Thickened oil viscosity reducer taking colloid as main viscosity contribution component and preparation method of thickened oil viscosity reducer

Abstract

The invention discloses a thick oil viscosity reducer taking colloid as a main viscosity contribution component and a preparation method of the thick oil viscosity reducer. Comprising the following components in percentage by weight: 25-35% of diethylene glycol monomethyl ether, 15-25% of propylene glycol formate, 5-8% of a dispersing agent, 2-4% of a chelating agent, 0.5-1% of a coke inhibitor, 1-2% of an anti-swelling agent and 1-2% of a corrosion inhibitor, and the balance of water. The solvent is a polar and aromatic-free solvent system; high-risk substances such as nonylphenol polyoxyethylene ether, petroleum sodium sulfonate and organochlorine are completely avoided; the metal-induced asphaltene bridging can be effectively inhibited through the targeted design; the maximum working condition of 300 DEG C can be tolerated from normal temperature to 250 DEG C; the thermal stability is obviously enhanced, and the residual carbon after aging is lower than 8%; the viscosity reduction efficiency is higher; the system is more stable, flexible in compatibility and suitable for on-site construction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil development, and specifically relates to a thickened oil viscosity reducer for which colloid is the main viscosity contributing component and a preparation method thereof. BACKGROUND

[0002] Super heavy oil poses great challenges for its exploitation and transportation due to its high viscosity, high density, and high content of colloid and asphaltene. Viscosity reducers are important means to improve the flowability of super heavy oil, usually composed of polymers, surfactants, or oilfield chemicals. Classical viscosity reducers reduce viscosity by changing the molecular structure of super heavy oil or reducing its internal friction. (1) Polymer viscosity reducers: Polymer viscosity reducers interact with wax hydrocarbons and asphaltene in super heavy oil to form a solution, reducing the viscosity of the oil. These viscosity reducers generally have good thermal stability and acid resistance, and can remain effective at high temperatures. (2) Surfactants: Surfactants improve flowability by reducing the interfacial tension of liquids, promoting oil-water phase separation. Specific surfactants can form complexes with colloid and asphaltene in super heavy oil, further reducing viscosity; (3) Solvent method: The solvent method uses light hydrocarbon solvents to dilute super heavy oil, reducing its viscosity. This method is relatively simple, but attention needs to be paid to the selection of solvents to avoid negative impacts on oil properties.

[0003] Despite the progress made in viscosity reduction by existing technologies, there are still technical bottlenecks: (1) High temperature stability: The injected steam for thermal recovery of super heavy oil is as high as 250℃ or above, requiring viscosity reducers to maintain their viscosity-reducing effect under such conditions. Most viscosity reducers degrade easily at high temperatures, resulting in a significant reduction in effectiveness; (2) Adaptability and selectivity: Super heavy oil has a complex composition, with a high proportion of colloid and asphaltene. Viscosity reducers need to have good compatibility with different components. Current viscosity reducer designs often lack specificity, making it difficult to optimize for specific oil products. (3) Metal ion influence: The enrichment of metal ions (such as Fe, Ni, Ca, etc.) in super heavy oil can negatively impact the performance of viscosity reducers, resulting in suboptimal viscosity reduction. Viscosity reducers need to have the ability to resist metal ion interference. (4) Economicity: High-performance viscosity reducers often have high costs, especially when used on a large scale. How to reduce costs while maintaining effectiveness is a problem that needs to be solved. (5) Environmental friendliness: The components of many viscosity reducers can have an impact on the environment. Developing environmentally friendly viscosity reducers is an important direction for future research.

[0004] In summary, in view of the characteristics of super heavy oil with colloid as the main viscosity contributing component, the research on viscosity reducers needs to continuously break through in improving high temperature stability, adaptability, resistance to metal ion interference, economicity, and environmental friendliness, in order to achieve efficient viscosity reduction. SUMMARY

[0005] The present application aims to provide a thickened oil viscosity reducer for colloid as the main viscosity contribution component.

[0006] A thickened oil viscosity reducer for colloid as the main viscosity contribution component, comprising the following components by weight percentage: 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%, corrosion inhibitor 1-2%; the balance is water.

[0007] The dispersant is one or several of alkyl polyglycoside APG1214, cocamide propyl betaine, erucamide propyl betaine.

[0008] The chelating agent is one or several of EDTA-tetrasodium, diethylene triamine pentamethylene phosphonic acid, phytic acid.

[0009] The anti-coking agent is one or several of 2, 6-di-tert-butyl-p-cresol, N- (3-dimethylaminopropyl) acrylamide, dodecylbenzenesulfonic acid.

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

[0011] The corrosion inhibitor is one or several of N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt, diethylene triamine, 2-amino benzothiazole.

[0012] The preparation method of the thickened oil viscosity reducer for colloid as the main viscosity contribution component is carried out according to the following steps: (1) add 250ml water to the container, stir with a magnetic stirrer, and after the vortex is stable, add diethylene glycol methyl ether 150-220ml, stir for 10-15 minutes, and add propylene glycol formate 90-150ml and stir for 10-15 minutes; (2) successively add the following to the vortex of the liquid in step (1): dispersant 30-50g; chelating agent 12-25g; anti-coking agent 3-6.5g; anti-swelling agent 6-12.5g; and continue stirring for 10-15 minutes; (3) add corrosion inhibitor 6-12.5g to the vortex of the liquid in step (2); and continue stirring for 25-30 minutes.

[0013] The stirring rate is 35-55 revolutions per minute.

[0014] The present 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 to effectively inhibit metal-induced asphaltene bridging; can withstand a working condition of from normal temperature to 250°C, and even up to 300°C; has significantly enhanced thermal stability, with a residual carbon after aging of less than 8%; has higher viscosity reduction efficiency; and has a more stable system, flexible compatibility and suitability for on-site construction. DETAILED DESCRIPTION

[0015] In order to facilitate the understanding of the present application, a more comprehensive description of the present application will be provided below. However, the present application can be realized in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0016] Example 1 A preparation method of a thickened oil viscosity reducer for a resin as a main viscosity contribution component is performed according to the following steps: (1) 250 ml of water is added to a container, stirring is performed by a magnetic stirrer (45 revolutions / minute), after the vortex is stabilized, 180 ml of diethylene glycol methyl ether is added, stirring is performed for 12 minutes, and 120 ml of propylene glycol formate is added and stirring is performed for 12 minutes; (2) The following is sequentially added to the vortex of the liquid in step (1): alkyl polyglycoside (APG1214) 40 g; EDTA-tetrasodium 10 g; diethylene triamine penta methylene phosphonic acid 10 g; 2, 6-di-tert-butyl-p-cresol 2 g; N-(3-dimethylaminopropyl) acrylamide 3 g; potassium chloride 10 g; and stirring is continuously performed for 12 minutes; (3) N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt 9 g is added to the vortex of the liquid in step (2); and stirring is continuously performed (45 revolutions / minute) for 28 minutes.

[0017] Example 2 A preparation method of a thickened oil viscosity reducer for a resin as a main viscosity contribution component is performed according to the following steps: (1) 250 ml of water is added to a container, stirring is performed by a magnetic stirrer (40 revolutions / minute), after the vortex is stabilized, 160 ml of diethylene glycol methyl ether is added, stirring is performed for 10 minutes, and 100 ml of propylene glycol formate is added and stirring is performed for 10 minutes; (2) The following is sequentially added to the vortex of the liquid in step (1): cocamide propyl betaine 32 g; chelating agent EDTA-tetrasodium 6 g; diethylene triamine penta methylene phosphonic acid 7 g; 2, 6-di-tert-butyl-p-cresol 2 g; N-(3-dimethylaminopropyl) acrylamide 2 g; dimethyl diallyl ammonium chloride 7 g; and stirring is continuously performed for 10 minutes; (3) Add diethylene triamine 7 g to the vortex of the liquid in step (2); and continue stirring (40 revolutions / minute) for 26 minutes.

[0018] Example 3 A method for preparing a viscosity reducer for heavy oil in which colloid is the main viscosity contributing component, is carried out according to the following steps: (1) Add 250 ml of water to a container, stir with a magnetic stirrer (50 revolutions / minute), after the vortex is stable, add diethylene glycol methyl ether 200 ml, stir for 15 minutes, add propylene glycol formate 140 ml, and stir for 15 minutes; (2) Add the following to the vortex of the liquid in step (1) in turn: erucamide propyl betaine 45 g; EDTA-tetrasodium 10 g, diethylene triamine pentamethylene phosphonic acid 12 g; 2, 6-di-tert-butyl-p-cresol 3 g, N-(3-dimethylaminopropyl) acrylamide 3 g; polydimethyl diallyl ammonium chloride 11 g; and continue stirring for 15 minutes; (3) Add 2-amino benzothiazole 11 g to the vortex of the liquid in step (2); and continue stirring (50 revolutions / minute) for 30 minutes.

[0019] Example 4 A method for preparing a viscosity reducer for heavy oil in which colloid is the main viscosity contributing component, is carried out according to the following steps: (1) Add 250 ml of water to a container, stir with a magnetic stirrer (45 revolutions / minute), after the vortex is stable, add diethylene glycol methyl ether 180 ml, stir for 12 minutes, add propylene glycol formate 120 ml, and stir for 12 minutes; (2) Add the following to the vortex of the liquid in step (1) in turn: alkyl polyglycoside (APG1214) 40 g; EDTA-tetrasodium 20 g; 2, 6-di-tert-butyl-p-cresol 2 g, N-(3-dimethylaminopropyl) acrylamide 3 g; potassium chloride 10 g; and continue stirring for 12 minutes; (3) Add N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt 9 g to the vortex of the liquid in step (2); and continue stirring (45 revolutions / minute) for 28 minutes.

[0020] Example 5 A method for preparing a viscosity reducer for heavy oil in which colloid is the main viscosity contributing component, is carried out according to the following steps: (1) Add 250 ml of water to a container, stir with a magnetic stirrer (45 revolutions / minute), after the vortex is stable, add diethylene glycol methyl ether 180 ml, stir for 12 minutes, add propylene glycol formate 120 ml, and stir for 12 minutes; (2) To the vortex of the liquid in step (1) add successively: alkyl polyglycoside (APG1214) 40 g; diethylene triamine penta methylene phosphonic acid 20 g; 2, 6-di-tert-butyl-p-cresol 2 g, N-(3-dimethylaminopropyl) acrylamide 3 g; potassium chloride 10 g; and continue stirring for 12 minutes; (3) To the vortex of the liquid in step (2) add N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt 9 g; and continue stirring (45 rpm) for 28 minutes.

[0021] Example 6 A method for preparing a viscosity reducer for heavy oil in which the colloid is the main viscosity contributing component, is carried out according to the following steps: (1) To a container add 250 ml of water, stir with a magnetic stirrer (45 rpm), after the vortex is stable, add diethylene glycol methyl ether 180 ml, stir for 12 minutes, add propylene glycol formate 120 ml, and stir for 12 minutes; (2) To the vortex of the liquid in step (1) add successively: alkyl polyglycoside (APG1214) 40 g; EDTA-tetrasodium 10 g; diethylene triamine penta methylene phosphonic acid 10 g; 2, 6-di-tert-butyl-p-cresol 5 g; potassium chloride 10 g; and continue stirring for 12 minutes; (3) To the vortex of the liquid in step (2) add N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt 9 g; and continue stirring (45 rpm) for 28 minutes.

[0022] Example 7 A method for preparing a viscosity reducer for heavy oil in which the colloid is the main viscosity contributing component, is carried out according to the following steps: (1) To a container add 250 ml of water, stir with a magnetic stirrer (45 rpm), after the vortex is stable, add diethylene glycol methyl ether 180 ml, stir for 12 minutes, add propylene glycol formate 120 ml, and stir for 12 minutes; (2) To the vortex of the liquid in step (1) add successively: alkyl polyglycoside (APG1214) 40 g; EDTA-tetrasodium 10 g; diethylene triamine penta methylene phosphonic acid 10 g; N-(3-dimethylaminopropyl) acrylamide 5 g; potassium chloride 10 g; and continue stirring for 12 minutes; (3) To the vortex of the liquid in step (2) add N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt 9 g; and continue stirring (45 rpm) for 28 minutes.

[0023] Performance evaluation: (1) Take the thickened oil viscosity reducer prepared in Example 1; prepare 0.5L test reagent (oil-water 3:7 oil sample), the control group is commercially available (manufacturer: Karamay City Sanda New Technology Co., Ltd.; product specification: viscosity reducer, surfactant SDCY; item number: SDCY batch number: 20250604) viscosity reducer 10.3%, Example 1 thickened oil viscosity reducer 8%. According to the provisions of Brookfield DV2T, the temperature-viscosity performance of thickened oil sample is determined when the oil-water ratio is 3:7.

[0024] The determination results are shown in Table 1. The viscosity of the pure reagent decreases faster and deeper: the self-formulation can be reduced to 150 mPa·s at 250℃, which is much better than the 300 mPa·s of the commercially available formulation; the viscosity of the test oil sample is lower after adding the viscosity reducer: the self-formulation (addition amount 8%) can be reduced to 95 mPa·s at 300℃, which is better than the 180 mPa·s of the commercially available formulation (addition amount 10.3%).

[0025] Table 1 Comparison of temperature-viscosity performance of viscosity reduction system

[0026] (2) Prepare 0.5L test reagent (oil-water 3:7 oil sample), and add 8% of the thickened oil viscosity reducer prepared in Examples 1-3 and Comparative Examples 1-2. The metal ion inhibition ability of the viscosity reduction system at 250℃ is determined by ICP-OES. The experimental results are statistically analyzed by SPSS24.0 software. The measurement data results are represented by x± (mean±standard deviation). The data normality test is performed by Kolmogorov-Smirnov test method. For data conforming to normal distribution, the mean difference between two groups is compared by t test. P<0.05 is considered to have statistical significance. The determination results are shown in Table 2: Table 2

[0027] Note: * represents P<0.05 compared with Example 1 group.

[0028] (3) Prepare 0.5L test reagent (oil-water 3:7 oil sample), and add 8% of the thickened oil viscosity reducer prepared in Examples 1-3 and Comparative Examples 3-4. The coking inhibition performance of the viscosity reduction system at 250℃ is analyzed according to the heavy component carbon residue. The experimental results are statistically analyzed by SPSS24.0 software. The measurement data results are represented by x± (mean±standard deviation). The data normality test is performed by Kolmogorov-Smirnov test method. For data conforming to normal distribution, the mean difference between two groups is compared by t test. P<0.05 is considered to have statistical significance. The determination results are shown in Table 3: Table 3

[0029] Note: * represents P < 0.05 compared with Example 1 group.

[0030] The above described examples only express several embodiments of the present application, which are described more specifically and in detail, but cannot be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to 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 in weight percentage: 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%, corrosion inhibitor 1-2%; the balance is water.

2. The viscosity-reducing agent for a heavy oil in which a colloid is a main viscosity contributing component according to claim 1, characterized by, The dispersant is one or several of alkyl polyglycoside APG1214, cocamide propyl betaine, erucamide propyl betaine.

3. The viscosity-reducing agent for a heavy oil in which a colloid is a main viscosity contributing component according to claim 1, characterized by, The chelating agent is one or several of EDTA-tetrasodium, diethylene triamine penta methylene phosphonic acid, phytic acid.

4. The viscosity-reducing agent for a heavy oil in which a colloid is a main viscosity contributing component according to claim 1, characterized by, The anti-coking agent is one or several of 2, 6-di-tert-butyl-p-cresol, N- (3-dimethylaminopropyl) acrylamide, dodecyl benzene sulfonic acid.

5. The viscosity-reducing agent for a heavy oil in which a colloid is a main viscosity contributing component according to claim 1, characterized by, The anti-swelling agent is one or several of potassium chloride, dimethyl diallyl ammonium chloride, polydimethyl diallyl ammonium chloride.

6. The viscosity-reducing agent for a heavy oil in which a colloid is a main viscosity contributing component according to claim 1, characterized by, The corrosion inhibitor is one or several of N-alkylamino-2-perfluoroalkyl imidazoline quaternary ammonium salt, diethylene triamine, 2-amino benzothiazole.

7. The process for the preparation of the viscosity reducing agent for viscous oil, in which the colloid is the main viscosity contributing component, according to claim 1, characterized by that, The following steps are taken: (1) 250ml water is added to a container, stirring is carried out with a magnetic stirrer, after the vortex is stable, diethylene glycol methyl ether 150-220ml is added, stirring for 10-15 minutes, propylene glycol formate 90-150ml is added, and stirring for 10-15 minutes; (2) the following is added successively to the vortex of the liquid in step (1): dispersant 30-50g; chelating agent 12-25g; anti-coking agent 3-6.5g; anti-swelling agent 6-12.5g; and stirring is continued for 10-15 minutes; (3) corrosion inhibitor 6-12.5g is added to the vortex of the liquid in step (2); and stirring is continued for 25-30 minutes.

8. The process for the preparation of a viscosity reducing agent for viscous oil whose main viscosity contribution component is colloid as claimed in claim 1, characterized in that, The stirring rate is 35-55 revolutions per minute.

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