Oil-soluble asphalt dispersant composition and performance testing method thereof

Abstract

The invention discloses an oil-soluble asphalt dispersing agent composition and a performance testing method thereof, and belongs to the field of oilfield chemicals, the oil-soluble asphalt dispersing agent composition is prepared by compounding 20-70% of a solvent A, 20-70% of a solvent B, 2-12% of a penetrant, 1-8% of a dispersing agent and 1-9% of an inhibitor, the solvent B is N-(2-mercaptoacetyl) methacrylamide; the invention also discloses a dispersing performance evaluation method of the asphalt dispersing agent, which comprises the following steps: preparing 1g of small balls from the high-asphaltene-content sediment, putting the small balls into a glass sample bottle, and adding the asphalt dispersing agent into the bottle; reacting in a constant-temperature test box at 20-90 DEG C for 2-8 hours, and observing the dissolving and dispersing conditions; after the reaction is finished, filtering by using a loaded steel wire mesh, drying the steel wire mesh and residual sediments in a drying oven, taking out, weighing, and recording the mass of residual insoluble substances; and calculating the asphaltene dissolution rate through the mass loss of the sediment before and after.

Description

Technical Field

[0001] This invention relates to the field of oilfield chemicals. Background Technology

[0002] During oil and gas field development, formation and wellbore blockage caused by the precipitation and deposition of asphaltenes is a significant reason for reduced production capacity and a serious problem currently facing the petroleum industry. Commonly used methods for removing asphaltenes deposits include reducing shear stress and pressure drop, periodic tubing scraping, solvent treatment, and injection of dispersants. Among these, injecting dispersants is considered an effective way to solve asphaltenes blockage due to its good dispersing effect, safe construction, and environmental friendliness. The main function of these dispersants is to encapsulate asphaltenes molecules, dissolving and dispersing them stably in the crude oil without causing re-flocculation and deposition that could lead to formation and wellbore blockage. In recent years, research and development of asphaltenes unblocking agents has been rapid, and related reports have increased year by year.

[0003] Asphaltene dispersants can be broadly classified into two categories: water-based dispersants and solvent-based dispersants. Water-based dispersants include surfactants, penetrants, and dispersion stabilizers, but they can only form emulsions with heavy oil and cannot disrupt the structure of deposited asphaltene. Solvent-based dispersants are a type of dispersant composed of solvents, co-solvents, and penetrants. These dispersants possess extremely strong abilities to dissolve and disperse asphaltene in heavy oil and to resist solidification and sedimentation. They can effectively dissolve and disperse deposited asphaltene to remove asphaltene blockages in formations and wellbores, thereby improving the pipeline transport capacity of crude oil in the formation. Their mechanism of action is: dissolution—dispersion—miscibility to form a low-viscosity, stable system, which will not stratify and precipitate under formation conditions and low temperatures, effectively solving the problem of asphaltene deposition and blockage, thus improving pipeline transport capacity.

[0004] However, existing asphaltene dispersants are not very effective at dissolving and dispersing high-asphaltene deposits, especially under high-temperature conditions, and the evaluation results differ somewhat from the field implementation process. Therefore, it is necessary to invent a dispersant for high-asphaltene deposits and its evaluation method, which can simulate the asphaltene deposition environment in wellbores or surface pipelines and determine the dissolving and dispersing effect of the added dispersant on high-asphaltene deposits. Summary of the Invention

[0005] The technical problem this invention aims to solve is to address the shortcomings of existing high-asphaltene sediment dispersants, such as poor performance and complex evaluation methods for their dissolution and dispersion properties. This invention provides an asphalt dispersant and a method for evaluating its performance. High-asphaltene sediment and the dispersant are added to a glass bottle in a specific ratio. After reacting for 2-9 hours, the mixture is filtered through a 120-mesh wire mesh. The dissolution and dispersion effect of the asphaltene is calculated based on the mass of the asphaltene sediment on the wire mesh. Compared to existing asphaltene sediment dispersants, this dispersant can be used not only for removing wellbore blockages and near-wellbore blockages, but also for dispersing asphaltene sediments in surface pipelines and equipment.

[0006] The present invention provides an oil-soluble asphalt dispersant composition, which is composed of 20-70 parts solvent A, 20-70 parts solvent B, 2-12 parts penetrant, 1-8 parts dispersant, and 1-9 parts inhibitor.

[0007] Solvent A is at least one of toluene, xylene, trimethylbenzene, tetramethylbenzene, S-100, S-150, S-180, and S-260; solvent B is at least one of N-(2-mercaptoacetyl)methacrylamide, C7, C8, C9, C10, methyl acetate, ethyl acetate, and propyl acetate; inhibitor is at least one of EVA40w, EVA150, EVA210, alkyd resin 389-9A, and alkyd resin 389-9B; penetrant is at least one of diethylene glycol butyl ether, ethylene glycol butyl ether, AEO-3, AEO-7, and AEO-9. Dispersant is at least one of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, dodecyl dimethyl betaine, Tween 40, Tween 60, and Tween 80.

[0008] This invention provides an oil-soluble asphalt dispersant composition and its evaluation method, comprising the following steps: 1) Make 1g pellets from the high-asphalt content sediment and place them in a glass sample bottle. Add an oil-soluble asphalt dispersant composition to the bottle. 2) React in a constant temperature test chamber at 20-90℃ for 2-8 hours, and observe its dissolution and dispersion. 3) After the reaction is complete, filter with a wire mesh. Place the wire mesh and residual sediment in an oven to dry, then remove and weigh them. Record the mass of the residual insoluble matter. Calculate the asphalt dissolution rate by the mass loss of the sediment before and after the reaction.

[0009] In a specific scheme, the oil-soluble asphalt dispersant composition and its evaluation method include the following: the dispersant dosage is 5–30 g; the mass ratio of high-asphalt content sediment to dispersant is 1:5–30, specifically 1:5, 1:10, 1:15, 1:20, 1:25, or 1:30; the wire mesh particle size is 60–120 mesh, specifically 120 mesh; the temperature for drying the wire mesh and residual sediment is 50°C, and the drying time is 12 hours.

[0010] The asphalt dispersant composition of this invention exhibits good temperature resistance, a simple injection method, and excellent dissolution and dispersion effects on asphalt deposits. It can be applied to various complex environments where asphalt deposits accumulate, including during crude oil extraction, wellbore lifting, and gathering and transportation. This invention utilizes a constant-temperature chamber operation, which better simulates the asphalt deposition environment in surface pipelines compared to conventional indoor evaluations. The asphalt dispersant of this invention uses widely available raw materials, has a simple mixing process, produces no pollution or reaction products, and exhibits low toxicity and high safety. Detailed Implementation

[0011] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0012] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0013] Experimental equipment: constant temperature test chamber Experimental solvent: oil-soluble asphalt dispersant composition Experimental equipment: high bituminous sediment balls, wire mesh, glass sample bottles Implementation steps: Step 1: Make 1g pellets from the high-asphalt content sediment and place them in a glass sample bottle. Add an oil-soluble asphalt dispersant composition to the bottle. Step 2: React in a constant temperature test chamber at 20-90℃ for 2-8 hours, and observe its dissolution and dispersion. Step 3: After the reaction is complete, filter the material using a pre-weighed wire mesh. Place the wire mesh and residual sediment in an oven to dry, then remove and weigh them. Record the mass of the remaining insoluble matter. Calculate the asphalt dissolution rate based on the mass loss of the sediment before and after the reaction.

[0014] Preparation of N-(2-mercaptoacetyl)methacrylamide: Methacrylamide chloride was added dropwise to a THF solution of mercaptoacetic acid containing 1 eq of pyridine at 2-4 degrees Celsius. The mixture was reacted at room temperature for 3 hours, extracted with diethyl ether, and then subjected to silica gel column chromatography. The eluents were ethyl acetate and n-hexane in a volume ratio of 1:1.

[0015] The reaction formula is as follows: .

[0016] Example 1 An oil-soluble asphalt dispersant composition was obtained by compounding 60% xylene, 27% C7, 3% sodium dodecylbenzenesulfonate, 3% EVA40w, and 7% diethylene glycol butyl ether. The mass ratio of asphalt sediment pellets to dispersant was 1:10. After reacting in a test chamber at 20°C for 2 hours, the asphalt sediment pellets were observed and filtered through a 120-mesh steel wire mesh. The solubility rate was calculated based on the mass loss of the sediment before and after the reaction.

[0017] Example 2 The method in this embodiment is the same as the method in Embodiment 1 of the present invention, except that: 50% trimethylbenzene, 37% C8, 3% sodium dodecylbenzenesulfonate, 4% EVA150, and 6% ethylene glycol butyl ether are compounded to obtain an oil-soluble asphalt dispersant composition. The mass ratio of asphalt sediment pellets to dispersant is 1:10. After reacting in a test chamber at 20°C for 2 hours, the asphalt sediment pellets are observed and filtered through a 120-mesh steel wire mesh. The solubility rate is calculated based on the mass loss of the sediment before and after the reaction.

[0018] Example 3 The method in this embodiment is the same as the method in Embodiment 1 of the present invention, except that: 70% trimethylbenzene, 17% C8, 3% sodium dodecylbenzenesulfonate, 5% EVA210, and 5% AEO-3 are compounded to obtain an oil-soluble asphalt dispersant composition. The mass ratio of asphalt sediment pellets to dispersant is 1:10. After reacting in a test chamber at 20°C for 2 hours, the asphalt sediment pellets are observed and filtered through a 120-mesh steel wire mesh. The solubility rate is calculated based on the mass loss of the sediment before and after the reaction.

[0019] Example 4 The method in this embodiment is the same as the method in Embodiment 1 of the present invention, except that: 45% S-100, 42% C10, 3% sodium dodecylbenzenesulfonate, 5% alkyd resin 389-9A, and 5% AEO-7 are compounded to obtain an oil-soluble asphalt dispersant composition. The mass ratio of asphalt sediment pellets to dispersant is 1:10. After reacting in a test chamber at 70°C for 2 hours, the asphalt pellets are observed and filtered through a 120-mesh steel wire mesh. The solubility rate is calculated based on the mass loss of the sediment before and after the reaction.

[0020] Example 5 The method in this embodiment is the same as the method in Embodiment 1 of the present invention, except that: 30% S-180, 57% methyl acetate, 3% sodium dodecylbenzenesulfonate, 4% alkyd resin 389-9B, and 6% AEO-9 are compounded to obtain an oil-soluble asphalt dispersant composition. The mass ratio of asphalt sediment pellets to dispersant is 1:10. After reacting in a test chamber at 70°C for 2 hours, the asphalt sediment pellets are observed and filtered through a 120-mesh steel wire mesh. The solubility rate is calculated based on the mass loss of the sediment before and after the reaction.

[0021] Example 6 The method in this embodiment is the same as the method in Embodiment 1 of the present invention, except that: 20% S-260, 63% ethyl acetate, 3% sodium dodecylbenzenesulfonate, 2% EVA210, and 8% diethylene glycol butyl ether are compounded to obtain an oil-soluble asphalt dispersant composition. The mass ratio of asphalt sediment pellets to dispersant is 1:10. After reacting in a test chamber at 70°C for 2 hours, the asphalt pellets are observed and filtered through a 120-mesh steel wire mesh. The solubility rate is calculated based on the mass loss of the sediment before and after the reaction.

[0022] Examples 7-12. The raw materials and preparation and testing methods are the same as those in Examples 1-6, except that solvent B is replaced with N-(2-mercaptoacetyl)methacrylamide.

[0023]

[0024] As can be seen from Table 1, when solvent B is replaced by N-(2-mercaptoacetyl)methacrylamide, the dispersant solubility at room temperature is not significantly different from that at room temperature. However, at high temperatures, the performance of the existing dispersant composition is reduced compared to that at room temperature. At high temperatures, the performance of the dispersant composition after replacing solvent B with N-(2-mercaptoacetyl)methacrylamide is not significantly different from that at room temperature, indicating that the dispersant composition after replacing solvent B with N-(2-mercaptoacetyl)methacrylamide has excellent high-temperature resistance.

Claims

1. An oil-soluble asphalt dispersant composition, comprising solvent A at an amount of 20-70%, solvent B at an amount of 20-70%, penetrant at an amount of 2%-12%, dispersant at an amount of 1%-8%, and inhibitor at an amount of 1%-9%; wherein solvent B is N-(2-mercaptoacetyl)methacrylamide.

2. The oil-soluble asphalt dispersant composition according to claim 1, characterized in that: Solvent A is at least one of toluene, xylene, trimethylbenzene, tetramethylbenzene, S-100, S-150, S-180, and S-260.

3. The oil-soluble asphalt dispersant composition according to claim 1, characterized in that: The inhibitor is at least one of EVA40w, EVA150, EVA210, alkyd resin 389-9A, and alkyd resin 389-9B.

4. The oil-soluble asphalt dispersant composition according to claim 1, characterized in that: The penetrant is at least one of diethylene glycol butyl ether, ethylene glycol butyl ether, AEO-3, AEO-7, and AEO-9.

5. The oil-soluble asphalt dispersant composition according to claim 1, characterized in that: The dispersant is at least one of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, dodecyl dimethyl betaine, Tween 40, Tween 60, and Tween 80.

6. A method for evaluating the dispersion performance of an asphalt dispersant, comprising the following steps: 1) Make 1g pellets from the high-asphalt content sediment and place them in a glass sample bottle. Add asphalt dispersant to the bottle. 2) React in a constant temperature test chamber at 20-90℃ for 2-8 hours, and observe its dissolution and dispersion. 3) After the reaction is complete, filter with a wire mesh. Place the wire mesh and residual sediment in an oven to dry, then remove and weigh them. Record the mass of the residual insoluble matter. Calculate the asphalt dissolution rate by the mass loss of the sediment before and after the reaction.

7. The method for evaluating the dispersion performance of an asphalt dispersant according to claim 6, characterized in that: The dispersant dosage is 5-30g, and the mass ratio of high asphaltene sediment to dispersant is 1:5-30.

8. The method for evaluating the dispersion performance of an asphalt dispersant according to claim 6, characterized in that: The particle size of the wire mesh is 60-120 mesh.

9. The method for evaluating the dispersion performance of an asphalt dispersant according to claim 6, characterized in that: The temperature for drying the wire mesh and residual deposits was 50℃, and the drying time was 12 hours.

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