Preparation method of medicament for removing organic sulfides in drilling flowback fluid

Abstract

The invention relates to the technical field of oil and gas field drilling and production wastewater treatment, in particular to a preparation method of an agent for removing organic sulfides in well drilling flow-back fluid, which comprises the following steps: dissolving HEDP-Na4 in heated deionized water, and compensating water temperature and stirring duration based on solution transmittance to obtain first pre-dispersion liquid; controlling the feeding speed, adding HEHMT, and dynamically adjusting feeding and stirring parameters based on the system turbidity monitored in real time to obtain a second pre-dispersion liquid; supplementing HEDP-Na4 or amino acid zinc according to the deviation condition of the pH value and the Zeta potential value to obtain a composite solution; and adjusting the pH value, curing, cooling and filtering to obtain the final medicament. Through multi-parameter real-time monitoring and intelligent compensation regulation and control, efficient and stable preparation of the agent is achieved, and an excellent removal effect on various organic sulfides such as H2S, mercaptan and thioether is achieved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field drilling wastewater treatment technology, and in particular to a method for preparing a reagent for removing organic sulfides from drilling flowback fluid. Background Technology

[0002] Drilling flowback fluid is one of the main wastewaters generated during oil extraction, rich in organic sulfides such as hydrogen sulfide (H2S), methanethiol, and dimethyl sulfide. These substances have an extremely strong odor (olfactory threshold as low as 0.001ppm to 0.1ppm), causing not only environmental pollution but also posing a threat to the health of on-site workers.

[0003] Existing organic sulfide removal technologies mainly include: Oxidation method: Oxidants such as ferrates and hypochlorites are used to decompose sulfides, but the oxidation efficiency for thiols and dimethyl sulfides is low (≤70%), and secondary pollutants such as chloride ions and iron ions are easily generated.

[0004] Adsorption method: This method uses adsorbents such as activated carbon and zeolite to physically adsorb sulfides, but it has drawbacks such as needing to replace the adsorbent when it is saturated, high cost (≥5 yuan / ton), and incomplete removal (removal rate ≤80%).

[0005] Chemical precipitation method: precipitates are formed by the reaction of iron salts, zinc salts and sulfides, but the precipitates are easily decomposed under acidic conditions (e.g., FeS releases H2S), and are ineffective against organic sulfides such as dimethyl sulfide.

[0006] In summary, there is an urgent need to develop a new agent that can efficiently remove various organic sulfides without causing secondary pollution. Summary of the Invention

[0007] Therefore, the present invention provides a method for preparing a reagent for removing organic sulfides from drilling flowback fluid, in order to overcome the problem that the prior art cannot simultaneously and efficiently remove multiple organic sulfides such as H2S, thiols and thioethers.

[0008] To achieve the above objectives, the present invention provides a method for preparing a reagent for removing organic sulfides from drilling flowback fluid, comprising the following steps: Step S1: Add HEDP-Na4 to deionized water at 50°C and stir. Based on the transmittance of the solution after stirring, determine the compensation for the temperature of the deionized water and the stirring time to obtain the first pre-dispersion. Step S2: HEHMT is added to the first pre-dispersion liquid at a preset feed rate, and then stirred at a first preset stirring speed. The turbidity of the system is monitored in real time during the stirring process, and a first execution parameter adjustment strategy is determined based on the system turbidity to obtain the second pre-dispersion liquid. The first execution parameter adjustment strategy includes adjusting the preset feeding speed and / or the first preset stirring speed; Step S3: Pre-dissolve zinc amino acids in 40°C warm water to obtain a 10% zinc amino acid concentrate. Step S4: During low-speed stirring, the concentrated amino acid zinc solution is added dropwise to the second pre-dispersion solution, and after the dropwise addition is completed, high-speed stirring is performed. Based on the deviation of pH value and Zeta potential value during high-speed stirring, it is determined to add HEDP-Na4 and / or the concentrated amino acid zinc solution to obtain a composite solution. Step S5: Perform accelerated stability testing and sulfur capacity testing on the composite solution to determine whether the composite solution meets the standards. Based on the result of non-compliance, determine whether to compensate the composite solution with PEG-400 or the amino acid zinc concentrate to obtain a compliant composite solution. The accelerated stability test involves allowing the composite solution to stand at 50°C for 2 hours and observing whether it separates into layers or precipitates. The sulfur capacity test involves passing a quantitative composite solution into a standard H2S gas and calculating the sulfur capacity value per unit weight of the reagent. Step S6: Adjust the pH value of the qualified composite solution to a preset range, mature it at 50°C for 2 hours, and filter it after cooling to complete the preparation.

[0009] Further, in step S1, determining the compensation for the temperature and stirring time of the deionized water based on the transmittance of the solution after stirring includes the following steps: Step S11: Obtain the transmittance of the solution after stirring; Step S12: Compare and analyze the transmittance of the solution with the preset transmittance; Step S13: Based on the result that the transmittance of the solution is less than the preset transmittance, it is determined that the temperature of the deionized water should be compensated to 55°C and the stirring time should be extended by 5 to 10 minutes.

[0010] Furthermore, the preset feeding speed is ≤5g / min, and the first preset stirring speed is 400rpm.

[0011] Further, in step S2, the process of determining the first execution parameter adjustment strategy based on the system turbidity during the stirring process includes: Step S21: Obtain the turbidity of the system, and determine the turbidity increase ratio based on the turbidity of the system and the initial turbidity of the system; Step S22: Compare and analyze the turbidity increase ratio with the preset turbidity increase ratio; Step S23: Based on the result that the turbidity increase ratio is greater than or equal to the preset turbidity increase ratio, determine to immediately stop adding HEHMT, and determine to reduce the preset feed rate and increase the first preset stirring rate; Step S24: Based on the result that the turbidity increase ratio is less than the preset turbidity increase ratio, further adjust the preset feed rate or the first preset stirring speed according to the rate of change of turbidity over time.

[0012] Further, in step S24, the process of determining whether to adjust the preset feed rate or the first preset stirring rate based on the rate of change of turbidity over time includes: Step S231: Obtain the time curve of the turbidity to obtain the instantaneous slope; Step S232: Compare and analyze the instantaneous slope with the preset instantaneous slope; Step S233: Based on the fact that the instantaneous slope is greater than the first preset instantaneous slope, determine to reduce the preset feed rate; Step S234: Based on the result that the instantaneous slope is less than the first preset instantaneous slope and the instantaneous slope is greater than the second preset instantaneous slope, it is determined to increase the first preset stirring speed.

[0013] Further, in step S4, determining the addition of HEDP-Na4 and / or the amino acid zinc concentrate based on the deviation of pH and Zeta potential values ​​during high-speed stirring includes the following steps: Step S41: Obtain the Zeta potential value and the pH value; Step S42: Compare and analyze the Zeta potential value with the preset Zeta potential value; Step S43: Compare and analyze the pH value with the preset pH value; Step S44: Based on the result that the absolute value of the Zeta potential is less than 30mV, determine to add 0.3% to 0.6% of HEDP-Na4 by weight of the total system. Step S45: Based on the result that the pH value exceeds the range of 7.5 to 8.5, it is determined to add 1% to 3% of the total weight of the amino acid zinc concentrate. Step S46, or, based on the result that the absolute value of the Zeta potential is less than 30 mV and the pH value is outside the range of 7.5 to 8.5, determine to simultaneously add 0.3% to 0.6% of HEDP-Na4 and 1% to 3% of the amino acid zinc concentrate, which is the total weight of the system.

[0014] Further, in step S5, the accelerated stability test involves standing the composite solution at 50°C for 2 hours and observing whether it separates into layers or precipitates. The sulfur capacity test involves passing a quantitative composite solution into a standard H2S gas and calculating the sulfur capacity value per unit weight of the reagent.

[0015] Further, in step S5, based on the result of the accelerated stability test failing to meet the standard, it is determined that 0.2% to 0.5% of PEG-400 will be added to the composite solution; Based on the result of the sulfur capacity test failing to meet the standard, it was determined that 1% to 3% of the amino acid zinc concentrate should be added to the composite solution.

[0016] Furthermore, in step S6, adjusting the pH value of the compliant composite solution to a preset range involves using citric acid or sodium hydroxide to adjust the pH value to the range of 8.0.

[0017] Furthermore, the zinc amino acid is any one of zinc glycine, zinc glutamate, or zinc aspartate.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: By compensating for water temperature and stirring time during the HEDP-Na4 dissolution process based on solution transmittance, a direct quantitative indicator of whether HEDP-Na4 has achieved true molecular-level solution dispersion is obtained when the transmittance is ≥95%. This completely eliminates undissolved microcrystals or agglomerates from the source, thereby improving product stability.

[0019] Furthermore, by monitoring the turbidity of the system in real time and dynamically adjusting the feeding and stirring parameters of HEHMT based on the turbidity increase ratio and instantaneous slope, the turbidity increase ratio macroscopically reflects whether uncontrollable agglomeration and Ostwald ripening of the particles occur. On this basis, the instantaneous slope microscopically reflects the dynamic balance between the local concentration gradient near the feeding point and the overall shear dispersion capacity of the system, thereby achieving uniform and stable dispersion of HEHMT particles, avoiding the loss of active sites and system instability caused by excessively rapid agglomeration, and ensuring the quality of high sulfur capacity.

[0020] Furthermore, by pre-dissolving zinc amino acids into a concentrated solution and adding it dropwise at a specific pH window, and supplementing it based on pH and zeta potential values, the pre-dissolution ensures the rapid and uniform integration of zinc amino acids. This ensures, on the one hand, that the synergistic effect of zinc amino acids with HEHMT and HEDP-Na4 occurs under optimal chemical conditions, and on the other hand, by maintaining a high zeta potential value in the system, it endows the agent with excellent long-term storage stability.

[0021] Furthermore, by introducing accelerated stability testing and sulfur capacity testing to conduct final verification and compensation of the composite solution, a final closed-loop verification of the aforementioned process control is formed. Targeted fine-tuning can be performed by adding PEG-400 or zinc amino acids, ensuring the performance lower limit of each batch of products and achieving dual protection from process control to result assurance. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the steps of a method for preparing a reagent to remove organic sulfides from drilling flowback fluid, as described in an embodiment of the present invention. Figure 2 This is a flowchart illustrating the steps of determining compensation for the temperature and stirring time of deionized water based on the transmittance of the solution after stirring, according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the steps of determining a first execution parameter adjustment strategy based on the system turbidity during the stirring process, according to an embodiment of the present invention. Figure 4 The flowchart illustrates the steps of adjusting a preset feed rate or a first preset stirring rate based on the rate of change of turbidity over time, as described in this embodiment of the invention. Detailed Implementation

[0023] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0024] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0025] Please see Figure 1 As shown, Figure 1 This is a flowchart illustrating the steps of a method for preparing a reagent to remove organic sulfides from drilling flowback fluid, as described in an embodiment of the present invention.

[0026] This invention provides a method for preparing a reagent for removing organic sulfides from drilling flowback fluid, comprising the following steps: Step S1: Add HEDP-Na4 to deionized water at 50°C and stir. Based on the transmittance of the solution after stirring, determine the compensation for the temperature of the deionized water and the stirring time to obtain the first pre-dispersion. Step S2: HEHMT is added to the first predispersant at a preset feed rate, and then stirred at a first preset stirring speed. The turbidity of the system is monitored in real time during the stirring process, and a first execution parameter adjustment strategy is determined based on the system turbidity to obtain the second predispersant. The first execution parameter adjustment strategy includes adjusting the preset feeding speed and / or the first preset stirring speed; Step S3: Pre-dissolve zinc amino acids in 40°C warm water to obtain a 10% zinc amino acid concentrate. Step S4: Add concentrated amino acid zinc solution dropwise to the second pre-dispersion solution during low-speed stirring, and then stir at high speed after the addition is completed. Based on the deviation of pH value and Zeta potential value during high-speed stirring, determine whether to add HEDP-Na4 and / or concentrated amino acid zinc solution to obtain a composite solution. Step S5 involves conducting accelerated stability testing and sulfur capacity testing on the composite solution to determine if it meets the standards. Based on the results of non-compliance, it is determined whether to add PEG-400 or concentrated amino acid zinc solution to the composite solution to obtain a compliant composite solution. The accelerated stability test involves allowing the composite solution to stand at 50°C for 2 hours and observing whether it separates into layers or precipitates. The sulfur capacity test involves passing a quantitative composite solution into a standard H2S gas and calculating the sulfur capacity value per unit weight of the reagent. Step S6: Adjust the pH value of the qualified composite solution to the preset range, mature it at 50°C for 2 hours, and filter it after cooling to complete the preparation.

[0027] Please see Figure 2 As shown, Figure 2 This is a flowchart illustrating the steps of determining compensation for the temperature and stirring time of deionized water based on the transmittance of the solution after stirring, according to an embodiment of the present invention.

[0028] Specifically, in step S1, based on the transmittance of the solution after stirring, compensation is determined for the temperature of the deionized water and the stirring time, including the following steps: Step S11: Obtain the transmittance of the solution after stirring; Step S12: Compare and analyze the transmittance of the solution with the preset transmittance; Step S13: Based on the result that the transmittance of the solution is less than the preset transmittance, it is determined to compensate the temperature of the deionized water to 55°C and extend the stirring time by 5 to 10 minutes.

[0029] In this embodiment of the invention, the preset transmittance is 95%. When HEDP-Na4 is completely dissolved to form a true solution, the transmittance measured at a wavelength of 660 nm should be ≥95%. If it is lower than this value, it indicates that there are undissolved microcrystals or agglomerates in the system. These particles will become heterogeneous nucleation centers for HEHMT and zinc amino acids in subsequent steps, leading to a decrease in product stability.

[0030] Specifically, the preset feed rate is ≤5g / min, and the first preset stirring speed is 400rpm.

[0031] Understandably, the core of determining compensation for the temperature and stirring time of deionized water based on the transmittance of the solution after stirring is to establish a quantitative quality control standard for the HEDP-Na4 dissolution process.

[0032] Please see Figure 3 As shown, Figure 3 This is a flowchart illustrating the steps of determining a first execution parameter adjustment strategy based on the turbidity of the system during the stirring process, according to an embodiment of the present invention.

[0033] Specifically, in step S2, the process of determining the first execution parameter adjustment strategy based on the system turbidity during the stirring process includes: Step S21: Obtain the turbidity of the system and determine the turbidity increase ratio based on the system turbidity and the initial system turbidity; Step S22: Compare and analyze the turbidity increase ratio with the preset turbidity increase ratio; Step S23: Based on the result that the turbidity increase ratio is greater than or equal to the preset turbidity increase ratio, determine to immediately stop adding HEHMT, and determine to reduce the preset feed rate and increase the first preset stirring rate; Step S24: Based on the result that the turbidity increase ratio is less than the preset turbidity increase ratio, further adjust the preset feed rate or the first preset stirring speed according to the rate of change of turbidity over time.

[0034] In this embodiment of the invention, the preset turbidity increase ratio is 10%. When the turbidity increase ratio reaches 10%, it indicates that the HEHMT particles have begun to undergo significant Ostwald ripening, and the system is at risk of phase separation. Strong intervention measures must be taken immediately. The turbidity increase ratio is calculated using the following formula: Turbidity increase ratio = (current turbidity - initial turbidity) / initial turbidity × 100%.

[0035] Please see Figure 4 As shown, Figure 4 The flowchart illustrates the steps of adjusting a preset feed rate or a first preset stirring rate based on the rate of change of turbidity over time, as described in this embodiment of the invention.

[0036] Specifically, in step S24, the process of determining the adjustment of the preset feed rate or the first preset stirring rate based on the rate of change of turbidity over time includes: Step S231: Obtain the time curve of turbidity to obtain the instantaneous slope; Step S232: Compare and analyze the instantaneous slope with the preset instantaneous slope; Step S233: Based on the instantaneous slope being greater than the first preset instantaneous slope, determine to reduce the preset feed rate; Step S234: Based on the result that the instantaneous slope is less than the first preset instantaneous slope and the instantaneous slope is greater than the second preset instantaneous slope, it is determined to increase the first preset stirring speed.

[0037] In step S231 of this embodiment of the invention, the specific method for obtaining the time curve of turbidity and calculating the instantaneous slope is as follows: 1. Data Acquisition: During the stirring and feeding process in step S2, the turbidity of the system is monitored in real time using an online turbidimeter (such as the Hach 2100N laboratory turbidimeter or its equivalent). The turbidimeter probe is immersed below the surface of the reaction liquid, avoiding the center of the stirring vortex, to ensure the representativeness of the measurement. The data acquisition frequency is set to no less than 1 time / second, and the real-time turbidity value (unit: NTU) and the corresponding timestamp are transmitted to the process control system (such as a PLC or industrial computer).

[0038] 2. Construction of time curves: The process control system plots the received time-turbidity data in a coordinate system in real time, with the horizontal axis representing time (t, unit: minutes) and the vertical axis representing the real-time turbidity value (T, unit: NTU), thus forming a turbidity-time curve.

[0039] 3. Instantaneous slope calculation: To quantify the severity of turbidity changes, the instantaneous slope of the curve (k, unit: NTU / min) needs to be calculated. Specifically, the central difference method is used for real-time calculation, which effectively reduces errors caused by measurement noise.

[0040] The calculation formula is: ; in: k represents the current time. The estimated instantaneous slope; and These are the turbidity values ​​of the nth data point after and the nth data point before the current data point i, respectively; and It corresponds to a specific point in time; Window selection: The parameter n determines the size of the window for calculating the slope. To balance response speed and data smoothness, n=5 is preferred, which uses a total of 10 data points, corresponding to a data window of approximately 10 seconds. The system automatically calculates the instantaneous slope value when each new data point arrives, using this formula.

[0041] The first preset instantaneous slope is 5 NTU / min. When the instantaneous slope > 5 NTU / min, it indicates the existence of a significant local concentration gradient. This is usually due to excessively high HEHMT concentration near the injection point caused by an excessively fast feed rate, leading to rapid aggregation. In this case, reducing the feed rate is the most effective control method. The second preset instantaneous slope is 2 NTU / min. When the instantaneous slope is between 2 NTU / min and 5 NTU / min, it indicates that the overall shear force of the system is insufficient and cannot effectively disperse the added HEHMT particles. At this time, increasing the stirring speed can enhance the degree of turbulence and improve the dispersion effect.

[0042] Understandably, step S2 establishes a hierarchical intelligent control system based on real-time turbidity monitoring, which achieves precise control of the HEHMT dispersion process by monitoring two dimensions: turbidity increase ratio and change rate.

[0043] Specifically, in step S4, based on the deviation of pH and Zeta potential during high-speed stirring, the addition of HEDP-Na4 and / or amino acid zinc concentrate is determined, including the following steps: Step S41: Obtain the Zeta potential and pH value; Step S42: Compare and analyze the Zeta potential value with the preset Zeta potential value; Step S43: Compare and analyze the pH value with the preset pH value; Step S44: Based on the result that the absolute value of the Zeta potential is less than 30mV, determine to add 0.3% to 0.6% of HEDP-Na4 by weight of the total system.

[0044] Specifically, based on the results showing that the pH value exceeded the range of 7.5 to 8.5, it was determined that 1% to 3% of the total weight of the amino acid zinc concentrate should be added to the system.

[0045] Specifically, or, based on the results that the absolute value of the Zeta potential is less than 30 mV and the pH value is outside the range of 7.5 to 8.5, it is determined that 0.3% to 0.6% of HEDP-Na4 and 1% to 3% of amino acid zinc concentrate by weight of the total system should be added simultaneously.

[0046] It is understandable that the pH range of 7.5–8.5 is based on precise calculations of the acid-base dissociation constants (pKa) of each component. The tertiary amine group of HEHMT can only be effectively protonated at pH > 7.5 to exert its H2S capture function; Amino acid zinc can retain Zn at pH < 8.5. 2+ The appropriate hydrolysis state ensures the coordination ability with organic sulfides; HEDP-Na4 exhibits optimal chelating and dispersing efficiency in the pH range of 7.5–8.5; The basis for determining the supplementary dosage of 0.3%–0.6% and 1%–3% is as follows: 0.3%–0.6% HEDP-Na4 can effectively restore the Zeta potential without significantly altering the ionic strength of the system; A 1%–3% amino acid zinc concentrate can ensure sufficient replenishment of active sites while avoiding the risk of precipitation caused by excessive amounts.

[0047] It is understandable that the core of the preparation method of this invention lies in establishing a multi-parameter real-time feedback and intelligent compensation quality control system. By monitoring the dissolution quality of the initial raw materials through transmittance, heterogeneous nucleation centers are eliminated at the source; the dispersion process is controlled in real time through turbidity and its rate of change to prevent particle agglomeration and Ostwald ripening; the chemical and colloidal stability of the system is monitored through pH and Zeta potential to ensure the effective presence of the active components; finally, accelerated stability and sulfur capacity tests are used to verify and fine-tune the functionality of the final product. This closed-loop control system ensures the high efficiency, stability, and batch consistency of the final reagent.

[0048] Specifically, in step S5, the stability acceleration test involves standing the composite solution at 50°C for 2 hours and observing whether it separates into layers or precipitates. The sulfur capacity test involves passing a quantitative composite solution into a standard H2S gas and calculating the sulfur capacity value per unit weight of the reagent.

[0049] Specifically, in step S5, based on the result of the accelerated stability test failing to meet the standard, it is determined that 0.2% to 0.5% of PEG-400 will be added to the composite solution; Based on the results of the sulfur capacity test not meeting the standard, it was determined that 1% to 3% of amino acid zinc concentrate should be added to the composite solution.

[0050] Specifically, in step S6, the pH value of the compliant composite solution is adjusted to a preset range, which is to adjust the pH value to the range of 8.0 using citric acid or sodium hydroxide.

[0051] Specifically, the amino acid zinc is any one of zinc glycine, zinc glutamate, or zinc aspartate.

[0052] The technical solution of the present invention is further illustrated below through specific embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0053] Example 1: Standard Preparation Process This embodiment is prepared according to all the aforementioned preferred parameters, with the preparation of 1000g of product as the baseline.

[0054] Raw material ratio: HEHMT: 200g; Zinc glycine: 80g; HEDP-Na4: 60g; PEG-400: 5g; Deionized water: 655g.

[0055] Preparation process: Step S1: Add 60g of HEDP-Na4 to 655g of deionized water at 50℃ and stir at 300rpm for 5 minutes. The transmittance was measured to be 98% (using a wavelength of 660nm), which is higher than the preset standard of 95%, so no compensation is required, and the first pre-dispersion is obtained.

[0056] Step S2: Add 200g HEHMT to the first pre-dispersion at a feed rate of 5g / min while stirring at 400rpm. Monitor the turbidity change of the system in real time. Initial turbidity: 15 NTU; Maximum turbidity: 71 NTU; Turbidity increase ratio: (71-15) / 15×100%=373%>10%; Peak instantaneous slope: 28 NTU / min > 5 NTU / min; According to the control strategy, feeding was immediately stopped, the feed rate was set to 3 g / min, and the stirring speed was increased to 500 rpm. The remaining material was then added to obtain the second pre-dispersion.

[0057] Step S3: Dissolve 80g of zinc glycine in 80g of warm water at 40℃ to prepare a 10% zinc amino acid concentrate.

[0058] Step S4: While stirring at a low speed of 150 rpm, slowly add the concentrated amino acid zinc solution dropwise to the second pre-dispersion solution over a period of about 15 minutes. After the addition is complete, switch to high speed stirring at 500 rpm for 40 minutes.

[0059] Monitoring parameters: pH=8.1, Zeta potential=-35mV. Both parameters are within the preset range and no addition is required to obtain a composite solution.

[0060] Step S5: Perform quality verification on the composite solution: Accelerated stability test: Take 100mL of sample and let it stand in a 50℃ water bath for 2 hours. If there is no layering or precipitation, it meets the standard.

[0061] Sulfur capacity test: A quantitative composite solution was introduced into standard H2S gas (concentration 1000ppm), and the sulfur capacity value was measured to be 320g / kg, which is higher than the standard of 300g / kg, thus obtaining a qualified composite solution.

[0062] Step S6: Finely adjust the pH of the qualified composite solution to 8.0 using a dilute citric acid solution. Place it in a 50°C constant temperature water bath for 2 hours to mature, cool to room temperature (25°C), and filter through a 0.45μm microporous membrane to obtain approximately 990g of the final product.

[0063] Performance testing: The prepared reagent was added to simulated drilling flowback fluid (containing 100 mg / L H2S, 50 mg / L methanethiol, and 30 mg / L dimethyl sulfide) at a dosage of 1 g / L. After reacting at 25°C for 15 minutes, the removal rate was measured. H2S removal rate: 99.5%; Methanethiol removal rate: 96%; Dimethyl sulfide removal rate: 92%.

[0064] Example 2: Distributed stability compensation condition This embodiment demonstrates the compensation process when the Zeta potential is abnormal.

[0065] The preparation process is the same as in Example 1, but during the high-speed stirring in step S4, the following was observed: Zeta potential = -25mV (absolute value <30mV); pH=8.0 (normal).

[0066] According to the control strategy, 0.5% HEDP-Na4 (5g) was added, and the mixture was stirred for another 20 minutes before retesting. The zeta potential recovered to -33mV, reaching the stability standard.

[0067] Example 3: Activity Compensation Condition This embodiment demonstrates the compensation process when sulfur capacity is insufficient.

[0068] The preparation process is the same as in Example 1, but the initial sulfur capacity value in step S5 is 280 g / kg, which is less than the standard of 300 g / kg.

[0069] According to the control strategy, after adding 2% amino acid zinc concentrate (20g), extending the high-speed stirring for 10 minutes, and retesting, the sulfur capacity value increased to 315g / kg.

[0070] Comparative example: Traditional simple mixing method To highlight the technical advantages of this invention, a comparative example was set up. This comparative example did not employ the stepwise feeding, real-time monitoring, and intelligent compensation strategy of this invention. Instead, all the raw materials from Example 1 (200g HEHMT, 80g zinc glycine, 60g HEDP-Na4, 5g PEG-400, 655g deionized water) were added to the reactor at once, stirred at 400 rpm for 1 hour, and then the pH was adjusted to 8.0 with citric acid before being discharged to obtain the control reagent.

[0071] Comparison results: The comparative reagent was tested under the exact same conditions as in Example 1 (dosage of 1 g / L, the same simulated drilling flowback fluid, and reaction at 25°C for 15 minutes). The results are shown in the table below: Table 1 Performance Data Comparison Table

[0072] In addition, the overall performance of the products is compared as follows: Storage stability: The reagent prepared by this invention showed no stratification or precipitation after being sealed and stored at room temperature for one month, and the system was homogeneous and stable; while the comparative reagent showed obvious precipitation at the bottom of the bottle after being stored under the same conditions for one month, and needed to be stirred and dispersed again before it could be used, indicating poor stability. Product uniformity: The sulfur capacity of the reagent produced in three consecutive batches of this invention fluctuated within a range of less than ±3%, demonstrating excellent batch stability; while the sulfur capacity of the three batches produced by the comparative method fluctuated within a range of more than ±15%, resulting in large performance fluctuations and difficulties in quality control.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a treatment agent for removing organic sulfides in a drilling fluid, characterized by, The method comprises the following steps: Step S1, adding HEDP-Na4 into deionized water at 50℃ and stirring, determining the compensation of the temperature and stirring time of the deionized water based on the light transmittance of the solution after stirring is completed, so as to obtain a first pre-dispersion liquid; Step S2, adding HEHMT into the first pre-dispersion liquid at a preset feeding speed and stirring at a first preset stirring speed, monitoring the system turbidity in the stirring process in real time, and determining a first execution parameter adjustment strategy based on the system turbidity, so as to obtain a second pre-dispersion liquid, Wherein, the first execution parameter adjustment strategy comprises adjusting the preset feeding speed and / or the first preset stirring speed; Step S3, pre-dissolving zinc amino acid in warm water at 40℃ to obtain a 10% zinc amino acid concentrate; Step S4, adding the zinc amino acid concentrate into the second pre-dispersion liquid in a low-speed stirring process, and high-speed stirring after the addition is completed, determining the additional HEDP-Na4 and / or the zinc amino acid concentrate based on the deviation of the pH value and the Zeta potential value in the high-speed stirring process, so as to obtain a composite solution; Step S5, performing stability accelerated test and sulfur capacity test on the composite solution to determine whether the composite solution meets the standard, and determining to compensate the composite solution with PEG-400 or the zinc amino acid concentrate based on the result of not meeting the standard, so as to obtain a standard composite solution, wherein, The stability accelerated test is to observe whether the composite solution is stratified or precipitated after being placed at 50℃ for 2 hours, and the sulfur capacity test is to calculate the sulfur capacity value of the unit weight of the medicament by introducing a certain amount of composite solution into standard H2S gas; Step S6, adjusting the pH value of the standard composite solution to a preset interval, aging at 50℃ for 2 hours, and filtering after cooling, so as to complete the preparation.

2. The method of claim 1, wherein the method is characterized by: In the step S1, the compensation of the temperature and stirring time of the deionized water based on the light transmittance of the solution after stirring is completed comprises the following steps: Step S11, obtaining the light transmittance of the solution after stirring is completed; Step S12, comparing and analyzing the light transmittance of the solution with a preset light transmittance; Step S13, based on the result that the light transmittance of the solution is less than the preset light transmittance, determining to compensate the temperature of the deionized water to 55℃ and extend the stirring time by 5-10 minutes.

3. The method of claim 2, wherein the method further comprises the step of: The preset feeding speed is ≤5g / min, and the first preset stirring speed is 400rpm.

4. The method of claim 3, wherein the method further comprises the step of: In the step S2, the process of determining the first execution parameter adjustment strategy based on the system turbidity in the stirring process comprises: Step S21, obtaining the system turbidity, and determining a turbidity increase ratio according to the system turbidity and the initial system turbidity; Step S22, comparing and analyzing the turbidity increase ratio with a preset turbidity increase ratio; Step S23, based on the result that the turbidity increase ratio is greater than or equal to the preset turbidity increase ratio, determining to immediately stop adding HEHMT, and determining to reduce the preset feeding speed and increase the first preset stirring speed; Step S24, based on the result that the turbidity increment ratio is less than the preset turbidity increment ratio, further adjusting the preset feeding speed or the first preset stirring speed according to the change rate of turbidity over time.

5. The method of claim 4, wherein the method further comprises the step of: In the step S24, the process of adjusting the preset feeding speed or the first preset stirring speed according to the change rate of turbidity over time includes: ​ Step S231, obtaining the time curve of the turbidity to obtain the instantaneous slope; Step S232, comparing and analyzing the instantaneous slope with the preset instantaneous slope; Step S233, based on the result that the instantaneous slope is greater than the first preset instantaneous slope, determining to reduce the preset feeding speed; Step S234, based on the result that the instantaneous slope is less than the first preset instantaneous slope and the instantaneous slope is greater than the second preset instantaneous slope, determining to increase the first preset stirring speed.

6. The method of claim 5, wherein the method further comprises the step of: In the step S4, the determination of supplementing the HEDP-Na4 and / or the amino acid zinc concentrate based on the deviation of the pH value and the Zeta potential value in the high-speed stirring process includes the following steps: Step S41, obtaining the Zeta potential value and the pH value; Step S42, comparing and analyzing the Zeta potential value with the preset Zeta potential value; Step S43, comparing and analyzing the pH value with the preset pH value; Step S44, based on the result that the absolute value of the Zeta potential value is less than 30mV, determining to supplement 0.3%-0.6% of HEDP-Na4 based on the total weight of the system; Step S45, based on the result that the pH value is out of the range of 7.5-8.5, determining to supplement 1%-3% of the amino acid zinc concentrate based on the total weight of the system; Step S46, or, based on the result that the absolute value of the Zeta potential value is less than 30mV and the pH value is out of the range of 7.5-8.5, determining to supplement 0.3%-0.6% of HEDP-Na4 and 1%-3% of the amino acid zinc concentrate based on the total weight of the system.

7. The method of claim 6, wherein the method further comprises the step of: In the step S5, the stability acceleration test is to place the composite solution at 50℃ for 2 hours to observe whether it is layered or precipitated; ​ The sulfur capacity test is to pass a certain amount of composite solution into standard H2S gas to calculate the sulfur capacity value per unit weight of the medicament.

8. The method of claim 7, wherein the method further comprises the step of: In the step S5, based on the result that the stability acceleration test is not up to standard, determining to supplement 0.2%-0.5% of PEG-400 to the composite solution; ​ Based on the result that the sulfur capacity test is not up to standard, determining to supplement 1%-3% of the amino acid zinc concentrate to the composite solution.

9. The method of claim 8, wherein the method further comprises the step of: In the step S6, the adjustment of the pH value of the qualified composite solution to the preset interval is to adjust the pH value to the range of 8.0 using citric acid or sodium hydroxide. ​ 10. The method of claim 9, wherein the method further comprises the step of: The amino acid zinc is any one of zinc glycinate, zinc glutamate or zinc aspartate. ​

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