A thickened oil viscosity-reducing mixed dispersant and application thereof

Abstract

This invention discloses a heavy oil viscosity-reducing mixed dispersant and its application, relating to the field of petroleum extraction technology. The key technical points are: the mixed dispersant comprises dodecylbenzenesulfonic acid and mixture A, wherein mixture A is petroleum ether and compound B, and compound B is one of water, a saturated sodium chloride solution at room temperature, and methanol. During the process of reducing heavy oil viscosity, the dispersant introduces carbon dioxide to reduce the amount of water or methanol used. This invention systematically studies the interaction between various dispersants such as petroleum ether, water, methanol, a saturated sodium chloride solution at room temperature, and dodecylbenzenesulfonic acid and heavy oil, explores the synergistic effects between different dispersants, and uses existing reagents to achieve reasonable proportions, forming different types of dispersants and constructing various mixed dispersants. Furthermore, it demonstrates that the effect of mixed dispersants is superior to that of individual dispersants, providing a theoretical basis for subsequent research on heavy oil viscosity reduction.

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, and more specifically, to a heavy oil viscosity-reducing dispersant and its application. Background Technology

[0002] Currently, heavy oil accounts for over 70% of the world's remaining oil reserves. Heavy oil refers to crude oil with a high viscosity, often exceeding 100 mPa·s, while the viscosity of conventional crude oil is typically in the range of 10-100 mPa·s. Due to its high viscosity, heavy oil has poor flowability in formations and pipelines, making viscosity reduction crucial for its extraction. However, the high viscosity of heavy oil presents numerous challenges in its harvesting, transportation, and processing.

[0003] In existing technologies, during the extraction of heavy oil, viscosity reducers are typically used to lower the viscosity of the heavy oil and improve its flowability in pipelines, making extraction, transportation, and processing easier. Therefore, developing more effective heavy oil viscosity reducers has become a current research focus. Summary of the Invention

[0004] The purpose of this invention is to provide a viscosity-reducing dispersant for heavy oil and its application, which can effectively reduce the viscosity of heavy oil.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a heavy oil viscosity reducing mixed dispersant, wherein the mixed dispersant comprises dodecylbenzenesulfonic acid and mixture A, wherein mixture A is petroleum ether and compound B, wherein compound B is one of water, a saturated sodium chloride solution at room temperature and methanol.

[0006] The present invention is further configured such that: when carbon dioxide is introduced into the dispersant during the process of reducing the viscosity of heavy oil, the viscosity-reducing effect can be further enhanced.

[0007] The present invention is further configured such that the optimal addition amount of dodecylbenzenesulfonic acid is 0.8g of dodecylbenzenesulfonic acid per 200g of heavy oil.

[0008] The present invention is further configured such that the ratio of petroleum ether to compound B is (1-2):(2-1).

[0009] The present invention is further configured such that the mixture B is preferably water.

[0010] The present invention is further configured such that the ratio of petroleum ether to water is preferably 1:1.

[0011] The present invention further provides the application of the above-mentioned mixed dispersant, which can be used to reduce the viscosity of heavy oil during the oil extraction process.

[0012] In summary, this invention has the following beneficial effects: It systematically studies the interaction mechanisms between various dispersants, such as petroleum ether, water, methanol, saturated sodium chloride solution at room temperature, and dodecylbenzenesulfonic acid, and heavy oil. It explores the synergistic effects between different dispersants, and uses existing reagents in reasonable proportions to form different types of dispersants, constructing various mixed dispersants. Furthermore, it demonstrates that the effect of mixed dispersants is superior to that of individual dispersants, providing a theoretical basis for subsequent research on viscosity reduction in heavy oil. Attached Figure Description

[0013] Figure 1 This describes the change in viscosity value of heavy oil in Example 1 of the present invention, where dodecylbenzenesulfonic acid is used as a dispersant.

[0014] Figure 2 This describes the change in viscosity of heavy oil after adding petroleum ether:water = 1:1 in Example 2 of the present invention.

[0015] Figure 3 This describes the change in viscosity of heavy oil after adding petroleum ether:water = 1:2 in Example 3 of the present invention.

[0016] Figure 4 This describes the change in viscosity of heavy oil after adding petroleum ether:water = 2:1 in Example 4 of the present invention.

[0017] Figure 5 This describes the change in viscosity of heavy oil after adding petroleum ether to a saturated sodium chloride solution at room temperature in Example 5 of this invention (ratio 1:1).

[0018] Figure 6 This describes the change in viscosity of heavy oil after adding petroleum ether to a saturated sodium chloride solution at room temperature in a ratio of 1:2 in Example 6 of this invention.

[0019] Figure 7 This describes the change in viscosity of heavy oil after adding petroleum ether:methanol = 1:1 in Example 7 of the present invention.

[0020] Figure 8 This describes the change in viscosity of heavy oil after adding petroleum ether:methanol = 1:2 in Example 8 of the present invention.

[0021] Figure 9 This describes the change in viscosity of heavy oil after carbon dioxide is introduced in Example 9 of the present invention. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-9 The present invention will be described in further detail below.

[0023] The heavy oil used in the following examples all came from heavy oil extracted in Ordos and was taken from the same barrel. However, since the viscosity of the heavy oil taken out each time will be different, the initial viscosity measurement of the heavy oil was performed separately for each example.

[0024] Example 1: Analysis of the effect of dodecylbenzenesulfonic acid (DBSA) as a dispersant on the viscosity of heavy oil

[0025] like Figure 1 As shown, the viscosity-reducing effect of dodecylbenzenesulfonic acid (DBSA) as a dispersant on heavy oil systems exhibits a significant concentration-dependent characteristic. When the DBSA addition amount gradually increases from 0 g to 0.8 g (relative to 200 g of heavy oil system), the system viscosity shows a decreasing trend, reaching the lowest viscosity value (881.4 mPa·s) at the 0.8 g addition amount, at which point the dispersant achieves its optimal effectiveness. It is noteworthy that when the DBSA addition amount exceeds the critical value of 0.8 g, the system viscosity exhibits an abnormal increase. Experimental data indicate that the optimal addition ratio of DBSA is 0.8 g / 200 g.

[0026] Example 2: Analysis of the effect of adding petroleum ether:water = 1:1 on the viscosity of heavy oil based on Example 1

[0027] like Figure 2 As shown, in a 200g heavy oil system, adding 0.8g of dodecylbenzenesulfonic acid, with the volume ratio of petroleum ether:water = 1:1 increasing from 0ml to 38ml, the initial viscosity of the heavy oil was 4263mPa·s. Without dispersant, adding only 0.8g of dodecylbenzenesulfonic acid reduced the viscosity to 1250mPa·s. With the volume of the mixture gradually increasing until reaching 38mL, the final viscosity decreased to 102.5mPa·s. The calculated viscosity reduction effect reached 97.6%. During the process, the viscosity value continuously decreased, demonstrating that petroleum ether:water = 1:1, as a dispersant, has a significant effect on reducing the viscosity of heavy oil when acting synergistically with dodecylbenzenesulfonic acid.

[0028] Example 3: Analysis of the effect of adding petroleum ether:water = 1:2 on the viscosity of heavy oil based on Example 1

[0029] like Figure 3As shown, in a 200g heavy oil system, the addition of 0.8g of dodecylbenzenesulfonic acid resulted in an initial viscosity of 5476 mPa·s as the volume ratio of petroleum ether to water (1:2) was gradually increased from 0ml. Without dispersant, the viscosity decreased to 737.9 mPa·s with only 0.8g of dodecylbenzenesulfonic acid. The viscosity continued to decrease with increasing mixture volume. When the volume reached 47.5mL, the viscosity stabilized at 102.5 mPa·s. The synergistic effect of petroleum ether:water (1:2) with dodecylbenzenesulfonic acid significantly reduced the viscosity of heavy oil, with a calculated reduction rate of approximately 98.13%.

[0030] Example 4: Analysis of the effect of adding petroleum ether:water = 2:1 on the viscosity of heavy oil based on Example 1

[0031] like Figure 4 As shown, in a 200g heavy oil system, adding 0.8g of dodecylbenzenesulfonic acid, when the volume ratio of petroleum ether to water (2:1) was gradually increased from 0ml, the initial viscosity of the heavy oil was 5230mPa·s. Without dispersant, adding only 0.8g of dodecylbenzenesulfonic acid reduced the viscosity to 717.4mPa·s. As the volume of the mixture increased further, the viscosity of the heavy oil continued to decrease. When the volume reached 39mL, the viscosity stabilized at 102.5mPa·s. This indicates that the synergistic effect of petroleum ether:water (2:1) and dodecylbenzenesulfonic acid significantly reduced the viscosity of heavy oil, with a calculated viscosity reduction rate of approximately 98.04%.

[0032] Example 5: Analysis of the effect of adding petroleum ether: saturated sodium chloride solution at room temperature = 1:1 on the viscosity of heavy oil based on Example 1.

[0033] like Figure 5 As shown, in a 200g heavy oil system, 0.8g of dodecylbenzenesulfonic acid was added. Starting from 0ml, the initial viscosity of the heavy oil was 4968mPa·s. With only 0.8g of dodecylbenzenesulfonic acid added and no dispersant, the viscosity decreased to 737.9mPa·s. As the amount of mixture added gradually increased, the viscosity of the heavy oil continued to decrease until it reached 102.5mPa·s when the amount added was 49ml.

[0034] This indicates that when petroleum ether:sodium chloride saturated solution at room temperature = 1:1 works synergistically with dodecylbenzenesulfonic acid, it has a significant viscosity-reducing effect on heavy oil, with a viscosity reduction rate of approximately 97.94%. However, in this example, the amount of petroleum ether added was too large, and the effect was not as good as that of petroleum ether:water = 1:1.

[0035] Example 6: Analysis of the effect of adding petroleum ether: saturated sodium chloride solution at room temperature = 1:2 on the viscosity of heavy oil based on Example 1.

[0036] like Figure 6 As shown, in a 200g heavy oil system, 0.8g of dodecylbenzenesulfonic acid was added. Starting from 0ml, the initial viscosity of the heavy oil was 4571mPa·s when a mixture with a volume ratio of petroleum ether to saturated sodium chloride solution at room temperature (1:2) was added. Without a dispersant, the viscosity decreased to 1619mPa·s when only 0.8g of dodecylbenzenesulfonic acid was added. As the amount of mixture added gradually increased, the viscosity of the heavy oil continued to decrease until it reached 102.5mPa·s when the added amount reached 58ml.

[0037] This indicates that when petroleum ether: sodium chloride saturated solution at room temperature = 1:2 works synergistically with dodecylbenzenesulfonic acid, it has a significant viscosity-reducing effect on heavy oil, with a viscosity reduction rate of approximately 97.76%.

[0038] Example 7: Analysis of the effect of adding petroleum ether:methanol = 1:1 on the viscosity of heavy oil based on Example 1

[0039] like Figure 7 As shown, in a 200g heavy oil system, the addition of 0.8g of dodecylbenzenesulfonic acid significantly reduced the viscosity of the heavy oil as the volume ratio of petroleum ether:methanol = 1:1 increased from 0ml. The initial viscosity was 5678mPa·s, which decreased to 1373mPa·s when only 0.8g of dodecylbenzenesulfonic acid was added without dispersant. With further increases in the volume of the mixture, the viscosity of the heavy oil continued to decrease, reaching 81.99 mPa·s when the final volume was 59ml, representing a viscosity reduction rate of 98.56%. This demonstrates that the synergistic effect of petroleum ether:methanol = 1:1 and dodecylbenzenesulfonic acid significantly reduced viscosity.

[0040] Example 8: Analysis of the effect of adding petroleum ether:methanol = 1:2 on the viscosity of heavy oil based on Example 1

[0041] like Figure 8 As shown, in a 200g heavy oil system, the addition of 0.8g of dodecylbenzenesulfonic acid significantly reduced the viscosity of the heavy oil as the amount of petroleum ether:methanol (1:1 ratio) increased from 0ml. The initial viscosity of the heavy oil was 5944mPa·s, which decreased to 1312mPa·s with only 0.8g of dodecylbenzenesulfonic acid added and no dispersant. With further increases in the petroleum ether:methanol (1:2 ratio), the viscosity decreased significantly. At a final addition of 41ml, the viscosity dropped to 81.99mPa·s, representing a viscosity reduction rate of 98.62%. This indicates that the synergistic effect of petroleum ether:methanol (1:2 ratio) and dodecylbenzenesulfonic acid on the viscosity of heavy oil is significant.

[0042] Example 9: Analysis of the effect of introducing carbon dioxide on the viscosity of heavy oil based on Example 2

[0043] like Figure 9 As shown, in a 200g heavy oil system, with the addition of 0.8g dodecylbenzenesulfonic acid, 10ml petroleum ether, and 10ml water, the initial viscosity of the heavy oil was 5637 mPa·s. After adding 0.8g dodecylbenzenesulfonic acid, the viscosity decreased to 1250 mPa·s. After adding a mixture of petroleum ether and water, the viscosity decreased to 594.4 mPa·s. Then, after passing carbon dioxide gas for 36 seconds, the viscosity of the heavy oil decreased to 307.5 mPa·s. This indicates that carbon dioxide, in synergy with dodecylbenzenesulfonic acid, petroleum ether, and water, has a significant viscosity-reducing effect on heavy oil.

[0044] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A viscosity-reducing dispersant for heavy oil, characterized in that: The mixed dispersant comprises dodecylbenzenesulfonic acid and mixture A, wherein mixture A is petroleum ether and compound B, wherein compound B is one of water, a saturated sodium chloride solution at room temperature, and methanol.

2. The heavy oil viscosity-reducing dispersant according to claim 1, characterized in that: The dispersant can further enhance the viscosity-reducing effect by introducing carbon dioxide during the process of reducing the viscosity of heavy oil.

3. A heavy oil viscosity-reducing dispersant according to claim 1 or 2, characterized in that: The optimal addition amount of dodecylbenzenesulfonic acid is 0.8g of dodecylbenzenesulfonic acid per 200g of heavy oil.

4. The heavy oil viscosity-reducing dispersant according to claim 1, characterized in that: The ratio of petroleum ether to compound B is (1-2):(2-1).

5. The heavy oil viscosity-reducing dispersant according to claim 1, characterized in that: The mixture B is preferably water.

6. The heavy oil viscosity-reducing dispersant according to claim 5, characterized in that: The preferred ratio of petroleum ether to water is 1:

1.

7. The application of a heavy oil viscosity-reducing dispersant according to any one of claims 1-6, characterized in that: The mixed dispersant can be used to reduce the viscosity of heavy oil during the oil extraction process.

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