An intelligent shut-in control method for a natural gas well

Abstract

The application provides an intelligent well opening and closing control method for a natural gas well, comprising the following steps: collecting and calculating key indicators; when a well closing state is detected and the gas well meets a minimum well opening pressure, if a well closing time exceeds a maximum well closing time preset value, a well opening operation is performed; otherwise, oil pressure is collected at the same frequency, and if the oil pressure variation value of a continuous preset sample number is less than a preset oil pressure variation threshold value, the well opening operation is performed; when a well opening state is detected, the key indicators are analyzed: instantaneous flow is collected at the same frequency, and the instantaneous flow of a continuous preset sample number is less than a critical liquid carrying flow; wellbore liquid loading height after well opening is greater than wellbore liquid loading height before well opening and reaches a preset proportion; a pressure difference between a transportation pressure and the oil pressure of the gas well is greater than a preset threshold value; if two of the above key indicators are met, a well closing operation is performed. The method provides an artificial well opening and closing control method, and is intelligent and accurate in analysis result.

Description

Technical Field

[0001] This invention relates to the field of natural gas extraction technology, and more specifically to an intelligent well-opening control method for natural gas wells. Background Technology

[0002] In the field of natural gas extraction, various remote automated control devices for wellheads already exist. These devices require supporting remote control software programs to achieve remote well opening, closing, and regulation functions. However, existing equipment and remote control programs only achieve digitization and automation. Whether a natural gas well should be opened or closed, and the duration of opening / closing operations, still requires manual analysis based on collected data to determine whether opening or closing is necessary. This analysis then involves manual remote control of the well opening, closing, or regulation.

[0003] However, given the large amount of historical gas well production data, the sheer number of gas wells, and the enormous workload of manual analysis, it is difficult for humans to conduct detailed analysis of each gas well. Furthermore, the manual analysis process is prone to variations due to differences in individual experience, resulting in vastly different analysis results. Ultimately, this leads to the failure to promptly operate wells, shut them down, or make remote adjustments, thus preventing gas wells from achieving efficient and safe production in full accordance with standard gas production technology. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an intelligent well-opening and shut-off control method for natural gas wells. The method aims to collect key data indicators, perform intelligent analysis and calculation on the collected key indicator data to derive various key dynamic indicators, and then combine these with various static indicator data to automatically execute the intelligent well-opening and shut-off real-time analysis process through a computer program.

[0005] The present invention provides the following technical solution.

[0006] A smart well-opening and closing control method for natural gas wells includes the following steps:

[0007] Collect key data throughout the entire life cycle of the gas well to be controlled, and based on the key data, obtain the critical fluid carrying flow rate, wellbore fluid accumulation height, gas well oil input differential pressure data, and key indicators of gas well oil pressure change trends.

[0008] When a gas well is detected to be in a shut-in state, and the gas well meets the minimum opening pressure, analyze the oil pressure change trend and the duration of shut-in:

[0009] If the shut-in time exceeds the preset maximum shut-in time, the well opening operation will be performed; otherwise, oil pressure will be collected at the same frequency. If the oil pressure change value of a preset number of consecutive samples is less than the preset oil pressure change threshold, the well opening operation will be performed.

[0010] When it is detected that the gas well is in the open well state, the key indicators are analyzed:

[0011] The same frequency is collected to collect the instantaneous flow rate, and the instantaneous flow rate of the continuous preset sample number is less than the critical liquid carrying flow rate; the wellbore liquid height after the well is opened is greater than the wellbore liquid height before the well is opened and reaches a preset ratio; the differential pressure between the delivery pressure and the gas well oil pressure is detected and calculated, and the differential pressure is greater than a preset threshold value;

[0012] If the above two key indicators are met, the well is closed.

[0013] Preferably, the key indicators include static indicator data and real-time dynamic parameters.

[0014] The static indicator data and real-time dynamic parameter data include the gas well production date, the drilled well depth, the artificial bottom hole, the casing inner diameter, the tubing inner diameter, the gas testing open flow capacity, the gas field water density, the wellhead real-time oil pressure, the wellhead real-time casing pressure, the wellhead real-time flow rate and the wellhead real-time temperature.

[0015] Preferably, it also includes the open well or closed well state of the gas well, which is obtained by collecting the wellhead opening value and judging.

[0016] Preferably, the same frequency is collected to collect the oil pressure, and when the oil pressure change value of the continuous preset sample number is less than a preset change threshold value, the well is opened. Specifically, the following steps are included:

[0017] The oil pressure is collected at a collection time interval t1, and when the oil pressure change value of the continuous n samples is less than a set oil pressure change threshold value P, it is determined that the current gas well is in an openable state; wherein the △P is the result of subtracting the previous sample value from the next sample value;

[0018] When the number of collected samples is less than n and the condition of △P greater than P occurs, the number of collected samples is cleared, the number of collected samples is re-counted, the sample collection analysis and counting are restarted, and the conditions are met until the instantaneous flow rate of the continuous n samples is less than the critical liquid carrying flow rate.

[0019] Preferably, it also includes optimizing the oil pressure change threshold value P, including the following steps:

[0020] For the first time, the experience threshold value is used for intelligent control, and the gas well opening rate and the gas production in the period are continuously monitored and analyzed. When the opening rate decreases and the gas production in the period decreases, the oil pressure change threshold value is automatically optimized and adjusted, the threshold value is reduced, the closing time is prolonged, and the gas well accumulates the energy of the gas layer;

[0021] If the opening rate and the gas production in the period do not improve after the threshold value is reduced, it is determined that increasing the closing period is not beneficial to the opening rate and the yield, and the total opening rate is reduced. At this time, the threshold value is automatically optimized to reduce the closing time and prolong the opening time.

[0022] Continue to optimize according to the above steps.

[0023] Preferably, the same frequency acquisition instantaneous flow rate, the instantaneous flow rate of a plurality of consecutive preset samples is less than the critical liquid carrying flow rate, specifically comprising the following steps:

[0024] With the acquisition time interval t1 as the frequency acquisition instantaneous flow rate, when the instantaneous flow rate of the consecutive n samples is less than the critical liquid carrying flow rate, it is determined that it meets one of the necessary conditions for shutting down;

[0025] When the number of samples meeting the condition is less than n, and a sample with an instantaneous flow rate greater than the critical liquid carrying flow rate appears, the number of samples meeting the condition is emptied, and sample acquisition analysis and counting are restarted until the condition that the instantaneous flow rate of the consecutive n samples is less than the critical liquid carrying flow rate is met.

[0026] Preferably, the critical liquid carrying flow rate is calculated by using the Li Min model; and the optimization of the critical liquid carrying flow rate coefficient is also included, comprising the following steps:

[0027] For the first time, a standard model is used for critical liquid carrying flow rate analysis and calculation, and the calculation result is used for gas well liquid carrying capacity evaluation; when the liquid carrying capacity is insufficient to carry liquid production, the well is shut down for recovery; the liquid carrying capacity in the current opening period is statistically evaluated; if the gas well liquid loading increases, the critical liquid carrying flow rate coefficient is automatically optimized, the coefficient is increased, and the detection is continuously performed for three periods; if the liquid loading amount in one opening period decreases and tends to be stable, the current coefficient is maintained for operation and continuous monitoring and analysis;

[0028] If the gas well liquid loading condition does not change, the critical liquid carrying flow rate coefficient is automatically optimized to be reduced, and data monitoring and analysis are performed for three gas production periods;

[0029] Continue to optimize according to the above steps.

[0030] The beneficial effects of the present application are:

[0031] The present application provides an intelligent opening and shutting down control method for a natural gas well. The present application aims to collect key data indicators, intelligently analyze and calculate the collected key indicator data, obtain various key dynamic indicators, combine various static indicator data, and automatically execute intelligent opening and shutting down real-time analysis processes through computer program calculation. The artificial resources are released, and the rationality of the analysis results is ensured; at the same time, with the help of computer high-speed operation, real-time and efficient analysis of gas well process data is realized, and efficient gas production management of a large number of gas wells is met. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The intelligent opening flowchart of the embodiment of the present application;

[0033] Figure 2 An intelligent shut-in flowchart for the embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0035] Embodiment 1

[0036] An intelligent shut-in control method for a natural gas well, as shown in Figures 1-2 , specifically comprising the following steps:

[0037] S1: Collecting key data of the whole life cycle of the gas well to be controlled, and obtaining critical liquid carrying flow rate, wellbore liquid loading height data, gas well oil input pressure difference data, and key indicators of gas well oil pressure change trend according to the key data.

[0038] S2: When it is detected that the gas well is in a shut-in state and the gas well meets the minimum open well pressure, analyzing the oil pressure change trend and the length of time when the well is shut in:

[0039] When the shut-in time exceeds the maximum shut-in time preset value, the well is opened; otherwise, the oil pressure is collected at the same frequency, and when the oil pressure change value of a continuous preset sample number is less than a preset oil pressure change threshold, the well is opened.

[0040] S3: When it is detected that the gas well is in an open well state, analyzing the key indicators:

[0041] Collecting the instantaneous flow rate at the same frequency, and the instantaneous flow rate of a continuous preset sample number is less than the critical liquid carrying flow rate; the wellbore liquid loading height after the well is opened is greater than the wellbore liquid loading height before the well is opened and reaches a preset proportion; the pressure difference between the export pressure and the gas well oil pressure is greater than a preset threshold;

[0042] When the above two key indicators are met, the well is shut in.

[0043] Specifically:

[0044] An intelligent open well control method for a natural gas well, as shown in Figure 1 , comprising the following steps:

[0045] 1. Collection of key indicators

[0046] The key data of each gas well in the whole life cycle is collected and stored by the Internet of Things technology and information management technology, mainly including the key static index data used in intelligent analysis process and real-time dynamic parameter data of gas well, such as gas well production date, completed well depth, artificial well bottom, casing inner diameter, tubing inner diameter, gas test open flow capacity, gas field water density, wellhead real-time oil pressure, wellhead real-time casing pressure, wellhead real-time flow, wellhead real-time temperature, etc.

[0047] 2、Intelligent analysis and calculation of key indicators

[0048] The key indicators in the process of gas well technology management are analyzed and calculated in real time by combining wellhead real-time data with related process algorithms, including:

[0049] The real-time analysis of the oil pressure change trend of the gas well is stored for use as a key indicator in the subsequent intelligent well opening analysis process.

[0050] 3、Intelligent well opening analysis

[0051] Through comprehensive analysis and management of various key dynamic indicators, combined with various static indicator data, the program automatically executes the intelligent well opening real-time analysis process, as follows:

[0052] 3.1、After each gas well meets the minimum well opening pressure, the oil pressure change trend analysis (2) and the well closure time counting process (3) are entered, otherwise the analysis is abandoned and the gas well production status is maintained.

[0053] 3.2、Oil pressure change trend analysis process: collect oil pressure at a frequency of collection time interval t1, when the change value of consecutive n samples (the result of subtracting the previous sample value from the next sample value) △P is less than the set change threshold P, it is determined that the current gas well is in an openable state, when the number of collected samples is less than n and the situation of △P greater than P occurs (where P is initially set according to experience and then automatically optimized by the program), the number of collected samples is cleared and the number of collected samples is counted again.

[0054] 3.3、According to the actual production status of the gas well and the need of production plan, a maximum well closure time configuration entry is provided, the system automatically counts from the last well closure time, and when the well closure time is greater than the maximum well closure time, the result is output, i.e. the well opening condition is reached, and the well opening operation can be performed.

[0055] Example 2

[0056] An intelligent well opening control method for a natural gas well, as shown in Figure 2 , comprising the following steps:

[0057] 1、Collection of key indicators

[0058] Through the Internet of Things technology and information management technology, the key data of each gas well in the whole life cycle is collected and stored, mainly including the key static index data used in intelligent analysis process and real-time dynamic parameter data of gas well, such as gas well production date, completed well depth, artificial well bottom, casing inner diameter, tubing inner diameter, gas test open flow capacity, gas field water density, wellhead real-time oil pressure, wellhead real-time casing pressure, wellhead real-time flow, wellhead real-time temperature, etc.

[0059] 2. Intelligent analysis and calculation of key indicators

[0060] Among them, the key indicators in the process of gas well technology management are analyzed and calculated in real time through wellhead real-time data combined with related process algorithms, including:

[0061] 2.1. Real-time analysis of critical liquid-carrying flow rate of gas well; Li Min model is used for calculation and storage of critical liquid-carrying flow rate and critical liquid-carrying flow rate, which is used as a key indicator in the subsequent intelligent well shut-in analysis process;

[0062] 2.2. The wellbore fluid height data is further analyzed and stored in real time through the automatic calculation of bottom hole flowing pressure from wellhead pressure, which is used as a key indicator in the subsequent intelligent well shut-in analysis process;

[0063] 2.3. The program automatically calculates and stores the gas well oil input pressure difference data, which is used as a key indicator in the subsequent intelligent well shut-in analysis process.

[0064] 3. Intelligent well shut-in analysis

[0065] Through comprehensive analysis and management of various key dynamic indicators, combined with various static indicator data, the program automatically executes intelligent well opening real-time analysis process, as follows:

[0066] 3.1. Collect instantaneous flow rate at a frequency of collection time interval t1, when the instantaneous flow rate of continuous n samples is less than the critical liquid-carrying flow rate, it is determined that it meets one of the necessary conditions for well shut-in, when the number of samples meeting the condition is less than n, and the sample of instantaneous flow rate greater than the critical liquid-carrying flow rate appears, then the number of samples meeting the condition is emptied, the sample collection and analysis is restarted and counted, until the condition of continuous n samples of instantaneous flow rate less than the critical liquid-carrying flow rate is met;

[0067] 3.2. When the wellbore fluid height after well opening is greater than 20% of the wellbore fluid height before well opening (the system automatically detects the opening and closing state of the gas well, and automatically analyzes and stores the wellbore fluid height once as the height before well opening during well opening operation), it is determined that it meets one of the necessary conditions for well shut-in;

[0068] 3.3, Real-time detection of gas well oil pressure and delivery pressure, when the delivery pressure minus the oil pressure is greater than the threshold value (P) (where P is initially set according to experience, and then automatically optimized by the program), it is determined that it meets one of the necessary conditions for closing the well;

[0069] 3.4, The intelligent analysis program analyzes the closing time according to the above three key indicators, and when two or more of the above three indicators meet, it is determined that the current gas well needs to be closed.

[0070] It also includes: key indicator intelligent learning optimization

[0071] The intelligent control program is responsible for intelligent evaluation and optimization of related key indicators, including continuous optimization of the critical liquid carrying flow coefficient and the oil pressure change threshold value in the opening well indicator.

[0072] 1) Critical liquid carrying flow coefficient optimization

[0073] For the first time, a standard model is used to analyze and calculate the critical liquid carrying flow, and the calculation results are used to evaluate the liquid carrying capacity of the gas well. When the liquid carrying capacity is insufficient to carry liquid production, the well is closed to recover. The liquid carrying capacity of the current opening period is evaluated, and if the gas well liquid accumulation increases significantly, the critical liquid carrying flow coefficient is automatically optimized by increasing the coefficient by 10 percentage points, and the detection is continuously performed for three periods. If the liquid accumulation in a well opening period decreases and tends to be stable, the current coefficient is maintained for operation and continuous monitoring and analysis; if the gas well liquid accumulation does not change significantly, the critical liquid carrying flow coefficient is automatically optimized to reduce it by 10 percentage points, and data monitoring and analysis are performed for three gas production periods. Continue to optimize.

[0074] 2) Oil pressure change threshold value optimization

[0075] For the first time, an empirical threshold value is used for intelligent control, and the gas well opening rate and the gas production in the period are continuously monitored and analyzed. When the opening rate decreases and the gas production in the period decreases significantly, the oil pressure change threshold value is automatically optimized and adjusted by 10 percentage points to extend the shut-in time, so that the gas well accumulates more gas layer energy. If the opening rate and the gas production in the period do not improve significantly after reducing the threshold value, it is determined that increasing the shut-in period is not beneficial to the opening rate and the production, and the total opening rate is reduced. At this time, the threshold value is automatically optimized and increased by 10 percentage points to reduce the shut-in time and extend the opening time. Continue to optimize, finally increase the gas well production.

[0076] The present application will greatly reduce the working pressure of natural gas well workers, provide efficient and reliable analysis results, and manage a large number of gas wells at the same time, so that they run in a safe and efficient state.

[0077] The above merely preferred embodiments of the present application are not used to limit the present application, any modification, equivalent replacement and improvement etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for intelligent shut-in control of a natural gas well, characterized in that, The method comprises the following steps: Collecting key data of the whole life cycle of the gas well to be controlled, and obtaining critical liquid carrying flow rate, wellbore liquid accumulation height data, gas well oil delivery pressure difference data, and key indicators of gas well oil pressure variation trend according to the key data; When it is detected that the gas well is in the closed state and the gas well meets the minimum opening pressure, the oil pressure variation trend and the length of time when the well is closed are analyzed: When the length of time when the well is closed exceeds the maximum preset value of the length of time when the well is closed, the well opening operation is performed; otherwise, the oil pressure is collected at the same frequency, and when the oil pressure variation values of the continuous preset sample quantity are less than the preset oil pressure variation threshold, the well opening operation is performed; When it is detected that the gas well is in the open state, the key indicators are analyzed: the instantaneous flow rate is collected at the same frequency, the instantaneous flow rate of the continuous preset sample quantity is less than the critical liquid carrying flow rate, the wellbore liquid accumulation height after the well is opened is greater than the wellbore liquid accumulation height before the well is opened and reaches a preset proportion, and the pressure difference between the delivery pressure and the gas well oil pressure is greater than a preset threshold; when two of the above key indicators are met, the well closing operation is performed; The oil pressure is collected at the same frequency, and when the oil pressure variation values of the continuous preset sample quantity are less than the preset oil pressure variation threshold, the well opening operation is performed, specifically comprising the following steps: The oil pressure is collected at the frequency of the collection time interval t1, and when the oil pressure variation values of the continuous n samples are less than the preset oil pressure variation threshold P, it is determined that the current gas well is in an openable state; wherein △P is the result of subtracting the previous sample value from the next sample value; When the number of collected samples is less than n and the condition of △P being greater than P occurs, the number of collected samples is cleared, and the number of collected samples is counted again; Further comprising: optimizing the oil pressure variation threshold P, comprising the following steps: For the first time, the intelligent control is performed by using an empirical threshold, and the gas well opening time rate and the gas production in the period are continuously monitored and analyzed; when the opening time rate decreases and the gas production in the period decreases, the oil pressure variation threshold is automatically optimized and adjusted, the threshold is reduced, the length of time when the well is closed is extended, and the gas well accumulates gas layer energy; If the opening time rate and the gas production in the period are not improved after the threshold is reduced, it is determined that increasing the length of time when the well is closed is not beneficial to the opening time rate and the production, and the total opening time rate is reduced; at this time, the threshold is automatically optimized and increased to reduce the length of time when the well is closed and extend the length of time when the well is opened; The above steps are continuously optimized.

2. The intelligent shut-in control method for a natural gas well according to claim 1, wherein, The key indicators include static indicator data and real-time dynamic parameter data; The static indicator data and real-time dynamic parameter data include the gas well production date, the completed well depth, the artificial well bottom, the casing inner diameter, the tubing inner diameter, the gas-free flow rate, the gas field water density, the wellhead real-time oil pressure, the wellhead real-time casing pressure, the wellhead real-time flow rate, and the wellhead real-time temperature.

3. The intelligent shut-in control method for a natural gas well according to claim 1, wherein, The instantaneous flow rate is collected at the same frequency, and the instantaneous flow rate of the continuous preset sample quantity is less than the critical liquid carrying flow rate, specifically comprising the following steps: The instantaneous flow rate is collected at the frequency of the collection time interval t1, and when the instantaneous flow rates of the continuous n samples are less than the critical liquid carrying flow rate, it is determined that one of the necessary conditions for closing the well is met; When the number of samples meeting the condition is less than n, and the sample of instantaneous flow greater than the critical liquid carrying flow appears, the samples meeting the condition are emptied, the sample collection and analysis are restarted and counted until the condition of the instantaneous flow of the continuous n samples being less than the critical liquid carrying flow is met.

4. The intelligent shut-in control method for a natural gas well according to claim 3, wherein, The critical liquid carrying flow is calculated by using the Li Min model; and the optimization of the critical liquid carrying flow coefficient is further included, including the following steps: The standard model is used for the first time to analyze and calculate the critical liquid carrying flow, and the calculation result is used for the gas well liquid carrying capacity evaluation; when the liquid carrying capacity is insufficient to carry liquid production, the well is closed to recover; the liquid carrying capacity in the current opening period is statistically evaluated; if the gas well liquid loading increases, the critical liquid carrying flow coefficient is automatically optimized, the coefficient is increased, and the detection is continuously performed for three periods; if the liquid loading in one opening period decreases and tends to be stable, the current coefficient is maintained for operation and continuous monitoring and analysis; If the gas well liquid loading condition does not change, the critical liquid carrying flow coefficient is automatically optimized to be reduced, and the data monitoring and analysis of three gas production periods are performed; The above steps are continuously optimized.

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