A viscosity reducer for thick oil with colloid as main viscosity contribution component and a preparation method thereof

Abstract

The application discloses a thickened oil viscosity reducer for a main viscosity contribution component of colloid and a preparation method thereof. The thickened oil viscosity reducer comprises the following components in percentage by weight: diethylene glycol methyl ether 25-35%, propylene glycol formate 15-25%, dispersant 5-8%, chelating agent 2-4%, anti-coking agent 0.5-1%, anti-swelling agent 1-2% and corrosion inhibitor 1-2%; and the balance is water. The application is a polar + non-aromatic hydrocarbon solvent system; completely avoids high-risk substances such as nonylphenol polyoxyethylene ether, petroleum sulfonate sodium and organic chlorine; is designed in pertinence and can effectively inhibit metal-induced asphaltene bridging; can withstand working conditions from normal temperature to 250 DEG C and up to 300 DEG C; thermal stability is significantly enhanced, and residual carbon after aging is lower than 8%; viscosity reduction efficiency is higher; the system is more stable, flexible in compounding and suitable for field construction.

Description

Technical Field

[0001] This invention belongs to the field of petroleum development technology, specifically relating to a viscosity reducer for heavy oil where gum is the main viscosity contributing component, and its preparation method. Background Technology

[0002] Extra-heavy oil presents significant challenges to extraction and transportation due to its high viscosity, high density, and high content of gums and asphaltenes. Viscosity reducers are an important means of improving the fluidity of extra-heavy oil, and are usually composed of polymers, surfactants, or oilfield chemicals. Classic viscosity reducer techniques reduce viscosity by altering the molecular structure of extra-heavy oil or reducing its internal friction. (1) Polymer viscosity reducers: Polymer viscosity reducers reduce the viscosity of oil by interacting with wax hydrocarbons and asphaltenes in extra-heavy oil to form a solution. These viscosity reducers generally have good thermal stability and acid resistance and can remain effective at higher temperatures. (2) Surfactants: Surfactants improve fluidity by reducing the interfacial tension of liquids and promoting the separation of oil and water phases. Specific surfactants can form complexes with gums and asphaltenes in extra-heavy oil to further reduce viscosity. (3) Solvent method: The solvent method uses light hydrocarbon solvents to dilute extra-heavy oil and reduce its viscosity. This method is relatively simple, but attention should be paid to the selection of solvents to avoid negative impacts on the properties of the oil.

[0003] Although existing technologies have made some progress in viscosity reduction, they still face the following technical bottlenecks: (1) High temperature stability: The steam injected during thermal recovery of extra-heavy oil reaches temperatures above 250°C, requiring viscosity reducers to maintain their viscosity reduction effect under such conditions. Most viscosity reducers are prone to degradation at high temperatures, resulting in a significant reduction in effectiveness; (2) Adaptability and selectivity: Extra-heavy oil has a complex composition, containing a high proportion of gums and asphaltenes, and viscosity reducers need to have good compatibility with different components. Current viscosity reducer designs often lack specificity and are difficult to optimize for specific oil products; (3) Influence of metal ions: The enrichment of metal ions (such as Fe, Ni, Ca, etc.) in extra-heavy oil may have a negative impact on the performance of viscosity reducers, resulting in unsatisfactory viscosity reduction effects. Viscosity reducers need to have the ability to resist interference from metal ions; (4) Economic efficiency: High-performance viscosity reducers are often expensive, especially in large-scale applications. How to reduce costs while ensuring effectiveness is an urgent problem to be solved; (5) Environmental friendliness: Many components of viscosity reducers may have an impact on the environment. How to develop environmentally friendly viscosity reducers is an important direction for future research.

[0004] In summary, given the characteristics of extra-heavy oils where gum is the main viscosity contributor, research on viscosity reducers needs to make continuous breakthroughs in improving high-temperature stability, adaptability, resistance to metal ion interference, economy, and environmental friendliness in order to achieve efficient viscosity reduction. Summary of the Invention

[0005] The purpose of this invention is to provide a viscosity reducer for heavy oils where the main viscosity-contributing component is gum.

[0006] A viscosity reducer for heavy oils where gum is the main viscosity contributor, comprising the following components by weight percentage: 25-35% diethylene glycol methyl ether, 15-25% propylene glycol methyl ester, 5-8% dispersant, 2-4% chelating agent, 0.5-1% coking inhibitor, 1-2% anti-swelling agent, 1-2% corrosion inhibitor; the balance being water.

[0007] The dispersant is one or more of alkyl polysaccharide APG1214, cocamidopropyl betaine, and erucamide propyl betaine.

[0008] The chelating agent is one or more of EDTA-tetrasodium, diethylenetriaminepentamethylenephosphonic acid, and phytic acid.

[0009] The scorch inhibitor is one or more of 2,6-di-tert-butyl-p-cresol, N-(3-dimethylaminopropyl)acrylamide, and dodecylbenzenesulfonic acid.

[0010] The anti-swelling agent is one or more of potassium chloride, dimethyl diallyl ammonium chloride, and polydimethyl diallyl ammonium chloride.

[0011] The corrosion inhibitor is one or more of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt, diethylenetriamine, and 2-aminobenzothiazole.

[0012] The preparation method of the viscosity reducer for heavy oil with gum as the main viscosity contributing component is carried out according to the following steps:

[0013] (1) Add 250ml of water to the container and stir with a magnetic stirrer. After the vortex stabilizes, add 150-220 ml of diethylene glycol methyl ether and stir for 10-15 minutes. Add 90-150 ml of propylene glycol formate and stir for 10-15 minutes.

[0014] (2) Add the following to the vortex of the liquid in step (1): 30-50g of dispersant; 12-25g of chelating agent; 3-6.5g of scorching inhibitor; 6-12.5g of anti-swelling agent; and continue stirring for 10-15 minutes;

[0015] (3) Add 6-12.5g of corrosion inhibitor to the vortex of the liquid in step (2); and continue stirring for 25-30 minutes.

[0016] The stirring rate is 35-55 revolutions per minute.

[0017] The beneficial effects of this invention are as follows: This invention is a polar solvent system without aromatic hydrocarbons; it completely avoids high-risk substances such as nonylphenol polyoxyethylene ether, sodium petroleum sulfonate, and organochlorines; its targeted design can effectively suppress metal-induced asphalt bridging; it can withstand working conditions from room temperature to 250℃ and up to 300℃; its thermal stability is significantly enhanced, and the residual carbon after aging is less than 8%; it has a higher viscosity reduction efficiency; the system is more stable and flexible in formulation, making it suitable for on-site construction. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0019] Example 1

[0020] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0021] (1) Add 250ml of water to the container and stir with a magnetic stirrer (45 rpm). After the vortex stabilizes, add 180ml of diethylene glycol methyl ether and stir for 12 minutes. Add 120ml of propylene glycol formate and stir for 12 minutes.

[0022] (2) In step (1), add the following to the vortex of the liquid: 40g of alkyl polysaccharide (APG1214); 10g of EDTA-tetrasodium; 10g of diethylenetriaminepentimethylenephosphonic acid; 2g of 2,6-di-tert-butyl-p-cresol; 3g of N-(3-dimethylaminopropyl)acrylamide; and 10g of potassium chloride; and continue stirring for 12 minutes.

[0023] (3) Add 9g of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt to the vortex of the liquid in step (2); and continue stirring (45 rpm) for 28 minutes.

[0024] Example 2

[0025] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0026] (1) Add 250ml of water to the container and stir with a magnetic stirrer (40 rpm). After the vortex stabilizes, add 160 ml of diethylene glycol methyl ether and stir for 10 minutes. Add 100 ml of propylene glycol formate and stir for 10 minutes.

[0027] (2) In step (1), the following are added sequentially to the vortex of the liquid: 32g of cocamidopropyl betaine; 6g of EDTA-tetrasodium chelating agent; 7g of diethylenetriaminepentamethylenephosphonic acid; 2g of 2,6-di-tert-butyl-p-cresol; 2g of N-(3-dimethylaminopropyl)acrylamide; 7g of dimethyldiallyl ammonium chloride; and stirred continuously for 10 minutes.

[0028] (3) Add 7g of diethylenetriamine to the vortex of the liquid in step (2); and continue stirring (40 rpm) for 26 minutes.

[0029] Example 3

[0030] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0031] (1) Add 250ml of water to the container and stir with a magnetic stirrer (50 rpm). After the vortex stabilizes, add 200ml of diethylene glycol methyl ether and stir for 15 minutes. Add 140ml of propylene glycol formate and stir for 15 minutes.

[0032] (2) In step (1), add the following to the vortex of the liquid: 45g of erucamide propyl betaine; 10g of EDTA-tetrasodium sodium; 12g of diethylenetriaminepentamethylenephosphonic acid; 3g of 2,6-di-tert-butyl-p-cresol; 3g of N-(3-dimethylaminopropyl)acrylamide; 11g of polydimethyldiallyl ammonium chloride; and continue stirring for 15 minutes.

[0033] (3) Add 11g of 2-aminobenzothiazole to the vortex of the liquid in step (2); and continue stirring (50 rpm) for 30 minutes.

[0034] Example 4

[0035] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0036] (1) Add 250ml of water to the container and stir with a magnetic stirrer (45 rpm). After the vortex stabilizes, add 180ml of diethylene glycol methyl ether and stir for 12 minutes. Add 120ml of propylene glycol formate and stir for 12 minutes.

[0037] (2) In step (1), add the following to the vortex of the liquid: 40g of alkyl polysaccharide (APG1214); 20g of EDTA-tetrasodium; 2g of 2,6-di-tert-butyl-p-cresol; 3g of N-(3-dimethylaminopropyl)acrylamide; and 10g of potassium chloride; and continue stirring for 12 minutes.

[0038] (3) Add 9g of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt to the vortex of the liquid in step (2); and continue stirring (45 rpm) for 28 minutes.

[0039] Example 5

[0040] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0041] (1) Add 250ml of water to the container and stir with a magnetic stirrer (45 rpm). After the vortex stabilizes, add 180ml of diethylene glycol methyl ether and stir for 12 minutes. Add 120ml of propylene glycol formate and stir for 12 minutes.

[0042] (2) In step (1), add the following to the vortex of the liquid: 40g of alkyl polysaccharide (APG1214); 20g of diethylenetriaminepentamethylenephosphonic acid; 2g of 2,6-di-tert-butyl-p-cresol; 3g of N-(3-dimethylaminopropyl)acrylamide; and 10g of potassium chloride; and continue stirring for 12 minutes.

[0043] (3) Add 9g of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt to the vortex of the liquid in step (2); and continue stirring (45 rpm) for 28 minutes.

[0044] Example 6

[0045] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0046] (1) Add 250ml of water to the container and stir with a magnetic stirrer (45 rpm). After the vortex stabilizes, add 180ml of diethylene glycol methyl ether and stir for 12 minutes. Add 120ml of propylene glycol formate and stir for 12 minutes.

[0047] (2) In step (1), add the following to the vortex of the liquid: 40g of alkyl polysaccharide (APG1214); 10g of EDTA-tetrasodium; 10g of diethylenetriaminepentimethylenephosphonic acid; 5g of 2,6-di-tert-butyl-p-cresol; 10g of potassium chloride; and continue stirring for 12 minutes.

[0048] (3) Add 9g of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt to the vortex of the liquid in step (2); and continue stirring (45 rpm) for 28 minutes.

[0049] Example 7

[0050] A method for preparing a viscosity reducer for heavy oil where gum is the main viscosity contributing component, comprising the following steps:

[0051] (1) Add 250ml of water to the container and stir with a magnetic stirrer (45 rpm). After the vortex stabilizes, add 180ml of diethylene glycol methyl ether and stir for 12 minutes. Add 120ml of propylene glycol formate and stir for 12 minutes.

[0052] (2) In step (1), add the following to the vortex of the liquid: 40g of alkyl polysaccharide (APG1214); 10g of EDTA-tetrasodium; 10g of diethylenetriaminepentimethylenephosphonic acid; 5g of N-(3-dimethylaminopropyl)acrylamide; 10g of potassium chloride; and continue stirring for 12 minutes.

[0053] (3) Add 9g of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt to the vortex of the liquid in step (2); and continue stirring (45 rpm) for 28 minutes.

[0054] Performance evaluation:

[0055] (1) Take the heavy oil viscosity reducer prepared in Example 1; prepare 0.5L of test reagent (oil sample prepared with oil-water ratio of 3:7), the control group is commercially available viscosity reducer (manufacturer: Karamay Sanda New Technology Co., Ltd.; product: viscosity reducer, surfactant SDCY; product number: SDCY batch number: 20250604) with an addition of 10.3%, and the heavy oil viscosity reducer of Example 1 with an addition of 8%. The temperature-viscosity properties of the heavy oil sample with an oil-water ratio of 3:7 were determined according to the Brookfield DV2T specification.

[0056] The test results are shown in Table 1. The viscosity of the pure agent decreased faster and more significantly: the self-developed formula could be reduced to 150 mPa·s at 250℃, which is far superior to the 300 mPa·s of the commercially available formula. The viscosity of the test oil sample was even lower after adding the viscosity reducer: the self-developed formula (8% addition) could be reduced to 95 mPa·s at 300℃, which is superior to the 180 mPa·s of the commercially available formula (10.3% addition).

[0057] Table 1. Comparison of Temperature-Viscosity Properties of Viscosity Reduction Systems

[0058]

[0059] (2) Prepare 0.5L of test reagent (oil sample prepared with oil and water in a 3:7 ratio). Add 8% of the heavy oil viscosity reducer prepared in Examples 1-3 and 4-5. Determine the metal ion inhibition ability of the viscosity reducer system at 250℃ according to ICP-OES. The experimental results were statistically analyzed using SPSS 24.0 software. The results of the measurement data are expressed as x ± (mean ± standard deviation). The Kolmogorov-Smirnov test was used to test the normality of the data. For data that conform to normal distribution, the difference between the means of the two groups was compared by t test. P < 0.05 was considered to be statistically significant. The test results are shown in Table 2:

[0060] Table 2

[0061]

[0062] Note: * indicates that compared with Example 1 group, P<0.05.

[0063] (3) Prepare 0.5L of test reagent (oil sample prepared with oil and water in a 3:7 ratio). Add 8% of the heavy oil viscosity reducer prepared in Examples 1-3 and 6-7. Analyze the 250℃ coking performance of the viscosity reducer system according to the residual carbon of the heavy components. The experimental results were statistically analyzed using SPSS 24.0 software. The results of the quantitative data are expressed as x ± (mean ± standard deviation). The Kolmogorov-Smirnov test was used to test the normality of the data. For data that conform to a normal distribution, the difference between the means of the two groups was compared using a t-test. P < 0.05 was considered statistically significant. The test results are shown in Table 3.

[0064] Table 3

[0065]

[0066] Note: * indicates P < 0.05 compared to Example 1. The above embodiments only illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A viscosity reducer for heavy oils where gum is the main viscosity-contributing component, characterized in that, It comprises the following components by weight percentage: 25-35% diethylene glycol methyl ether, 15-25% propylene glycol methyl ester, 5-8% dispersant, 2-4% chelating agent, 0.5-1% coking inhibitor, 1-2% anti-swelling agent, 1-2% corrosion inhibitor; the balance is water. The dispersant is one or more of alkyl polysaccharide glycoside APG1214, cocamidopropyl betaine, and erucamide propyl betaine; The chelating agent is one or more of EDTA-tetrasodium, diethylenetriaminepentamethylenephosphonic acid, and phytic acid. The scorching inhibitor is one or more of 2,6-di-tert-butyl-p-cresol, N-(3-dimethylaminopropyl)acrylamide, and dodecylbenzenesulfonic acid; The anti-swelling agent is one or more of potassium chloride, dimethyl diallyl ammonium chloride, and polydimethyl diallyl ammonium chloride; The corrosion inhibitor is one or more of N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt, diethylenetriamine, and 2-aminobenzothiazole.

2. The method for preparing the viscosity reducer for heavy oil with gum as the main viscosity contributing component as described in claim 1, characterized in that, Follow these steps: (1) Add 250ml of water to the container and stir with a magnetic stirrer. After the vortex stabilizes, add 150-220 ml of diethylene glycol methyl ether and stir for 10-15 minutes. Add 90-150 ml of propylene glycol formate and stir for 10-15 minutes. (2) Add the following to the vortex of the liquid in step (1): 30-50g of dispersant; 12-25g of chelating agent; 3-6.5g of scorching inhibitor; 6-12.5g of anti-swelling agent; and continue stirring for 10-15 minutes; (3) Add 6-12.5g of corrosion inhibitor to the vortex of the liquid in step (2); and continue stirring for 25-30 minutes.

3. The method for preparing a viscosity reducer for heavy oil with gum as the main viscosity contributing component according to claim 2, characterized in that, The stirring rate is 35-55 revolutions per minute.

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