquire real-time data on gas flow rate and liquid flow rate from the sensors;

[0016] Step S52: Calculate the average value: For data over a period of time, calculate the average value of the gas flow rate and the liquid flow rate. Assuming the gas flow rate is G and the liquid flow rate is L, then...

[0017] Average gas flow rate (G avg )=(G1+G2+…+Gn) / n

[0018] Average liquid flow rate (L) avg )=(L1+L2+…+Ln) / n

[0019] Where G1+G2+…+Gn and L1+L2+…+Ln represent gas flow rate and liquid flow rate data over a period of time, and n is the total number of data points;

[0020] Step S53, Calculate the product-liquid ratio: Calculate the product-liquid ratio using the average gas flow rate and average liquid flow rate:

[0021] WOR (Work-to-Oil Ratio) = L avg / G_avg

[0022] WOR represents the production ratio. By calculating the production ratio, the production situation in the gas lift oil production process is evaluated. When the production ratio increases, it means that the liquid flow rate is increasing relative to the gas flow rate, that is, the production of liquid increases or the gas flow rate decreases. Conversely, when the production ratio decreases, it means that the liquid flow rate is decreasing relative to the gas flow rate, that is, the production of liquid decreases or the gas flow rate increases.

[0023] Preferably, in step S6, the oil extraction process is judged and decided based on the results of data analysis, which specifically includes the following: Judgment and decision-making are made based on the changing trend of the production ratio, including the following situations:

[0024] a. Product-to-liquid ratio continues to increase: If the product-to-liquid ratio continues to increase, it indicates that the liquid flow rate is increasing relative to the gas flow rate, i.e., the liquid production is increasing or the gas flow rate is decreasing. The following decision-making measures need to be taken:

[0025] Check the gas supply system to ensure the stability and sufficiency of gas input;

[0026] Check the liquid drainage system to ensure the drainage pipes are clear.

[0027] Inspect the liquid pumps and piping system to ensure they are functioning properly;

[0028] b. Continuously decreasing product-to-liquid ratio: If the product-to-liquid ratio continues to decrease, it indicates that the liquid flow rate is decreasing relative to the gas flow rate, i.e., the liquid production is decreasing or the gas flow rate is increasing. The following decision-making measures need to be taken:

[0029] Check the gas injection system to ensure sufficient gas injection and stable flow rate;

[0030] Inspect the liquid delivery system to check for blockages or other problems in the delivery pipelines;

[0031] Inspect the liquid pumps and piping system to ensure they are functioning properly;

[0032] c. Small and stable production ratio fluctuations: If the production ratio fluctuates within a small range and remains relatively stable, meaning the balance between liquid and gas flow rates is relatively good during oil production, the following decision-making measures are required:

[0033] Check the accuracy of the gas and liquid flow measurement devices and perform necessary calibrations;

[0034] Continue to monitor the data to ensure the stability of the oil production process and handle any abnormal situations promptly.

[0035] Preferably, the generation of the corresponding control strategy in step S7 specifically includes the following process:

[0036] Monitor changes in the production-liquid ratio: Monitor and calculate the error between the production-liquid ratio and the target production-liquid ratio in real time;

[0037] Cumulative error: Accumulate the error over a period of time to obtain the integral term;

[0038] Calculate the liquid input adjustment: Based on the PI controller algorithm, calculate the liquid input adjustment according to the error and integral term;

[0039] Execute control commands: Convert the calculated liquid input adjustment amount into actual control commands, specifically adjusting the flow rate of the liquid pump or the amount of gas supply to achieve the adjustment of liquid input.

[0040] Preferably, the specific process by which the PI controller algorithm calculates the liquid input adjustment amount is as follows:

[0041] Input parameters: Error: The difference between the current production ratio and the target production ratio; IntegralTerm: The cumulative value of the error over a period of time;

[0042] Output parameter: The adjustment amount calculated by the PI controller, used to adjust the flow rate of the liquid input; the specific calculation formula is as follows:

[0043] Liquid input adjustment amount = Kp * Error + Ki * Integral term

[0044] In the above formula, Kp represents the proportional coefficient and Ki represents the integral coefficient. The proportional coefficient controls the linear relationship between the output and the error, while the integral coefficient controls the relationship between the output and the integral of the error.

[0045] Preferably, a gas lift oil production control system is characterized by comprising: sensors for real-time monitoring of key parameters during the gas lift oil production process; a controller for receiving parameter data monitored by the sensors, processing and analyzing it, and generating feedback results; and an actuator for controlling the input, discharge, and pressure of liquids and gases based on the feedback results from the controller.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] The gas lift oil production control method and system provided by this invention can monitor key parameters in real time, accurately control the oil production process, and improve oil production efficiency; it adopts a preset algorithm to realize the automated control of the system, reduce manual intervention, and lower operating costs; through real-time feedback results, the controller can quickly respond to abnormal system conditions, take timely emergency measures, and protect the safe and effective operation of equipment; the system has a simple structure and is easy to operate, and can flexibly adapt to different oil production scenarios and needs. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Please see Figure 1 This invention provides a technical solution: a gas lift oil recovery control method, characterized by comprising the following steps:

[0051] Step S1: Monitor key parameters in the gas lift oil production process in real time using sensors;

[0052] Step S2: The controller acquires key parameter data of the gas lift oil production process from the sensors, specifically gas flow rate, liquid flow rate, pressure, and temperature;

[0053] Step S3: Preprocess the collected raw data. Preprocessing includes filtering, noise reduction, and compensation operations to obtain more accurate and reliable data.

[0054] Step S4: Extract features from the preprocessed data;

[0055] Step S5: Based on the extracted features, perform data analysis to determine the state and performance of the oil production process, specifically calculate the ratio of gas flow rate to liquid flow rate, and determine the liquid production situation of the gas lift oil production process.

[0056] Step S6: Based on the data analysis results, make judgments and decisions on the oil production process, determine the adjustment needs of liquid input based on the trend of liquid level change, and determine the control strategy for gas emission based on pressure changes.

[0057] Step S7: Based on the data analysis results and oil production requirements, generate corresponding control strategies;

[0058] Step S8: Convert the generated control strategy into control commands and send them to the actuator to control the input, discharge and pressure of liquids and gases.

[0059] Furthermore, in step S4, features are extracted from the preprocessed data. Specifically, the extracted features include: average liquid flow rate: the average value of the liquid flow rate over a period of time is calculated, and the liquid transport status during the oil recovery process is determined by monitoring the average value of the liquid flow rate changes; liquid flow rate variance: the variance of the liquid flow rate over a period of time is calculated, and the variance reflects the fluctuation of the liquid flow rate.

[0060] Furthermore, step S5 calculates the ratio of gas flow rate to liquid flow rate to determine the liquid production status of the gas lift oil recovery process, specifically including:

[0061] Step S51, Data Collection: First, acquire real-time data on gas flow rate and liquid flow rate from the sensors;

[0062] Step S52: Calculate the average value: For data over a period of time, calculate the average value of the gas flow rate and the liquid flow rate. Assuming the gas flow rate is G and the liquid flow rate is L, then...

[0063] Average gas flow rate (G avg )=(G1+G2+…+Gn) / n

[0064] Average liquid flow rate (L) avg )=(L1+L2+…+Ln) / n

[0065] Where G1+G2+…+Gn and L1+L2+…+Ln represent gas flow rate and liquid flow rate data over a period of time, and n is the total number of data points;

[0066] Step S53, Calculate the product-liquid ratio: Calculate the product-liquid ratio using the average gas flow rate and average liquid flow rate:

[0067] WOR (Work-to-Oil Ratio) = L avg / G_avg

[0068] Here, WOR represents the production ratio. By calculating the production ratio, the production situation in the gas lift oil recovery process is evaluated. When the production ratio increases, it indicates that the liquid flow rate is increasing relative to the gas flow rate, that is, the production of liquid increases or the gas flow rate decreases; conversely, when the production ratio decreases, it indicates that the liquid flow rate is decreasing relative to the gas flow rate, that is, the production of liquid decreases or the gas flow rate increases.

[0069] Furthermore, in step S6, based on the results of data analysis, judgments and decisions are made regarding the oil extraction process. Specifically, this includes the following: Judgments and decisions are made based on the changing trend of the production ratio, with the following possible scenarios:

[0070] a. Product-to-liquid ratio continues to increase: If the product-to-liquid ratio continues to increase, it indicates that the liquid flow rate is increasing relative to the gas flow rate, i.e., the liquid production is increasing or the gas flow rate is decreasing. The following decision-making measures need to be taken:

[0071] Check the gas supply system to ensure the stability and sufficiency of gas input;

[0072] Check the liquid drainage system to ensure the drainage pipes are clear.

[0073] Inspect the liquid pumps and piping system to ensure they are functioning properly;

[0074] b. Continuously decreasing product-to-liquid ratio: If the product-to-liquid ratio continues to decrease, it indicates that the liquid flow rate is decreasing relative to the gas flow rate, i.e., the liquid production is decreasing or the gas flow rate is increasing. The following decision-making measures need to be taken:

[0075] Check the gas injection system to ensure sufficient gas injection and stable flow rate;

[0076] Inspect the liquid delivery system to check for blockages or other problems in the delivery pipelines;

[0077] Inspect the liquid pumps and piping system to ensure they are functioning properly;

[0078] c. Small and stable production ratio fluctuations: If the production ratio fluctuates within a small range and remains relatively stable, meaning the balance between liquid and gas flow rates is relatively good during oil production, the following decision-making measures are required:

[0079] Check the accuracy of the gas and liquid flow measurement devices and perform necessary calibrations;

[0080] Continue monitoring of data to ensure the stability of the oil production process and promptly handle any abnormalities. Further, step S7 generates a corresponding control strategy, specifically including the following processes:

[0081] Monitor changes in the production-liquid ratio: Monitor and calculate the error between the production-liquid ratio and the target production-liquid ratio in real time;

[0082] Cumulative error: Accumulate the error over a period of time to obtain the integral term;

[0083] Calculate the liquid input adjustment: Based on the PI controller algorithm, calculate the liquid input adjustment according to the error and integral term;

[0084] Execute control commands: The calculated liquid input adjustment is converted into actual control commands, specifically adjusting the liquid pump flow rate or the gas supply amount to achieve liquid input adjustment. Further, the specific process of the PI controller algorithm calculating the liquid input adjustment is as follows:

[0085] Input parameters: Error: The difference between the current production ratio and the target production ratio; IntegralTerm: The cumulative value of the error over a period of time;

[0086] Output parameter: The adjustment amount calculated by the PI controller, used to adjust the flow rate of the liquid input; the specific calculation formula is as follows:

[0087] Liquid input adjustment amount = Kp * Error + Ki * Integral term

[0088] In the above formula, Kp represents the proportional coefficient, and Ki represents the integral coefficient. The proportional coefficient controls the linear relationship between the output and the error, while the integral coefficient controls the relationship between the output and the integral of the error.

[0089] Furthermore, a gas lift oil production control system includes sensors for real-time monitoring of key parameters during the gas lift oil production process; a controller for receiving parameter data monitored by the sensors, processing and analyzing it, and generating feedback results; and an actuator for controlling the input, discharge, and pressure of liquids and gases based on the feedback results from the controller.

[0090] In the method of this invention, firstly, sensors monitor key parameters in the gas lift oil production process in real time and transmit these parameter data to the controller. The controller receives the sensor data, processes and analyzes it to determine the current state and performance of the oil production process. Based on this data and oil production requirements, the controller generates a corresponding control strategy and feeds it back to the actuator. The actuator then controls the input, discharge, and pressure of liquids and gases according to the feedback from the controller to maintain the oil production process in a stable state.

[0091] The gas lift oil production control method and system provided by this invention can monitor key parameters in real time, accurately control the oil production process, and improve oil production efficiency; it adopts a preset algorithm to realize the automated control of the system, reduce manual intervention, and lower operating costs; through real-time feedback results, the controller can quickly respond to abnormal system conditions, take timely emergency measures, and protect the safe and effective operation of equipment; the system has a simple structure and is easy to operate, and can flexibly adapt to different oil production scenarios and needs.

[0092] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gas lift oil recovery control method, characterized in that, Includes the following steps: Step S1: Monitor key parameters in the gas lift oil production process in real time using sensors; Step S2: The controller acquires key parameter data of the gas lift oil production process from the sensors, specifically gas flow rate, liquid flow rate, pressure, and temperature; Step S3: Preprocess the collected raw data. Preprocessing includes filtering, noise reduction, and compensation operations to obtain more accurate and reliable data. Step S4: Extract features from the preprocessed data; Step S5: Based on the extracted features, perform data analysis to determine the state and performance of the oil production process, specifically calculate the ratio of gas flow rate to liquid flow rate, and determine the liquid production situation of the gas lift oil production process. Step S6: Based on the data analysis results, make judgments and decisions on the oil production process, determine the adjustment needs of liquid input based on the trend of liquid level change, and determine the control strategy for gas emission based on pressure changes. Step S7: Based on the data analysis results and oil production requirements, generate corresponding control strategies; Step S8: Convert the generated control strategy into control commands and send them to the actuator to control the input, discharge, and pressure of liquids and gases; In step S4, features are extracted from the preprocessed data. Specifically, the extracted features include: average liquid flow rate: the average value of the liquid flow rate over a period of time is calculated, and the liquid transport status during the oil recovery process is determined by monitoring the average value of the liquid flow rate changes; and liquid flow rate variance: the variance of the liquid flow rate over a period of time is calculated, and the variance reflects the fluctuation of the liquid flow rate. Specifically, step S5, which calculates the ratio of gas flow rate to liquid flow rate to determine the liquid production status of the gas lift oil recovery process, includes: Step S51, Data Collection: First, acquire real-time data on gas flow rate and liquid flow rate from the sensors; Step S52: Calculate the average value: For data over a period of time, calculate the average value of the gas flow rate and the liquid flow rate. Assume the gas flow rate is... The liquid flow rate is ,but Average gas flow rate ; Average liquid flow rate ; in, and This represents gas flow rate and liquid flow rate data over a period of time. This represents the total number of data points. Step S53, Calculate the product-liquid ratio: Calculate the product-liquid ratio using the average gas flow rate and average liquid flow rate: Product ratio ; in, The production ratio represents the liquid production rate. By calculating the production ratio, the liquid production situation in the gas lift oil production process can be evaluated. When the production ratio increases, it means that the liquid flow rate is increasing relative to the gas flow rate, that is, the liquid production is increasing or the gas flow rate is decreasing. Conversely, when the production ratio decreases, it means that the liquid flow rate is decreasing relative to the gas flow rate, that is, the liquid production is decreasing or the gas flow rate is increasing. In step S6, the oil extraction process is judged and decided based on the results of data analysis. This specifically includes the following: Judgment and decision-making are made based on the changing trend of the production ratio, including the following situations: a. Product-to-liquid ratio continues to increase: If the product-to-liquid ratio continues to increase, it indicates that the liquid flow rate is increasing relative to the gas flow rate, i.e., the liquid production is increasing or the gas flow rate is decreasing. The following decision-making measures need to be taken: Check the gas supply system to ensure the stability and sufficiency of gas input; Check the liquid drainage system to ensure the drainage pipes are clear. Inspect the liquid pumps and piping system to ensure they are functioning properly; b. Continuously decreasing product-to-liquid ratio: If the product-to-liquid ratio continues to decrease, it indicates that the liquid flow rate is decreasing relative to the gas flow rate, i.e., the liquid production is decreasing or the gas flow rate is increasing. The following decision-making measures need to be taken: Check the gas injection system to ensure sufficient gas injection and stable flow rate; Inspect the liquid delivery system to check for blockages in the delivery pipes; Inspect the liquid pumps and piping system to ensure they are functioning properly; c. Small and stable production ratio fluctuations: If the production ratio fluctuates within a small range and remains relatively stable, meaning the balance between liquid and gas flow rates is relatively good during oil production, the following decision-making measures are required: Check the accuracy of the gas and liquid flow measurement devices and perform necessary calibrations; Continue to monitor the data to ensure the stability of the oil production process and handle any abnormal situations promptly; The generation of the corresponding control strategy in step S7 specifically includes the following process: Monitor changes in the production-liquid ratio: Monitor and calculate the error between the production-liquid ratio and the target production-liquid ratio in real time; Cumulative error: Accumulate the error over a period of time to obtain the integral term; Calculate the liquid input adjustment: Based on the PI controller algorithm, calculate the liquid input adjustment according to the error and integral term; Execute control commands: Convert the calculated liquid input adjustment amount into actual control commands, specifically adjusting the flow rate of the liquid pump or the amount of gas supply to achieve the adjustment of liquid input; The specific process by which the PI controller algorithm calculates the liquid input adjustment is as follows: Input parameters: Error: The difference between the current production ratio and the target production ratio; IntegralTerm: The cumulative value of the error over a period of time; Output parameter: The adjustment amount calculated by the PI controller, used to adjust the flow rate of the liquid input; the specific calculation formula is as follows: ； In the above formula, This represents the proportionality coefficient. The integral coefficient represents the proportional coefficient, which controls the linear relationship between the output and the error, while the integral coefficient controls the relationship between the output and the integral of the error.

2. A gas lift oil recovery control system, applied to the gas lift oil recovery control method of claim 1, characterized in that, Includes sensors: used for real-time monitoring of key parameters during the gas lift oil recovery process; Controller: Used to receive parameter data monitored by sensors, process and analyze it, and generate feedback results; Actuator: Used to control the input, discharge, and pressure of liquids and gases based on the feedback results from the controller.

Images