A gas well multiphase flow drainage and production gas storage tank control drainage system

Abstract

The present invention belongs to the technical field of gas tank drainage control, and specifically discloses a gas well multiphase flow drainage and production gas tank control drainage system. By monitoring the spatial distribution of liquid level, temperature and viscosity in the gas tank, combining the temperature field to identify potential condensation areas, and integrating viscosity changes to perform liquid film solidification risk assessment, the drainage demand is judged based on the comprehensive liquid level and liquid film solidification risk. Compared with the traditional control strategy that only relies on liquid level height, this method can identify the fluidity deterioration trend when the liquid level does not reach the threshold, start drainage in advance, and improve decision-making accuracy and adaptability. At the same time, under the drainage demand based on the liquid film solidification risk assessment, targeted vibration treatment is first implemented on the high-risk area according to the risk degree, and then the pulse frequency and opening of the drainage valve are dynamically adjusted according to the viscosity change in the tank after vibration. Through this operation, the liquid fluidity can be effectively improved, drainage blockage can be prevented, and the drainage efficiency and system stability can be enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of gas storage tank drainage control, and specifically discloses a gas well multiphase flow drainage and production gas storage tank control drainage system. Background Art

[0002] In the later stages of gas well production or during the operation of low-pressure gas wells, gas and liquid accumulation at the bottom of the well often leads to a decrease in gas well production or even a shutdown. To alleviate this problem, gas storage tanks are commonly used in existing technologies to collect and separate gas-liquid mixtures. After entering the gas storage tank through the inlet, the multiphase fluid undergoes gravity sedimentation, cyclone separation, and demisting steps in sequence to achieve effective separation of the gas-liquid-solid three-phase system: the purified gas is transported from the top outlet to the gas pipeline network, and the separated liquid accumulates at the bottom of the tank and is discharged through the liquid level control system driving the drain valve.

[0003] Solutions for draining gas tanks are already available. For example, Chinese invention patent publication number CN105299460A proposes an automatic residual liquid draining gas tank. The tank comprises a tank body, a support, an air inlet, and an air outlet. A drain port is located at the bottom of the tank, connected to a drain pipe and equipped with a solenoid valve for automatic drainage. This solution controls the opening and closing of the solenoid valve by detecting the liquid level in the tank, automating the drainage process and reducing the need for manual maintenance.

[0004] The drainage control in the above scheme mainly relies on the height of the liquid level in the tank as a single judgment basis, that is, the drainage operation is triggered when the liquid level reaches the set threshold. However, this strategy ignores the impact of changes in the physical properties of the liquid inside the gas storage tank on the drainage efficiency. Specifically, during the gas-liquid separation process, some fine solid particles or high-viscosity components may settle to the bottom of the tank along with the liquid. These substances are prone to physical or chemical reactions with the liquid under the action of long-term accumulation and temperature changes, forming a colloidal or semi-solid sediment layer with a certain viscoelasticity. Such colloidal sediments have high viscosity and poor fluidity and cannot flow to the drain port as quickly as conventional liquids. If the drainage is initiated only based on the liquid level signal, on the one hand, the colloidal sediments cannot be effectively discharged, resulting in continuous accumulation of liquid at the bottom of the tank. On the other hand, even if they enter the drainage pipe, they are likely to cause local blockage, increasing the system failure rate. Summary of the Invention

[0005] In view of this, the present invention aims to propose a gas well multiphase flow drainage and production gas storage tank control drainage system, which evaluates the risk of liquid film solidification by detecting the viscosity distribution in the tank, and makes drainage decisions based on the liquid level height, thereby realizing precise drainage control based on risk identification, and effectively solving the problems mentioned in the background technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A gas well multiphase flow drainage and production gas storage tank control drainage system, including: a global sensing module: composed of a micro-rotating viscosity probe array, an axial vertical liquid level gauge, and a distributed temperature sensor group, which obtains the liquid level height, viscosity spatial distribution characteristics and temperature distribution characteristics in the gas storage tank in real time.

[0007] Risk analysis module: Based on the neighborhood gradient of temperature distribution characteristics and temperature time series change analysis, the potential condensation area is divided, and the viscosity time variation and viscosity deviation are integrated to evaluate the liquid film solidification risk index of each potential condensation area.

[0008] Drainage decision module: Make dual-factor drainage demand decisions based on the liquid level height in the tank and the regional liquid film solidification risk coverage ratio.

[0009] Direct discharge module: Starts basic pulse discharge when the discharge is triggered solely by the liquid level in the tank.

[0010] Vibration drainage module: When drainage is triggered by the regional liquid film solidification risk index, the piezoelectric ceramic vibration array deployed at the bottom of the tank is used to implement regional differentiated vibration according to the liquid film solidification risk index-frequency mapping relationship, and monitor the viscosity drop curve in the tank after vibration. Based on the viscosity drop curve, supplementary vibration control is performed or the pulse frequency and opening of the drainage valve are dynamically adjusted.

[0011] Compared with the existing technology, the beneficial effects of the present invention are as follows: 1. The present invention monitors the spatial distribution of liquid level, temperature and viscosity in the gas tank, identifies potential condensation areas in combination with the temperature field, and integrates viscosity changes to perform liquid film solidification risk assessment, thereby judging the drainage demand based on the comprehensive liquid level and liquid film solidification risk. Compared with the traditional control strategy that only relies on liquid level height, this method can identify the trend of fluidity deterioration when the liquid level does not reach the threshold, start drainage in advance, improve decision-making accuracy and adaptability, effectively prevent poor drainage and equipment damage caused by colloidal deposition, and enhance the stability and intelligence level of system operation.

[0012] 2. Based on the drainage demand of liquid film solidification risk assessment, the present invention first implements targeted vibration treatment on high-risk areas according to the risk level, and then dynamically adjusts the pulse frequency and opening of the drainage valve according to the change in viscosity in the tank after vibration. This operation can effectively improve liquid fluidity, prevent drainage blockage, enhance drainage efficiency and system stability, and realize intelligent coordinated control of the drainage process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 Schematic diagram of the system composition of the present invention.

[0015] Figure 2 Schematic diagram of the implementation process of drainage decision-making in the present invention.

[0016] Figure 3 This is a schematic diagram of the operation of supplementary vibration control or dynamic adjustment of the pulse frequency and opening of the discharge valve based on the viscosity drop curve in the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0018] See also Figure 1 As shown, the present invention proposes a gas well multiphase flow drainage and gas storage tank control drainage system, which includes a global perception module, a risk analysis module, a drainage decision module, a direct drainage module and a vibration drainage module.

[0019] In the above modules, the global perception module is connected to the risk analysis module, the risk analysis module is connected to the drainage decision module, and the drainage decision module is connected to the direct drainage module and the vibration drainage module respectively, forming a complete data flow closed loop from data collection to risk assessment, and then to drainage decision and execution.

[0020] The global sensing module is composed of a micro-rotating viscosity probe array, an axial vertical liquid level gauge, and a distributed temperature sensor group, which can obtain the liquid level height, viscosity spatial distribution characteristics and temperature distribution characteristics in the gas storage tank in real time.

[0021] In the specific implementation of the above scheme, the miniature rotary viscosity probe, axial vertical liquid level gauge, and distributed temperature sensor group are arranged as follows: a mesh-distributed rotary viscosity probe array is set at the bottom of the gas tank. Since the rotary viscosity probe has the advantages of sensitive response, high measurement accuracy, and strong anti-interference ability, it is suitable for viscosity monitoring of non-Newtonian fluids or liquids containing impurities under complex working conditions. It can realize multi-point synchronous monitoring of the viscosity of the liquid at the bottom of the tank and accurately capture the spatial heterogeneous distribution characteristics of the viscosity.

[0022] The vertical liquid level gauge is arranged along the axial direction of the tank body to achieve continuous, high-resolution dynamic monitoring of the liquid level height in the tank.

[0023] The distributed temperature sensor group is deployed on the inner side of the tank wall in a honeycomb topology structure, which can realize high-density and spatially continuous monitoring of the liquid temperature field in the tank.

[0024] The risk analysis module is used to divide potential condensation areas based on the neighborhood gradient of temperature distribution characteristics and temperature time series change analysis, and integrate viscosity time variation and viscosity deviation to evaluate the liquid film solidification risk index of each potential condensation area.

[0025] As a preferred implementation of the above scheme, the potential condensation area is divided based on the neighborhood gradient of the temperature distribution characteristics and the temperature time series change analysis as follows: a real-time three-dimensional temperature field model is constructed using the tank temperature data collected in real time by the distributed temperature sensor group.

[0026] It's important to note that because the temperature data collected by distributed temperature sensors within the tank is measured at discrete points, constructing a three-dimensional temperature field model may result in incomplete spatial coverage or missing temperature information in some areas. To address this limitation, spatial interpolation is used to reconstruct and fill in the gaps between discrete temperature measurement points, thereby improving the spatial continuity and integrity of the temperature field.

[0027] At each sampling moment, the entire tank is divided into several temperature sub-regions according to the temperature cluster analysis in the current three-dimensional temperature field, and the spatial boundary position and average temperature value of each sub-region are recorded.

[0028] The above-mentioned division of different temperature sub-regions by temperature clustering is used to reveal the differences in thermal states of different regions in the tank, which facilitates subsequent refined monitoring of local areas, while avoiding point-by-point processing of the entire space and reducing computational complexity.

[0029] For each temperature sub-area, the temperature change rate between the current moment and the previous moment is calculated. Specifically, the temperature change rate is calculated by taking the difference between the temperature at the current moment and the temperature at the previous moment and dividing it by the time interval. A positive value of the temperature change rate indicates that the area is in a heating process; a negative value indicates that it is in a cooling process; and the absolute value reflects the temperature change rate.

[0030] At the current moment, the temperature distribution area adjacent to each temperature sub-area is identified, a local neighborhood relationship is constructed, and the local ambient temperature gradient is calculated by comparing the temperature difference between the area and its adjacent areas. Specifically, the local ambient temperature gradient calculation is to take the average of the temperature differences between each temperature sub-area and its adjacent temperature distribution areas.

[0031] It should be noted that constructing the neighborhood relationship between each temperature sub-region helps to reveal the thermal coupling characteristics between regions. According to the basic principle of heat conduction, heat always migrates from high-temperature areas to low-temperature areas, and the temperature gradient is the key factor driving the heat flux density. When there is a significant temperature gradient between a certain temperature sub-region and its adjacent area, it indicates that the area has a tendency to transfer heat to the surrounding area, reflecting a strong heat dissipation capacity. This continuous heat output may cause the temperature of the area to gradually drop, thereby forming a local low-temperature environment, which is conducive to the occurrence of water vapor condensation or liquid film accumulation.

[0032] A sliding time window is used to perform time series statistical analysis on the historical temperature change rate of each temperature sub-region and its surrounding temperature gradient, and its average temperature change trend and average surrounding temperature gradient level are extracted.

[0033] It should be noted that performing time series statistics on the historical temperature change rate and the surrounding temperature gradient of each temperature sub-area through a sliding time window to obtain the average temperature change trend and the average surrounding temperature gradient level can effectively filter out instantaneous noise interference, capture long-term thermal behavior characteristics, and improve recognition stability.

[0034] Potential condensation areas are identified based on the following two classification rules: a) The average temperature change rate of a certain temperature sub-area is negative and its absolute value is lower than a preset threshold.

[0035] It's important to explain that under these conditions, the area is experiencing a sustained, slow cooling rate, indicating limited heat exchange. This means the temperature has stabilized and is no longer dropping significantly, indicating a state of thermal equilibrium or quasi-steady state. Under these conditions, water vapor in the air is more likely to condense on cold surfaces because, lacking sufficient thermal disturbance to maintain its gaseous state, the probability of liquid formation and accumulation increases significantly, leading to a stable condensation environment.

[0036] The preset threshold of the temperature change rate in the above-mentioned process represents the minimum effective cooling rate acceptable to the system. Changes below this value are considered to be quasi-static or insignificant temperature evolution processes. The specific setting can be achieved by collecting the time series data of the temperature change rate of the gas storage tank during its historical operation, extracting the time series data of the cooling stage from it, and performing statistical analysis on the temperature change rates of all cooling stages to construct a probability distribution diagram of the temperature drop rate. A representative quantile point on the probability distribution diagram is selected as the preset threshold of the temperature change rate.

[0037] b) The average local ambient temperature gradient of a certain temperature distribution area is higher than the average gradient level of its environment.

[0038] It needs to be explained that under the above conditions, there is obvious thermal asymmetry between this area and its adjacent areas. The high-gradient area is often the main path for heat transfer from the high-temperature area to the low-temperature area. In these areas, the temperature drops rapidly, which easily forms the starting point of the condensation process. It is a typical thermodynamic characteristic of the early stage of condensation.

[0039] The average gradient level of the environment mentioned above reflects the overall temperature gradient background value in the gas tank. It represents the degree of temperature difference generally existing inside the tank. Specifically, the temperature gradient of all temperature sub-areas in the entire gas tank is calculated and its average is obtained.

[0040] The temperature sub-regions that meet the above conditions a) or b) are marked as potential condensation areas.

[0041] This method, which combines spatiotemporal analysis of the temperature distribution within the gas tank, fully accounts for the physical property that condensation typically occurs in areas with lower temperatures, greater heat dissipation capacity, and significant differences in heat conduction. This method does not rely on a single temperature threshold for judgment, but rather dynamically identifies temperature trends and thermal gradient characteristics to continuously track and precisely locate condensation risk areas during their initial formation and stable development stages. This provides key area-oriented support for subsequent liquid film solidification risk assessments, allowing in-depth analysis to be conducted only in high-risk sub-areas where solidification is most likely to occur, making risk assessments more spatially targeted and computationally efficient.

[0042] As a further preferred implementation of the above scheme, the liquid film solidification risk index of each potential condensation area is evaluated by integrating the time-varying viscosity and the viscosity deviation as follows: based on the spatial boundary position of each potential condensation area, the viscosity data is collected in real time using a micro-rotating viscosity probe covered by the area.

[0043] The obtained viscosity time series data are subjected to time difference processing to calculate the viscosity growth rate of the region between the current moment and the previous moment.

[0044] The viscosity deviation is calculated by combining the current viscosity of the potential condensation zone with the safe viscosity. Then, the liquid film solidification risk index is constructed with the viscosity deviation as the base and the viscosity growth rate as the exponent to obtain the liquid film solidification risk index of each potential condensation zone.

[0045] It's important to note that the safety viscosity mentioned above refers to the maximum viscosity of the liquid that, under the current drainage system conditions, will not affect the normal discharge of the drain valve. In other words, when the liquid viscosity is below this threshold, the drainage process maintains fluidity and is less likely to cause problems such as blockage or poor drainage. This parameter can be obtained from the drainage valve's specific structural parameters, including the equipment's technical documentation or the manufacturer's instructions.

[0046] It is important to understand that viscosity deviation is defined as the difference between the current measured viscosity and the set safety viscosity, and is used to characterize the degree to which the liquid viscosity deviates from the normal flow state. This parameter is a basic static risk item for assessing whether the liquid film tends to solidify, while the viscosity growth rate reflects the rate of viscosity change over time and is a dynamic trend item that measures the deterioration trend of the liquid film's fluidity. The liquid film solidification risk index model, constructed with viscosity deviation as the base and viscosity growth rate as the exponent, implements a combined static and dynamic risk assessment of the liquid film state. The overall modeling using an exponential function can effectively capture the nonlinear amplification effect of risk development. Specifically, when the viscosity deviation is small and grows slowly, the risk index grows gently, indicating that the system is in a low-risk state. However, when the viscosity deviates significantly from the safety value and grows rapidly, the risk index rises exponentially, accurately reflecting the accelerated deterioration behavior of the liquid film during solidification.

[0047] Applied to the above-mentioned operation embodiment, the expression of the liquid film solidification risk index is: , where Indicates the viscosity deviation, represents the viscosity growth rate, It represents the gain coefficient, which is used to adjust the sensitivity of the viscosity growth rate to risk. It can be calibrated according to the type of medium and process requirements.

[0048] Regarding the above expression, it's important to note that when the viscosity deviation is less than or equal to zero, the current liquid viscosity has not reached the set safety viscosity threshold. This means the liquid is still flowing smoothly, and there's no significant risk of film solidification. At this point, regardless of whether the viscosity is increasing, the risk index is set to zero, indicating that the system doesn't need to trigger any risk intervention mechanisms. This design logic is based on the following considerations: even if viscosity is increasing, as long as it hasn't exceeded the safety threshold, the system still has a buffer time. Once the viscosity rises above the threshold, it's not too late to activate the risk assessment model and intervene.

[0049] The risk assessment model, constructed with viscosity deviation as the base and viscosity growth rate as the exponent, is activated only when the viscosity deviation is greater than zero—meaning the liquid viscosity has exceeded the safe range, fluidity has deteriorated, and solidification may have occurred. At this point, the risk index begins outputting non-zero values ​​and increases nonlinearly with increasing viscosity deviation and rate of increase, thereby enabling dynamic identification and quantitative characterization of the risk of liquid film solidification. This modeling approach not only improves the sensitivity and accuracy of risk warnings but also reflects a phased control strategy for the evolution of the liquid film state, contributing to the refinement and intelligence of liquid drainage control.

[0050] In addition, when the viscosity deviation is greater than zero, the base part is processed in the form of (1+viscosity deviation) to ensure that the base is always greater than 1, thereby avoiding numerical attenuation or zeroing in the exponential calculation, and ensuring that the risk index can accurately reflect the increasing trend of the risk level.

[0051] See also Figure 2 As shown in FIG, the drainage decision module makes a dual-factor drainage demand decision based on the liquid level height in the tank and the regional liquid film solidification risk coverage ratio. The specific contents are as follows: (1) Compare the current liquid level height of the gas storage tank with the warning liquid level height. If the actual liquid level reaches or exceeds the warning liquid level height, the drainage demand is triggered. Otherwise, steps (2) to (3) are executed.

[0052] It should be pointed out that the warning water level mentioned above refers to the maximum safe operating liquid level limit allowed by the liquid volume in the gas tank. The liquid level is the most direct indicator to measure the degree of liquid accumulation in the gas tank. When the liquid level reaches or exceeds this limit, it means that the liquid in the tank is close to the safety upper limit of the system design, and there are risks such as overflow and obstruction of the gas channel. Therefore, the drainage operation must be started in time.

[0053] (2) Compare the liquid film solidification risk index of each potential condensation area with the configured critical solidification risk index, and screen out the areas where the risk index exceeds the critical value and mark them as solidification risk areas.

[0054] Applied to the expression of the above-mentioned liquid film solidification risk index, the above-mentioned critical solidification risk index can be set to 0, the purpose of which is to establish a judgment benchmark for risk triggering.

[0055] (3) Based on the spatial boundary information of the solidification risk zone, the volume or area ratio occupied by the solidification risk zone inside the tank is calculated to obtain the solidification space coverage ratio, and then compared with the coverage ratio threshold. If the solidification space coverage ratio reaches or exceeds the threshold, the drainage demand is triggered, otherwise the drainage demand is not triggered.

[0056] The coverage ratio threshold mentioned above reflects the upper tolerance limit of the distribution breadth of the high solidification risk area in the tank body. Specifically, the coverage ratio when fluidity deterioration or solidification events occurred in historical operation can be analyzed to extract typical critical values.

[0057] It should be pointed out that the solidification space coverage ratio is used to quantify the breadth of distribution of high-risk liquid film solidification areas in the entire gas storage tank, reflecting the spatial expansion of the fluidity deterioration area. When the ratio reaches or exceeds the set coverage ratio threshold, it indicates that a large range of viscosity increase and fluidity decrease has occurred in the tank. Although the current liquid level is not high, multiple potential condensation areas have simultaneously shown a high solidification risk. This indicates that the system is tending to enter a more dangerous operating state. If not intervened in time, the local liquid film may further solidify, resulting in blockage of the flow channel and triggering a chain reaction, expanding the scope of solidification impact, and increasing the difficulty of subsequent maintenance and the risk of equipment damage. Therefore, by starting the drainage operation in advance, the high-viscosity liquid can be effectively disturbed and discharged, the development of the solidification trend can be suppressed, and the overall deterioration of fluidity can be prevented.

[0058] This method uses a dual-factor approach to determine drainage requirements, combining the tank's liquid level with the percentage of regional liquid film solidification risk coverage. Compared to traditional single-level control strategies that rely solely on liquid level thresholds, this method more comprehensively reflects the internal operating status of the tank. Even when the liquid level has not yet reached the warning value but multiple high-solidification risk areas have appeared, it can still proactively trigger drainage operations, embodying the principles of preventive maintenance and proactive control. This method helps to proactively intervene in fluidity deterioration trends, preventing problems such as solidification and blockage caused by increased local viscosity, thereby effectively reducing system failure rates and subsequent maintenance costs.

[0059] The direct drainage module is used to start basic pulse drainage when drainage is triggered solely by the height of the liquid level in the tank.

[0060] It should be noted that the above-mentioned single drainage triggered by the liquid level in the tank refers to the drainage triggered simply when the liquid level reaches or exceeds the warning level when there is no risk of liquid film solidification. At this time, the basic pulse drainage is started, where the basic pulse drainage is a pulse drainage control method with fixed parameter configuration. The purpose is to maintain drainage efficiency while avoiding excessive energy consumption or mechanical shock.

[0061] The vibration drainage module is used to implement regional differentiated vibration according to the liquid film solidification risk index-frequency mapping relationship using the piezoelectric ceramic vibration array deployed at the bottom of the tank when drainage is triggered by the regional liquid film solidification risk index, and monitor the viscosity drop curve in the tank after the vibration, and then perform supplementary vibration control or dynamically adjust the pulse frequency and opening of the drainage valve based on the viscosity drop curve.

[0062] One possible way to implement the above module is to implement regional differentiated vibration based on the liquid film solidification risk index-frequency mapping relationship. The specific implementation is as follows: the vibration array is divided into fan-shaped sub-arrays with independently controllable phases. Each sub-array is responsible for covering a specific angle range, thereby realizing partitioned controllable vibration coverage of the tank space.

[0063] According to the spatial boundary information of the solidification risk area, the fan-shaped sub-array in the corresponding direction is activated to ensure that the vibration energy acts accurately on the target area.

[0064] The liquid film solidification risk index corresponding to each solidification risk zone is input into a preset liquid film solidification risk index-vibration frequency mapping relationship to obtain the target vibration frequency of each solidification risk zone.

[0065] It should be added that the above-mentioned liquid film solidification risk index-vibration frequency mapping relationship can be established based on experimental calibration. The specific calibration operations are as follows: Step 1: Reproduce the typical structure and liquid distribution state at the bottom of the gas tank in the laboratory or test platform, and configure simulated liquid films of different viscosity grades.

[0066] Step 2: According to the set liquid film solidification risk index range, set the corresponding risk index for each group of experiments.

[0067] Step 3: Apply a series of vibration excitations of different frequencies to the liquid film at each risk level, and record its flow state changes, viscosity decrease trend, and whether effective disturbance occurs.

[0068] Step 4: Evaluate the intervention effect of each vibration frequency on different risk levels by measuring indicators such as the degree of improvement in liquid film fluidity, drainage smoothness, and viscosity reduction.

[0069] Step 5: Based on the experimental data, an empirical or semi-empirical functional relationship between the liquid film solidification risk index and the optimal vibration frequency is fitted to form a mapping table that can be embedded in the control system.

[0070] For each activated sub-array, a vibration operation is performed according to the target vibration frequency of the corresponding coagulation risk zone.

[0071] The above-mentioned directional vibration operation in the high solidification risk area before the drainage operation can effectively destroy the liquid film structure, reduce local viscosity, and improve liquid fluidity, thereby significantly enhancing the efficiency and thoroughness of the subsequent drainage process.

[0072] For further implementation of the above modules, see Figure 3 As shown in the figure, the specific implementation process of supplementary vibration control or dynamic adjustment of the pulse frequency and opening of the drain valve based on the viscosity drop curve is as follows: within the preset buffer time window after the directional vibration is implemented in the solidification risk area, the average viscosity in the tank is monitored in real time using a micro-rotating viscosity probe, and a viscosity drop curve that changes with time is constructed.

[0073] The viscosity drop rate and the current average viscosity in the tank are extracted from the viscosity drop curve according to the set time sampling interval. The viscosity drop rate reflects the dynamic response rate of liquid film structure destruction and fluidity recovery under vibration. The current average viscosity in the tank reflects the overall flow state level of the liquid viscosity in the entire gas storage tank after vibration intervention. The current average viscosity in the tank is compared with the safe viscosity. If the current viscosity value is higher than the safe viscosity, it means that the vibration effect has not fully improved the fluidity of the liquid and the liquid is still in a high viscosity and low fluidity state. At this time, it is not appropriate to drain the liquid immediately. Supplementary vibration control needs to be triggered. Otherwise, it is determined that the fluidity meets the drainage conditions and enters the drainage execution phase. At the same time, the viscosity drop rate is compared with the preset response threshold. If it is less than the response threshold, the basic pulse frequency is maintained for step-by-step opening adjustment. If it reaches the response threshold, the basic opening is maintained and the response stability time is tracked for step-by-step pulse frequency adjustment.

[0074] It's important to note that the response threshold mentioned above refers to the critical value for the rate of viscosity reduction after vibration intervention, used to differentiate the degree of improvement in fluid flow. This threshold reflects the system's minimum acceptable response to vibration intervention. The minimum required fluidity recovery rate can be determined based on industry regulations and process safety requirements.

[0075] When the viscosity drop rate is less than the response threshold, it means that the viscosity drop tends to be gentle, indicating that the improvement of liquid fluidity is limited. At this time, the basic pulse frequency is maintained unchanged, and the valve opening is gradually increased by a step-by-step opening adjustment strategy. The single discharge volume can be increased under limited fluidity, thereby improving the overall discharge efficiency. When the viscosity drop rate reaches or exceeds the response threshold, it means that the liquid fluidity has been significantly improved. The basic valve opening is maintained unchanged, and the step-by-step pulse frequency adjustment strategy is adopted to gradually increase the discharge frequency. This can more effectively utilize the flow capacity of the liquid. Keeping the opening unchanged can avoid excessive disturbance of the tank structure and improve the continuity of discharge.

[0076] In the innovative implementation of the above scheme, the supplementary vibration control is implemented as follows: when the supplementary vibration control is triggered, the existing solidification risk area inside the gas tank is obtained, and the original risk area that has returned to normal is identified.

[0077] For each original risk area that has returned to normal, the corresponding liquid film solidification risk index before the vibration and the target vibration frequency used at that time are retrieved, thereby correcting the initially set liquid film solidification risk index-vibration frequency mapping relationship.

[0078] The specific corrections mentioned above can be made by using the liquid film solidification risk index of the original risk area that has returned to normal before the vibration intervention and the applied target vibration frequency to form a new sample pair, which is input as feedback data into the initially set risk index-vibration frequency mapping model. The mapping relationship is dynamically updated and corrected through regression analysis or interpolation methods, thereby improving the model's adaptability to actual working conditions and control accuracy.

[0079] The modified mapping relationship is combined with the current liquid film solidification risk index of the existing solidification risk area to extract the optimized target vibration frequency suitable for the area, and then the fan-shaped vibration sub-array corresponding to the spatial position of the existing solidification risk area is activated for supplementary vibration control.

[0080] By dynamically correcting the mapping relationship, the system can continuously optimize the control strategy based on the historical intervention effects, avoid a one-size-fits-all fixed-frequency vibration, and achieve matching control of risk level and vibration intensity, which helps to improve viscosity reduction efficiency and shorten liquidity recovery time.

[0081] In a further innovative implementation of the above scheme, the step opening adjustment is implemented as follows: the opening step is set according to the adjustable opening range of the drain valve, and the entire opening range is divided into several discrete opening levels to form an orderly opening sequence.

[0082] Applied to the above solution, the opening step size can be preset according to valve characteristics, system response capabilities and process requirements.

[0083] When the step-by-step opening adjustment mechanism is triggered, the first opening value is selected from the opening sequence as the initial drainage opening to perform the drainage operation.

[0084] In each time sampling interval of discharge, the system switches to the next opening in sequence, and at the same time continuously extracts the current viscosity drop rate from the viscosity drop curve and compares it with the preset response threshold. If the preset response threshold is reached at a certain opening level, the current opening is locked. If the viscosity drop rate does not reach the response threshold during the entire adjustment process, the opening is continuously increased step by step according to the set step size until the maximum allowable opening is reached or the liquid level in the tank drops to a safe range.

[0085] The present invention realizes a progressive and controllable liquid discharge process by gradually increasing the opening, avoiding the impact, energy consumption surge or equipment damage caused by a one-time large-scale opening of the valve, and making the liquid discharge process more stable and controllable.

[0086] In the further innovative implementation of the above scheme, the response stability time is tracked and the step-by-step pulse frequency adjustment is implemented as follows: when the viscosity drop rate reaches the response threshold, the response duration is tracked. The response duration reflects the stability of the improvement in liquid fluidity and is compared with the set stability judgment time. If the response duration reaches or exceeds the stability judgment time, indicating that the liquid fluidity has stabilized, the current pulse frequency of the exhaust valve is maintained to maintain a stable discharge rhythm; otherwise, it indicates that the fluidity is still in the dynamic adjustment stage, and the frequency is gradually increased in a step-by-step manner according to the set step size starting from the basic pulse frequency until the increase is terminated under any of the following conditions: the response duration reaches or exceeds the stability judgment time.

[0087] The preset maximum permissible pulse frequency has been reached.

[0088] The liquid level in the tank has dropped to a safe level.

[0089] The stability determination time mentioned above reflects the time window required to maintain a stable state after the liquid fluidity improves. It is the key criterion for determining whether the system has transitioned from the dynamic response stage to the stable drainage stage. The flow recovery process of liquids with different viscosities after vibration intervention can be simulated under laboratory conditions. The time required from the viscosity drop to the stabilization of the flow state can be recorded as the basis for setting the stability determination time.

[0090] It should be understood that a single viscosity reduction rate meeting the standard may be an accidental fluctuation, while continuous meeting the standard indicates that the system has entered a stable improvement stage. By introducing the time dimension of response duration, the robustness and credibility of the judgment are enhanced, and the frequency is gradually increased from the base frequency to avoid the impact of frequency mutations on the system.

[0091] When drainage is triggered by the regional liquid film solidification risk index, the present invention introduces a response threshold as a criterion for the viscosity drop rate. When the response is weak, an opening priority adjustment strategy is adopted to improve the single drainage capacity; when the response is good, a frequency priority adjustment strategy is adopted to improve the overall drainage efficiency and stability.

[0092] The parameters involved in the above formula are all dimensionless and calculated numerically. The formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0093] The above embodiments may be implemented in whole or in part through software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0094] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0095] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0096] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0097] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gas well multiphase flow drainage and gas storage tank control drainage system, characterized in that: include: Global sensing module: Consists of a micro-rotating viscosity probe array, an axial vertical liquid level gauge, and a distributed temperature sensor group, which can obtain the liquid level height, viscosity spatial distribution characteristics, and temperature distribution characteristics in the gas storage tank in real time; Risk Analysis Module: This module divides potential condensation zones based on the neighborhood gradient of temperature distribution characteristics and temperature time series variation analysis, and integrates viscosity time variation and viscosity deviation to evaluate the liquid film solidification risk index of each potential condensation zone; Drainage decision module: This module makes dual-factor drainage demand decisions based on the liquid level in the tank and the risk coverage ratio of regional liquid film solidification. Direct discharge module: starts basic pulse discharge when the discharge is triggered by the liquid level in the tank alone; Vibration drainage module: When drainage is triggered by the regional liquid film solidification risk index, the piezoelectric ceramic vibration array deployed at the bottom of the tank is used to implement regional differentiated vibration according to the liquid film solidification risk index-frequency mapping relationship, and monitor the viscosity drop curve in the tank after vibration. Based on the viscosity drop curve, supplementary vibration control is performed or the pulse frequency and opening of the drainage valve are dynamically adjusted.

2. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 1, characterized in that: The micro-rotating viscosity probe array, axial vertical liquid level gauge, and distributed temperature sensor group are arranged as follows: An array of rotating viscosity probes distributed in a grid pattern is set at the bottom of the gas storage tank; An axial vertical liquid level gauge is arranged along the axial direction of the tank body; The distributed temperature sensor group is deployed on the inside of the tank wall in a honeycomb topology.

3. The gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 1, characterized in that: The potential condensation zone is divided into the following process: A real-time three-dimensional temperature field model is constructed using the tank temperature data collected in real time by a distributed temperature sensor group; At each sampling moment, the entire tank is divided into several temperature sub-regions according to the temperature cluster analysis in the current three-dimensional temperature field, and the spatial boundary position and average temperature value of each sub-region are recorded; For each temperature sub-region, calculate the temperature change rate between the current moment and the previous moment; Identify the temperature distribution area adjacent to each temperature sub-area at the current moment, build a local neighborhood relationship, and calculate its local surrounding temperature gradient by comparing the temperature difference between the area and its adjacent areas; A sliding time window is used to perform time series statistical analysis on the historical temperature change rate of each temperature sub-area and its surrounding temperature gradient, and its average temperature change trend and average surrounding temperature gradient level are extracted: Potential condensation areas are identified according to the following two classification rules: a) The average temperature change rate of a certain temperature sub-area is negative, and its absolute value is lower than the preset threshold; b) The average local ambient temperature gradient of a temperature sub-area is higher than the average gradient level of its environment; The temperature sub-regions that meet the above conditions a) or b) are marked as potential condensation areas.

4. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 3, characterized in that: The evaluation of the liquid film solidification risk index of each potential condensation zone is performed as follows: Based on the spatial boundary position of each potential condensation zone, the viscosity data is collected in real time using a micro-rotating viscosity probe covered by the zone; Perform time difference processing on the acquired viscosity time series data to calculate the viscosity growth rate of the area between the current moment and the previous moment; The viscosity deviation is calculated by combining the current viscosity of the potential condensation zone with the safe viscosity. Then, the liquid film solidification risk index is constructed with the viscosity deviation as the base and the viscosity growth rate as the exponent to obtain the liquid film solidification risk index of each potential condensation zone.

5. The gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 1, characterized in that: The contents of the drainage decision module are as follows: (1) Compare the current liquid level of the gas tank with the warning liquid level. If the actual liquid level reaches or exceeds the warning liquid level, the discharge demand is triggered. Otherwise, steps (2) to (3) are executed. (2) Compare the liquid film solidification risk index of each potential condensation area with the configured critical solidification risk index, and screen out the areas where the risk index exceeds the critical value and mark them as solidification risk areas; (3) Based on the spatial boundary information of the solidification risk zone, the volume or area ratio occupied by the solidification risk zone inside the tank is calculated to obtain the solidification space coverage ratio, and then compared with the coverage ratio threshold. If the solidification space coverage ratio reaches or exceeds the threshold, the drainage demand is triggered, otherwise the drainage demand is not triggered.

6. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 1, characterized in that: The specific implementation of regional differentiated vibration based on the liquid film solidification risk index-frequency mapping relationship is as follows: The vibration array is divided into independently phase-controlled sector-shaped sub-arrays, each of which is responsible for covering a specific angle range; Activate the fan-shaped sub-array in the corresponding direction according to the spatial boundary information of the solidification risk area; Inputting the liquid film solidification risk index corresponding to each solidification risk zone into a preset liquid film solidification risk index-vibration frequency mapping relationship to obtain a target vibration frequency for each solidification risk zone; Each activated sub-array performs a vibration operation according to the target vibration frequency of its corresponding coagulation risk zone.

7. The gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 1, characterized in that: The specific implementation process of the supplementary vibration control or dynamic adjustment of the pulse frequency and opening of the drain valve based on the viscosity drop curve is as follows: After directional vibration is applied to the solidification risk area, a micro-rotational viscosity probe is used to monitor the average viscosity in the tank in real time within a preset buffer time window, and a viscosity drop curve over time is constructed. According to the set time sampling interval, the viscosity drop rate and the current average viscosity in the tank are extracted from the viscosity drop curve, and the current average viscosity in the tank is compared with the safety viscosity. If the current viscosity value is higher than the safety viscosity, the supplementary vibration control is triggered, otherwise the discharge execution stage is entered. At the same time, the viscosity drop rate is compared with the preset response threshold. If it is less than the response threshold, the basic pulse frequency is maintained for step-by-step opening adjustment. If the response threshold is reached, the basic opening is maintained and the response stability time is tracked for step-by-step pulse frequency adjustment.

8. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 7, characterized in that: The supplementary vibration control is implemented as follows: Acquire the existing solidification risk area inside the gas tank when the supplementary vibration control is triggered, and identify the original risk area that has returned to normal; For each original risk zone that has returned to normal, the corresponding liquid film solidification risk index before the vibration and the target vibration frequency used at that time are retrieved, and the initially set liquid film solidification risk index-vibration frequency mapping relationship is corrected accordingly; The modified mapping relationship is combined with the current liquid film solidification risk index of the existing solidification risk area to extract the optimized target vibration frequency suitable for the area, and then the fan-shaped vibration sub-array corresponding to the spatial position of the existing solidification risk area is activated for supplementary vibration control.

9. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 7, characterized in that: The step opening adjustment is implemented as follows: The opening step is set according to the adjustable opening range of the drain valve to divide the entire opening range into several discrete opening levels to form an orderly opening sequence; When the step-by-step opening adjustment mechanism is triggered, the first opening value is selected from the opening sequence as the initial drainage opening to perform the drainage operation; In each time sampling interval of discharge, the system switches to the next opening in sequence, and at the same time continuously extracts the current viscosity drop rate from the viscosity drop curve and compares it with the preset response threshold. If the preset response threshold is reached at a certain opening level, the current opening is locked. If the viscosity drop rate does not reach the response threshold during the entire adjustment process, the opening is continuously increased step by step according to the set step size until the maximum allowable opening is reached or the liquid level in the tank drops to a safe range.

10. A gas well multiphase flow drainage and gas storage tank control and drainage system according to claim 7, characterized in that: The step pulse frequency adjustment is implemented as follows: When the viscosity drop rate reaches the response threshold, the response duration is tracked and compared with the set stability judgment duration. If the response duration reaches or exceeds the stability judgment duration, the current exhaust valve pulse frequency is maintained; otherwise, the frequency is gradually increased in a step-by-step manner according to the set step size starting from the base pulse frequency until the increase is terminated under any of the following conditions: The duration of the response reaches or exceeds the stability determination duration; Reaching the preset maximum permissible pulse frequency; The liquid level in the tank has dropped to a safe level.

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