Method and device for determining contents of wax and colloid in crude oil

Abstract

The invention discloses a method and a device for determining the content of wax and colloid in crude oil. The method specifically comprises the following steps: separating wax and colloid in the crude oil through chromatography; according to the chromatography method, activated clay and silica gel are used as adsorbents, and petroleum ether and absolute ethyl alcohol are used as flushing reagents; according to the method, activated clay and silica gel are used as packed columns, petroleum ether and absolute ethyl alcohol are used as washing reagents, wax and colloid components in crude oil can be effectively separated out, the analysis time is short, the accuracy of experimental results is high, and repeatability is good; in addition, the experimental operation process is simple, the period is short, the used chemical reagents are few in variety and non-toxic, operation in the fuming cupboard is matched, the open area is small, the chemical reagents can be prevented from escaping out of the fuming cupboard to the greatest extent, and the whole process is safe and environmentally friendly.

Description

Technical Field

[0001] This disclosure relates to the field of testing and analysis technology, and in particular to a method for testing and analyzing the content of wax and gum in crude oil. Background Technology

[0002] The detection of wax and gum content in crude oil is an important analytical item in crude oil analysis. It is of great significance for petroleum exploration, oilfield development, oil production process design, analysis and evaluation of crude oil properties, research on oil and gas migration, and understanding of oil reservoirs.

[0003] Traditional methods for determining the wax and gum content in crude oil are quite cumbersome, involving processes such as distillation, dissolution, filtration, and adsorption separation, with the experimental process taking more than 32 hours. They also require a large amount of chemical reagents such as benzene, toluene, acetone, and n-heptane, and the determination process generates a large amount of toxic and harmful vapors, which can cause certain harm to the health of experimental personnel. In addition, there is also the problem of large human error.

[0004] The rod-shaped thin-layer chromatography method for determining the wax and gum content in crude oil, which has emerged in recent years, is still immature and its measurement results differ significantly from those of traditional methods.

[0005] Therefore, in response to the problems of current testing methods, there is an urgent need for testing methods that have short analysis time, high accuracy of experimental results, good repeatability, and minimal harm to the human body. Summary of the Invention

[0006] In view of this, this disclosure provides a method and apparatus for determining the wax and gum content in crude oil, which solves the problems of current determination methods being cumbersome, having long experimental cycles, using large amounts of various toxic reagents, and generating large amounts of toxic and harmful vapors during the experimental process, endangering the health of experimental operators.

[0007] To achieve the above-mentioned objective, in a first aspect, the method for determining the wax and gum content in crude oil includes:

[0008] Wax and gum in crude oil were separated by chromatography;

[0009] The chromatography method uses activated clay and silica gel as adsorbents, and petroleum ether and anhydrous ethanol as washing reagents.

[0010] In this disclosure and possible embodiments, the method for separating waxes and gums from crude oil by chromatography includes:

[0011] Packing chromatography column;

[0012] The method for packing the chromatography column is to place defatted cotton at the bottom of the chromatography column, add 2-3g of silica gel, 8-10g of activated clay-silica gel mixture and 2-3g of silica gel on the defatted cotton in sequence, and then shake the chromatography column to make the adsorbent firm.

[0013] The mass ratio of activated clay to silica gel in the activated clay-silica gel mixture is 1:7 to 9.

[0014] In this disclosure and possible embodiments, the mass ratio of activated clay to silica gel in the activated clay-silica gel mixture is 1:8; and / or,

[0015] The activated clay has a mesh size of 60-120, and the silica gel has a mesh size of 100-200.

[0016] The activated clay and the silica gel are activated at a temperature of 150℃ to 180℃ for a duration of 24 hours or more.

[0017] The mixing method of the activated clay-silica gel mixture is as follows: after the activated clay and silica gel are mixed evenly according to the mass ratio, the mixture is activated again at 150°C for 8 hours to obtain the activated clay-silica gel mixture.

[0018] In this disclosure and possible embodiments, after the chromatography column is packed, it is rinsed with petroleum ether to completely wet the adsorbent inside the chromatography column.

[0019] In this disclosure and possible embodiments, the method for separating wax from crude oil by chromatography includes:

[0020] The oil sample is completely dissolved in petroleum ether to obtain a test solution. The entire test solution is transferred to the chromatography column, and the chromatography column is eluted with petroleum ether with a boiling range of 60℃~90℃ to separate the oil. The eluent is collected.

[0021] After heating to remove the solvent from the effluent, petroleum ether with a boiling range of 90°C to 120°C is added to dissolve the wax therein, resulting in a wax-containing solution.

[0022] The wax-containing solution is cooled to allow wax to precipitate, the wax is collected, and the wax content of the crude oil sample is calculated. In this disclosure and possible embodiments, the method of completely dissolving the oil sample in petroleum ether to obtain a test solution includes: weighing 0.05 ± 0.005 g of the oil sample into a weighing bottle, accurate to 0.0001 g, and dissolving the oil sample in 10 ml of petroleum ether with a boiling range of 60°C to 90°C until the oil sample is completely dissolved; and / or,

[0023] The method for transferring all of the test solution to the chromatography column includes:

[0024] After transferring the test solution from the weighing bottle to the chromatography column using a funnel, rinse the weighing bottle, the inner wall of the chromatography column, and the funnel with petroleum ether with a boiling range of 60°C to 90°C, ensuring that all the rinsing solution flows into the chromatography column; and / or,

[0025] The method for removing solvent from the effluent by heating includes: placing the effluent on a hot plate at a temperature of 80℃±10℃ to allow the solvent in the effluent to evaporate until the solvent has completely evaporated.

[0026] In this disclosure and possible embodiments, the method of cooling the wax-containing solution to precipitate wax includes: cooling the wax-containing solution to room temperature, adding anhydrous ethanol at 6°C to 8°C, and allowing it to stand at 6°C to 8°C for at least 4 hours to allow wax precipitation; and / or,

[0027] The method for collecting the wax includes: filtering the precipitated wax and mother liquor through a funnel at 6℃~8℃ to remove the mother liquor, and then dissolving the wax in the funnel and the residual wax in each step of the filtration process with petroleum ether at 40℃~45℃ and a boiling range of 60℃~90℃ to collect the wax solution.

[0028] After the wax solution is volatilized and subjected to constant weight treatment, wax separated from crude oil is obtained.

[0029] In this disclosure and possible embodiments, the method for separating colloids from crude oil by chromatography includes:

[0030] The chromatography column after oil separation is washed with an anhydrous ethanol-petroleum ether mixed solution, and the washing liquid is collected; the volume ratio of ethanol to petroleum ether in the mixed solution is 1:3, and the boiling range of the petroleum ether is 60℃~90℃.

[0031] After the flushing fluid is volatilized and subjected to constant weight treatment, the gum separated from the crude oil is obtained.

[0032] In this disclosure and possible embodiments, the method for evaporating and maintaining a constant weight of the wax solution and the rinsing solution includes:

[0033] The wax solution or the rinsing solution is placed on a hot plate at a temperature of 90℃±5℃ to allow the solvent in the wax solution or the rinsing solution to evaporate completely. After that, it is kept at a constant temperature of 105℃ for 4 hours. Then, it is taken out and placed in a desiccator to cool for 1 hour. The first weighing is performed, and then it is placed in the desiccator to cool for 30 minutes. The second weighing is performed, until the difference between the two weighings is less than 0.0004g.

[0034] Secondly, the apparatus for determining the wax and gum content in crude oil includes:

[0035] A chromatography column, which is placed inside a fume hood;

[0036] The wax and gum in crude oil are separated using the chromatography column to determine the wax and gum content in the crude oil; the determination is performed in the fume hood.

[0037] In this disclosure and possible embodiments, the fume hood is equipped with a side sliding door, the chromatography column is fixed to a rotating stage by a clamp, the rotating stage includes a base, a rotating shaft is provided at the center of the base, and the rotating shaft is connected to a turntable.

[0038] The beneficial effects of this invention are as follows:

[0039] The method disclosed herein for determining the wax and gum content in crude oil is a chromatography method using activated clay and silica gel as packed columns and petroleum ether and anhydrous ethanol as washing reagents. It can effectively separate wax and gum components in crude oil, and has a short analysis time, high accuracy and good repeatability of experimental results. In addition, the experimental operation is simple and short-term, uses few types of chemical reagents and is non-toxic. Combined with operation in a fume hood, the open area is small, which can minimize the escape of chemical reagents outside the fume hood and achieve safety and environmental protection throughout the process. Attached Figure Description

[0040] The above and other objects, features, and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0041] Figure 1 This is a schematic diagram of the glass chromatography column (unit: mm, wall thickness: 1 mm) used in the embodiments of this disclosure;

[0042] Figure 2 This is a schematic diagram of the rotating separation stage structure according to an embodiment of the present disclosure;

[0043] The components are: 1. Rotating shaft, 2. Clamping device, 3. Upper rotating disk, 4. Base, and 5. Chromatography column. Detailed Implementation

[0044] The present disclosure is described below based on specific embodiments; however, it is worth noting that the present disclosure is not limited to these specific embodiments. In the following detailed description of the present disclosure, certain specific details are described in detail. However, those skilled in the art will fully understand the present disclosure for the parts not described in detail.

[0045] Furthermore, unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to."

[0046] Unless otherwise specified, all materials and reagents used in the following embodiments are commercially available.

[0047] In the embodiments of this disclosure, when determining the wax and gum content in crude oil, the following methods are used: Figure 2 The rotating separation stage is placed inside a fume hood equipped with a side sliding door. The chromatography column 5 is fixed to the rotating stage by a clamp 2. The rotating stage includes a base 4 with a rotating shaft 1 at its center, which is connected to an upper turntable 3. Under the action of the rotating shaft 1, the upper turntable 3 has a rotation function, which facilitates rotating different chromatography columns 5 to the side sliding door position of the fume hood for more environmentally friendly and safer testing experiments.

[0048] The methods for determining the wax and gum content in crude oil used in the embodiments of this disclosure include the following specific steps:

[0049] 1. Preparation of chromatography column:

[0050] (1) Packing the chromatography column: Using activated clay and silica gel as adsorbents, select a glass chromatography column, put degreased cotton at the bottom of the glass chromatography column to prevent the adsorbent from leaking out, and then add 2-3g of silica gel, 8-10g of a mixture of activated clay and silica gel, and 2-3g of silica gel in sequence. Shake the chromatography column to make the adsorbent firm, and install the rotary chromatography separation device in a constant temperature fume hood at 35±5℃.

[0051] In this embodiment, the activated clay and silica gel need to be activated in an oven at 150℃-180℃ for more than 24 hours before use to ensure that the activated clay and silica gel are fully dried. Experiments have shown that the drying effect is poor and the efficiency is low when the temperature is below 150℃, while the temperature is too high and it is easy to damage the components of the activated clay and silica gel. Therefore, this disclosure selects a drying temperature of 150℃-180℃ and an activation time of more than 24 hours to achieve the ideal drying effect.

[0052] (2) Washing the chromatography column: In this embodiment, the adsorbent in the glass chromatography column is completely wetted three times with about 30 ml of petroleum ether. Unless otherwise stated, the petroleum ether used in this embodiment has a boiling range of 60°C to 90°C and is of analytical grade.

[0053] 2. Separate the wax from the crude oil:

[0054] (1) Preparation of test solution:

[0055] In this embodiment of the present disclosure, 0.05±0.005g of oil sample, accurate to 0.0001g, is weighed into a 50ml weighing bottle using an analytical balance, and 10ml of petroleum ether is added to fully dissolve the oil sample to obtain the test solution.

[0056] The amount of oil sample taken was 0.05±0.005g because if the sample amount is too small, the experimental random error will be large and it will not be representative. If the sample size is too large, it will not be able to fully separate the wax and gum components due to the constraints of the chromatography column size, packing material and the amount of eluent used.

[0057] (2) Separation of oil and grease:

[0058] All the test solution was transferred to the chromatography column. In this embodiment, the transfer was specifically performed using a funnel. The weighing bottle, the inner wall of the upper end of the chromatography column, and the funnel were rinsed with petroleum ether to ensure that all the rinsing solution flowed into the chromatography column. When the liquid level was close to the upper silica gel layer, the chromatography column was rinsed three times with 30 mL of petroleum ether. The effluent was collected in a 50 mL beaker and designated as solution A.

[0059] The above-mentioned oil separation process is carried out in a fume hood. When adding petroleum ether, a rotating separation stage and a side door of the fume hood are used to ensure that only one set of chromatography columns is at the opening of the fume hood. After adding petroleum ether, the side door is closed immediately to minimize the escape of petroleum ether outside the fume hood.

[0060] (3) Reagent recovery:

[0061] In this embodiment of the disclosure, solution A collected in a 50ml beaker is placed on a hot plate at a temperature of 80℃±10℃ to recover the reagent until the petroleum ether has completely evaporated.

[0062] (4) Wax precipitation by cooling:

[0063] In this embodiment, after the reagent recovery is complete, 2 mL of petroleum ether with a boiling range of 90℃~120℃ is added while the solution is still hot to dissolve all the wax. After the solution cools to room temperature, 10 mL of anhydrous ethanol with a boiling range of 6℃~8℃ is quickly added, the solution is shaken for 1 minute, the lid is closed, and the solution is placed in a refrigerator at 6℃~8℃ for at least 4 hours to allow the wax to precipitate.

[0064] At 6℃~8℃, the precipitated wax and mother liquor were filtered through a glass funnel plugged with degreased cotton. After filtering out the mother liquor, a pre-weighed 50mL beaker was placed below the funnel. The wax adsorbed on the mother liquor beaker was completely dissolved with petroleum ether at 40℃~45℃ (60℃~90℃) and transferred to the funnel containing the wax. The wax on and around the degreased cotton was then washed with the same petroleum ether at 40℃~45℃ (60℃~90℃). Finally, the outlet of the glass funnel was rinsed with petroleum ether at 40℃~45℃. The wax solution obtained in this way is designated as solution B.

[0065] (5) Volatilization, constant weight:

[0066] In this embodiment, the collected solution B is placed on a hot plate to evaporate the reagent at 90°C. Then it is placed in a constant temperature oven at 105°C for 4 hours, removed and cooled in a desiccator for 1 hour, and weighed for the first time. After that, it is placed in the desiccator to cool for 30 minutes, removed and weighed for the second time, until the difference between the two weighings is less than 0.0004g.

[0067] 3. Wax content calculation:

[0068] The wax content of crude oil samples is calculated using the following formula:

[0069] x1 = (m2-m1) / m0 × 100%;

[0070] In the formula: x1 is the wax content of the crude oil sample, %; m2 is the mass of the weighing bottle containing wax, in g; m1 is the mass of the empty weighing bottle, in g; m0 is the mass of the crude oil sample, in g.

[0071] 4. Separate the gum from the crude oil:

[0072] (1) Separation of colloidal substances:

[0073] In this embodiment, the separation of colloids is carried out in a fume hood, using a rotating separation stage and a side-opening door of the fume hood. Only one set of chromatography columns is positioned at the fume hood opening. 30 ml of anhydrous ethanol-petroleum ether (60℃~90℃) mixed solution is added to the glass chromatography column after oil separation. The volume ratio of ethanol to petroleum ether in the mixed solution is 1:3. The chromatography column is eluted three times, with 10 ml of reagent added each time. The side-opening door is immediately closed after adding reagent to prevent reagent from escaping outside the fume hood. After elution and waiting for all the solution to flow out, the weighing Erlenmeyer flask is removed, and the effluent from the colloid separation process is collected in a 50 mL Erlenmeyer flask that has been pre-weighed and designated as solution C.

[0074] (2) Volatilization, constant weight:

[0075] Place solution C on a hot plate to evaporate the reagent at 90°C, then place it in a constant temperature oven at 105°C for 4 hours. Remove it and place it in a desiccator to cool for 1 hour. Weigh it for the first time, then place it in the desiccator to cool for 30 minutes and weigh it for the second time. Repeat this process until the difference between the two weighings is less than 0.0004g.

[0076] 5. Calculation of gelatin content:

[0077] The gum content of crude oil samples is calculated using the following formula:

[0078] x2 = (m3-m1) / m0 × 100%;

[0079] In the formula: x2 is the gum content of the crude oil sample, %; m3 is the mass of the weighing bottle containing gum, in g; m1 is the mass of the empty weighing bottle, in g; m0 is the mass of the crude oil sample, in g.

[0080] Example 1

[0081] 1. Preparation of chromatography column:

[0082] (1) Packed chromatography column: using a column such as Figure 1 Glass chromatography column of the dimensions shown; combined with Figure 2 As shown, place a small piece of degreased cotton at the bottom of the glass chromatography column 5 to prevent the adsorbent from leaking out. Then, add 2g of silica gel, 8g of activated clay-silica gel mixture, and 2g of silica gel in sequence. Shake the chromatography column 5 appropriately to make the adsorbent firm. Install it on the clamp 2 of the rotary chromatography separation device in a constant temperature fume hood at 37°C.

[0083] The above-mentioned activated clay has a mesh size of 60-120 mesh, and silica gel has a mesh size of 100-200 mesh. After activating the activated clay and silica gel in an oven at 150℃ for 24 hours, the activated clay and silica gel are mixed evenly at a mass ratio of 1:8 to obtain a primary activated clay-silica gel mixture. Then, the primary activated clay-silica gel mixture is further activated in an oven at 150℃ for 8 hours to obtain an activated clay-silica gel mixture for use in chromatography columns.

[0084] (2) Rinse the chromatography column: Use about 30 ml of petroleum ether of analytical grade to completely wet the adsorbent in column 5 in three separate applications.

[0085] 2. Separate the wax from the crude oil:

[0086] (1) Preparation of test solution:

[0087] Weigh 0.0550 g of oil sample into a 50 ml weighing bottle using an analytical balance, and dissolve it in 10 ml of petroleum ether until the oil sample is fully dissolved.

[0088] (2) Separation of oil and grease:

[0089] Transfer the fully dissolved test solution to the chromatography column 5 using a funnel. Then rinse the weighing bottle, the inner wall of the upper end of the glass chromatography column, and the funnel with petroleum ether to ensure that all the solution flows into the chromatography column 5.

[0090] When the liquid level is close to the upper silica gel layer, wash column 5 with 30 mL of petroleum ether three times. Collect the effluent in a 50 mL beaker and record it as solution A.

[0091] The above oil separation process is carried out in a fume hood, and reagents are added in conjunction with the above process. Figure 2The rotating stage shown has an upper turntable 3 and a side door for the fume hood, which ensure that only one set of chromatography columns is at the fume hood opening. After adding reagents, the side door is closed immediately to prevent reagents from escaping outside the fume hood.

[0092] (3) Reagent recovery:

[0093] Solution A is placed on a hot plate at 80°C to recover the petroleum ether reagent, allowing the petroleum ether to evaporate completely.

[0094] (4) Wax precipitation by cooling:

[0095] After the petroleum ether has just completely evaporated, add 2 mL of petroleum ether while it is still hot (the process is 90-120℃) to dissolve all the wax. After the solution cools to room temperature, quickly add 10 mL of chilled 8℃ anhydrous ethanol, shake for 1 minute, cover and place in the refrigerator to allow the wax to precipitate at 8℃ for 5 hours. Filter the precipitated wax and mother liquor through a glass funnel plugged with absorbent cotton at 8℃. After filtering out the mother liquor, replace the funnel with a pre-weighed 50 mL weighing bottle. Dissolve all the wax adsorbed on the mother liquor cup with 42℃ petroleum ether and transfer it to the funnel containing the wax. Wash the absorbent cotton and surrounding area with 42℃ petroleum ether to remove the wax. Finally, rinse the outlet of the glass funnel with 42℃ petroleum ether. The resulting wax solution is designated as solution B.

[0096] (5) Volatilization, constant weight:

[0097] Solution B was placed on a hot plate and the reagent was evaporated at 90°C. Then it was placed in a constant temperature oven at 105°C for 4 hours. After that, it was placed in a desiccator to cool for 1 hour and weighed for the first time. The mass was 30.0318 g. After that, it was placed in a desiccator to cool for 30 minutes and weighed for the second time. The mass was 33.0320 g. The difference between the two weighings was 0.0002 g.

[0098] 3. Wax content calculation:

[0099] The wax content of crude oil samples is calculated using the following formula.

[0100] x1=(m2-m1) / m0×100%=(33.0320-33.0211) / 0.0550×100%=19.81%.

[0101] 4. Separate the gum from the crude oil:

[0102] (1) Separation of colloidal substances:

[0103] The separation of colloids was performed inside a fume hood, using a rotating separation stage and a side-opening door of the fume hood. Only one column was positioned at the fume hood opening. After separating the oil, 30 ml of anhydrous ethanol-petroleum ether (60℃~90℃) mixed solution (1:3) was added to column 5. Column 5 was rinsed three times, with 10 ml of reagent added each time. The side-opening door was immediately closed after each reagent addition to prevent reagent from escaping outside the fume hood. After rinsing and waiting for all the solution to flow out, the weighing Erlenmeyer flask was removed, and the eluent from the colloid separation process was collected in a 50 mL Erlenmeyer flask that had been pre-weighed; this was designated as solution C.

[0104] (2) Volatilization, constant weight:

[0105] Solution C was placed on a hot plate and the reagent was evaporated at 90°C. Then it was placed in a constant temperature oven at 105°C for 4 hours. After that, it was placed in a desiccator to cool for 1 hour and weighed for the first time. The mass was 32.4557 g. After that, it was placed in a desiccator to cool for 30 minutes and weighed for the second time. The mass was 32.4558 g. The difference between the two weighings was 0.0001 g.

[0106] 5. Calculation of gelatin content:

[0107] The gum content of crude oil samples is calculated using the following formula.

[0108] x2=(m3-m1) / m0×100%=(32.4558-32.4501) / 0.0550×100%=10.36%.

[0109] Example 2

[0110] 1. Take oil samples and weigh three portions using a 0.0500g, 0.0500g, and 0.0500g balance, respectively. Prepare three test solutions using the same method as in Example 1, and number them 1#-1, 1#-2, and 1#-3, respectively. The wax content and gum content of the samples are analyzed by the same operator, A. The experimental results are shown in Table 1 below: the standard deviation and relative standard deviation of wax content are 0.04% and 0.13%, respectively, and the standard deviation and relative standard deviation of gum content are 0.02% and 0.19%, respectively. As shown in Table 1, the precision of the determination method disclosed in this paper is good.

[0111] Table 1. Results of wax and gum content determination in sample A.

[0112]

[0113] 2. Take three oil samples, weigh them using a 0.0500g, 0.0500g, and 0.0500g balance respectively. Prepare three test solutions according to the above test solution preparation method. Three people, A, B, and C, analyze the wax content and gum content of the samples respectively. The experimental results are shown in Table 2 below: the maximum absolute deviation and maximum relative deviation of wax content are 0.24% and 0.85% respectively, and the standard deviation and relative standard deviation of gum content are 0.09% and 0.75% respectively. As shown in Table 2, the method disclosed in this paper has good reproducibility.

[0114] Table 2. Results of wax and gum content determination in oil samples A, B, and C.

[0115]

[0116] The embodiments described above are merely illustrative of implementation methods of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent disclosure. It should be noted that those skilled in the art can make various modifications, equivalent substitutions, and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent disclosure should be determined by the appended claims.

Claims

1. A method for determining the wax and gum content in crude oil, characterized in that, include: Wax and gum in crude oil were separated by chromatography; The chromatography method uses activated clay and silica gel as adsorbents, and petroleum ether and anhydrous ethanol as washing reagents.

2. The method for determining the wax and gum content in crude oil according to claim 1, characterized in that, The method for separating waxes and gums from crude oil by chromatography includes: Packing the chromatography column; The method for packing the chromatography column is to place defatted cotton at the bottom of the chromatography column, add 2-3g of silica gel, 8-10g of activated clay-silica gel mixture and 2-3g of silica gel on the defatted cotton in sequence, and then shake the chromatography column to make the adsorbent firm. The mass ratio of activated clay to silica gel in the activated clay-silica gel mixture is 1:7 to 9.

3. The method for determining the wax and gum content in crude oil according to claim 2, characterized in that: The activated clay-silica gel mixture has an activated clay to silica gel mass ratio of 1:8; and / or The activated clay has a mesh size of 60-120, and the silica gel has a mesh size of 100-200. The activated clay and the silica gel are activated at a temperature of 150℃ to 180℃ for a duration of 24 hours or more. The mixing method of the activated clay-silica gel mixture is as follows: after the activated clay and silica gel are mixed evenly according to the mass ratio, the mixture is activated again at 150°C for 8 hours to obtain the activated clay-silica gel mixture.

4. The method for determining the wax and gum content in crude oil according to claim 3, characterized in that: After packing the chromatography column, the column is rinsed with petroleum ether to ensure that the adsorbent inside the column is completely wetted.

5. The method for determining the wax and gum content in crude oil according to any one of claims 1-4, characterized in that, The method for separating wax from crude oil by chromatography includes: The oil sample is completely dissolved in petroleum ether to obtain a test solution. The entire test solution is transferred to the chromatography column, and the chromatography column is eluted with petroleum ether with a boiling range of 60℃~90℃ to separate the oil. The eluent is collected. After heating to remove the solvent from the effluent, petroleum ether with a boiling range of 90°C to 120°C is added to dissolve the wax therein, resulting in a wax-containing solution. The wax-containing solution is cooled to allow the wax to precipitate, the wax is collected, and the wax content of the crude oil sample is calculated.

6. The method for determining the wax and gum content in crude oil according to claim 5, characterized in that: The method for completely dissolving an oil sample in petroleum ether to obtain a test solution includes: weighing 0.05 ± 0.005 g of the oil sample into a weighing bottle, accurate to 0.0001 g, and dissolving the oil sample in 10 ml of petroleum ether with a boiling range of 60°C to 90°C until the oil sample is completely dissolved; and / or, The method for transferring all of the test solution to the chromatography column includes: After transferring the test solution from the weighing bottle to the chromatography column using a funnel, rinse the weighing bottle, the inner wall of the chromatography column, and the funnel with petroleum ether with a boiling range of 60°C to 90°C, ensuring that all the rinsing solution flows into the chromatography column; and / or, The method for removing solvent from the effluent by heating includes: placing the effluent on a hot plate at a temperature of 80℃±10℃ to allow the solvent in the effluent to evaporate until the solvent has completely evaporated.

7. The method for determining the wax and gum content in crude oil according to claim 6, characterized in that: The method for cooling the wax-containing solution to precipitate wax includes: cooling the wax-containing solution to room temperature, adding anhydrous ethanol at 6°C to 8°C, and allowing it to stand at 6°C to 8°C for at least 4 hours to allow wax precipitation; and / or, The method for collecting the wax includes: filtering the precipitated wax and mother liquor through a funnel at 6℃~8℃ to remove the mother liquor, and then dissolving the wax in the funnel and the residual wax in each step of the filtration process with petroleum ether at 40℃~45℃ and a boiling range of 60℃~90℃ to obtain a wax solution. After the wax solution is volatilized and subjected to constant weight treatment, wax separated from crude oil is obtained.

8. The method for determining the wax and gum content in crude oil according to claim 5, characterized in that, The method for separating colloids from crude oil by chromatography includes: The chromatography column after oil separation is washed with an anhydrous ethanol-petroleum ether mixed solution, and the washing liquid is collected; the volume ratio of ethanol to petroleum ether in the mixed solution is 1:3, and the boiling range of the petroleum ether is 60℃~90℃. After the flushing fluid is volatilized and subjected to constant weight treatment, the gum separated from the crude oil is obtained.

9. The method for determining the wax and gum content in crude oil according to claim 7, characterized in that, The method for evaporating and maintaining a constant weight of the wax solution and the rinsing solution includes: The wax solution or the rinsing solution is placed on a hot plate at a temperature of 90℃±5℃ to allow the solvent in the wax solution or the rinsing solution to evaporate completely. After that, it is kept at a constant temperature of 105℃ for 4 hours. Then, it is taken out and placed in a desiccator to cool for 1 hour. The first weighing is performed, and then it is placed in the desiccator to cool for 30 minutes. The second weighing is performed, until the difference between the two weighings is less than 0.0004g.

10. An apparatus for determining the wax and gum content in crude oil, characterized in that, include: A chromatography column (5) is placed inside a fume hood; The wax and gum in crude oil are separated by the chromatography column (5) to complete the determination of the wax and gum content in crude oil; The measurements were performed in the fume hood.

Images