Gas well mouth pressure drop control method and system, electronic equipment and medium

Abstract

The invention belongs to the field of natural gas well exploitation control, and discloses a gas well wellhead pressure drop control method and system, electronic equipment and a medium. Judging whether the wellhead pressure is greater than a pressure threshold, and if so, calculating the wellhead pressure drop of the gas well in the current comparison period; judging whether the wellhead pressure drop is greater than the maximum pressure drop threshold value, if so, controlling the valve opening to be reduced, and then obtaining the wellhead pressure of the gas well in the preset comparison period again, if not, judging whether the wellhead pressure drop is less than the minimum pressure drop threshold value, if so, controlling the valve opening to be increased, and then obtaining the wellhead pressure of the gas well again, and if not, controlling the valve opening to be reduced. And re-acquiring the wellhead pressure of the gas well. According to the method, the pressure drop of the wellhead is controlled within a stable range, accurate control over the gas well is achieved, the effects of delaying fracture closing, reducing the formation sand production amount and the like can be achieved, stable exploitation of the gas well is guaranteed, and meanwhile the EUR of the gas well is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas well production control, and in particular relates to a gas well wellhead pressure drop control method, system, electronic equipment and medium. Background Art

[0002] With the development of society, the consumption of natural gas energy is also increasing. Shale gas is an unconventional natural gas stored in organic-rich shale. The recoverable reserves of shale gas in my country are large. Therefore, the development of shale gas acquisition technology is of great significance in China. Shale gas is usually mined by large-scale sand fracturing during development. Excessive production pressure difference will cause the loss of proppant in the formation, resulting in flow channel closure, which is not conducive to the output of natural gas. Therefore, reasonable control of production pressure difference is crucial in the shale gas mining process.

[0003] There are at least the following problems in the existing technology: for shale gas wells, the pressure drops too quickly during the production process, which can easily cause the closure of wellhead fractures and secondary sand production in the formation, resulting in a decrease in the EUR (Estimated Ultimate Recovery, the abbreviation of the ultimate recoverable reserves evaluated by a single well, which refers to the ultimate recoverable reserves of a development well that has been in production for more than many years, evaluated based on the law of capacity decline and using a trend prediction method) of the gas well; in the existing technology, gas wells are usually produced at a fixed opening, and the wellhead pressure drop value (pressure drop value) cannot be controlled within the required range, which is not conducive to the exploitation of the gas well. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a gas wellhead pressure drop control method, system, electronic equipment and medium, by obtaining the wellhead pressure of the gas well, and then when the wellhead pressure is greater than the pressure threshold, obtaining the wellhead pressure drop of the gas well within a preset comparison period, and then comparing the wellhead pressure drop with the preset maximum pressure drop threshold and minimum pressure drop threshold, and controlling the valve opening to decrease when the wellhead pressure drop is greater than the maximum pressure drop threshold, and controlling the valve opening to increase when the wellhead pressure drop is less than the minimum pressure drop threshold, thereby controlling the wellhead pressure drop within a stable range, achieving precise control of the gas well, and delaying the closure of cracks, reducing the amount of sand produced in the formation, etc., thereby ensuring the stable exploitation of the gas well and improving the EUR of the gas well.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for controlling the wellhead pressure drop of a gas well comprises the following steps:

[0007] Obtain the wellhead pressure of the gas well;

[0008] Determine whether the wellhead pressure is greater than a pressure threshold, and if so, obtain the wellhead pressure drop of the gas well in the current comparison period based on multiple wellhead pressures in a preset comparison period;

[0009] Determine whether the wellhead pressure drop is greater than the maximum pressure drop threshold. If so, control the valve opening to decrease, and then re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, proceed to the next step.

[0010] It is determined whether the wellhead pressure drop is less than the minimum pressure drop threshold. If so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is obtained again. If not, the wellhead pressure of the gas well is obtained again.

[0011] Furthermore, the wellhead pressure includes oil pressure and / or casing pressure.

[0012] Furthermore, obtaining the wellhead pressure of the gas well includes:

[0013] Within a preset comparison period, obtaining the average pressure of multiple acquisition periods;

[0014] Calculating the sliding average pressure of multiple sliding periods in the current comparison period according to the average pressure of multiple acquisition periods, and setting the sliding average pressure as the wellhead pressure of the gas well in the preset comparison period;

[0015] Among them, the duration of the sliding period is greater than the collection period.

[0016] Furthermore, the average pressure of multiple acquisition cycles is obtained, including:

[0017] According to the preset frequency, the wellhead pressure in multiple collection cycles is collected respectively;

[0018] In any acquisition cycle, multiple wellhead pressures are sorted by size to obtain a wellhead pressure data column;

[0019] Removing a preset number of maximum and minimum values ​​from the wellhead pressure data column to obtain a filtered wellhead pressure data column;

[0020] Calculate the average value of the filtered wellhead pressure data column to obtain the average pressure of the current acquisition period;

[0021] The average pressure in the next acquisition cycle is calculated until the average pressure of multiple acquisition cycles in the comparison period is obtained.

[0022] Further, the average value of the filtered wellhead pressure data column is calculated, including:

[0023] The average value of the filtered wellhead pressure data column is calculated using the arithmetic average method or the weighted average method.

[0024] Further, the comparison period includes at least one sliding period, and the sliding period includes at least one acquisition period;

[0025] Set a sliding window, which includes two sliding periods;

[0026] When the current moment is within the comparison period, if the number of average pressures of the acquired collection period is less than the number of collection periods within a sliding period, wait for a sliding period and re-acquire the number of average pressures of the collection periods within the current comparison period;

[0027] When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods within a sliding period and is less than the number of collection periods within a sliding window, the average pressures of the acquired collection periods are summed and averaged to be the sliding average pressure of the current comparison period;

[0028] When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods of the sliding window, the sliding average pressure of the current comparison period is calculated by the average pressures of the acquired collection periods within the sliding window, and then the next sliding period is entered, and a sliding period moment is waited again.

[0029] Further, it is determined whether the wellhead pressure drop is greater than the maximum pressure drop threshold. If so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-obtained, including:

[0030] Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop outside the maximum extended pressure drop interval, and then proceed to the next step, where the minimum value of the maximum extended pressure drop interval is the maximum pressure drop threshold, and the maximum value of the maximum extended pressure drop interval is the sum of the maximum pressure drop threshold and the extended pressure drop value;

[0031] Determine whether the count of the wellhead pressure drop outside the maximum extended pressure drop range is greater than the preset count, if so, proceed to the next step, if not, output the valve opening reduction adjustment step length instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period;

[0032] Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening reduction adjustment step instruction, and then re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening reduction adjustment step instruction and the valve opening reduction set amplitude instruction, and then re-obtain the wellhead pressure of the gas well within the preset comparison period.

[0033] Further, it is determined whether the wellhead pressure drop is greater than the maximum pressure drop threshold, and if so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-obtained, which also includes:

[0034] Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value. If not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the maximum extended pressure drop range. If so, re-obtain the wellhead pressure of the gas well in the preset comparison period. If not, output the valve opening reduction adjustment step instruction to re-obtain the wellhead pressure of the gas well in the preset comparison period.

[0035] Further, it is determined whether the wellhead pressure drop is less than the minimum pressure drop threshold. If so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is obtained again, including:

[0036] Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop being outside the minimum extended pressure drop interval, and proceed to the next step, wherein the minimum value of the minimum extended pressure drop interval is the difference between the maximum pressure drop threshold and the extended pressure drop value, and the maximum value of the minimum extended pressure drop interval is the maximum pressure drop threshold;

[0037] Determine whether the count of the wellhead pressure drop outside the minimum extended pressure drop range is greater than the preset count. If so, proceed to the next step. If not, output the valve opening increase adjustment step length instruction to re-acquire the wellhead pressure of the gas well within the preset comparison period.

[0038] Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening increase adjustment step instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening increase adjustment step instruction and the valve opening increase set amplitude instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period.

[0039] Further, it is determined whether the wellhead pressure drop is less than the minimum pressure drop threshold value. If so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is obtained again, which also includes:

[0040] Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value. If not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the minimum extended pressure drop range. If so, re-obtain the wellhead pressure of the gas well in the preset comparison period. If not, output the valve opening increase adjustment step instruction, and then re-obtain the wellhead pressure of the gas well in the preset comparison period.

[0041] Furthermore, when the pressure threshold is set to 10 MPa, the maximum pressure drop threshold is set to 0.03 MPa / d, and the minimum pressure drop threshold is set to 0.01 MPa / d;

[0042] When the pressure threshold is set to 20MPa, the maximum pressure drop threshold is set to 0.1MPa / d, and the minimum pressure drop threshold is set to 0.07MPa / d;

[0043] When the pressure threshold is set to 10MPa-20MPa, the maximum pressure drop threshold is set to 0.07MPa / d, and the minimum pressure drop threshold is set to 0.03MPa / d.

[0044] In a second aspect, the present invention further discloses a gas wellhead pressure drop control system, comprising:

[0045] A wellhead pressure acquisition module, used to obtain the wellhead pressure of the gas well;

[0046] The wellhead pressure processing module is connected to the wellhead pressure acquisition module for determining whether the wellhead pressure is greater than a pressure threshold, and if so, obtaining the wellhead pressure drop of the gas well in the current comparison period according to multiple wellhead pressures in a preset comparison period;

[0047] The wellhead pressure drop processing module is communicated with the wellhead pressure processing module and is used to determine whether the wellhead pressure drop is greater than the maximum pressure drop threshold. If so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-obtained. If not, it is determined whether the wellhead pressure drop is less than the minimum pressure drop threshold. If so, the valve opening is controlled to increase and the wellhead pressure of the gas well is re-obtained. If not, the wellhead pressure of the gas well is re-obtained.

[0048] In a third aspect, the present invention further discloses an electronic device, comprising:

[0049] a memory for storing computer program instructions;

[0050] The processor is used to execute the computer program instructions to complete the operation of the above-mentioned gas wellhead pressure drop control method.

[0051] In a fourth aspect, the present invention further discloses a computer-readable storage medium.

[0052] Used to store computer-readable computer program instructions, the computer program instructions are configured to execute the operations of the above-mentioned gas well wellhead pressure drop control method when running.

[0053] Technical effects and advantages of the present invention:

[0054] 1. The present invention obtains the wellhead pressure of the gas well, and then when the wellhead pressure is greater than the pressure threshold, obtains the wellhead pressure drop of the gas well within a preset comparison period, and then compares the wellhead pressure drop with the preset maximum pressure drop threshold and minimum pressure drop threshold, and controls the valve opening to decrease when the wellhead pressure drop is greater than the maximum pressure drop threshold, and controls the valve opening to increase when the wellhead pressure drop is less than the minimum pressure drop threshold, thereby controlling the wellhead pressure drop within a stable range, achieving precise control of the gas well, delaying the closure of cracks, reducing the amount of sand produced in the formation, etc., thereby facilitating stable exploitation of the gas well and improving the EUR of the gas well.

[0055] 2. The present invention adaptively adjusts the valve opening amplitude by judging whether the valve opening is at the linear inflection point of the valve core, thereby facilitating accurate adjustment of the valve in different states and avoiding the problem of inaccurate flow regulation caused by different valve states.

[0056] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A flow chart of a gas wellhead pressure drop control method of the present invention;

[0058] Figure 2 A flow chart of calculating the sliding average pressure of multiple sliding cycles within a comparison cycle according to the present invention;

[0059] Figure 3 It is a flow chart of a method for controlling the pressure drop at the wellhead of a gas well when the pressure threshold is set to 20 MPa;

[0060] Figure 4 This is a structural diagram of a gas wellhead pressure drop control system in the present invention;

[0061] Figure 5 This is a module block diagram of an electronic device in the present invention. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Figure 1 FIG. 1 is a flow chart of a gas wellhead pressure drop control method of the present invention, as shown in FIG. Figure 1 As shown, the present invention provides a method for controlling the wellhead pressure drop of a gas well, comprising the following steps:

[0064] Obtain the wellhead pressure of the gas well;

[0065] Determine whether the wellhead pressure is greater than a pressure threshold, and if so, obtain the wellhead pressure drop of the gas well in the current comparison period based on multiple wellhead pressures in a preset comparison period;

[0066] Determine whether the wellhead pressure drop is greater than the maximum pressure drop threshold. If so, control the valve opening to decrease, and then re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, proceed to the next step.

[0067] It is determined whether the wellhead pressure drop is less than a minimum pressure drop threshold value. If so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is re-obtained. If not, the wellhead pressure of the gas well is re-obtained.

[0068] In some embodiments of the present invention, the wellhead pressure includes oil pressure and / or casing pressure. The Christmas tree is a wellhead device used for oil production in self-flowing wells and machine-extracted wells. It is the main equipment for controlling and regulating oil and gas production at the top of the oil and gas well, and is mainly composed of three parts: casing head, tubing head, and Christmas (gas) tree body. The oil pressure is the residual pressure of the oil flow from the bottom of the well to the wellhead. The pressure gauge for measuring the oil pressure is installed at the position connected to the oil pipe in front of the Christmas tree nozzle. If the measured oil pressure is high, it means that the oil well has a strong liquid supply capacity. If the measured oil pressure is low, it means that the oil well has a weak liquid supply capacity. The casing pressure is the casing pressure, which is the pressure applied to the casing in the well by the ground. The pressure gauge for measuring the casing pressure is installed at the Christmas tree casing gate and is connected to the annular space between the oil pipe and the casing. The size of the casing pressure reflects the size of the annular space pressure and the amount of natural gas separated from the oil. Among them, the oil pressure can be used to monitor the working condition of the oil pump and to monitor whether the ground process is smooth. The casing pressure can be used to monitor whether the casing constant pressure vent valve is easy to use. Therefore, both oil pressure and casing pressure can reflect the working status of the gas well, thereby achieving precise control of the gas well. It should be noted that data such as pre-valve pressure, post-valve pressure, wellhead temperature, pre-valve temperature and post-valve temperature can also be collected to provide auxiliary data for gas wellhead pressure monitoring, so as to facilitate management users to judge the wellhead pressure.

[0069] In some embodiments of the present invention, when obtaining the wellhead pressure of a gas well,

[0070] Within a preset comparison period, obtaining the average pressure of multiple acquisition periods;

[0071] Calculating the sliding average pressure of multiple sliding periods in the current comparison period according to the average pressure of multiple acquisition periods, and setting the sliding average pressure as the wellhead pressure of the gas well in the preset comparison period;

[0072] Among them, the duration of the sliding period is greater than the collection period.

[0073] In some embodiments of the present invention, when obtaining the average pressure of multiple acquisition cycles,

[0074] According to the preset frequency, the wellhead pressure in multiple collection cycles is collected respectively;

[0075] In any acquisition cycle, multiple wellhead pressures are sorted by size to obtain a wellhead pressure data column;

[0076] Removing a preset number of maximum and minimum values ​​from the wellhead pressure data column to obtain a filtered wellhead pressure data column;

[0077] Calculate the average value of the filtered wellhead pressure data column to obtain the average pressure of the current acquisition period;

[0078] Calculate the average pressure in the next acquisition cycle until the average pressure of multiple acquisition cycles in the comparison cycle is obtained;

[0079] In some embodiments of the present invention, when calculating the average value of the filtered wellhead pressure data column, an arithmetic average method or a weighted average method is used for calculation.

[0080] For example, when collecting wellhead pressures within multiple collection cycles, data collection starts at the full minute, and data is collected once every 0.8 seconds. First, the oil pressure and casing pressure are collected at intervals, and each is collected 30 times cumulatively, and then the accumulated 30 oil pressure and casing pressures are used to calculate the average pressure. When obtaining the average pressure of multiple collection cycles, the 30 collected oil pressure and casing pressure data are first sorted, and then the maximum and minimum values, a total of 10 data, are removed, and then the remaining 20 data are averaged by arithmetic averaging or weighted averaging. The calculation result is used as the average pressure at the full minute, and the data is accumulated and recorded until the average pressure of multiple collection cycles in the comparison period is obtained.

[0081] In some embodiments of the present invention, the comparison period includes at least one sliding period, and the sliding period includes at least one acquisition period;

[0082] Set a sliding window, which includes two sliding periods;

[0083] When the current moment is within the comparison period, if the number of average pressures of the acquired collection period is less than the number of collection periods within a sliding period, wait for a sliding period and re-acquire the number of average pressures of the collection periods within the current comparison period;

[0084] When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods within a sliding period and is less than the number of collection periods within a sliding window, the average pressures of the acquired collection periods are summed and averaged to be the sliding average pressure of the current comparison period;

[0085] When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods of the sliding window, the sliding average pressure of the sliding period in the current sliding window is calculated by the average pressure of the acquired collection period, and then the next sliding period is entered, and the moment of a sliding period is waited again.

[0086] Figure 2 The flow chart for calculating the sliding average pressure of multiple sliding cycles within the comparison cycle is as follows: Figure 2 As shown, 1 hour is used as a comparison period, 5 minutes is used as a sliding period, 1 minute is used as a collection period, and the sliding window is set to 10. When the current moment is within the comparison period, if the number of average pressures of the collection periods within the current comparison period is less than 5, wait for 5 minutes to re-acquire the number of average pressures of the collection periods within the current comparison period; when the number of average pressures of the collection periods is greater than or equal to 5, directly add and average the average pressures of the collection periods obtained as the sliding average pressure of the current comparison period; when the number of average pressures of the collection periods obtained is greater than or equal to the number of collection periods in the sliding window, the sliding average pressures of multiple sliding periods within the current comparison period are calculated by the average pressures of 10 collection periods within the sliding window, and the calculation formula includes:

[0087]

[0088] Where P is the sliding average pressure in the current comparison period, P -4 -P0 and P -9 -P -5 are the average pressures of the acquisition cycles in the two sliding cycles in the sliding window, respectively. Then, the next sliding cycle is entered, and the full 5 minutes are waited again.

[0089] It should be noted that using the sliding mean pressure as the wellhead pressure of the gas well can improve the accuracy of the wellhead pressure and avoid the influence of the subsequent pressure drop calculation on the pressure value due to a short-term sudden change, thereby achieving stable regulation of the wellhead pressure of the gas well.

[0090] In some embodiments of the present invention, when the wellhead pressure is not greater than the pressure threshold, a corresponding pressure drop threshold may also be set to facilitate complete regulation of the wellhead pressure drop of the gas well.

[0091] In some embodiments of the present invention, it is determined whether the wellhead pressure drop is greater than the maximum pressure drop threshold, and if so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-acquired, including:

[0092] Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop outside the maximum extended pressure drop interval, and then proceed to the next step, where the minimum value of the maximum extended pressure drop interval is the maximum pressure drop threshold, and the maximum value of the maximum extended pressure drop interval is the sum of the maximum pressure drop threshold and the extended pressure drop value;

[0093] Determine whether the count of the wellhead pressure drop outside the maximum extended pressure drop range is greater than the preset count, if so, proceed to the next step, if not, output a valve opening reduction adjustment step length instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period;

[0094] Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening reduction adjustment step instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening reduction adjustment step instruction and the valve opening reduction set amplitude instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period.

[0095] It should be noted that, during the gradual opening of the valve core, there will be an inflection point phenomenon where the flow rate increases from the first linear growth segment to the second linear growth segment as the opening increases. That is, as the valve core opening gradually increases, the valve port flow rate will change from the first linear growth segment of linear growth to the second linear growth segment of flow rate linear growth. In most cases, the slope of the second linear growth segment is greater than the slope of the first linear growth segment, that is, an inflection point phenomenon will occur, resulting in a sudden change in the main valve flow rate, affecting pressure stability. If the valve opening is not at the linear inflection point of the valve core, the valve opening amplitude can be increased, that is, the valve opening reduction adjustment step length instruction and the valve opening reduction set amplitude instruction are output successively. If the valve opening is at the linear inflection point of the valve core, the valve opening reduction adjustment step length instruction is output, thereby facilitating the precise adjustment of the valve in different states and avoiding the problem of inaccurate flow regulation caused by different valve states.

[0096] In some embodiments of the present invention, when determining whether the wellhead pressure drop is greater than the maximum pressure drop threshold, and if so, controlling the valve opening to decrease, and then reacquiring the wellhead pressure of the gas well within a preset comparison period, the method further includes:

[0097] Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value. If not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the maximum extended pressure drop range. If so, re-obtain the wellhead pressure of the gas well in the preset comparison period. If not, output the valve opening reduction adjustment step instruction to re-obtain the wellhead pressure of the gas well in the preset comparison period.

[0098] In some embodiments of the present invention, it is determined whether the wellhead pressure drop is less than a minimum pressure drop threshold value, and if so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is re-acquired, including:

[0099] Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop being outside the minimum extended pressure drop interval, and proceed to the next step, wherein the minimum value of the minimum extended pressure drop interval is the difference between the maximum pressure drop threshold and the extended pressure drop value, and the maximum value of the minimum extended pressure drop interval is the maximum pressure drop threshold;

[0100] Determine whether the count of the wellhead pressure drop outside the minimum extended pressure drop interval is greater than the preset count, if so, proceed to the next step, if not, output a valve opening increase adjustment step length instruction, and re-acquire the wellhead pressure of the gas well within the preset comparison period;

[0101] Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening increase adjustment step instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening increase adjustment step instruction and the valve opening increase set amplitude instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period.

[0102] In some embodiments of the present invention, when determining whether the wellhead pressure drop is less than a minimum pressure drop threshold, and if so, controlling the valve opening to increase, and then reacquiring the wellhead pressure of the gas well, the method further includes:

[0103] Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value. If not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the minimum extended pressure drop range. If so, re-obtain the wellhead pressure of the gas well in the preset comparison period. If not, output the valve opening increase adjustment step instruction, and then re-obtain the wellhead pressure of the gas well in the preset comparison period.

[0104] Specifically, when the pressure threshold is set to 10MPa, the maximum pressure drop threshold is preferably 0.03MPa / d, and the minimum pressure drop threshold is preferably 0.01MPa / d; when the pressure threshold is set to 20MPa, the maximum pressure drop threshold is preferably 0.1MPa / d, and the minimum pressure drop threshold is preferably 0.07MPa / d; when the pressure threshold is set to 10MPa-20MPa, the maximum pressure drop threshold is preferably 0.07MPa / d, and the minimum pressure drop threshold is preferably 0.03MPa / d.

[0105] For example, the flow chart of the gas wellhead pressure drop control method when the pressure threshold is set to 20 MPa is as follows: Figure 3 As shown, the preset count is set to 5.

[0106] In some embodiments of the present invention, before obtaining the wellhead pressure of the gas well, the method further includes:

[0107] Initialize system parameters, average pressure and sliding average pressure;

[0108] Clear the historical acquisition data and historical execution data stored in the pressure control system.

[0109] It should be noted that the pressure control system in this embodiment includes an industrial computer, which is connected to a valve drive motor for adjusting the valve opening. System parameters, average pressure, sliding average pressure, historical collected data, historical execution data, communication data and other data are all stored in the industrial computer. The system parameters and other data are initialized, and the historical collected data and other data stored in the pressure control system are cleared. This allows the pressure control system to ensure data accuracy in subsequent steps such as wellhead pressure acquisition and avoid the collected data being affected by the original data.

[0110] The method of the present invention is conducive to ensuring the stability of the wellhead pressure of the gas well, thereby improving the production of the gas well, by obtaining the wellhead pressure of the gas well, and then when the wellhead pressure is greater than the pressure threshold, obtaining the wellhead pressure drop of the gas well within a preset comparison period, then comparing the wellhead pressure drop with the preset maximum pressure drop threshold and minimum pressure drop threshold, and controlling the valve opening to decrease when the wellhead pressure drop is greater than the maximum pressure drop threshold, and controlling the valve opening to increase when the wellhead pressure drop is less than the minimum pressure drop threshold, thereby controlling the wellhead pressure drop within a stable range, achieving precise control of the gas well, delaying the closure of the cracks, reducing the amount of sand produced by the formation, and thus ensuring the stable exploitation of the gas well, while improving the production of the gas well. When the wellhead pressure is higher than a certain pressure value, the gas carrying liquid capacity is in a strong state; when the wellhead pressure is lower than a certain pressure value, the gas carrying liquid capacity deteriorates, or cannot carry out liquid, at this time, controlling the valve opening to increase, the gas flow rate will be increased to enhance the carrying liquid capacity. In order to ensure stable control of the valve opening and avoid the influence of short-term sudden changes in pressure values ​​on the subsequent pressure drop calculation, when the wellhead pressure is greater than the pressure threshold, the wellhead pressure drop of the gas well is obtained, and the valve opening is adjusted through the difference between the pressure drop and the preset maximum pressure drop threshold and minimum pressure drop threshold. In this way, stable adjustment of the wellhead pressure of the gas well can be achieved, which is conducive to ensuring the stability of gas well collection.

[0111] Second, as Figure 4 As shown, the present invention also discloses a gas wellhead pressure drop control system, comprising:

[0112] A wellhead pressure acquisition module, used to obtain the wellhead pressure of the gas well;

[0113] A wellhead pressure processing module, which is in communication with the wellhead pressure acquisition module, is used to determine whether the wellhead pressure is greater than a pressure threshold, and if so, obtain the wellhead pressure drop of the gas well in the current comparison period based on a plurality of wellhead pressures in a preset comparison period;

[0114] The wellhead pressure drop processing module is communicatively connected with the wellhead pressure processing module, and is used to determine whether the wellhead pressure drop is greater than a maximum pressure drop threshold. If so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-obtained. If not, it is determined whether the wellhead pressure drop is less than a minimum pressure drop threshold. If so, the valve opening is controlled to be increased, and the wellhead pressure of the gas well is re-obtained. If not, the wellhead pressure of the gas well is re-obtained.

[0115] Thirdly, Figure 5 As shown, the present invention also discloses an electronic device, including:

[0116] a memory for storing computer program instructions;

[0117] The processor is used to execute the computer program instructions to complete the operation of the above-mentioned gas wellhead pressure drop control method.

[0118] Specifically, the processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0119] In some embodiments of the present invention, the processor may be integrated with a GPU (Graphics Processing Unit), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen.

[0120] The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory, and non-volatile memory, such as one or more disk storage devices, flash memory storage devices.

[0121] In some embodiments of the present invention, a non-transitory computer-readable storage medium in a memory is used to store at least one instruction, which is used to be executed by a processor to implement the gas wellhead pressure drop control method of the present invention.

[0122] In some embodiments of the present invention, the terminal includes: a communication interface and at least one peripheral device. The processor, the memory and the communication interface may be connected via a bus or a signal line. Each peripheral device may be connected to the communication interface via a bus, a signal line or a circuit board. Specifically, the peripheral device includes: at least one of a radio frequency circuit, a display screen and a power supply.

[0123] The communication interface may be used to connect at least one peripheral device related to I / O (Input / Output) to the processor and the memory.

[0124] In some embodiments of the present invention, the processor, memory and communication interface are integrated on the same chip or circuit board.

[0125] In some embodiments of the present invention, any one or two of the processor, memory, and communication interface may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

[0126] Radio frequency circuits are used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. Radio frequency circuits communicate with communication networks and other communication devices through electromagnetic signals.

[0127] The display screen is used to display a UI (User Interface). The UI may include graphics, text, icons, videos, and any combination thereof.

[0128] Power supplies are used to power various components in electronic devices.

[0129] In a fourth aspect, the present invention further discloses a computer-readable storage medium for storing computer program instructions readable by a computer, wherein the computer program instructions are configured to execute the operations of the above-mentioned gas wellhead pressure drop control method when run.

[0130] It should be noted that if the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0131] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the pressure drop at a gas wellhead, characterized in that: The following steps are involved: Obtain the wellhead pressure of the gas well; Determine whether the wellhead pressure is greater than a pressure threshold, and if so, obtain the wellhead pressure drop of the gas well in the current comparison period according to a plurality of wellhead pressures in a preset comparison period; Determine whether the wellhead pressure drop is greater than the maximum pressure drop threshold. If so, control the valve opening to decrease, and then re-acquire the wellhead pressure of the gas well within a preset comparison period. If not, proceed to the next step. It is determined whether the wellhead pressure drop is less than a minimum pressure drop threshold value. If so, the valve opening is controlled to increase, and then the wellhead pressure of the gas well is re-obtained. If not, the wellhead pressure of the gas well is re-obtained.

2. A gas wellhead pressure drop control method according to claim 1, characterized in that: The wellhead pressure includes oil pressure and / or casing pressure.

3. A gas wellhead pressure drop control method according to claim 1, characterized in that: The obtaining of the wellhead pressure of the gas well comprises: Within a preset comparison period, obtaining the average pressure of multiple acquisition periods; Calculating the sliding average pressure of multiple sliding periods in the current comparison period according to the average pressure of the multiple acquisition periods, and setting the sliding average pressure as the wellhead pressure of the gas well in the preset comparison period; The duration of the sliding period is greater than the acquisition period.

4. A gas wellhead pressure drop control method according to claim 3, characterized in that , the obtaining of the average pressure of multiple acquisition cycles includes: According to the preset frequency, the wellhead pressure in multiple collection cycles is collected respectively; In any acquisition cycle, multiple wellhead pressures are sorted by size to obtain a wellhead pressure data column; Removing a preset number of maximum and minimum values ​​from the wellhead pressure data column to obtain a filtered wellhead pressure data column; Calculate the average value of the filtered wellhead pressure data column to obtain the average pressure of the current acquisition period; The average pressure in the next acquisition cycle is calculated until the average pressure of multiple acquisition cycles in the comparison cycle is obtained.

5. A gas wellhead pressure drop control method according to claim 4, characterized in that: The calculating the average value of the filtered wellhead pressure data column comprises: The average value of the filtered wellhead pressure data column is calculated by arithmetic mean or weighted mean.

6. A gas wellhead pressure drop control method according to claim 4, characterized in that: The comparison period includes at least one sliding period, and the sliding period includes at least one acquisition period; Setting a sliding window, wherein the sliding window includes two sliding periods; When the current moment is within the comparison period, if the number of average pressures of the acquired collection period is less than the number of collection periods within a sliding period, wait for a sliding period and re-acquire the number of average pressures of the collection periods within the current comparison period; When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods within a sliding period and is less than the number of collection periods within a sliding window, the average pressures of the acquired collection periods are summed and averaged to be the sliding average pressure of the current comparison period; When the current moment is within the comparison period, if the number of average pressures of the acquired collection periods is greater than or equal to the number of collection periods of the sliding window, the sliding average pressure of the current comparison period is calculated by the average pressures of the acquired collection periods within the sliding window, and then the next sliding period is entered, and the moment of a sliding period is waited again.

7. A gas wellhead pressure drop control method according to claim 1, characterized in that: The determining whether the wellhead pressure drop is greater than the maximum pressure drop threshold, and if so, controlling the valve opening to decrease, and then reacquiring the wellhead pressure of the gas well within a preset comparison period, includes: Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop outside the maximum extended pressure drop interval, and then proceed to the next step, wherein the minimum value of the maximum extended pressure drop interval is the maximum pressure drop threshold, and the maximum value of the maximum extended pressure drop interval is the sum of the maximum pressure drop threshold and the extended pressure drop value; Determine whether the count of the wellhead pressure drop outside the maximum extended pressure drop interval is greater than a preset count, if so, proceed to the next step, if not, output a valve opening reduction adjustment step length instruction, and then re-acquire the wellhead pressure of the gas well within a preset comparison period; Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening reduction adjustment step instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening reduction adjustment step instruction and the valve opening reduction set amplitude instruction, and then re-acquire the wellhead pressure of the gas well within the preset comparison period.

8. A gas wellhead pressure drop control method according to claim 7, characterized in that: The method of judging whether the wellhead pressure drop is greater than a maximum pressure drop threshold, and if so, controlling the valve opening to decrease, and then reacquiring the wellhead pressure of the gas well within a preset comparison period, further includes: Determine whether the wellhead pressure drop is greater than the sum of the maximum pressure drop threshold and the extended pressure drop value; if not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the maximum extended pressure drop range; if so, re-obtain the wellhead pressure of the gas well in the preset comparison period; if not, output a valve opening reduction adjustment step length instruction to re-obtain the wellhead pressure of the gas well in the preset comparison period.

9. A gas wellhead pressure drop control method according to claim 1, characterized in that: The determining whether the wellhead pressure drop is less than a minimum pressure drop threshold, and if so, controlling the valve opening to increase, and then reacquiring the wellhead pressure of the gas well, includes: Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value. If so, add 1 to the count of the wellhead pressure drop outside the minimum extended pressure drop interval, and proceed to the next step, wherein the minimum value of the minimum extended pressure drop interval is the difference between the maximum pressure drop threshold and the extended pressure drop value, and the maximum value of the minimum extended pressure drop interval is the maximum pressure drop threshold; Determine whether the count of the wellhead pressure drop outside the minimum extended pressure drop interval is greater than a preset count, if so, proceed to the next step, if not, output a valve opening increase adjustment step length instruction, and re-acquire the wellhead pressure of the gas well within a preset comparison period; Determine whether the valve opening is at the linear inflection point of the valve core. If so, output the valve opening increase adjustment step instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period. If not, output the valve opening increase adjustment step instruction and the valve opening increase set amplitude instruction to re-obtain the wellhead pressure of the gas well within the preset comparison period.

10. A gas wellhead pressure drop control method according to claim 9, characterized in that: The method of judging whether the wellhead pressure drop is less than a minimum pressure drop threshold, and if so, controlling the valve opening to increase, and then re-obtaining the wellhead pressure of the gas well, further includes: Determine whether the wellhead pressure drop is less than the difference between the maximum pressure drop threshold and the extended pressure drop value; if not, determine whether the wellhead pressure drop of the gas well in the previous comparison period is within the minimum extended pressure drop interval; if so, re-obtain the wellhead pressure of the gas well in the preset comparison period; if not, output the valve opening increase adjustment step instruction, and then re-obtain the wellhead pressure of the gas well in the preset comparison period.

11. A gas wellhead pressure drop control method according to any one of claims 1 to 10, characterized in that: When the pressure threshold is set to 10 MPa, the maximum pressure drop threshold is set to 0.03 MPa / d, and the minimum pressure drop threshold is set to 0.01 MPa / d; When the pressure threshold is set to 20 MPa, the maximum pressure drop threshold is set to 0.1 MPa / d, and the minimum pressure drop threshold is set to 0.07 MPa / d; When the pressure threshold is set to 10MPa-20MPa, the maximum pressure drop threshold is set to 0.07MPa / d, and the minimum pressure drop threshold is set to 0.03MPa / d.

12. A gas wellhead pressure drop control system, characterized in that: include: A wellhead pressure acquisition module, used to obtain the wellhead pressure of the gas well; A wellhead pressure processing module, which is in communication with the wellhead pressure acquisition module, is used to determine whether the wellhead pressure is greater than a pressure threshold, and if so, obtain the wellhead pressure drop of the gas well in the current comparison period based on a plurality of wellhead pressures in a preset comparison period; The wellhead pressure drop processing module is communicatively connected with the wellhead pressure processing module, and is used to determine whether the wellhead pressure drop is greater than a maximum pressure drop threshold. If so, the valve opening is controlled to be reduced, and then the wellhead pressure of the gas well within a preset comparison period is re-obtained. If not, it is determined whether the wellhead pressure drop is less than a minimum pressure drop threshold. If so, the valve opening is controlled to be increased, and then the wellhead pressure of the gas well is re-obtained. If not, the wellhead pressure of the gas well is re-obtained.

13. An electronic device, characterized in that: include: a memory for storing computer program instructions; A processor is used to execute the computer program instructions to complete the operation of the gas wellhead pressure drop control method described in any one of claims 1-11.

14. A computer-readable storage medium, characterized in that: Used to store computer-readable computer program instructions, wherein the computer program instructions are configured to execute the operations of the gas wellhead pressure drop control method according to any one of claims 1 to 11 when running.

Images