Method and device for detecting chlorine component in oilfield chemical agent and application

Abstract

The invention provides a method and device for detecting chlorine components in an oilfield chemical agent and application, and the method for detecting the chlorine components in the oilfield chemical agent comprises the following steps: pretreating a sample, and extracting the total chlorine components in the sample to obtain a to-be-detected solution containing the total chlorine components of the sample; mixing a potassium chromate aqueous solution with the to-be-detected solution; diluting the silver nitrate aqueous solution into a standard working solution with a concentration gradient; dropwise adding the standard working solution into the to-be-detected solution according to the concentration sequence from low to high until the color of the solution is just changed; and recording the consumption drop number of the standard working solution under each concentration so as to calculate the total chlorine component content. According to the method, a series of standard working solutions diluted by the silver nitrate aqueous solution with the concentration gradient are prepared, so that the measuring range is enlarged, the method is suitable for detecting the oilfield chemical agents with different chloride ion concentrations, and the chlorine content in the oilfield chemical agents can be rapidly detected.

Description

Technical Field

[0001] The present application relates to the technical field of oilfield quality control, and in particular to a method, device and application for detecting chlorine content in oilfield chemicals. Background Art

[0002] The increase in organochlorine content in crude oil has a significant impact on crude oil quality and subsequent processing. Studies have shown that chlorine-containing oilfield chemicals added during the oil production process are one of the main sources of organochlorine in crude oil. All oil fields are required to conduct mandatory inspections and strictly control the organochlorine content in oilfield chemicals.

[0003] Currently, the standard method for determining the content of organochlorine in oilfield chemicals is primarily SY / T 7329-2016, "Determination of Organochlorine Content in Oilfield Chemicals." This involves burning and decomposing the sample in an oxygen combustion flask, converting the organic chlorine into inorganic chlorine. After absorption in a sodium hydroxide solution, the total chlorine content is measured using a salt analyzer. The inorganic chlorine content in the oilfield chemical is then determined. The difference between the total chlorine content and the inorganic chlorine content is the organochlorine content in the oilfield chemical. Summary of the Invention

[0004] In order to achieve rapid detection of chlorine content in oilfield chemicals, this application proposes a method, device and application for detecting chlorine content in oilfield chemicals, and adopts the following technical solutions:

[0005] In a first aspect, the present application discloses a method for detecting chlorine content in oilfield chemicals, the method comprising:

[0006] Pre-treating the sample, extracting the total chlorine content in the sample, and obtaining a test solution containing the total chlorine content of the sample;

[0007] Mixing the potassium chromate aqueous solution with the liquid to be tested;

[0008] Diluting the silver nitrate aqueous solution into a standard working solution with a concentration gradient, and packaging the standard working solution at each concentration gradient into reagent bottles;

[0009] Add the standard working solution dropwise to the test solution in the order of concentration gradient from low to high until the solution just changes color;

[0010] The number of drops of the standard working solution consumed at each concentration was recorded to calculate the total chlorine content.

[0011] By adopting the above technical solution, when the method in the embodiment of the present application is used to determine the chlorine content in the oilfield chemical, the potassium chromate aqueous solution is used as an indicator and the silver nitrate aqueous solution is used as a titrant, and the titration end point is reflected by color change. Compared with the method of titrating with a single concentration of a detection reagent, the present application improves the measurement range by preparing a series of standard working solutions diluted from silver nitrate aqueous solution with a concentration gradient, which is suitable for the detection of oilfield chemicals with different chloride ion concentrations, and realizes rapid detection of the chlorine content in the oilfield chemical. And because the titration is carried out in order from low to high concentration, excessive titration can be avoided, and there is no need to estimate the chlorine content in the oilfield chemical.

[0012] Optionally, the concentration gradient range of the standard working solution is 0.01 mol / L-1 mol / L.

[0013] Optionally, the concentration gradient of the standard working solution is 0.01 mol / L, 0.1 mol / L and 1 mol / L.

[0014] By adopting the above technical solution, compared with the method of titrating with a single concentration of detection reagent, the present application expands the measurement range to 0.01 mol / L-1 mol / L by preparing standard working solutions diluted from silver nitrate aqueous solution at three concentrations, which is suitable for the detection of oilfield chemicals with different chloride ion concentrations.

[0015] Optionally, the concentration of the potassium chromate aqueous solution is in the range of 0.05% to 5%.

[0016] By adopting the above technical solution, before the silver nitrate solution is added, the test solution is bright yellow due to the addition of potassium chromate solution. After the silver nitrate solution is added, the silver nitrate reacts with chloride ions to form a white precipitate. When the silver nitrate consumes the chloride ions, the excess silver nitrate continues to react with potassium chromate to form a brick-red precipitate. This color change thus reflects the titration endpoint.

[0017] Optionally, the calculation formula for the total chlorine content is:

[0018]

[0019] Where: ω is the total chlorine content in the sample, N is the number of standard working fluid drops consumed, V1 is the volume of one drop of standard working fluid, c is the concentration of the standard working fluid, V0 is the consumed sample volume, ρ is the density of the oilfield chemical, and M is the molar mass of chlorine.

[0020] By adopting the above technical solution, when calculating the total chlorine content in the oilfield chemical sample, the number of drops of standard working solution consumed at each concentration is recorded, and the corresponding chlorine content value is substituted into the above formula to calculate the corresponding chlorine content value. The chlorine content value at each concentration is then added together to obtain the total chlorine content in the sample.

[0021] Optionally, the pretreatment of the sample and the extraction of the total chlorine component in the sample refers to: converting the organic chlorine component in the sample into an inorganic chlorine component using an oxygen combustion flask method, and then extracting the inorganic chlorine component in the sample.

[0022] By adopting the above technical solution, the sample is pretreated by oxygen combustion method, and all the organic chlorine components in the sample are converted into inorganic chlorine components through combustion. The content is then detected by the detection method of inorganic chlorine components to obtain the total chlorine content.

[0023] Optionally, the method further includes: extracting inorganic chlorine components from the sample and calculating the content of the inorganic chlorine components.

[0024] By adopting the above technical solution, the content of inorganic chlorine components in the sample is obtained, and combined with the total chlorine content, the content of inorganic chlorine components is subtracted from the total chlorine content to obtain the content of organic chlorine components.

[0025] In a second aspect, the present application discloses a device for detecting chlorine content in oilfield chemicals, the device being used to implement the method for detecting chlorine content in oilfield chemicals as described in the first aspect, the device comprising a detection box, the detection box being provided with an oxygen combustion bottle, an oxygen tank, and a micro-injector, as well as a potassium chromate aqueous solution, a standard working solution, an absorption solution, and a flushing solution packaged in reagent bottles;

[0026] A combustion rod is provided in the oxygen combustion bottle, and the oxygen tank is communicated with the oxygen combustion bottle.

[0027] By adopting the above-mentioned technical solution, the chlorine content detection device in the embodiment of the present application integrates sample pretreatment and detection, achieving rapid on-site pretreatment and detection. Furthermore, the device has low dependence on laboratory instruments, is easy to operate, and offers fast analysis speed and high sensitivity, making it suitable for rapid on-site screening and determination of organochlorine content in oilfield chemicals. The detection reagent bottles are available in different concentration models, suitable for detecting oilfield chemicals with different chloride ion concentrations, and suitable for standardized on-site operations.

[0028] Optionally, a vent pipe is provided at the bottom of the oxygen combustion bottle, and the oxygen tank is connected to the vent pipe.

[0029] By adopting the above technical solution, the oxygen combustion bottle in the present application is designed to be bottom-ventilated, which simplifies the oxygen replacement operation and improves the oxygen replacement efficiency.

[0030] In a third aspect, the present application discloses an application of the device described in the second aspect in the detection and analysis of chlorine components in oilfield chemicals.

[0031] Based on the above technical solution, the beneficial effects of this application compared with the prior art are as follows:

[0032] 1. Compared to methods using a single concentration of a detection reagent for titration, the chlorine content detection method in the present embodiment utilizes a series of standard working solutions diluted from silver nitrate aqueous solution in a concentration gradient, thereby extending the measurement range and making it suitable for detecting oilfield chemicals with varying chloride ion concentrations. Furthermore, because titration is performed sequentially from low to high concentration, overtitration is avoided, eliminating the need to estimate the chlorine content in the oilfield chemical, thereby enabling rapid detection of the chlorine content in the oilfield chemical.

[0033] 2. This application utilizes reagent bottles for packaging, including potassium chromate aqueous solution and standard working solutions at varying concentration gradients. This design offers the advantages of small packaging, portability, and rapid testing. The bottles, available in various concentrations, are suitable for testing oilfield chemicals with varying chloride ion concentrations, offering a wide detection range and scalability for standardized on-site operations.

[0034] 3. The chlorine content detection device in the embodiment of the present application integrates sample pretreatment and detection. The device has low dependence on laboratory instruments, is easy to operate, has a fast analysis speed and high sensitivity, and is suitable for on-site rapid screening and content determination of organic chlorine content in oilfield chemicals. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the method for detecting chlorine content in an embodiment of the present application.

[0036] Figure 2 It is a schematic diagram of a chlorine content detection device in an embodiment of the present application.

[0037] Description of the accompanying drawings:

[0038] 1. Oxygen tank; 2. Oxygen combustion bottle; 21. Ventilation tube; 3. Combustion rod; 4. Microinjector; 5. Potassium chromate aqueous solution; 6. Standard working solution; 7. Absorption solution; 8. Flushing solution. DETAILED DESCRIPTION

[0039] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0041] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this disclosure and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on the specific circumstances.

[0043] The inventors discovered that current methods for testing chlorine content in oilfield chemicals rely heavily on laboratory equipment and instruments. This is because the common laboratory approach is to first estimate the chlorine content in the oilfield chemical and then select a detection reagent with an appropriate concentration for quantitative detection. However, the chlorine content in oilfield chemicals often has significant uncertainty, which makes it difficult to select the appropriate concentration of the detection reagent, easily increasing detection errors and hindering rapid on-site detection.

[0044] Therefore, based on the above problems, in order to quickly detect the chlorine content in oilfield chemicals, the inventors further developed and made the present invention.

[0045] In the first aspect, the present application discloses a method for detecting chlorine content in oilfield chemicals, referring to Figure 1 , the method comprising:

[0046] S1: Pre-treat the sample, extract the total chlorine content in the sample, and obtain a test solution containing the total chlorine content of the sample;

[0047] S2: Mix the potassium chromate aqueous solution with the test solution;

[0048] S3: diluting the silver nitrate aqueous solution into a standard working solution with a concentration gradient, and packaging the standard working solution at each concentration gradient into a reagent bottle;

[0049] S4: Add the standard working solution to the test solution dropwise in order of concentration from low to high until the solution just changes color;

[0050] S5: Record the number of drops of standard working solution consumed at each concentration to calculate the total chlorine content.

[0051] The detection method in the embodiment of the present application can first convert the organic chlorine component into an inorganic chlorine component through the pretreatment step in S1 when detecting the total chlorine content, and then determine the total chlorine content through the steps in S2-S3.

[0052] When the method in the embodiment of the present application is utilized to measure the chlorine content in oilfield chemicals, potassium chromate aqueous solution is used as an indicator, and silver nitrate aqueous solution is used as a titrant, and the titration end point is reflected by color change. Specifically, the silver nitrate aqueous solution is diluted according to a certain concentration gradient to obtain a series of standard working solutions of concentration gradients, and the standard working solution under each concentration gradient is packaged in a reagent bottle, so as to be conducive to carrying for standardized operation. During titration, it is sequentially added dropwise to the solution to be measured containing potassium chromate aqueous solution in the order from low to high according to concentration. In a specific titration process, when the system does not change after several drops are added using a low-concentration standard working solution, a medium-concentration standard working solution is used instead to continue to drip. If the system still does not change after several drops are added, a high-concentration standard working solution is used instead to continue to drip until the system solution just changes color, and the number of drops consumed by the different concentration standard working solutions is recorded. Compared to methods using a single concentration of test reagent for titration, this application increases the measurement range by preparing a series of standard working solutions diluted from silver nitrate aqueous solution with a concentration gradient. This solution is suitable for testing oilfield chemicals with varying chloride ion concentrations, enabling rapid detection of the chlorine content in oilfield chemicals. Furthermore, because titration is performed sequentially from low to high concentration, overtitration is avoided, eliminating the need for pre-estimation of the chlorine content in oilfield chemicals.

[0053] In an optional embodiment, in step S1, the organic chlorine components in the sample are converted to inorganic chlorine components using an oxygen combustion flask method. Specifically, the oxygen combustion flask method involves the following steps: 0.1 mL of oilfield chemical is drawn up using a microinjector and injected onto a cotton ball inside a combustion rod, which is then clamped to the platinum wire of the combustion rod's support rod. After adding an absorption liquid to the combustion flask, the air in the flask is replaced with oxygen. The combustion rod is then ignited and quickly inserted into the oxygen-filled combustion flask. After combustion is complete and the smoke has dissipated, the flask walls and support rod are rinsed with a rinse solution. During this process, the organic chlorine components are converted to inorganic chlorine components. Due to the good sealing properties of the oxygen combustion flask, the inorganic chlorine components generated during combustion are fully absorbed by the absorption liquid. Some of the inorganic chlorine components remaining on the combustion rod are also dissolved in the absorption liquid by the rinse solution. The total chlorine content is then determined by measuring the chloride ion content in the absorption liquid. It should be noted that the absorption liquid can be a mixture of hydrogen peroxide and sodium hydroxide in a 1:1 volume ratio, and distilled water can be used as the rinse solution.

[0054] In an optional embodiment, in steps S2-S5, the concentration of the potassium chromate aqueous solution ranges from 0.05% to 5%, and the concentration gradient of the standard working solution prepared by dilution with silver nitrate ranges from 0.01 mol / L to 1 mol / L. Specifically, the concentration gradient of the standard working solution can be set to 0.01 mol / L, 0.1 mol / L, and 1 mol / L. After the potassium chromate aqueous solution is mixed with the test solution, the test solution becomes bright yellow. The silver nitrate aqueous solution is then added dropwise to the test solution until the test solution turns brick red, completing the titration process.

[0055] In an optional embodiment, based on the above oilfield chemical sample pretreatment and detection process, the total chlorine content is calculated as follows:

[0056]

[0057] Where: ω is the total chlorine content in the sample, N is the number of standard working fluid drops consumed, V1 is the volume of one drop of standard working fluid, c is the concentration of the standard working fluid, V0 is the consumed sample volume, ρ is the density of the oilfield chemical, and M is the molar mass of chlorine.

[0058] Furthermore, for ease of calculation, in this example, the volume V1 of a drop of standard working solution is set to 0.05 mL, the density of the oilfield chemical is set to 1 g / mL, the consumed sample volume V0 is quantified by a microinjector to 0.1 mL, and the molar mass of chlorine is 35.45 g / mL. Therefore, the calculation formula for the total chlorine content can be simplified to:

[0059] ω=N×c×1.7725;

[0060] It should be noted that when titrating with standard working solutions of different concentrations, the total chlorine content calculated using the standard working solutions of each concentration should be added together when calculating the total chlorine content. That is, the total chlorine content is calculated using the following formula:

[0061] ω=N1×c1×1.7725+N z ×c2×1.7725+N3×c3×1.7725;

[0062] Wherein, N1, N2 and N3 are the number of drops of standard working solution consumed at different concentrations, and c1, c2 and c3 are the concentrations of the corresponding standard working solution.

[0063] In an optional embodiment, the detection method in the embodiment of the present application further includes: extracting the inorganic chlorine component in the sample and calculating the inorganic chlorine component content. When calculating the inorganic chlorine component content, 0.1mL of oil-soluble oilfield chemical is drawn through a microinjector, directly mixed with the flushing fluid, and then the inorganic chlorine component content in the sample is detected using the method in S2-S3 above. The organic chlorine component content is calculated by subtracting the inorganic chlorine component content from the total chlorine component content. In the actual detection process, if the total chlorine content is lower than 0.2%, it can be determined that the organic chlorine component in the oilfield chemical does not exceed the standard. If the total chlorine content is higher than 0.2%, the inorganic chlorine component in the sample is detected at the same time, and the determination is made after calculating the organic chlorine content.

[0064] In the second aspect, the present application discloses a device for detecting chlorine content in oilfield chemicals, referring to Figure 2 The apparatus is used to implement the method for detecting chlorine content in oilfield chemicals according to the first aspect. The apparatus includes a detection box, which contains an oxygen tank 1, an oxygen combustion bottle 2, a microinjector 4, and a potassium chromate aqueous solution 5, a standard working solution 6, an absorption solution 7, and a flushing solution 8, all packaged in reagent bottles. The potassium chromate aqueous solution 5, the standard working solution 6, the absorption solution 7, and the flushing solution 8 can all be provided in multiple portions. The oxygen tank 1 is connected to the oxygen combustion bottle 2, which contains a combustion rod 3.

[0065] Further, refer to Figure 2 The bottom of the oxygen combustion bottle 2 is provided with a vent pipe 21, and the oxygen tank 1 is communicated with the vent pipe 21. The oxygen tank 1 ventilates to the bottom of the oxygen combustion bottle 2 through the vent pipe 21, which is conducive to oxygen filling, thereby completely replacing the air in the oxygen combustion bottle 2 with oxygen.

[0066] In a third aspect, the present application discloses the application of the chlorine content detection method of the first aspect for the detection and analysis of chlorine content in oilfield chemicals. The chlorine content detection device in the embodiments of the present application integrates sample pretreatment and determination, is easy to use, and simple to operate, enabling rapid on-site pretreatment and detection. The device utilizes an oxygen tank, eliminating the need for laboratory aeration systems, enabling on-site oxygen replacement. The oxygen combustion bottle utilizes a bottom ventilation design to improve oxygen replacement efficiency. The combustion rod, absorption liquid, and detection reagent are all packaged in small, suitable packages for standardized on-site operations. Standard working solutions are available in different concentrations, suitable for detecting oilfield chemicals with varying chloride ion concentrations. During the actual titration test, the number of standard working solution drops consumed can be used to preliminarily determine whether the total organic chlorine content of the oilfield chemical sample exceeds the standard. Specifically, when titrating with a 0.01 mol / L standard working solution, if the solution turns brick red within 11 drops, the total chlorine content of the oilfield chemical sample can be determined to be within 0.2%, directly confirming that the organic chlorine content of the oilfield chemical sample does not exceed the standard. If there is no change in the system after adding 11 drops, it indicates that the organic chlorine content of the oilfield chemical sample may exceed 0.2%. It is necessary to test the total chlorine content and the inorganic chlorine content in sequence and calculate the organic chlorine content.

[0067] For ease of understanding, the present application is described in detail below through specific examples:

[0068] Example 1

[0069] It should be noted that the reagents and materials used in the present embodiment are as follows: the burning rod is prepared by wrapping 0.05g of absorbent cotton with sulfuric acid paper and vacuum packaging. The absorption liquid is a mixed system formed by mixing 2mL of hydrogen peroxide with 2mL of sodium hydroxide, and the rinsing fluid is distilled water. The mass fraction of the potassium chromate aqueous solution is 1%. The silver nitrate aqueous solution is diluted to a series of standard working solutions with a concentration gradient of 0.01mol / L, 0.1mol / L and 1mol / L. The absorption liquid, rinsing fluid, potassium chromate aqueous solution and standard working solution are all packaged in plastic reagent bottles.

[0070] The following is a test of oilfield chemical sample 1 using the chlorine component detection method in this application:

[0071] Use a microinjector to draw up 100μL of the oilfield chemical sample and inject it onto the absorbent cotton inside the combustion rod, which is then clamped to the platinum wire of the combustion flask support rod. After adding the absorption liquid to the combustion flask, use an oxygen tank to pass oxygen through the oxygen combustion flask at an appropriate flow rate for 1-2 minutes, replacing the flask's contents with oxygen. The flask is then tightly capped with a standard ground-mouth stopper. After igniting the combustion rod, remove the stopper and quickly insert the combustion flask filled with oxygen. After combustion is complete and the smoke disappears, rinse the combustion flask walls and support rod with 6mL of rinse solution, completing the pretreatment process for sample one and obtaining the test solution.

[0072] Add 1 mL of potassium chromate aqueous solution to the test solution and shake to dissolve. The solution turns bright yellow. Add the standard working solution dropwise while shaking until the solution turns brick red. Record the number of drops of standard working solution consumed at each concentration and calculate the total chlorine content. Specifically, in this example, oilfield chemical sample 1 consumed 8 drops of 0.01 mol / L standard working solution when testing for total chlorine content. The calculated total chlorine content was 0.1418%, indicating that sample 1's organochlorine content was acceptable.

[0073] To verify the accuracy of the test results obtained using the chlorine content detection method in the examples of this application, after pre-treating Sample 1 using the oxygen combustion flask method, the total chlorine content in the test liquid was further measured using a salt content analyzer, resulting in a total chlorine content of 0.1457%. The relative error of the test results obtained using the chlorine content detection method in the examples of this application was 2.68%, which met the accuracy requirements.

[0074] Example 2

[0075] The difference between this embodiment and embodiment 1 is that the above-mentioned detection method is used to detect the second oilfield chemical sample. In this embodiment, when detecting the total chlorine content of the second oilfield chemical sample, 10 drops of 0.01 mol / L standard working solution and 7 drops of 0.1 mol / L standard working solution are consumed, and the total chlorine content is calculated to be 1.4179%. When further detecting the inorganic chlorine content, 8 drops of 0.01 mol / L standard working solution are consumed, and the inorganic chlorine content is calculated to be 0.1418%, that is, the organic chlorine content is 1.2761%, and the organic chlorine content of the second sample is determined to be unqualified.

[0076] Similarly, after pre-treating Sample 2 using the oxygen combustion flask method, the total chlorine content in the test solution was further measured using a salt content meter, resulting in a total chlorine content of 1.4335%. Further direct measurement of the inorganic chlorine content in Sample 2 using the salt content meter yielded a value of 0.1438%, i.e., an organic chlorine content of 1.2897%. In this embodiment, the relative error for the total chlorine content detection was 1.09%, and the relative error for the inorganic chlorine content detection was 1.39%, both meeting the accuracy requirements.

[0077] Example 3

[0078] The difference between this embodiment and embodiment 1 is that the above-mentioned detection method is used to detect the oilfield chemical sample 3. In this embodiment, when detecting the total chlorine content of the oilfield chemical sample 2, 10 drops of 0.01 mol / L standard working solution and 6 drops of 0.1 mol / L standard working solution are consumed, and the total chlorine content is calculated to be 1.2407%. When further detecting the inorganic chlorine content, 10 drops of 0.01 mol / L standard working solution and 5 drops of 0.1 mol / L standard working solution are consumed, and the inorganic chlorine content is calculated to be 1.0634%, that is, the organic chlorine content is 0.1773%, and the organic chlorine content of sample 3 is determined to be qualified.

[0079] Similarly, after pre-treating Sample 2 using the oxygen combustion flask method, the total chlorine content in the test solution was further measured using a salt content meter, resulting in a total chlorine content of 1.2647%. Further direct measurement of the inorganic chlorine content in Sample 2 using the salt content meter yielded a content of 1.1002%, i.e., an organic chlorine content of 0.1645%. In this embodiment, the relative error for the total chlorine content was 1.90%, and the relative error for the inorganic chlorine content was 3.34%, both meeting the accuracy requirements.

[0080] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it will be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, to the extent that the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including", as explained by the use of "including" as a transitional word in the claims. In addition, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or".

Claims

1. A method for detecting chlorine content in oilfield chemicals, characterized in that: The method comprises: Pre-treating the sample, extracting the total chlorine content in the sample, and obtaining a test solution containing the total chlorine content of the sample; Mixing the potassium chromate aqueous solution with the liquid to be tested; Diluting the silver nitrate aqueous solution into a standard working solution with a concentration gradient, and packaging the standard working solution at each concentration gradient into reagent bottles; Add the standard working solution dropwise to the test solution containing the potassium chromate aqueous solution in the order of concentration gradient from low to high until the solution just changes color; The number of drops of the standard working solution consumed at each concentration was recorded to calculate the total chlorine content.

2. The method according to claim 1, characterized in that The concentration gradient of the standard working solution is in the range of 0.01 mol / L to 1 mol / L.

3. The method according to claim 2, characterized in that The concentration gradient of the standard working solution is 0.01 mol / L, 0.1 mol / L and 1 mol / L.

4. The method according to claim 1, wherein The concentration of the potassium chromate aqueous solution is in the range of 0.05% to 5%.

5. The method according to claim 1, wherein The calculation formula of the total chlorine content is: Where: ω is the total chlorine content in the sample, N is the number of standard working fluid drops consumed, V1 is the volume of one drop of standard working fluid, c is the concentration of the standard working fluid, V0 is the consumed sample volume, ρ is the density of the oilfield chemical, and M is the molar mass of chlorine.

6. The method according to claim 1, wherein The pretreatment of the sample and extraction of the total chlorine component in the sample refers to: converting the organic chlorine component in the sample into inorganic chlorine component by an oxygen combustion flask method, and then extracting the inorganic chlorine component in the sample.

7. The method according to claim 1, characterized in that The method further includes: extracting inorganic chlorine components from the sample and calculating the content of the inorganic chlorine components.

8. A device for detecting chlorine content in oilfield chemicals, characterized in that: The device is used to implement the method for detecting chlorine content in oilfield chemicals according to any one of claims 1 to 7, and the device comprises a detection box, wherein the detection box is provided with an oxygen combustion bottle, an oxygen tank and a micro-injector, as well as a potassium chromate aqueous solution, a standard working solution, an absorption solution and a flushing solution packaged in reagent bottles; The oxygen tank is communicated with the oxygen combustion bottle.

9. The device according to claim 8, characterized in that A vent pipe is provided at the bottom of the oxygen combustion bottle, and the oxygen tank is communicated with the vent pipe.

10. Use of the method according to any one of claims 1 to 7 in the detection and analysis of chlorine content in oilfield chemicals.

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