Double-closed-loop self-adaptive control method and system for plunger gas lift natural gas well

Abstract

The invention discloses a double-closed-loop self-adaptive control method and system for a plunger gas lift natural gas well, and designs a double-closed-loop self-adaptive control strategy based on analysis of real-time wellbore oil pipe pressure data and wellbore casing pressure data within a period of time. In combination with a physical model and an actual production curve of natural gas well plunger gas lift liquid drainage, the strategy evaluates a single-round well opening and closing period according to the deviation between the actual ascending speed and the liquid production capacity of a plunger and the reference ascending speed and the reference liquid production capacity in an inner ring control loop, and the load coefficient and the pressure microliter set value of the single-round period are dynamically adjusted; in an outer loop control loop, an oil casing pressure curve after multiple rounds of well opening and closing cycles is compared with an expected curve, and control parameters of an inner loop loop are dynamically adjusted, so that self-adaptive optimization of single cycle and medium and long term gas production and liquid drainage of the gas lift of the natural gas well is realized.

Description

Background Art

[0002] As a new and widely used low-carbon fossil energy, natural gas is clean and efficient. Therefore, natural gas is an inevitable choice for China to create a clean and low-carbon energy system. The consumption of natural gas remains high and shows a trend of steep increase year by year. At the same time, the production rate is less than the consumption rate, and the external dependence gradually increases. With the continuous rise of domestic demand, the contradiction between supply and demand has become increasingly prominent. The efficient exploitation of natural gas is crucial for alleviating the contradiction between supply and demand of natural gas.

[0003] As the degree of natural gas exploitation increases, more and more gas wells have continuously decreasing bottom-hole pressures due to factors such as long exploitation cycles, resulting in continuous reduction of gas well production and continuous decrease of flow velocity, which is insufficient to carry the liquid accumulation generated at the bottom of the well out of the wellbore. To address this problem, plunger devices have been installed in various regions for such natural gas wells to achieve better production and liquid drainage effects. However, this transformation has led to significant changes in the management of the natural gas well field dispatching center. Not only has manual operation been required for each single well all the time, but also the gas production has decreased when the scale of the well group increases. To improve the above problems and at the same time enhance the targeted well-opening and well-closing operations for different well bottom conditions, many gas production centers have started to carry out automated well-opening and well-closing operations. The gas production and liquid drainage of natural gas wells with automated well-opening and well-closing operations have increased, and at the same time, the work complexity of manual operation has been reduced. Although certain results have been achieved with this method, the logic of automated well-opening and well-closing still manually sets the well-opening and well-closing times and manually adjusts the times, and still has not been combined with the physical model of plunger gas lift liquid drainage. Currently, how to adaptively adjust the well-opening and well-closing times according to the physical model of gas production and liquid drainage of natural gas wells has become a research hotspot in this field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a double-closed-loop adaptive control method and system for plunger gas lift natural gas wells, which can adaptively improve the gas production and gas production efficiency of natural gas wells, reduce the bottom-hole liquid accumulation of natural gas wells, and improve the efficiency of discharging liquid accumulation from natural gas wells while ensuring the safety and high-efficiency operation of natural gas wells, so as to solve the technical problems of the disconnection of the physical model and the lack of dynamic adaptability in traditional automated control.

[0005] The present invention adopts the following technical solutions: A double-closed-loop adaptive control method for plunger gas lift natural gas wells, comprising the following steps: Based on the physical model of plunger gas lift liquid drainage of natural gas wells and the actual production curve, and comprehensively considering the actual pipeline pressure of natural gas wells, the bottom-hole liquid accumulation situation, the gas well depth, the time for the plunger to move upward, and the reference gas production and liquid drainage volume, set the initial values and boundary values of the load coefficient and the pressure rise. An internal closed-loop circuit is established. Starting from the initial values of the load factor and the pressure rise as the optimization starting point, with the boundary values as the limitations of the search space, an objective function for optimizing the set value of the load factor is established based on the deviation between the upward velocity of the plunger within a single-round cycle and the reference upward velocity, and an objective function for optimizing the set value of the pressure rise is established based on the deviation between the liquid production volume within a single-round cycle and the reference liquid production volume. An external closed-loop circuit is established. Using the actual tubing-casing pressure curve during multiple on-off well cycles of the gas well as the feedback, with the desired tubing-casing pressure difference change curve as the reference, the morphological differences between the two curves and the medium- and long-term gas production volume are used to evaluate the reference input of the internal closed-loop circuit, and the reference upward velocity and the reference liquid production volume of the internal closed-loop circuit are adjusted to achieve the adaptive optimization of gas production and liquid drainage under the long-term operating conditions of the gas well.

[0006] Preferably, the load factor value is:

[0007] where is the tubing pressure value, is the casing pressure value, is the external pipeline pressure value.

[0008] Preferably, the physical model of plunger gas lift liquid drainage for the gas well is:

[0009]

[0010] where is the change in tubing pressure; is the change in casing pressure, is the mass change of the annular tubing gas; Zgc is the average deviation coefficient of the annular tubing gas; Tgc is the average temperature of the annular tubing gas; R is Zgc 、 Tgc the gas constant under the conditions of ho is the tubing length.

[0011] Preferably, during the well shut-in and pressure build-up stage, when the load factor is less than the preset value, an open-well command is issued, the gas well starts to produce gas, and the plunger is lifted to carry the accumulated liquid to the wellhead for discharge. During the open-well afterflow stage, the gas in the tubing satisfies the following conditions:

[0012] where is the annular gas mass; is the gas mass in the tubing; is the mass flow rate of the formation-produced gas. is the mass flow rate of the produced gas at the wellhead.

[0013] Preferably, the micro-pressure increase value is the increment that continues to rise after the casing pressure drops to the lowest point after the well is opened. When the preset micro-pressure increase value is exceeded, a well shut-down command is issued, and the gas well starts to build up pressure again, waiting for the next round of well opening production. The calculation method of the theoretical liquid production during well opening is as follows:

[0014] where, is the theoretical liquid production; is the pressure difference between the lowest point of the tubing head pressure during well opening production and the tubing head pressure when the plunger reaches the blowout preventer pipe; is the density of the liquid accumulation; g is the acceleration due to gravity; is the inner diameter of the tubing.

[0015] Preferably, in the internal closed-loop circuit, obtain the well depth, well opening time, and plunger arrival time of the gas well in this round of well opening and shutting cycle, and calculate the average upward speed of the plunger in the wellbore; Analyze the bottom hole pressure and well depth of the gas well, set the reference value of the plunger upward speed, calculate the deviation between the actual plunger upward speed and the reference upward speed, and adjust the set value of the load coefficient; Obtain the actual liquid production of the gas well in this round of well opening and shutting cycle, calculate the deviation between the actual liquid production and the reference liquid production, dynamically adjust the set value of the micro-pressure increase, and realize the optimization of the well opening and shutting time for a single round.

[0016] Preferably, the expression of the objective function for optimizing the set value of the load coefficient is established based on the deviation between the plunger upward speed and the reference upward speed within a single-round cycle as follows:

[0017] where, is the adjusted set value of the load coefficient, is the set value of the load coefficient in the previous round, is the step adjustment coefficient, is the deviation between the actual upward speed and the reference upward speed.

[0018] Preferably, the expression of the objective function for optimizing the set value of the micro-pressure increase is established based on the deviation between the liquid production and the reference liquid production within a single-round cycle as follows:

[0019] where, is the adjusted set value of the load coefficient, is the set value of the load coefficient in the previous round, is the step adjustment coefficient, is the deviation between the actual liquid production volume and the reference liquid production volume.

[0020] Preferably, in the external closed-loop circuit, the actual expected curve is a curve in which the casing-tubing pressure difference shows a smaller trend or a decreasing trend; measure the gas production volume and liquid drainage volume, and evaluate the current strategy based on the gas production and liquid drainage volumes within a set time; use the morphological differences between the casing-tubing pressure difference curves of multiple cycles and the actual expected curve and the medium- and long-term gas production volume as the evaluation basis, and dynamically adjust the reference upward speed of the plunger and the reference liquid production volume in the internal closed-loop circuit to achieve adaptive control of medium- and long-term gas production and liquid drainage.

[0021] In a second aspect, an embodiment of the present invention provides a dual-closed-loop adaptive control system for a plunger gas lift natural gas well, including: A setting module, based on the physical model of plunger gas lift liquid drainage in a natural gas well and the actual production curve, and comprehensively considering the actual pipeline pressure of the natural gas well, the bottom-hole liquid accumulation situation, the gas well depth, the time for the plunger to move upward, and the reference gas production volume and liquid drainage volume, sets the initial values and boundary values of the load coefficient and the pressure rise. An internal module, which establishes an internal closed-loop circuit, takes the initial values of the load coefficient and the pressure rise as the optimization starting point, the boundary values as the limitations of the search space, establishes an objective function for optimizing the set value of the load coefficient based on the deviation between the upward speed of the plunger within a single cycle and the reference upward speed, and establishes an objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume within a single cycle and the reference liquid production volume. A control module, which establishes an external closed-loop circuit, uses the actual casing-tubing pressure curve of multiple well-switching cycles in the natural gas well as the feedback, uses the expected casing-tubing pressure difference change curve as the reference, evaluates the reference input of the internal closed-loop circuit based on the morphological differences between the two curves and the medium- and long-term gas production volume, and adjusts the reference upward speed and the reference liquid production volume of the internal closed-loop circuit to achieve adaptive optimization of gas production and liquid drainage under the long-term operating conditions of the natural gas well.

[0022] In a third aspect, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned dual-closed-loop adaptive control method for a plunger gas lift natural gas well are implemented.

[0023] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, including a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned dual-closed-loop adaptive control method for a plunger gas lift natural gas well are implemented.

[0024] In a fifth aspect, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned dual-closed-loop adaptive control method for a plunger gas lift natural gas well are implemented.

[0025] In a sixth aspect, an embodiment of the present invention provides an electronic device, including a computer program, which, when executed by the electronic device, implements the steps of the above-mentioned double-closed-loop adaptive control method for a plunger gas lift natural gas well.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects: A double-closed-loop adaptive control method for a plunger gas lift natural gas well correlates the wellbore state with the plunger movement through a physical model and actual production curves, avoiding the blindness of the traditional empirical method; for a single cycle, the load coefficient is optimized through the plunger speed deviation, and the pressure rise is optimized through the liquid production deviation to match the dynamically changing bottomhole conditions in real time; based on the morphological differences of the tubing-casing pressure curves in multiple cycles and the long-term gas production, the reference input of the internal closed loop is dynamically adjusted to adapt to long-term changes such as formation pressure decay; the double closed loop autonomously adjusts parameters through real-time feedback without the need for manual frequent resetting of the well opening and closing time.

[0027] Furthermore, the plunger operation efficiency is directly reflected by real-time data, avoiding the errors of traditional empirical estimation. Combining with the gas well depth parameter, the actual stroke length is dynamically corrected to ensure that the speed calculation matches the real wellbore conditions. The average upward speed, as the core feedback quantity, is a key indicator for judging the drainage efficiency, providing data support for adjusting the load coefficient. The reference upward speed is set according to the bottomhole pressure and gas well depth, the deviation between the actual speed and the reference value is calculated, and the set value of the load coefficient is dynamically adjusted. Through boundary value constraints, over-adjustment leading to equipment overload or plunger out-of-control is avoided. Through fine adjustment of the pressure rise, on the premise of ensuring the drainage effect, the increase in natural gas backpressure caused by excessive pressurization is avoided, and the coordinated optimization of gas production and liquid drainage is achieved.

[0028] Furthermore, through real-time speed and liquid production feedback, a closed-loop control chain of "monitoring → analysis → adjustment" is formed to solve the problem of parameter mismatch caused by model errors or working condition fluctuations in traditional open-loop control. Parameters are optimized immediately after each well opening and closing cycle to avoid multi-cycle cumulative errors, especially suitable for scenarios with frequent well condition changes. Automatic parameter adjustment replaces manual trial and error, reducing production losses caused by insufficient experience or operation delays, and is suitable for unmanned or large-scale well sites. By optimizing the load coefficient and pressure rise, the mechanical wear of the plunger is reduced, the risk of wellbore erosion is lowered, and the reliability of the equipment is improved.

[0029] Furthermore, the internal closed loop integrates core objectives such as plunger movement, drainage efficiency, and energy consumption control into a quantifiable optimization problem through the coupling of real-time data-driven and physical constraints, realizing the transformation from "passive response" to "active prediction". Its advantages are not only reflected in the improvement of single-well efficiency, but also provide a high-precision underlying control basis for the long-term optimization of the external closed loop.

[0030] Furthermore, the coordinated control of the well closing and re-pressurization and well opening and continuing flow phases solves the inefficiency problem caused by blindly opening and closing wells in traditional plunger gas lift through energy threshold triggering and fluid mechanics condition constraints. Its core advantages are: accurate matching of gas reservoir dynamics; deep integration of physical mechanisms and automated control; full life cycle cost optimization, providing an extensible technical framework for intelligent gas well management, especially suitable for the efficient development of low-yield, high-water-content, and complex gas wells.

[0031] It can be understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0032] In summary, the present invention optimizes the force of plunger lifting and pressure control (slight increase in pressure) in real time, and can efficiently discharge accumulated liquid each time a well is opened, thus avoiding wasted work without producing oil. While increasing the single gas production, it can also reduce equipment wear and energy waste, extend the life of the gas well, and the system can automatically adjust parameters. In the short term, each round of opening and closing wells is more efficient, and in the long term, it can stabilize gas production, which is particularly suitable for large-scale well group management, avoiding the problem of manual adjustment of one thing and losing another.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a schematic diagram of the structure of the double closed-loop control strategy of the present invention; Figure 2 A schematic diagram of a computer device provided by an embodiment of the present invention; Figure 3 The present invention is a block diagram of an electronic device provided according to an embodiment.

[0036] Among them, 60. computer equipment; 61. processor; 62. memory; 63. computer program; 600. electronic device; 610. processing unit; 620. storage unit; 6201. random access storage unit; 6202. cache storage unit; 6203. read-only storage unit; 6204. program / utility; 6205. program module; 630. bus; 640. display unit; 650. input / output interface; 660. network adapter; 700. external device. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "include" and "comprise" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0039] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0040] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the contextually related objects.

[0041] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0042] Depending on the context, the word "if" as used herein can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0043] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are only exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0044] The present invention provides a double-closed-loop adaptive control method for a plunger gas lift natural gas well, aiming to adaptively optimize the load coefficient and the pressure differential rise value by designing a double-closed-loop control strategy, realize the automatic control of the on-off timing of the natural gas well, ensure the gas production volume, and maintain the long-term continuous and efficient gas production and liquid drainage of the natural gas well. This method relies on the analysis of real-time wellbore tubing pressure (oil pressure) data and wellbore casing pressure (casing pressure) data over a period of time to design a double-closed-loop adaptive control strategy. Combining the physical model of plunger gas lift liquid drainage in a natural gas well and the actual production curve, this strategy evaluates the strategy of the single-round on-off well cycle based on the deviation between the actual upward speed of the plunger and the liquid production volume and the reference upward speed and reference liquid production volume in the inner loop control circuit, and dynamically adjusts the load coefficient and the pressure differential rise setting value of the single-round cycle; in the outer loop control circuit, it compares the oil-casing pressure curve after multiple rounds of on-off well cycles with the desired curve, and dynamically adjusts the control parameters of the inner loop circuit, so as to realize the adaptive optimization of gas production and liquid drainage in a single cycle and in the medium and long term of the gas lift of the natural gas well.

[0045] Embodiment 1 A double-closed-loop adaptive control method for a plunger gas lift natural gas well according to the present invention includes the following steps: S1. Through the physical model of plunger gas lift liquid drainage in a natural gas well and the actual production curve, and comprehensively considering the actual pipeline pressure of the natural gas well, the bottom-hole liquid accumulation situation, the gas well depth, the time of the plunger ascending, as well as the reference gas production volume and liquid drainage volume, preliminarily set the initial values and boundary values of the load coefficient and the pressure differential rise. The model for constructing the plunger gas lift liquid drainage in a natural gas well is: When the well is shut in, the bottom-hole pressure recovers, the oil pressure and the casing pressure values rise, and the calculation method of the pressure in the wellbore is as follows:

[0046]

[0047] Among them, is the change in oil pressure, MPa; is the change in casing pressure, MPa. is the change in the mass of the annular air in the tubing, kg; Zgc is the average deviation coefficient of the annular air in the tubing, dimensionless;Tgc is the average temperature of the tubing annulus gas, K; R is Zgc , Tgc the gas constant under the conditions of ; ho is the tubing length, m.

[0048] The load coefficient is a comprehensive coefficient reflecting the lifting capacity and liquid accumulation situation of a natural gas well. The larger the load coefficient, the more liquid accumulates at the bottom of the well, the weaker the lifting capacity, and the more difficult it is for the plunger to lift to the wellhead. The calculation method of the load coefficient is as follows:

[0049] where is the value of the load coefficient, is the tubing head pressure value, MPa, is the casing pressure value, MPa, is the pressure value of the export pipeline, MPa.

[0050] In the well shut-in and pressure build-up stage, as the casing pressure value and tubing head pressure value continuously rise, the pressure of the export pipeline remains unchanged, and the load coefficient Z continuously decreases. When the load coefficient is less than the preset value, it indicates that the lifting capacity and liquid accumulation situation of the gas well have reached the best at this time, and the well opening instruction is issued. The gas well starts to produce gas and lifts the plunger to carry the liquid accumulation to the wellhead for discharge.

[0051] During the well opening and continuous flow stage, the gas in the tubing satisfies:

[0052] where is the mass of the annulus gas, kg; is the mass of the gas in the tubing, kg; is the mass flow rate of the formation-produced gas, kg / s; is the mass flow rate of the wellhead-produced gas, kg / s.

[0053] After the well is opened, the tubing is connected to the external pipeline, and the tubing head pressure value rapidly drops to the level of the export pipeline pressure value. The casing pressure value drops more slowly compared to the tubing head pressure value. During the well opening production process, the degree of liquid accumulation in the wellbore is such that in the later stage of the gas well opening production, the gas velocity is lower than the critical liquid-carrying flow rate, and the liquid falls back to the bottom of the well, resulting in a continuous increase in the casing pressure value. The pressure differential value is the increment of the continuous increase after the casing pressure drops to the lowest point after the well is opened. When it exceeds the preset pressure differential value, the well shut-in instruction is issued, and the gas well starts to build pressure again, waiting for the next round of well opening production. The calculation method of the theoretical liquid production during the well opening period is as follows:

[0054] where is the theoretical liquid production, ; is the pressure difference between the lowest oil pressure during open - well production and the oil pressure when the plunger reaches the blowout preventer pipe, MPa; is the density of the liquid accumulation, ; g is the acceleration due to gravity, ; is the inner diameter of the tubing, .

[0055] S2. Establish an internal closed - loop circuit. Establish an objective function for optimizing the set value of the load coefficient based on the deviation between the upward speed of the plunger in a single - cycle period and the reference upward speed, and establish an objective function for optimizing the set value of the pressure increase based on the deviation between the liquid production volume in a single - cycle period and the reference liquid production volume; In the inner - loop circuit, the theoretical upward speed of the plunger is the control variable for evaluating the load coefficient and the set value of the pressure increase in the inner - loop circuit. Its calculation method is the ratio of the well depth to the upward time. Since the arrival time of the plunger after the well is opened is monitored, the upward speed of the plunger in the wellbore can be calculated through the arrival time of the plunger after the well is opened. The reference upward speed is within a reasonable range, and a reference upward - time range can be obtained according to the ratio of the well depth to the reference upward speed. By comparing the actual arrival time of the plunger, the actual upward speed of the plunger in the wellbore can be reflected.

[0056] The expression of the objective function for optimizing the set value of the load coefficient based on the deviation between the upward speed of the plunger in a single - cycle period and the reference upward speed is as follows:

[0057] Among them, is the adjusted set value of the load coefficient, is the set value of the load coefficient in the previous round, is the step - size adjustment coefficient, is the deviation between the actual upward speed and the reference upward speed.

[0058] The expression of the objective function for optimizing the set value of the pressure increase based on the deviation between the liquid production volume in a single - cycle period and the reference liquid production volume is as follows:

[0059] Among them, is the adjusted set value of the load coefficient, is the set value of the load coefficient in the previous round, is the step - size adjustment coefficient, is the deviation between the actual liquid production volume and the reference liquid production volume.

[0060] S3. Establish an external closed-loop circuit, using the actual tubing-casing pressure curve of the multiple on-off well cycles of the gas well as feedback, using the desired tubing-casing pressure difference change curve as a reference, and using the morphological differences between the two curves and the medium- and long-term gas production volume as the basis for evaluating whether the reference input of the inner loop is reasonable. Adjust the reference upward speed and reference liquid production volume of the internal closed-loop circuit, so as to achieve the adaptive optimization of gas production and liquid drainage under the long-term operating state of the gas well.

[0061] After multiple rounds of production cycles, perform morphological analysis on the tubing pressure and casing pressure curves to evaluate the current reference upward speed and reference liquid production volume, and adaptively adjust the parameters of the two to optimize the gas production and liquid drainage effects of a single round of cycle.

[0062] Furthermore, the tubing-casing pressure curve can reflect the severity of liquid accumulation in the current gas well to a certain extent. After optimizing the control of the on-off well in each single-round cycle, it is necessary to examine the medium- and long-term tubing-casing pressure curve to reflect the liquid accumulation situation of the current gas well, so as to evaluate the parameters and strategies of a single-round cycle, and adjust the plunger reference upward speed and reference liquid production volume of a single-round cycle to achieve the adaptive control of the double closed-loop circuit.

[0063] Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, method, or program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuit", "module", or "platform" here.

[0064] Embodiment 2 The present invention provides a double closed-loop adaptive control system for a plunger gas lift gas well, which can be used to implement the double closed-loop adaptive control method for a plunger gas lift gas well described above. Specifically, the double closed-loop adaptive control system for a plunger gas lift gas well includes a setting module, an internal module, and a control module.

[0065] Among them, the setting module, based on the physical model of plunger gas lift liquid drainage of the gas well and the actual production curve, and comprehensively considering the actual pipeline pressure of the gas well, the bottom-hole liquid accumulation situation, the gas well depth, the time for the plunger to move upward, and the reference gas production volume and liquid drainage volume, sets the initial values and boundary values of the load coefficient and pressure rise. The internal module establishes an internal closed-loop circuit, with the initial values of the load coefficient and pressure rise as the optimization starting point and the boundary values as the limitations of the search space. An objective function for optimizing the load coefficient setting value is established based on the deviation between the plunger upward speed and the reference upward speed within a single-round cycle, and an objective function for optimizing the pressure rise setting value is established based on the deviation between the liquid production volume and the reference liquid production volume within a single-round cycle. The control module establishes an external closed-loop circuit, uses the actual tubing-casing pressure curve of the multi-round well-switching cycle of the gas well as feedback, uses the expected tubing-casing pressure difference change curve as a reference, and uses the morphological differences between the two curves and the medium- and long-term gas production volume to evaluate the reference input of the internal closed-loop circuit, adjusts the reference upward speed and reference liquid production volume of the internal closed-loop circuit, and realizes the adaptive optimization of gas production and liquid drainage under the long-term operation state of the gas well.

[0066] Embodiment 3 The present invention provides a terminal device, which includes a processor and a memory. The memory is used to store a computer program. The computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Graphics Processing Units (GPU), Tensor Processing Units (TPU), Digital Signal Processors (DSP), Application Specific Integrated Circuits (ASIC), Field-Programmable Gate Arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the double-closed-loop adaptive control method for plunger gas lift gas wells, including: Based on the physical model and actual production curve of gas lift drainage in a natural gas well, and comprehensively considering the actual pipeline pressure, bottom-hole liquid accumulation situation, gas well depth, the time for the plunger to move upward, and the reference gas production and liquid drainage volumes, set the initial values and boundary values of the load coefficient and pressure rise. Establish an internal closed-loop circuit. Taking the initial values of the load coefficient and pressure rise as the optimization starting point and the boundary values as the constraints of the search space, establish an objective function for optimizing the set value of the load coefficient based on the deviation between the plunger upward movement speed within a single cycle and the reference upward movement speed, and establish an objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume within a single cycle and the reference liquid production volume. Establish an external closed-loop circuit. Using the actual casing pressure curve of multiple on-off well cycles in the natural gas well as the feedback, and the desired casing pressure difference change curve as the reference, evaluate the reference input of the internal closed-loop circuit based on the morphological differences between the two curves and the medium- and long-term gas production volume, and adjust the reference upward movement speed and reference liquid production volume of the internal closed-loop circuit to achieve the adaptive optimization of gas production and liquid drainage in the long-term operation state of the natural gas well.

[0067] Please refer to Figure 2 , the terminal device is a computer device. The computer device 60 in this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, it implements the double-closed-loop adaptive control method for the plunger gas lift natural gas well in the embodiment. To avoid repetition, it will not be elaborated here one by one. Alternatively, when the computer program 63 is executed by the processor 61, it implements the functions of each model / unit in the double-closed-loop adaptive control system of the plunger gas lift natural gas well in the embodiment. To avoid repetition, it will not be elaborated here one by one.

[0068] The computer device 60 can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art can understand that Figure 2 These are just examples of the computer device 60 and do not constitute a limitation on the computer device 60. It may include more or fewer components than shown in the figure, or combine some components, or different components. For example, the computer device may also include input / output devices, network access devices, a bus, etc.

[0069] The so-called processor 61 may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Graphics Processing Unit (GPU), Tensor Processing Unit (TPU), Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0070] The memory 62 may be an internal storage unit of the computer device 60, such as the hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk equipped on the computer device 60, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc.

[0071] Furthermore, the memory 62 may also include both the internal storage unit of the computer device 60 and the external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store the data that has been output or will be output.

[0072] Please refer to Figure 3 , the terminal device is the electronic device 600, and the electronic device 600 is presented in the form of a general computing device. The components of the electronic device may include but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0073] Among them, the storage unit stores program codes, and the program codes can be executed by the processing unit 610, so that the processing unit 610 executes the steps according to various exemplary embodiments of the present invention described in the above method part of this specification. For example, the processing unit 610 may execute the steps as shown in Figure 1 .

[0074] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 6201 and / or a cache storage unit 6202, and may further include a read-only storage unit (ROM) 6203.

[0075] The storage unit 620 may also include a program / utilities 6204 having a set (at least one) of program modules 6205. Such program modules 6205 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment.

[0076] The bus 630 may represent one or more of several types of bus structures, including a storage unit bus or storage unit controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of a variety of bus structures.

[0077] The electronic device 600 may also communicate with one or more external devices 700 (such as a keyboard, a pointing device, a Bluetooth device, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or may communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (such as a router, a modem). Such communication may be carried out through the input / output interface 650. Also, the electronic device 600 may communicate with one or more networks (such as a local area network, a wide area network, and / or a public network, such as the Internet) through the network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 through the bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0078] Embodiment 4 The present invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and, of course, the extended storage medium supported by the terminal device. It can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, device, or component. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by a processor are stored in this storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that more specific examples of the computer-readable storage medium here include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0079] The computer-readable storage medium also includes data signals propagated in a baseband or as part of a carrier wave, in which the readable program code is carried. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than the readable storage medium, and this readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, device, or component. The program code contained on the readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, radio frequency, etc., or any suitable combination of the above.

[0080] The program code for performing the operations of the present invention can be written in any combination of one or more programming languages. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as an independent software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network or a wide area network, or can be connected to an external computing device (for example, by using an Internet service provider to connect through the Internet).

[0081] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the dual-closed-loop adaptive control method for plunger gas lift in natural gas wells in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps: Based on the physical model of liquid drainage by plunger gas lift in natural gas wells and the actual production curve, and comprehensively considering the actual pipeline pressure of natural gas wells, the bottom-hole liquid accumulation situation, the gas well depth, the time of plunger upward movement, as well as the reference gas production volume and liquid drainage volume, set the initial values and boundary values of the load coefficient and pressure rise; establish an internal closed-loop circuit, with the initial values of the load coefficient and pressure rise as the optimization starting point and the boundary values as the limitations of the search space, establish an objective function for optimizing the set value of the load coefficient based on the deviation between the plunger upward movement speed and the reference upward movement speed within a single-round cycle, and establish an objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume and the reference liquid production volume within a single-round cycle; establish an external closed-loop circuit, using the actual casing pressure curve of multiple on-off well cycles of the natural gas well as feedback, the desired casing pressure difference change curve as reference, and the morphological differences between the two curves and the medium- and long-term gas production volume to evaluate the reference input of the internal closed-loop circuit, and adjust the reference upward movement speed and reference liquid production volume of the internal closed-loop circuit to achieve the adaptive optimization of gas production and liquid drainage under the long-term operating conditions of natural gas wells.

[0082] The databases involved in the embodiments provided in the present application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., and is not limited thereto. The processors involved in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., and is not limited thereto.

[0083] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0084] The intelligent gas lift dual-closed-loop adaptive control method mainly consists of three parts, specifically as follows: 1. Wellhead monitoring point sensor device; Measure and collect real-time data such as the oil pressure and casing pressure of a single well; the collected real-time data can be uploaded to the wellsite dispatching center through communication means; the on-off well control valve at the wellhead can be automatically controlled according to the instructions issued by the wellsite dispatching center.

[0085] 2. Gas production and liquid drainage measurement device; Measure the gas production and liquid drainage volume in a single cycle, and conduct real-time measurement and monitoring of the gas production and liquid drainage volume in a single cycle, which is used as the basis for preset values of the load coefficient and the pressure micro-increase value.

[0086] 3. Oil-casing pressure curve morphology analyzer device.

[0087] Conduct fitting analysis on the trends of the oil pressure and casing pressure curves in multiple cycles, and judge whether the oil pressure curve and the casing pressure curve are moving in the direction of "separation" or "aggregation", so as to evaluate the preset values of the current load coefficient and the pressure micro-increase and make adaptive adjustments.

[0088] The intelligent gas lift adaptive control method for a natural gas well is as follows: The first step: The sensor device at the wellhead monitoring point measures and collects the latest real-time data of the natural gas well, and uploads the collected real-time data to the wellsite control center; The second step: After receiving the latest real-time data, the sensor device at the wellhead monitoring point controls the on-off well of the wellhead by calculating whether the load coefficient or the pressure micro-increase preset value is reached; The third step: The gas production and liquid drainage measurement device sets reasonable preset values of the load coefficient and the pressure micro-increase according to the effect of gas production and liquid drainage in a single cycle, and real-time detects the effect of gas production and liquid drainage in a single cycle, so as to realize the control of the internal closed-loop circuit; The fourth step: After multiple on-off well cycles are completed, the oil-casing pressure curve morphology analyzer device analyzes the morphological trends of the oil pressure and casing pressure curves, which is used as the evaluation basis for the reference upward speed and reference liquid production volume of the plunger in the medium and long term, and then adaptively adjusts these two preset values to make the subsequent gas production and liquid drainage develop in a better direction, so as to realize the control of the external closed-loop circuit.

[0089] Taking the gas production report of a certain plunger well in a certain period as an example, compare the control effect and the benefits.

[0090] Comparison of control effects

[0091] The daily gas and water production of natural gas wells under the statistical control strategy. Although the gas and water production can be improved under different timing modes, the adaptive control strategy cannot be implemented in this mode. After the control strategy of the method of the present invention is used, the well opening and closing instructions can be issued at the optimal time, and the current load factor and the preset value of the pressure rise can be adaptively adjusted through the medium- and long-term oil pressure and casing pressure curves, effectively improving the gas production and drainage efficiency of the natural gas well.

[0092] In summary, the present invention provides a double closed-loop adaptive control method and system for a plunger gas lift natural gas well. By real-time monitoring of bottom hole pressure, liquid production and other data, the optimal time for opening and closing the well is automatically calculated without frequent manual adjustment of parameters. The system can dynamically adjust the force of the plunger lift and the rhythm of pressure change according to the actual state of each well, ensuring efficient drainage and more gas production each time the well is opened and closed. Each time the well is opened, the accumulated liquid can be accurately discharged to avoid the gas well from working with a disease, and the single gas production is increased by 10%-20%. At the same time, the situation of plunger empty running and gas waste is reduced, equipment wear and energy consumption are reduced, the service life of the gas well is extended, and maintenance costs are saved by more than 30%. Whether it is a short-term change in a single well or a long-term formation pressure attenuation, the system can automatically adjust the strategy. It is particularly suitable for managing large-scale gas fields with hundreds of wells to ensure continuous and stable gas production in the entire gas field.

[0093] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0094] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0095] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present invention can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0096] In the embodiments provided by the present invention, it should be understood that the disclosed device / terminal and method can be implemented in other ways. For example, the device / terminal embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be electrical, mechanical or other forms.

[0097] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0098] In addition, the functional units in each embodiment of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0099] When the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0100] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses, and computer program products according to embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0101] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are executed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions for implementing the functions specified in one process or a plurality of processes and / or blocks Figure 1 one process or a plurality of processes and / or blocks Figure 1 steps of the functions specified in one block or a plurality of blocks.

[0103] The above is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A dual-closed-loop adaptive control method for plunger gas lift natural gas wells, characterized in that, The steps include: Based on the physical model of gas-lift liquid drainage by plunger in a gas well and the actual production curve, comprehensively considering the actual pipeline pressure of the gas well, the liquid accumulation situation at the bottom of the well, the gas well depth, the time for the plunger to move upward, and the reference gas production and liquid drainage volumes, set the initial values and boundary values of the load coefficient and the pressure rise. Establish an internal closed-loop. Taking the initial values of the load coefficient and the pressure rise as the optimization starting point and the boundary values as the limitations of the search space, establish an objective function for optimizing the set value of the load coefficient based on the deviation between the upward velocity of the plunger within a single cycle and the reference upward velocity, and establish an objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume within a single cycle and the reference liquid production volume. Establish an external closed-loop. Using the actual casing-tubing pressure curve of multiple on-off well cycles of the gas well as feedback, taking the desired casing-tubing pressure difference change curve as a reference, and evaluating the reference input of the internal closed-loop based on the morphological differences between the two curves and the medium- and long-term gas production volume, adjust the reference upward velocity and the reference liquid production volume of the internal closed-loop to achieve the adaptive optimization of gas production and liquid drainage under the long-term operating conditions of the gas well.

2. The double closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 1, characterized in that, Load factor value is as follows: Among them, is the oil pressure value, is the casing pressure value, is the external pipeline pressure value.

3. The double closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 2, wherein The physical model of gas-lift liquid drainage by plunger in a gas well is: Among them, is the change in oil pressure; is the change in casing pressure, is the mass change of the tubing annulus air; Zgc is the average deviation coefficient of the tubing annulus air; Tgc is the average temperature of the tubing annulus air; R is Zgc 、 Tgc the gas constant under the conditions of; ho is the tubing length.

4. The double-closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 3, wherein During the well shut-in and pressure build-up stage, when the load coefficient is less than the preset value, issue an open-well command, and the gas well starts to produce gas, and the plunger lifts the accumulated liquid to the wellhead for discharge. During the open-well afterflow stage, the gas in the tubing satisfies the following conditions: Among them, is the annular gas mass; is the gas mass in the tubing; is the mass flow rate of formation-produced gas; is the mass flow rate of wellhead-produced gas.

5. The dual-closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 1, characterized in that, The pressure rise value is the increment of the casing pressure after it drops to the lowest point and then continuously rises after the well is opened. When it exceeds the preset pressure rise value, issue a shut-in command, and the gas well starts to build pressure again and waits for the next round of open-well production. The calculation method for the theoretical liquid production volume during the open-well period is as follows: Among them, is the theoretical liquid production volume; is the pressure difference between the lowest oil pressure during open - well production and the oil pressure when the plunger reaches the blowout preventer pipe; is the density of the accumulated liquid; g is the acceleration due to gravity; is the inner diameter of the tubing.

6. The double closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 1, wherein In the internal closed-loop, obtain the gas well depth, open-well time, and plunger arrival time of the gas well in this on-off well cycle, and calculate the average upward velocity of the plunger in the wellbore. Analyze the bottom-hole pressure and gas well depth of the gas well, set the reference value of the plunger upward velocity, calculate the deviation between the actual plunger upward velocity and the reference upward velocity, and adjust the set value of the load coefficient. Obtain the actual liquid production volume of the gas well in this on-off well cycle, calculate the deviation between the actual liquid production volume and the reference liquid production volume, and dynamically adjust the set value of the pressure rise to achieve the optimization of the on-off well time for a single cycle.

7. The dual closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 6, characterized in that, The expression of the objective function for optimizing the set value of the load coefficient based on the deviation between the upward velocity of the plunger within a single cycle and the reference upward velocity is as follows: Among them, is the set value of the adjusted load factor, is the set value of the load factor in the previous round, is the step adjustment coefficient, is the deviation between the actual upward speed and the reference upward speed.

8. The dual-closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 6, wherein, The expression of the objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume within a single cycle and the reference liquid production volume is as follows: Among them, is the adjusted load factor setting value, is the load factor setting value of the previous round, is the step size adjustment coefficient, is the deviation between the actual liquid production and the reference liquid production.

9. The dual-closed-loop adaptive control method for a plunger gas lift natural gas well according to claim 1, wherein In the external closed-loop, the actual desired curve is a curve with a smaller or decreasing trend of the casing-tubing pressure difference; measure the gas production volume and liquid drainage volume, and evaluate the current strategy based on the gas production and liquid drainage volumes within the set time; using the morphological differences between the casing-tubing pressure difference curves of multiple cycles and the actual desired curve and the medium- and long-term gas production volume as the evaluation basis, dynamically adjust the reference upward velocity of the plunger and the reference liquid production volume in the internal closed-loop to achieve the adaptive control of medium- and long-term gas production and liquid drainage.

10. A double closed-loop adaptive control system for a plunger gas lift natural gas well, characterized in that, It includes: Setting module, based on the physical model of plunger gas lift liquid drainage in gas wells and the actual production curve, and comprehensively considering the actual pipeline pressure of gas wells, the bottom-hole liquid accumulation situation, the gas well depth, the time for the plunger to move upward, as well as the reference gas production rate and liquid drainage volume, sets the initial values and boundary values of the load coefficient and pressure rise. Internal module, establishes an internal closed-loop circuit, takes the initial values of the load coefficient and pressure rise as the optimization starting point, the boundary values as the restrictions of the search space, establishes an objective function for optimizing the set value of the load coefficient based on the deviation between the plunger upward speed within a single-round cycle and the reference upward speed, and establishes an objective function for optimizing the set value of the pressure rise based on the deviation between the liquid production volume within a single-round cycle and the reference liquid production volume. Control module, establishes an external closed-loop circuit, takes the actual casing pressure curve of multiple on-off well cycles in gas wells as feedback, takes the expected casing pressure difference change curve as reference, evaluates the reference input of the internal closed-loop circuit based on the morphological differences between the two curves and the medium- and long-term gas production volume, and adjusts the reference upward speed and reference liquid production volume of the internal closed-loop circuit to achieve the adaptive optimization of gas production and liquid drainage in the long-term operating state of gas wells.

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