Method for crude oil component analysis experiment

Abstract

The invention belongs to the technical field of crude oil analysis, and discloses a method for crude oil component analysis experiments. Comprising the steps of designing and selecting a chromatographic column, preferably selecting the use amount of a crude oil sample, preferably selecting the use amount of an adsorbent, preferably selecting the type and use amount of leacheate, performing a recovery experiment and performing a repetitive experiment. According to the method, the wax effluent is completely volatilized, then the wax is precipitated, and experiments show that the precipitated wax is more complete, the wax content is higher, the recovery rate is higher, and the result is better.

Description

Technical Field

[0001] This invention belongs to the field of crude oil analysis technology, and specifically relates to a method for crude oil component analysis experiments. Background Technology

[0002] In the later stages of development, the physical properties of crude oil in most blocks of the oilfield have changed, leading to problems such as scaling, sand production, and wax precipitation in some production wells during extraction. Under these circumstances, data such as wax content, gum content, and wax melting point in the crude oil of each development well become more important. However, due to limitations in experimental conditions, the laboratory can only analyze no more than 400 samples per year, and the reagent consumption is large, requiring infrared drying ovens to dry the samples, which poses safety hazards. This has created some experimental research and development needs, leading to the development of a new crude oil component analysis method that shortens the analysis cycle, saves on analytical reagent consumption, and increases the safety of the analysis cycle. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a method for crude oil component analysis experiments. By employing a novel chromatography column and optimizing the amounts of crude oil sample, adsorbent, and eluent, the optimal indicators for the crude oil component analysis method are finally selected. The method is then validated through repeatability and comparative experiments, ultimately establishing a new method for crude oil component analysis to meet production needs.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: a method for crude oil component analysis experiments, comprising the following steps:

[0005] 1. Design and selection of chromatography columns;

[0006] 2. Optimize the amount of crude oil sample used;

[0007] 3. Optimize the adsorbent dosage;

[0008] 4. Optimize the type and dosage of rinsing solution;

[0009] 5. Recovery experiment;

[0010] 6. Repeatability experiments.

[0011] Furthermore, step 1 specifically involves designing a chromatography column with a wide opening and a certain inner diameter, length, and wall thickness, based on the specific experimental requirements.

[0012] Furthermore, step 2 specifically involves: weighing crude oil samples of different masses for chromatographic analysis, and selecting the amount of crude oil sample within the error range.

[0013] Furthermore, step 3 specifically involves:

[0014] A. Comparative experiments were conducted using different masses of silicone to select the optimal amount of silicone.

[0015] B. Comparative experiments were conducted using different masses of silica gel and clay mixtures, and the optimal amount of silica gel and clay mixture was selected first.

[0016] C. Determine the optimal ratio of silica gel and kaolin silica gel in the adsorbent through steps A and B.

[0017] Furthermore, step 4 specifically involves:

[0018] a. Use different volumes of petroleum ether for rinsing, determine the gum content of crude oil, and select the better amount of petroleum ether;

[0019] b. Use different volumes of ethanol-petroleum ether 1:3 mixed solution for rinsing, determine the wax content of crude oil, and select the better amount of ethanol-petroleum ether mixed solution.

[0020] Furthermore, step 5 specifically involves: preparing pure gum and pure wax according to the dosage selected in step 4, preparing standard samples according to different wax contents, and filling the chromatography column sequentially with silica gel, kaolin silica gel, and silica gel.

[0021] Furthermore, step 6 specifically involves obtaining two independent test results under the condition of repeating steps 1-5, and screening out results where the absolute difference error between the two independent test results is less than 5%.

[0022] In a further preferred embodiment of the present invention, the chromatography column in step 1 has a wide mouth, an inner diameter of 8-10 mm, a length of 450-500 mm, and a wall thickness of 0.8-1 mm.

[0023] In a further preferred embodiment of the present invention, the optimal amount of crude oil sample used in step 2 is not less than 0.05g.

[0024] In a further preferred embodiment of the present invention, the optimal mass ratio of the adsorbent in step 3 is silica gel: kaolin silica gel: silica gel = 1:4:1, wherein the mass ratio of kaolin silica gel is kaolin: silica gel = 1:8.

[0025] In a further preferred embodiment of the present invention, the optimal amount of petroleum ether used in step 4 is not less than 30 ml, and the optimal amount of ethanol petroleum ether used is not less than 30 ml.

[0026] The advantages of this invention compared to the prior art are as follows: the prior art has an additional step of recovering wax and glue, which takes 4 hours to recover wax and 4 hours to recover glue. The present invention also differs from the prior art in the wax precipitation process. The prior art recovers the wax effluent to 3-5 mL for wax precipitation, while the present invention completely evaporates the wax effluent before wax precipitation. Experiments show that the wax precipitated by the present invention is more complete, has a higher wax content, a higher recovery rate, and better results. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] Figure 1 This is a schematic diagram of the chromatography column structure used in this invention;

[0029] Figure 2 This is a comparison chart of the amount of gum in different crude oil samples according to the present invention;

[0030] Figure 3 This is a comparison chart of wax content in different crude oil sample quantities according to the present invention;

[0031] Figure 4 This is a comparison chart of experimental data for different adsorbent ratios (silica gel: clay silica gel: silica gel) of the present invention;

[0032] Figure 5 This is a comparison chart of experimental data for different amounts of rinsing solution used in this invention. Detailed Implementation

[0033] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0034] Example 1

[0035] This method, developed to address the growing inadequacy of existing enterprise standards to meet production demands, presents a novel approach for crude oil component analysis. It primarily utilizes a new type of chromatography column.

[0036] Then, by optimizing the amount of crude oil sample, adsorbent, and eluent, the optimal indicators for each component in the crude oil analysis method were finally selected. The method was then verified through repeatability and comparative experiments, and a new method for analyzing crude oil components was finally established to meet production needs.

[0037] (1) Design and selection of chromatography columns

[0038] Design a chromatography column with a wide opening, an inner diameter of 10 mm, a length of 500 mm, and a wall thickness of 1 mm to replace the chromatography column with an inner diameter of 25–30 mm used in the original method.

[0039] (2) Optimal Crude Oil Sample Amount

[0040] Crude oil samples of 0.01g, 0.03g, 0.05g, 0.08g, 0.10g, 0.12g, and 0.15g were weighed respectively. 1g of silica gel, 8g of silica gel-clay mixture, and 1g of silica gel were added sequentially as adsorbent. The eluent was then rinsed sequentially with 30ml of petroleum ether and 30ml of a mixture of anhydrous ethanol and petroleum ether. The results were compared with existing enterprise standards, and the optimal amount of crude oil sample within the error range was finally selected.

[0041] from Figure 2 and Figure 3 As can be seen, the experimental data for crude oil samples of 0.05g are basically close to the current method. The results for crude oil samples smaller than 0.05g are too large, while the results for crude oil samples larger than 0.05g are too small. Finally, 0.05g was determined to be the optimal amount of crude oil sample.

[0042] (3) Optimal dosage of adsorbent

[0043] ①Optimal use of silicone

[0044] Comparative experiments were conducted by filling 0.5g, 1g, 1.5g, 2g, 2.5g, and 3g of silicone respectively, and the amount of silicone used that was better compared with the original method was selected.

[0045] ②Optimal dosage of silica gel and clay mixture

[0046] Comparative experiments were conducted by filling silica gel and clay mixtures with 2g, 3g, 4g, and 6g respectively, and the optimal amount of silica gel and clay mixture compared with the original method was selected.

[0047] Crude oil sample volume: 0.05g. Under infrared constant temperature conditions, the eluents were 30ml petroleum ether and 30ml ethanol:petroleum ether = 1:3 mixed solvent. The adsorbents were silica gel: bleaching clay silica gel (1:8 mixed): silica gel = 1:8:1; 1:6:1; 1:5:1; 1:4:1; 1:4:0.7.

[0048] from Figure 4 It can be seen that the adsorbent ratios of silica gel:clay silica gel:silica gel = 1:4:1 and 1:4:0.7 show better results than other adsorbent ratios. The results for determining the colloidal content also show good correlation between these two ratios. Furthermore, the new method exhibits a higher recovery rate than the old method. Considering all factors, we ultimately selected silica gel:clay silica gel:silica gel = 1:4:1 as the optimal adsorbent ratio.

[0049] (4) Optimization of the type and dosage of rinsing solution

[0050] ①Petroleum ether dosage

[0051] The crude oil was rinsed with 10 mL, 20 mL, 30 mL, 40 mL, and 50 mL of petroleum ether, respectively, and the gum content was determined. The optimal amount of petroleum ether was compared with the original method.

[0052] ② Dosage of ethanol-petroleum ether mixed solution

[0053] The crude oil was rinsed with 10 mL, 20 mL, 30 mL, 40 mL, and 50 mL of a 1:3 mixture of ethanol and petroleum ether, and the wax content was determined. The optimal amount of ethanol-petroleum ether mixture was compared with the original method.

[0054] The quality of chromatography is greatly affected by the height of the eluent. If we want to maintain a liquid level roughly the same as the existing standard, since the current chromatography column diameter is 1 cm, the current eluent volume should be between 0.16 and 0.11 times the original eluent volume. The original eluent volume was 200 ml, while the new method uses 30 ml. A comparative experiment between the old and new methods was conducted.

[0055] from Figure 5 It can be seen that the data correspond well with a rinsing solution volume of 30ml, and the overall recovery rate is higher than that of the original method.

[0056] (5) Recycling Experiment

[0057] Pure gum and pure wax were prepared, and then standard samples were prepared according to wax content of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. The chromatography column was filled with silica gel, bleached clay and silica gel (1:8 mixture), and silica gel 1g:4g:1g. The eluent was used for recovery experiments with 30mL. The experimental data are shown in Table 1. The repeatability test results met the repeatability limit table, and the recovery rate was greater than 93%, which meets the requirement of 85% to 100%.

[0058] Table 1. Data from the Recovery Experiment

[0059]

[0060] (6) Repeatable experiments

[0061] The absolute difference between two independent test results obtained under repeatability conditions should meet the given value of the repeatability limit table, with the standard that the repeatability limit value does not exceed 5%.

[0062] The error is less than 5%, and the repeatability is good.

[0063] Table 2. Repeatability Experiment Data

[0064]

[0065] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for crude oil component analysis experiments, characterized in that, Includes the following steps: S1. Design and selection of chromatography columns; S2. Optimize the amount of crude oil sample used; S3. Optimize the amount of adsorbent; S4. Optimize the type and dosage of the rinsing solution; S5. Recycling experiment; S6. Repeatability test.

2. The method for crude oil component analysis experiments according to claim 1, characterized in that, Step S1 specifically involves designing a wide-mouth chromatography column with a certain inner diameter, length, and wall thickness, based on the specific experimental requirements.

3. The method for crude oil component analysis experiments according to claim 1, characterized in that, Step S2 specifically involves weighing crude oil samples of different masses for chromatographic analysis and selecting the optimal amount of crude oil sample within the error range.

4. The method for crude oil component analysis experiments according to claim 1, characterized in that, Step S3 specifically involves: A. Comparative experiments were conducted using different masses of silicone to select the optimal amount of silicone. B. Comparative experiments were conducted using different masses of silica gel and clay mixtures, and the optimal amount of silica gel and clay mixture was selected first. C. Determine the optimal ratio of silica gel and kaolin silica gel in the adsorbent through steps A and B.

5. The method for crude oil component analysis experiments according to claim 1, characterized in that, Step S4 specifically involves: a. Use different volumes of petroleum ether for rinsing, determine the gum content of crude oil, and select the better amount of petroleum ether; b. Use different volumes of ethanol-petroleum ether 1:3 mixed solution for rinsing, determine the wax content of crude oil, and select the better amount of ethanol-petroleum ether mixed solution.

6. The method for crude oil component analysis experiments according to claim 5, characterized in that, Step S5 specifically involves preparing pure gum and pure wax according to the dosage selected in step 4, preparing standard samples according to different wax contents, and filling the chromatography column sequentially with silica gel, kaolin silica gel, and silica gel.

7. The method for crude oil component analysis experiments according to claim 1, characterized in that, Step S6 specifically involves obtaining two independent test results under the condition of repeating steps 1-5, and screening out results where the absolute difference error between the two independent test results is less than 5%.

8. The method for crude oil component analysis experiments according to claim 2, characterized in that, The chromatography column in step S1 has a wide opening, an inner diameter of 8-10 mm, a length of 450-500 mm, and a wall thickness of 0.8-1 mm.

9. The method for crude oil component analysis experiments according to claim 3, characterized in that, The optimal amount of crude oil sample used in step S2 is not less than 0.05g.

10. The method for crude oil component analysis experiments according to claim 5, characterized in that, In step S4, the optimal amount of petroleum ether is not less than 30 ml, and the optimal amount of ethanol petroleum ether is not less than 30 ml.

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