Method for detecting total chlorine content in oilfield chemical agent

Abstract

The invention provides a method for detecting the total chlorine content in an oilfield chemical agent, which comprises the following steps of: (1) respectively preparing chlorine reference substance standard solutions with different solubilities, detecting by adopting an X-ray fluorescence spectrophotometer to obtain standard curves of chlorine reference substances with different solubilities, and fitting to obtain a standard curve equation; and (2) preparing a sample solution to be detected according to the solubility of the oilfield chemical agent sample solution, detecting by adopting the X-ray fluorescence spectrophotometer, and calculating according to the standard curve equation obtained in the step (1) to obtain the content of the chlorine element in the oilfield chemical agent. By constructing different solvent detection modes and adopting a portable X-ray fluorescence spectrometer to determine the total chlorine content in the oilfield chemical agent, the method has the advantages of simplicity and convenience in detection operation, short detection time, no damage to the component structure of a sample, high analysis speed, high sensitivity and the like, and the detected sample is not influenced by the color of a system; the method is suitable for on-site rapid screening of the chlorine content in the oilfield chemical agent.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil field chemical quality control, and relates to a non-destructive rapid screening method for chlorine content in oil field chemicals, in particular to a detection method for total chlorine content in oil field chemicals. BACKGROUND

[0002] Oil field chemicals are a kind of fine chemical products gradually formed and perfected with the development of the oil industry, and are widely used in various links of oil field exploration and development production such as drilling, well cementing, fracturing acidizing, oil production and oil well produced liquid treatment. Most of the oil field chemicals are chemical mixtures with complex components and difficult to identify hazards.

[0003] In the production process of oil field chemicals, organic chlorine-containing raw materials or solvents are inevitably used, and the use of oil field chemicals increases the risk of increasing the organic chlorine content in crude oil, thereby causing adverse effects on crude oil refining and processing. Therefore, the organic chlorine content in oil field chemicals must be strictly controlled within a certain range.

[0004] At present, the detection method for organic chlorine in oil field chemicals is to first burn the sample in an oxygen combustion bottle to convert organic chlorine into inorganic chlorine, then determine the total chlorine content by titration, and then subtract the inorganic chlorine content directly measured. In this process, the determination of total chlorine content is the key to detection, and if the total chlorine content does not exceed the standard, the oil field chemicals are judged to be qualified. However, the existing total chlorine content detection technology needs to process and convert the organic chlorine components in the sample, which destroys the structure of the sample, the processing method is complicated, the equipment is strongly dependent, which is not conducive to on-site rapid detection. In addition, pure oxygen is needed in the experimental process, which can easily cause fire and explosion, and poses a potential threat to safety production. Moreover, the titration detection method has a sudden end point, which is difficult to judge and has a large error.

[0005] In summary, it is an urgent problem for those skilled in the art to establish a detection method with good repeatability, simplicity, safety and applicability to on-site rapid screening. SUMMARY

[0006] The purpose of the present application is to provide a detection method for total chlorine content in oil field chemicals, which constructs different solvent detection modes and uses a portable X-ray fluorescence spectrometer to determine the total chlorine content in oil field chemicals. The method has the advantages of simple detection operation, no destruction of sample component structure, fast analysis speed, high sensitivity and the like, and is suitable for on-site rapid screening of chlorine content in oil field chemicals.

[0007] To achieve the purpose of the present application, the following technical solutions are adopted:

[0008] The application provides a detection method of total chlorine content in oil field chemicals, and the detection method comprises the following steps:

[0009] (1) Prepare chlorine reference standard solutions with different solubilities respectively, detect by using an X-ray fluorescence spectrometer, obtain standard curves of chlorine references with different solubilities, and fit to obtain standard curve equations;

[0010] (2) Prepare sample solutions to be detected according to the solubility of the oil field chemical sample solutions, detect by using an X-ray fluorescence spectrometer, and calculate according to the standard curve equations obtained in step (1) to obtain the chlorine content in the oil field chemicals.

[0011] In the application, the standard curve is a standard curve of fluorescence intensity-chlorine concentration.

[0012] In the application, the solubility of the sample to be detected is determined according to the main components and product use of the oil field chemicals.

[0013] The detection method provided by the application is based on the solubility of the oil field chemicals, chlorine reference standard solutions with different solubilities are prepared, and detection is performed by using a portable X-ray fluorescence spectrometer (XRF), standard curve equations with different solubilities are constructed, then sample to be detected is prepared according to the solubility of the oil field chemicals, and detection is performed by using a portable XRF analyzer, so that the chlorine content in the oil field chemicals is quantitatively analyzed quickly and non-destructively without burning the sample to be detected. The detection method has the advantages of wide detection range, simple detection operation, no destruction of sample component structure, fast analysis speed, high sensitivity, no influence of sample detection on system color, short detection time, accurate data, and suitability for on-site rapid screening of the chlorine content in the oil field chemicals.

[0014] The following is a preferred technical scheme of the application, but is not a limitation on the technical scheme provided by the application. Through the following preferred technical scheme, the technical purpose and beneficial effects of the application can be better achieved and realized.

[0015] As a preferred technical scheme of the application, the chlorine reference standard solution in step (1) comprises a water-soluble chlorine reference standard solution or an oil-soluble chlorine reference standard solution.

[0016] In the application, according to the solubility of the oil field chemicals, water-soluble or oil-soluble chlorine reference standard solutions are prepared respectively.

[0017] Preferably, the mass concentration of the chlorine reference standard solution in step (1) is 20-2000 μg / mL, for example, it can be 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL, 500 μg / mL, 700 μg / mL, 1000 μg / mL, 1200 μg / mL, 1500 μg / mL or 1800 μg / mL, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0018] In the present application, the chlorine reference standard solution in step (1) is a chlorine reference standard solution with different concentration gradients.

[0019] As a preferred technical solution of the present application, the water-soluble chlorine reference standard solution comprises a water-soluble chlorine reference and a first solvent.

[0020] Preferably, the water-soluble chlorine reference comprises an inorganic chlorine salt.

[0021] Preferably, the inorganic chlorine salt comprises any one or a combination of at least two of sodium chloride, potassium chloride or lithium chloride, wherein the combination typically but not limitedly includes: a combination of sodium chloride and potassium chloride, a combination of sodium chloride and lithium chloride, sodium chloride, potassium chloride and lithium chloride, etc.

[0022] Preferably, the first solvent comprises water.

[0023] As a preferred technical solution of the present application, the oil-soluble chlorine reference standard solution comprises an oil-soluble chlorine reference and a second solvent.

[0024] Preferably, the oil-soluble chlorine reference comprises an organic chloride.

[0025] Preferably, the organic chloride comprises any one or a combination of at least two of carbon tetrachloride, chloroform, dichloromethane, monochlorotoluene or dichlorotoluene, wherein the combination typically but not limitedly includes: a combination of carbon tetrachloride and chloroform, a combination of chloroform and dichloromethane, monochlorotoluene and dichlorotoluene, etc.

[0026] Preferably, the second solvent comprises a non-chlorine-substituted solvent.

[0027] Preferably, the non-chlorine-substituted solvent comprises any one or a combination of at least two of light petroleum, a non-chlorine-substituted alkane or a non-chlorine-substituted aromatic hydrocarbon, wherein the combination typically but not limitedly includes: a combination of light petroleum and a non-chlorine-substituted alkane, a combination of light petroleum and a non-chlorine-substituted aromatic hydrocarbon, light petroleum, a non-chlorine-substituted alkane and a non-chlorine-substituted aromatic hydrocarbon, etc.

[0028] Preferably, the light petroleum comprises kerosene and / or diesel.

[0029] As a preferred technical scheme of the present application, the X-ray fluorescence spectrometer in step (1) and step (2) comprises a portable XRF analyzer (portable benchtop energy dispersive X-ray fluorescence spectrometer).

[0030] It is worth noting that the portable XRF analyzer is selected to detect the chlorine content in the oil field chemical agent, without destroying the composition of the product to be measured, and is not affected by the color of the sample system to be detected, is not limited by time and place, and can realize in-situ detection on site.

[0031] In the present application, the portable XRF analyzer used can directly read out the chlorine content in the sample, without converting the relationship between the fluorescence intensity and the chlorine content.

[0032] As a preferred technical scheme of the present application, the detection conditions of the X-ray fluorescence spectrometer in step (1) and step (2) are as follows:

[0033] The voltage is 38-42kV, the current is 90-110μA, and the detection time is 28-32s.

[0034] In the present application, the detection voltage of the X-ray fluorescence spectrometer is 38-42kV, for example, it can be 38.5kV, 39kV, 39.5kV, 40kV, 40.5kV, 41kV or 41.5kV, etc., but not limited to the listed values, other values not listed in the value range are also applicable, and the preferred value is 40kV.

[0035] In the present application, the detection current of the X-ray fluorescence spectrometer is 90-110μA, for example, it can be 92μA, 95μA, 97μA, 100μA, 102μA, 105μA or 107μA, etc., but not limited to the listed values, other values not listed in the value range are also applicable, and the preferred value is 100μA.

[0036] In the present application, the detection time of the X-ray fluorescence spectrometer is 28-32s, for example, it can be 28.5s, 29s, 29.5s, 30s, 30.5s, 31s or 31.5s, etc., but not limited to the listed values, other values not listed in the value range are also applicable, and the preferred value is 30s.

[0037] It is worth noting that in the detection of step (1), the minimum detection limit of the chlorine content of the portable XRF analyzer is 20μg / mL.

[0038] As a preferred technical scheme of the present application, the preparation method of the sample solution to be measured in step (2) comprises:

[0039] Mixing the oil field chemical sample and sample solvent to obtain an oil field chemical sample solution with a volume fraction of 1-20%; wherein, according to the solubility of the oil field chemical sample, the sample solvent is a first solvent or a second solvent.

[0040] In the present application, the volume fraction of the oil field chemical sample solution is 1-20%, for example, it can be 2%, 4%, 5%, 7%, 10%, 12%, 15%, 17% or 19%, etc., but not limited to the listed values, other values not listed in the value range are also applicable.

[0041] In the present application, the dilution factor of the oil field chemical needs to be controlled within a certain range, if the volume fraction of the oil field chemical sample solution is too low or too high, it will affect the detection result, resulting in inaccurate detection result.

[0042] As a preferred technical solution of the present application, the calculation formula of the chlorine element content in step (2) is shown as formula (I):

[0043]

[0044] In formula (I), ω is the chlorine content in the oil field chemical sample solution (μg / mL);

[0045] C is the chlorine content calculated according to the standard curve equation (μg / mL);

[0046] Φ is the volume fraction of the oil field chemical sample solution (%).

[0047] As a preferred technical solution of the present application, after calculating the chlorine element content in the oil field chemical in step (2), it further includes:

[0048] Analyzing the chlorine element content, if the chlorine element content is ≤2000 μg / mL, the organic chlorine content in the oil field chemical is qualified; if the chlorine element content is >2000 μg / mL, the inorganic chlorine and organic chlorine contents in the oil field chemical need to be detected and calculated.

[0049] In the present application, if the chlorine element content is >2000 μg / mL, the organic chlorine content in the oil field chemical may exceed the standard, and the SY / T 7329-2016 standard method needs to be used to determine the organic chlorine content in the oil field chemical.

[0050] As a preferred technical solution of the present application, the detection method includes the following steps:

[0051] (1) Respectively preparing chlorine reference standard solutions with different solubilities and mass concentrations of 20-2000 μg / mL, using X-ray fluorescence spectrometer for detection, obtaining standard curves of chlorine reference standards with different solubilities, and fitting to obtain a standard curve equation;

[0052] The chlorine reference standard solution comprises a water-soluble chlorine reference standard solution or an oil-soluble chlorine reference standard solution; the water-soluble chlorine reference standard solution comprises a water-soluble chlorine reference and a first solvent; the water-soluble chlorine reference comprises an inorganic chlorine salt; the first solvent comprises water; the oil-soluble chlorine reference standard solution comprises an oil-soluble chlorine reference and a second solvent; the oil-soluble chlorine reference comprises an organic chlorine compound; and the second solvent comprises a non-chlorine-substituted solvent.

[0053] (2) mixing the oil field chemical agent sample and a sample solvent to obtain an oil field chemical agent sample solution with a volume fraction of 1-20%, detecting by an X-ray fluorescence spectrometer, and calculating according to the standard curve equation obtained in step (1) to obtain the chlorine element content in the oil field chemical agent;

[0054] According to the solubility of the oil field chemical agent sample, the sample solvent is a first solvent or a second solvent.

[0055] The X-ray fluorescence spectrometer in steps (1) and (2) comprises a portable XRF analyzer; and the detection conditions of the X-ray fluorescence spectrometer in steps (1) and (2) are as follows: voltage is 38-42 kV, current is 90-110 mu A, and detection time is 28-32 s.

[0056] (3) analyzing the chlorine element content obtained in step (2), if the chlorine element content is less than or equal to 2000 mu g / mL, the organic chlorine content in the oil field chemical agent is qualified; and if the chlorine element content is greater than 2000 mu g / mL, the inorganic chlorine and organic chlorine contents in the oil field chemical agent need to be detected and calculated.

[0057] Compared with the prior art, the present application has the following beneficial effects:

[0058] The present application provides a detection method for the total chlorine content in an oil field chemical agent, based on the solubility of the oil field chemical agent, different solubility standard curve equations are constructed, then the sample to be detected is prepared according to the solubility of the oil field chemical agent, and a portable XRF analyzer is used for detection, realizing the rapid and non-destructive quantitative analysis of the chlorine content in the oil field chemical agent; the detection method has the advantages of wide detection range, simple operation, no destruction of sample component structure, fast analysis speed, high sensitivity, on-site detection, etc., the detection sample is not affected by the color of the system, the detection time is short, the data is accurate, and it is suitable for on-site rapid screening of the chlorine content in the oil field chemical agent. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 The standard curve and the equation obtained by fitting thereof for Example 1 are provided.

[0060] Figure 2 The standard curve and the equation obtained by fitting thereof for Example 2 are provided. DETAILED DESCRIPTION

[0061] The technical solutions of the present application are further illustrated below by means of specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0062] The present application provides a method for detecting the total chlorine content in oil field chemicals, which comprises the following steps:

[0063] (1) Prepare chlorine reference standard solutions with different solubilities and mass concentrations of 20-2000 μg / mL, respectively, and detect them by using an X-ray fluorescence spectrometer to obtain standard curves of chlorine references with different solubilities, and fit to obtain a standard curve equation;

[0064] The chlorine reference standard solution comprises a water-soluble chlorine reference standard solution or an oil-soluble chlorine reference standard solution; the water-soluble chlorine reference standard solution comprises a water-soluble chlorine reference and a first solvent; the water-soluble chlorine reference comprises an inorganic chlorine salt; the first solvent comprises water; the oil-soluble chlorine reference standard solution comprises an oil-soluble chlorine reference and a second solvent; the oil-soluble chlorine reference comprises an organic chloride; and the second solvent comprises a non-chlorine-substituted solvent.

[0065] (2) Mix the oil field chemical sample and a sample solvent to obtain an oil field chemical sample solution with a volume fraction of 1%-20%, detect it by using an X-ray fluorescence spectrometer, and calculate it according to the standard curve equation obtained in step (1) to obtain the chlorine content in the oil field chemical;

[0066] According to the solubility of the oil field chemical sample, the sample solvent is the first solvent or the second solvent.

[0067] The X-ray fluorescence spectrometer in steps (1) and (2) both comprises a portable XRF analyzer; and the detection conditions of the X-ray fluorescence spectrometer in steps (1) and (2) are as follows: voltage: 38-42 kV; current: 90-110 μA; and detection time: 28-32 s.

[0068] The calculation formula of the chlorine content is shown in formula (I):

[0069]

[0070] In formula (I), ω is the chlorine content in the oil field chemical sample solution (μg / mL);

[0071] C is the chlorine content calculated according to the standard curve equation (μg / mL);

[0072] Volume fraction (%) of Φ-oil field chemical sample solution

[0073] (3) The chlorine element content obtained in step (2) is analyzed, if the chlorine element content is ≤2000 μg / mL, the organic chlorine content in the oil field chemical is qualified; if the chlorine element content is >2000 μg / mL, the inorganic chlorine and organic chlorine contents in the oil field chemical need to be calculated after detection.

[0074] The carbon tetrachloride, anhydrous sodium chloride and kerosene used in the following examples and comparative examples are chemical pure reagents, which are purchased from China Pharmaceutical.

[0075] Methodology verification

[0076] The water-soluble oil field chemical negative sample and the oil-soluble oil field chemical negative sample are independently used to perform the standard addition recovery rate and precision determination. Different masses of sodium chloride are added to the negative sample with water as the solvent or different masses of carbon tetrachloride are added to the negative sample with kerosene as the solvent, and a portable benchtop energy dispersive X-ray fluorescence spectrometer is used for detection, and the detection conditions are: voltage is 40 kV, current is 100 μA, and detection time is 30 s; each group of samples is determined in parallel for 3 times to take the average value, and the recovery rate and precision results are shown in Table 1 (water-soluble) and Table 2 (oil-soluble).

[0077] Table 1

[0078] sample Actual value (μg / mL) Detection value (μg / mL) Recovery rate (%) Relative deviation (n=3, %) 1 50 47 97.3 6.0％ 2 100 110 94.6 10％ 3 300 326 96.2 8.6％ 4 500 537 94.5 7.4％

[0079] From Table 1, it can be seen that the relative deviation of the content of chlorine element in the sample to be tested is within 10%, which indicates that the detection method provided by the present application has good precision and accuracy.

[0080] Table 2

[0081] sample Actual value (μg / mL) Detection value (μg / mL) Recovery rate (%) Relative deviation (n=3, %) 1 20 21 95.6 5％ 2 40 39 96.2 2.5％ 3 200 210 96.4 5％ 4 400 422 94.7 5.5％ 5 600 636 95.1 6％

[0082] From Table 2, it can be seen that the relative deviation of the content of chlorine element in the sample to be tested is within 6%, which indicates that the detection method provided by the present application has good precision and accuracy.

[0083] Example 1

[0084] The present embodiment provides a detection method for the total chlorine content in an oil field chemical, which comprises the following steps:

[0085] (1) Prepare water-soluble chlorine reference standard solutions with mass concentration gradients of 250 μg / mL, 500 μg / mL, 750 μg / mL and 1000 μg / mL, and detect them by using a portable benchtop energy dispersive X-ray fluorescence spectrometer to obtain a standard curve of the water-soluble chlorine reference, and fit the standard curve equation to be y = 1.0008x-0.2743, R 2 = 0.994;

[0086] The water-soluble chlorine reference standard solution is anhydrous sodium chloride and ultrapure water;

[0087] (2) According to the solubility characteristics of the sample to be measured, mix the oilfield chemical agent sample to be measured and ultrapure water to obtain a sample solution of the oilfield chemical agent to be measured with a volume fraction of 10%, and detect it by using a portable benchtop energy dispersive X-ray fluorescence spectrometer, and calculate it according to the standard curve equation obtained in step (1) to obtain the chlorine content in the oilfield chemical agent;

[0088] The detection conditions of the portable benchtop energy dispersive X-ray fluorescence spectrometer in steps (1) and (2) are as follows: voltage 40 kV, current 100 μA, and detection time 30 s;

[0089] The calculation formula of the chlorine content is shown as formula (I):

[0090]

[0091] In formula (I), ω is the chlorine content in the oilfield chemical agent sample solution (μg / mL);

[0092] C is the chlorine content calculated according to the standard curve equation (μg / mL);

[0093] Φ is the volume fraction of the oilfield chemical agent sample solution (%).

[0094] Example 2

[0095] The present embodiment provides a method for detecting the total chlorine content in an oilfield chemical agent, which comprises the following steps:

[0096] (1) Prepare oil-soluble chlorine reference standard solutions with mass concentration gradients of 250 μg / mL, 500 μg / mL, 750 μg / mL and 1000 μg / mL, and detect them by using a portable benchtop energy dispersive X-ray fluorescence spectrometer to obtain a standard curve of the oil-soluble chlorine reference, and fit the standard curve equation to be y = 1.0066x-3.8747, R 2 = 0.9941;

[0097] The oil-soluble chlorine reference standard solution is carbon tetrachloride and kerosene;

[0098] (2) according to the solubility characteristics of the sample to be tested, the sample of the oil field chemical agent to be tested and kerosene are mixed to obtain a sample solution of the oil field chemical agent to be tested with a volume fraction of 10%, a portable benchtop energy dispersive X-ray fluorescence spectrometer is used for detection, and the content of chlorine in the oil field chemical agent is calculated according to the standard curve equation obtained in step (1);

[0099] The detection conditions of the portable benchtop energy dispersive X-ray fluorescence spectrometer in steps (1) and (2) are as follows: voltage is 40 kV, current is 95 μA, and detection time is 30 s;

[0100] The calculation formula of the content of chlorine is shown as formula (I):

[0101]

[0102] In formula (I), ω is the content of chlorine in the sample solution of the oil field chemical agent (μg / mL);

[0103] C is the content of chlorine calculated according to the standard curve equation (μg / mL);

[0104] Φ is the volume fraction of the sample solution of the oil field chemical agent (%).

[0105] Example 3

[0106] The example provides a method for detecting the total chlorine content in an oil field chemical agent. Except that the sample of the oil field chemical agent to be tested is replaced, and the volume fraction of the sample solution of the oil field chemical agent to be tested in step (2) is 5%, other conditions are the same as those in example 1.

[0107] Example 4

[0108] The example provides a method for detecting the total chlorine content in an oil field chemical agent. Except that the sample of the oil field chemical agent to be tested is replaced, and the “kerosene” in steps (1) and (2) is replaced with “toluene”, other conditions are the same as those in example 2.

[0109] Comparative Example 1

[0110] The comparative example uses the method provided in the standard method SY / T 7329-2016 to detect the content of organic chlorine in the oil field chemical agent.

[0111] Although the above method can accurately detect the content of organic chlorine in the oil field chemical agent, it destroys the structural components of the sample, the treatment method is complicated, it takes more than 3 hours to detect one sample to be tested, and it cannot be detected on site, so it cannot provide data in time for on-site researchers to analyze.

[0112] The results of the content of chlorine in the samples to be tested in examples 1-4 are shown in Table 3.

[0113] Table 3

[0114]

[0115] From Table 3, it can be seen that:

[0116] (1) The relative error of the detection method provided by the present application and the detection result of the classical SY / T 7329-2016 standard method is within 10%, which indicates that the detection method provided by the present application has good accuracy. In addition, compared with the classical method, the detection method provided by the present application is simple to operate, short in detection time, does not destroy the sample component structure, fast in analysis speed, and can realize in-situ detection on site.

[0117] (2) The chlorine content in the oil field chemical agent samples of examples 1-2 is 560 μg / mL and 720 μg / mL respectively, which is lower than the organic chlorine content index 2000 μg / mL in the oil field chemical agent, indicating that the organic chlorine content of the oil field chemical agent is qualified. The chlorine content in the oil field chemical agent samples of examples 3-4 is 2480 μg / mL and 3010 μg / mL respectively, which exceeds the organic chlorine content index 2000 μg / mL in the oil field chemical agent, indicating that the organic chlorine content of the oil field chemical agent may exceed the standard, and further detection and calculation of the inorganic chlorine and organic chlorine content in the sample are required.

[0118] The applicant declares that the present application is illustrated by the above examples to explain the detailed structural features of the present application, but the present application is not limited to the above detailed structural features, that is, it does not mean that the present application must rely on the above detailed structural features to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of the components selected by the present application, increase of auxiliary components, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for detecting the total chlorine content in an oil field chemical agent, characterized by, The detection method comprises the following steps: (1) Prepare different solubility chlorine reference standard solutions respectively, detect by using an X-ray fluorescence spectrometer, obtain standard curves of chlorine references with different solubilities, and fit to obtain standard curve equations; (2) Prepare a sample solution to be detected according to the solubility of the oil field chemical agent sample solution, detect by using an X-ray fluorescence spectrometer, and calculate according to the standard curve equation obtained in step (1) to obtain the chlorine content in the oil field chemical agent.

2. The detection method according to claim 1, characterized in that, The chlorine reference standard solution in step (1) comprises a water-soluble chlorine reference standard solution or an oil-soluble chlorine reference standard solution; Preferably, the mass concentration of the chlorine reference standard solution in step (1) is 20-2000 μg / mL.

3. The detection method according to claim 2, characterized in that, The water-soluble chlorine reference standard solution comprises a water-soluble chlorine reference and a first solvent; Preferably, the water-soluble chlorine reference comprises an inorganic chlorine salt; Preferably, the inorganic chlorine salt comprises any one or a combination of at least two of sodium chloride, potassium chloride or lithium chloride; Preferably, the first solvent comprises water.

4. The detection method according to claim 2, characterized in that, The oil-soluble chlorine reference standard solution comprises an oil-soluble chlorine reference and a second solvent; Preferably, the oil-soluble chlorine reference comprises an organic chloride; Preferably, the organic chloride comprises any one or a combination of at least two of carbon tetrachloride, chloroform, dichloromethane, monochlorotoluene or dichlorotoluene; Preferably, the second solvent comprises a non-chlorine-substituted solvent; Preferably, the non-chlorine-substituted solvent comprises any one or a combination of at least two of light petroleum, a non-chlorine-substituted alkane or a non-chlorine-substituted aromatic hydrocarbon; Preferably, the light petroleum comprises kerosene and / or diesel.

5. The assay of any one of claims 1-4, wherein, The X-ray fluorescence spectrometer in steps (1) and (2) both comprises a portable XRF analyzer.

6. The assay of any one of claims 1-5, wherein, The detection conditions of the X-ray fluorescence spectrometer in steps (1) and (2) are as follows: The voltage is 38-42 kV, the current is 90-110 μA, and the detection time is 28-32 s.

7. The assay of any one of claims 1-6, wherein, The preparation method of the sample solution to be detected in step (2) comprises: Mix the oil field chemical agent sample and a sample solvent to obtain an oil field chemical agent sample solution with a volume fraction of 1%-20%; wherein, according to the solubility of the oil field chemical agent sample, the sample solvent is the first solvent or the second solvent.

8. The assay of any one of claims 1-7, wherein, The calculation formula of the chlorine content in step (2) is shown as formula (I): In formula (I), ω is the chlorine content in the oil field chemical agent sample solution (μg / mL); C is the chlorine content calculated according to the standard curve equation (μg / mL); and Φ is the volume fraction of the oil field chemical agent sample solution (%). After calculating the chlorine content in the oil field chemical agent in step (2), the following step is further included: Analyze the chlorine content, if the chlorine content is ≤2000 μg / mL, the organic chlorine content in the oil field chemical agent is qualified; if the chlorine content is >2000 μg / mL, the inorganic chlorine and organic chlorine contents in the oil field chemical agent need to be detected and calculated.

9. The assay of any one of claims 1-8, wherein, The detection method comprises the following steps: ​ 10. The assay of any one of claims 1-9, wherein, ​ (1) Prepare chlorine reference standard solutions with different solubilities and mass concentrations of 20-2000 μg / mL respectively, detect by X-ray fluorescence spectrometer, obtain standard curves of chlorine reference standards with different solubilities, and fit to obtain standard curve equations; The chlorine reference standard solution includes a water-soluble chlorine reference standard solution or an oil-soluble chlorine reference standard solution; the water-soluble chlorine reference standard solution includes a water-soluble chlorine reference and a first solvent; the water-soluble chlorine reference includes an inorganic chlorine salt; the first solvent includes water; the oil-soluble chlorine reference standard solution includes an oil-soluble chlorine reference and a second solvent; the oil-soluble chlorine reference includes an organic chlorine compound; and the second solvent includes a non-chlorine-substituted solvent; (2) Mix the oil field chemical agent sample and the sample solvent to obtain an oil field chemical agent sample solution with a volume fraction of 1%-20%, detect by X-ray fluorescence spectrometer, and calculate according to the standard curve equation obtained in step (1) to obtain the chlorine element content in the oil field chemical agent; According to the solubility of the oil field chemical agent sample, the sample solvent is the first solvent or the second solvent; The X-ray fluorescence spectrometer in steps (1) and (2) includes a portable XRF analyzer; and the detection conditions of the X-ray fluorescence spectrometer in steps (1) and (2) are as follows: voltage 38-42 kV, current 90-110 μA, and detection time 28-32 s; (3) Analyze the chlorine element content obtained in step (2), if the chlorine element content is ≤2000 μg / mL, the organic chlorine content in the oil field chemical agent is qualified; if the chlorine element content is >2000 μg / mL, the inorganic chlorine and organic chlorine contents in the oil field chemical agent need to be detected and calculated.

Images