Sulphur-containing wastewater corrosion inhibitor effect evaluation method based on field data processing

Abstract

The present application belongs to the technical field of data processing, and particularly relates to a sulfur-containing sewage corrosion inhibitor effect evaluation method based on field data processing, which comprises the following steps: obtaining environmental physical quantity data of the sulfur-containing sewage, and obtaining a corrosion deterioration index in combination with a benchmark parameter; obtaining an initial corrosion rate, and obtaining a net corrosion inhibition index in combination with a benchmark corrosion rate and the corrosion deterioration index; obtaining a dynamic environmental fluctuation degree according to a historical corrosion deterioration index, and then obtaining an adaptive sliding window size; extracting a centralized trend feature and a discrete distribution feature of the net corrosion inhibition index in the adaptive sliding window size interval, and obtaining a film forming stability coefficient; and comparing the film forming stability coefficient with a preset judgment threshold, and outputting a corrosion inhibitor efficiency grade judgment result. The present application objectively restores the real protection level of the agent under complex working conditions, and makes the corrosion inhibitor efficiency evaluation more accurate.

Description

Technical Field

[0001] This invention relates to the field of data processing technology. More specifically, this invention relates to a method for evaluating the effectiveness of corrosion inhibitors in sulfur-containing wastewater based on on-site data processing. Background Technology

[0002] Oilfield wastewater pipelines are a crucial component of oilfield production systems, primarily used to transport media such as sulfur-containing wastewater. As oilfield exploration and development enters its later stages, the increasing number of deep and ultra-deep wells in major oilfields leads to greater depth and temperature. The use of high-concentration acidic solutions during construction exacerbates corrosion problems in the downhole oilfield wastewater pipelines. Corrosion inhibitors are typically added to these pipelines. These inhibitors deposit on the metal pipe walls to form a dynamically balanced molecular film, providing corrosion protection. To monitor the safe operation of the pipeline network and guide the application of these inhibitors, it is necessary to evaluate their effectiveness in preventing corrosion damage within the pipeline network.

[0003] Currently, when evaluating the effectiveness of corrosion inhibitors in oilfield wastewater pipelines, the common practice is to deploy electrochemical corrosion probes at pipeline monitoring nodes to directly obtain the initial corrosion rate and assess the protective efficacy of the corrosion inhibitors.

[0004] However, the corrosion process inside the oilfield wastewater pipeline network is affected by the coupling of multiple physical fields, such as the chemical depolarization reaction caused by high concentrations of hydrogen sulfide, the mechanical shear force generated by high-velocity fluid on the pipe wall, and the reaction rate changed by temperature fluctuations. Sudden changes in on-site operating conditions can instantly destroy the not-yet-dense corrosion inhibitor molecular film, causing the corrosion rate to surge. Existing methods fail to eliminate the physical influence of environmental stress, and are prone to misjudging numerical anomalies caused by severe environmental shocks as the failure of the corrosion inhibitor's own components, failing to restore the film-forming and shock-resistant capabilities of the agent molecules. At the same time, when there are violent fluctuations in physical quantities on-site, existing technologies have difficulty balancing the sensitivity of anomaly detection with the noise resistance of steady-state assessment, resulting in inaccurate evaluation of the corrosion inhibitor's effectiveness. Summary of the Invention

[0005] To address the aforementioned technical problem of inadequate evaluation of existing corrosion inhibitor effects, which hinders corrosion protection of oilfield wastewater pipelines, this invention provides a method for evaluating the effectiveness of corrosion inhibitors in sulfur-containing wastewater based on field data processing. The method includes: acquiring environmental physical quantity data of sulfur-containing wastewater at various sampling times; obtaining the corrosion deterioration index corresponding to each sampling time based on the environmental physical quantity data and pre-acquired baseline environmental parameters; acquiring the initial corrosion rate measured at each sampling time; obtaining the net corrosion inhibition index at each sampling time based on the initial corrosion rate, pre-calibrated baseline corrosion rate, and the corresponding corrosion deterioration index; and using the current time as the target sampling time, and using the continuous sampling times prior to the target sampling time... The standard deviation of the corrosion deterioration index corresponding to a preset number of historical sampling times is used as the dynamic environmental fluctuation. The preset baseline window size is adjusted according to the dynamic environmental fluctuation to obtain the adaptive sliding window size corresponding to the target sampling time. Taking the target sampling time as the endpoint, a continuous interval containing the number of sampling times equal to the adaptive sliding window size is extracted. The mean and standard deviation of the net corrosion inhibition index corresponding to all sampling times within the continuous interval are calculated. The mean is used as the central tendency feature, and the standard deviation is used as the discrete distribution feature. The film stability coefficient of the target sampling time is obtained based on the central tendency feature and the discrete distribution feature. The corrosion inhibitor effect is evaluated based on the film stability coefficient.

[0006] This invention acquires environmental physical quantity data of sulfur-containing wastewater at various sampling times, determines the relative change scale of each physical quantity by combining it with baseline environmental parameters, performs an exponential mapping on the relative change scale including temperature attributes, and fuses it with the relative change scales of other physical quantities to obtain a corrosion deterioration index. This eliminates background interference caused by the coupling effects of multiple external conditions and restores the comprehensive impact of complex working conditions on corrosion aggravation. It also acquires the corresponding initial corrosion rate, combines the baseline corrosion rate with the corresponding corrosion deterioration index to obtain the net corrosion inhibition index, eliminates misjudgments caused by the physical influence of environmental stress, and restores the true protective effect of the agent itself. The invention uses continuous historical sampling times... The corresponding corrosion deterioration index is used to obtain the dynamic environmental fluctuation. The baseline window size is mapped to obtain the adaptive sliding window size, achieving a balance between the sensitivity of anomaly detection and the noise resistance of steady-state assessment, thus improving the detection sensitivity of short-term film rupture characteristics. The central tendency and discrete distribution characteristics of the net corrosion inhibition index within the size-defined range are extracted to obtain the film formation stability coefficient, which comprehensively measures the static protective efficacy of the agent. The film formation stability coefficient is correlated with the preset efficacy judgment threshold to output the corrosion inhibitor efficacy level judgment result, improving the objectivity of the state assessment under abnormal operating conditions and making the evaluation of corrosion inhibitor efficacy in oilfield sewage pipe networks more accurate.

[0007] Preferably, the environmental physical quantity data includes: hydrogen sulfide concentration, fluid flow rate, and wastewater temperature.

[0008] Preferably, the corrosion deterioration index satisfies the following relationship: In the formula, For the first Corrosion deterioration index at each sampling time, , , The first Hydrogen sulfide concentration, fluid flow rate, and wastewater temperature at each sampling time. , , These are the baseline hydrogen sulfide concentration, baseline fluid flow rate, and baseline wastewater temperature, which are the baseline environmental parameters. For temperature sensitivity coefficient, It is an exponential function with the natural constant as the base.

[0009] This invention extracts the ratio between the concentration of various physical quantities at the actual sampling time and the baseline parameter as the relative change scale of each physical quantity. It then exponentially expands the relative change scale, which includes temperature attributes, and merges it with the relative change scales of other physical quantities to obtain the corrosion deterioration index corresponding to each sampling time. This reflects the severity of the deviation of the actual working conditions from the baseline state. At the same time, it gives the temperature attribute a more sensitive mapping method, enhances the ability to capture small temperature fluctuations, and makes the data processing process more consistent with the physical evolution process of corrosion aggravation in the actual industrial environment. Ultimately, this helps to make the evaluation of corrosion inhibitor effectiveness more accurate.

[0010] Preferably, the net corrosion inhibition index satisfies the following relationship: In the formula, For the first Net corrosion inhibition index at each sampling time, For the first The initial corrosion rate at each sampling time. As the baseline corrosion rate, For the first Corrosion deterioration index at each sampling time, This is the environmental stress coupling compensation factor.

[0011] This invention corrects the initial corrosion rate by division based on the baseline corrosion rate and the corresponding severity of corrosion deterioration, and introduces an environmental stress coupling compensation factor to adjust the denominator to obtain the net corrosion inhibition index. When the environment is severely deteriorated, the downward correction is increased to reduce the interference of harsh environmental impacts, while the downward correction is reduced when the environment is stable to retain the protective defect characteristics of the agent itself. This preserves the high-risk state caused by the agent's protective defects and eliminates the characteristics of false deterioration, thereby improving the reliability of the corrosion inhibitor performance evaluation results.

[0012] Preferably, the adaptive sliding window size satisfies the following relationship: In the formula, To adapt to the sliding window size, Based on the reference window size, Minimum window size, For dynamic environmental fluctuations, It is an exponential function with the natural constant as its base. This is the rounding function. This refers to the window shrinkage sensitivity.

[0013] This invention processes a preset window shrinkage sensitivity by controlling the dynamic environmental fluctuation and applies it to a reference time interval size. Combined with a preset minimum limit value and rounding operation, the final adaptive sliding window size is obtained. When the field environment experiences severe shocks, it suppresses the shrinkage of the reference size, making the time interval smaller and improving the sensitivity to capture short-term film rupture. When the environment is stable for a long period of time, the shrinkage attenuation effect weakens, and the adaptive time interval size approaches the reference size, improving the smoothness and noise resistance of normal data statistics. This allows the corrosion inhibitor performance evaluation process to better adapt to complex working conditions.

[0014] Preferably, the film-forming stability coefficient satisfies the following relationship: In the formula, The film formation stability coefficient corresponding to the target sampling time. The central tendency characteristics of the net corrosion inhibition index within the interval defined by the adaptive sliding window size. Discrete distribution characteristics of the net corrosion inhibition index within an interval defined by the adaptive sliding window size. It is an exponential function with the natural constant as its base. This is the dynamic oscillation penalty coefficient.

[0015] This invention amplifies the extracted discrete distribution features using a dynamic oscillation penalty coefficient, then adds them to the central tendency features to obtain the film formation stability coefficient. This penalizes the drastic temporal fluctuations caused by film rupture. Larger central tendency and discrete distribution features indicate poorer overall protection of the corrosion inhibitor and a greater susceptibility to film rupture fluctuations, resulting in smaller final values. This objectively measures the density and toughness of the film. At the same time, the dynamic oscillation penalty coefficient increases the tolerance for fluctuations during film formation, ultimately improving the rationality of the corrosion inhibitor performance evaluation results.

[0016] Preferably, the reference corrosion rate is obtained by: calibrating and obtaining the reference corrosion rate using a pure water medium through an electrochemical corrosion probe during the system's power-on initialization phase.

[0017] Preferably, the reference environmental parameters are obtained by recording the hydrogen sulfide concentration, fluid flow rate, and wastewater temperature obtained by the sensor sequence within a continuous preset time period during the normal stable operation phase of the system without sudden changes in operating conditions, and then calculating the average value of the corresponding parameters.

[0018] Preferably, the evaluation of the corrosion inhibitor effect based on the film-forming stability coefficient includes: in response to the film-forming stability coefficient being greater than or equal to the performance threshold, determining that the corrosion inhibitor performance meets the standard, and maintaining the current injection frequency of the dosing pump.

[0019] Preferably, the step of evaluating the corrosion inhibitor effect based on the film-forming stability coefficient includes: in response to the film-forming stability coefficient being less than the effectiveness warning threshold, determining that the corrosion inhibitor's effectiveness is substandard, and generating a linkage compensation command to increase the injection concentration of the dosing pump.

[0020] The beneficial effects of this invention are as follows: This invention integrates the changes in hydrogen sulfide concentration, fluid flow rate, and wastewater temperature deviating from normal conditions under actual working conditions, measuring the comprehensive destructive force brought about by complex working conditions. Based on this, it eliminates the abnormal spikes in probe test results caused by environmental physical stress, avoiding the misjudgment of short-term deterioration caused by sudden environmental changes as failure of the agent itself, and restoring the true protective state of the agent. This invention adaptively adjusts the length of the analysis segment based on recent environmental fluctuations. When the environment experiences severe fluctuations, the analysis interval is shortened to improve the sensitivity of capturing short-term membrane damage sites. When the environment is stable for a long period, a longer analysis interval is maintained to improve the noise resistance of data statistics. This allows for the acquisition of objective and usable evaluation data under different working conditions. Furthermore, by extracting the central tendency and dispersion distribution of the data within this adaptive analysis interval, the static protective efficacy and dynamic repair level of the agent are comprehensively evaluated. This invention guides the injection action of the dosing equipment based on objectively extracted data characteristics. When the agent's shock resistance is determined to be insufficient, the injection concentration is increased in a timely manner, reducing the lag and subjective differences caused by human experience judgment, making the evaluation of corrosion inhibitor efficacy and subsequent protective actions more accurate in complex pipe network environments. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the method for evaluating the effectiveness of sulfur-containing wastewater corrosion inhibitors based on on-site data processing in this invention;

[0022] Figure 2 This is a schematic diagram illustrating the results of the corrosion inhibitor performance level determination in this invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] This invention discloses a method for evaluating the effectiveness of corrosion inhibitors in sulfur-containing wastewater based on on-site data processing, referring to... Figure 1 This includes steps S1 to S5:

[0026] S1. Obtain environmental physical quantity data of sulfur-containing wastewater through sensor sequence, and combine with benchmark environmental parameters to obtain the corrosion deterioration index corresponding to each sampling time.

[0027] It should be noted that the corrosion process inside the oilfield wastewater pipe network is affected by the coupling of multiple physical fields. High concentrations of hydrogen sulfide can induce chemical depolarization reactions, high-velocity fluids can exert mechanical shear forces on the pipe walls, and temperature fluctuations can directly alter the electrochemical reaction kinetics. This means that the corrosion data measured by the probe is not only affected by the properties of the reagents but also by the background noise from environmental fluctuations. Therefore, this invention combines baseline environmental parameters to obtain the corrosion deterioration index at each sampling time to measure the comprehensive driving force of complex operating conditions on corrosion aggravation.

[0028] Specifically, environmental physical quantity data of sulfur-containing wastewater are acquired, including hydrogen sulfide concentration, fluid flow rate, and wastewater temperature at each sampling time. Pre-calibrated and stored baseline environmental parameters are retrieved, and the relative change scale of each physical quantity is determined by combining the environmental physical quantity data at each sampling time with the corresponding baseline environmental parameters. An exponential mapping is performed on the relative change scale including temperature attributes, and this mapping result is fused with the relative change scales of other physical quantities to obtain the corrosion deterioration index corresponding to each sampling time.

[0029] For example, the baseline environmental parameters are obtained by recording the hydrogen sulfide concentration, fluid flow rate, and wastewater temperature of the sensor sequence within a continuous preset time period during the normal stable operation phase of the system without sudden changes in operating conditions, and then calculating the average value of the corresponding parameters. For example, the length of the continuous preset time period is 30 minutes.

[0030] Specifically, the corrosion deterioration index satisfies the following relationship:

[0031] ;

[0032] In the formula, For the first Corrosion deterioration index at each sampling time, , , The first Hydrogen sulfide concentration, fluid flow rate, and wastewater temperature at each sampling time. , , These are the baseline hydrogen sulfide concentration, baseline fluid flow rate, and baseline wastewater temperature, which are the baseline environmental parameters. For temperature sensitivity coefficient, It is an exponential function with the natural constant as the base. The empirical value range is [1, 2.5]. In this embodiment... The value is 1.2. Implementers can determine the temperature sensitivity coefficient based on the actual situation. When the pipeline network is located in a deep well area with high temperature and high pressure, the electrochemical reaction kinetics are more intensely excited by thermodynamics. This parameter can be appropriately increased to enhance the index's ability to capture small temperature fluctuations. When the pipeline is located in a shallow transport section at normal temperature, this parameter can be appropriately decreased to reduce the driving weight of the temperature term in the overall model.

[0033] in, , and These ratios represent the severity of the deviation of the actual working conditions from the baseline state. The larger the ratio, the more severe the on-site environmental deterioration, resulting in a higher corrosion deterioration index; the smaller the ratio, the more stable the on-site environment, resulting in a lower corrosion deterioration index.

[0034] S2. Based on the initial corrosion rate obtained at each sampling time, and combined with the corresponding corrosion deterioration index, obtain the net corrosion inhibition index corresponding to each sampling time.

[0035] It should be noted that sudden changes in on-site operating conditions can instantly tear apart the nascent corrosion inhibitor molecular film, causing a dramatic spike in the initial corrosion rate measured by the probe. If the physical effects of environmental stress are not eliminated, this could be misinterpreted as a failure of the corrosion inhibitor itself. To accurately reflect the film-forming impact resistance of the inhibitor molecules, this invention uses the initial corrosion rate obtained at each sampling time, combined with the corresponding corrosion deterioration index, to obtain the net corrosion inhibition index for each sampling time.

[0036] Specifically, the initial corrosion rate measured by electrochemical corrosion probes deployed at the same monitoring node at each sampling time is obtained. The baseline corrosion rate calibrated and stored using pure water during the system power-on initialization phase is retrieved, and combined with the initial corrosion rate and the corrosion deterioration index corresponding to each sampling time, the net corrosion inhibition index corresponding to each sampling time is obtained.

[0037] Specifically, the net corrosion inhibition index satisfies the following relationship:

[0038] ;

[0039] In the formula, For the first Net corrosion inhibition index at each sampling time, For the first The initial corrosion rate at each sampling time. As the baseline corrosion rate, For the first Corrosion deterioration index at each sampling time, This is an environmental stress coupling compensation factor. The empirical value range is [0.5, 1.5]. In this embodiment... The value is 0.8, which can be determined by the implementers based on the actual situation. When the pipeline material is low-carbon steel, which is extremely sensitive to corrosive environments, this parameter can be appropriately increased to enhance the explanatory power of environmental factors for abnormally high corrosion rates. When the pipe material itself has strong corrosion resistance through alloying treatment, this parameter can be appropriately reduced to prevent data distortion caused by overcompensation.

[0040] Among them, when the corrosion deterioration index The larger the value, the more likely the high corrosion rate is caused by harsh environmental impact rather than reagent failure, which has a greater impact on... The stronger the amplification effect, the greater the downward correction to the initial corrosion rate, thus eliminating pseudo-deterioration characteristics; when the corrosion deterioration index... The smaller the value, the more stable the environment. If the initial corrosion rate is still high at this time, it is mainly due to the protective defects of the agent itself. The weaker its expansion effect on the denominator, the smaller the downward correction, so that the net corrosion inhibition index objectively retains its high-risk state.

[0041] S3. Obtain the dynamic environmental fluctuation degree based on the corrosion deterioration index corresponding to multiple consecutive historical sampling times before the target sampling time, and obtain the adaptive sliding window size corresponding to the target sampling time by combining it with the preset benchmark window size.

[0042] It should be noted that the protective mechanism of corrosion inhibitors relies on a dynamically balanced molecular film deposited on the metal pipe wall. The net corrosion inhibition index at a single sampling moment can only reflect the instantaneous local corrosion state and cannot characterize the overall toughness and anti-stripping performance of the molecular film under continuous fluid scouring. Therefore, the assessment of film stability must rely on a continuous time window. However, a fixed time window is usually unable to adapt to the frequent environmental changes in oilfield wastewater pipe networks. When there are drastic fluctuations in hydrogen sulfide concentration or flow rate, a fixed long window will mask the short-term corrosion inhibitor film rupture characteristics due to the averaging effect of internal data, resulting in detection lag; while a fixed short window is highly susceptible to misjudgment due to random electrical noise interference from electrochemical probes during stable environmental periods. Therefore, this invention dynamically contracts or expands the time window according to the severity of environmental fluctuations to balance the sensitivity of anomaly detection and the noise resistance of steady-state assessment.

[0043] Specifically, the current time is taken as the target sampling time, and the standard deviation of the corrosion deterioration index corresponding to a preset number of consecutive historical sampling times prior to the target sampling time is taken as the dynamic environmental fluctuation. The dynamic environmental fluctuation is used to map a preset baseline window size to obtain the adaptive sliding window size corresponding to the target sampling time.

[0044] For example, the baseline window size is 60 sampling times. The implementer can determine the baseline window size according to the actual situation. For example, when the monitoring node is located on a large-diameter main pipeline and the daily flow is extremely stable, this parameter can be appropriately increased to obtain a longer period of macroscopic film formation stability assessment and further smooth out the random small electrical noise of the electrochemical probe. When the monitoring node is located on a front branch near the dosing point or in the early stage of film formation when a new corrosion inhibitor is added, this parameter can be appropriately decreased to shorten the assessment cycle and accelerate the system's response to the initial film formation effect.

[0045] Specifically, the adaptive sliding window size satisfies the following relationship:

[0046] ;

[0047] In the formula, To adapt to the sliding window size, Based on the reference window size, Minimum window size, For dynamic environmental fluctuations, It is an exponential function with the natural constant as its base. This is the rounding function. For window shrink sensitivity, The empirical value range is [1,3]. In this embodiment... The value is 1.5, which can be determined by the implementers based on the actual situation. When the monitoring node is located at a bend in the pipe where severe impacts of gas-liquid two-phase flow are likely to occur, this parameter can be appropriately increased to ensure that the window can be rapidly contracted at the moment of impact to lock the moment of membrane rupture; when the monitoring node is located in a straight pipe section that is flat and hydraulically stable, this parameter can be appropriately decreased.

[0048] For example, the minimum window size is 3.

[0049] Among them, dynamic environmental fluctuation reflects the recent severe changes in operating conditions. The larger the value, the more severe the turbulence in the site environment, leading to... Approaching 0, this shrinkage effect suppresses the reference window size, reducing the adaptive sliding window size and improving the sensitivity to capturing short-term film ruptures; a smaller value indicates a more stable long-term environment, leading to... Approaching 1 weakens its contraction and attenuation effect, and the adaptive sliding window size approaches the reference window size, ensuring the smoothness and noise resistance of the statistics on normal corrosion rate.

[0050] S4. Extract the central tendency and discrete distribution characteristics of the net corrosion inhibition index corresponding to all sampling times within the adaptive sliding window size limit interval, and obtain the corresponding film formation stability coefficient.

[0051] It should be noted that excellent oilfield wastewater corrosion inhibitors not only need to possess extremely low average corrosion rates, but also need to maintain the integrity of the protective film when encountering external fluid impacts, preventing localized rupture and peeling. If the agent has poor shear resistance, its protective effect will exhibit high-frequency fluctuations over time. Therefore, this invention extracts the central tendency and discrete distribution characteristics of the net corrosion inhibition index corresponding to all sampling times within the adaptive sliding window size limit range, obtains the corresponding film-forming stability coefficient, and measures the static protective efficacy and dynamic repair capability of the agent.

[0052] Specifically, taking the target sampling time as the endpoint, a continuous interval containing the number of sampling times equal to the size of the adaptive sliding window is extracted. The average net corrosion inhibition index corresponding to all sampling times within this interval is used as the central tendency feature. The standard deviation of the net corrosion inhibition index corresponding to all sampling times within this interval is used as the discrete distribution feature. Combining the central tendency feature and the discrete distribution feature, the film stability coefficient corresponding to the target sampling time is obtained.

[0053] Specifically, the film-forming stability coefficient satisfies the following relationship:

[0054] ;

[0055] In the formula, The film formation stability coefficient corresponding to the target sampling time. The central tendency characteristics of the net corrosion inhibition index within the interval defined by the adaptive sliding window size. Discrete distribution characteristics of the net corrosion inhibition index within an interval defined by the adaptive sliding window size. It is an exponential function with the natural constant as its base. The dynamic oscillation penalty coefficient. The empirical value range is [1, 3.5]. In this embodiment... The value is 2, and the implementers can determine the number based on the actual situation. When the requirements for long-term water quality stability in oilfield injection wells are extremely high, this parameter can be appropriately increased to severely punish the drastic fluctuations in time caused by film rupture; when a certain amount of data fluctuation is allowed in the initial film-building stage of chemical dosing, this parameter can be appropriately decreased to increase the tolerance for reasonable fluctuations during the film-building period.

[0056] Among them, the central tendency feature It reflects the overall effectiveness of the drug, while the discrete distribution characteristics This reflects the stability of the drug against shock. Central tendency characteristics. With discrete distribution characteristics The larger the value, the worse the overall protective ability of the corrosion inhibitor and the more prone the film layer is to rupture and fluctuation, resulting in a smaller film stability coefficient and thus playing a role in attenuation suppression; (Mediterranean tendency characteristics) With discrete distribution characteristics The smaller the value, the denser and tougher the film layer, resulting in a larger film stability coefficient.

[0057] S5. Based on the film-forming stability coefficient and the preset performance judgment threshold, the performance level of the corrosion inhibitor is determined by numerical correlation.

[0058] Specifically, the system retrieves the pre-stored performance warning threshold and performance compliance threshold in the controller. The film-forming stability coefficient is then compared with both the performance warning threshold and the performance compliance threshold, and the corrosion inhibitor performance level is determined based on the comparison results.

[0059] In one embodiment, in response to a film stability coefficient greater than or equal to the performance threshold, the current corrosion inhibitor forms a dense film and has excellent impact resistance under complex working conditions, and the corrosion inhibitor performance is determined to meet the standard, and the injection frequency of the current dosing pump is maintained.

[0060] In another embodiment, in response to the film stability coefficient being less than the performance warning threshold, the corrosion inhibitor molecular film has been substantially detached or failed due to environmental shear, the corrosion inhibitor performance is determined to be substandard, and a linkage compensation command is generated to increase the injection concentration of the dosing pump.

[0061] For example, the performance compliance threshold is 0.85 and the performance warning threshold is 0.6. The implementers can set these thresholds according to the actual corrosion tolerance of the oilfield sewage pipeline equipment.

[0062] For example, Figure 2 This diagram illustrates the results of determining the effectiveness level of the corrosion inhibitor in this invention. As can be seen from the diagram, this invention achieves accurate identification of the true effectiveness of the agent by introducing a corrosion deterioration index to compensate for environmental stress in the initial corrosion rate. Within the sampling time range of 50 to 75, although the initial corrosion rate spikes significantly due to drastic fluctuations in operating conditions, the film layer still exhibits strong impact resistance and toughness, accurately indicating a compliant state and effectively eliminating false degradation characteristics caused by environmental background noise. Within the sampling time range of 75 to 100, although the absolute value of the initial corrosion rate is low, the system decisively determines it as non-compliant due to the drastic fluctuations in the net corrosion inhibition index and the film stability coefficient being lower than the warning threshold, thus revealing the protective defects of the corrosion inhibitor under stable operating conditions.

Claims

1. A method for evaluating the effectiveness of corrosion inhibitors in sulfur-containing wastewater based on on-site data processing, characterized in that, include: The environmental physical quantity data of sulfur-containing wastewater at each sampling time are obtained. Based on the environmental physical quantity data and the pre-acquired baseline environmental parameters, the corrosion deterioration index corresponding to each sampling time is obtained. The initial corrosion rate measured at each sampling time is obtained. Based on the initial corrosion rate, the pre-calibrated baseline corrosion rate and the corresponding corrosion deterioration index, the net corrosion inhibition index at each sampling time is obtained. Using the current time as the target sampling time, and the standard deviation of the corrosion deterioration index corresponding to a preset number of historical sampling times preceding the target sampling time as the dynamic environmental fluctuation, the preset baseline window size is adjusted according to the dynamic environmental fluctuation to obtain the adaptive sliding window size corresponding to the target sampling time. Using the target sampling time as the endpoint, a continuous interval containing the number of sampling times equal to the adaptive sliding window size is extracted. The average value and standard deviation of the net corrosion inhibition index corresponding to all sampling times within the continuous interval are calculated. The average value is used as the central tendency feature, and the standard deviation is used as the discrete distribution feature. The film stability coefficient of the target sampling time is obtained based on the central tendency feature and the discrete distribution feature. The effectiveness of corrosion inhibitors is evaluated based on the film-forming stability coefficient.

2. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The environmental physical quantity data include: hydrogen sulfide concentration, fluid flow rate, and wastewater temperature.

3. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 2, characterized in that, The corrosion deterioration index satisfies the following relationship: ； In the formula, For the first Corrosion deterioration index at each sampling time, , , The first Hydrogen sulfide concentration, fluid flow rate, and wastewater temperature at each sampling time. , , These are the baseline hydrogen sulfide concentration, baseline fluid flow rate, and baseline wastewater temperature, which are the baseline environmental parameters. For temperature sensitivity coefficient, It is an exponential function with the natural constant as the base.

4. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The net corrosion inhibition index satisfies the following relationship: ； In the formula, For the first Net corrosion inhibition index at each sampling time, For the first The initial corrosion rate at each sampling time. As the baseline corrosion rate, For the first Corrosion deterioration index at each sampling time, This is the environmental stress coupling compensation factor.

5. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The adaptive sliding window size satisfies the following relationship: ； In the formula, To adapt to the sliding window size, Based on the reference window size, Minimum window size, For dynamic environmental fluctuations, It is an exponential function with the natural constant as its base. This is the rounding function. This refers to the window shrinkage sensitivity.

6. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The film-forming stability coefficient satisfies the following relationship: ； In the formula, The film formation stability coefficient corresponding to the target sampling time. The central tendency characteristics of the net corrosion inhibition index within the interval defined by the adaptive sliding window size. Discrete distribution characteristics of the net corrosion inhibition index within an interval defined by the adaptive sliding window size. It is an exponential function with the natural constant as its base. This is the dynamic oscillation penalty coefficient.

7. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The method for obtaining the baseline corrosion rate includes: calibrating and obtaining the baseline corrosion rate using a pure water medium through an electrochemical corrosion probe during the system's power-on initialization phase.

8. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The baseline environmental parameters are obtained by recording the hydrogen sulfide concentration, fluid flow rate, and wastewater temperature of the sensor sequence within a continuous preset time period during the normal stable operation phase of the system without sudden changes in operating conditions, and then calculating the average value of the corresponding parameters.

9. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The method of evaluating the effectiveness of corrosion inhibitors based on the film-forming stability coefficient includes: determining that the corrosion inhibitor's effectiveness meets the standard when the film-forming stability coefficient is greater than or equal to the performance threshold, and maintaining the current injection frequency of the dosing pump.

10. The method for evaluating the effect of sulfur-containing wastewater corrosion inhibitors based on on-site data processing according to claim 1, characterized in that, The method of evaluating the effectiveness of corrosion inhibitors based on the film-forming stability coefficient includes: in response to the film-forming stability coefficient being less than the effectiveness warning threshold, determining that the effectiveness of the corrosion inhibitor is substandard, and generating a linkage compensation command to increase the injection concentration of the dosing pump.

Images