Demulsifier for extra heavy crude oil

Abstract

The application belongs to the technical field of oil and gas field chemistry, and particularly discloses a demulsifier for super-heavy crude oil. The demulsifier comprises the following components: deionized water 17%-21%, sulfonated asphalt powder 3%-4%, diethylene glycol monobutyl ether 26%-28%, L-64 type propylene glycol block polyether 40%-44%, oleic acid amide polyoxyethylene ether 7%-8%, and sodium octadecyl benzene sulfonate 1%, and the total amount of the above components is 100%. The demulsifier can reach a dehydration rate of more than 80% for super-heavy crude oil, effectively reduces the difficulty of oil-water separation of super-heavy crude oil, and has a low oil content of separated water.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field chemical technology, specifically relating to a demulsifier for extra-heavy crude oil. Background Technology

[0002] Crude oil extracted from oil wells is not a pure substance; it generally exists as a water-in-oil emulsion. Extra-heavy crude oil refers to crude oil with a density greater than or equal to 0.998 g / cm³ at 20°C. 3 Dehydrated crude oil. Asphaltenes and gums are natural emulsifiers, and extra-heavy crude oil has a high content of asphaltenes and gums, resulting in high viscosity and increased emulsion stability. Therefore, chemical demulsification of extra-heavy crude oil has always been a challenge. There are few demulsifiers in China that can achieve a dehydration rate of over 80% for extra-heavy crude oil. There is an urgent need in the market for a high-efficiency demulsifier for extra-heavy crude oil. Summary of the Invention

[0003] To address the shortcomings of the existing technology, the present invention aims to provide a demulsifier for extra-heavy crude oil. This demulsifier can achieve a dehydration rate of over 80% for extra-heavy crude oil, with a clear oil-water interface and an oil content in the extracted water of less than 300 mg / L.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A demulsifier for extra-heavy crude oil comprises the following components: 17%-21% deionized water, 3%-4% sulfonated asphalt powder, 26%-28% diethylene glycol monobutyl ether, 40%-44% L-64 type propylene glycol block polyether, 7%-8% oleamide polyoxyethylene ether, and 1% sodium octadecylbenzenesulfonate, with the total of the above components being 100%. The sulfonated asphalt powder contains 80%-85% water-soluble components, with a moisture content <10.0%, and its 2% aqueous solution has a pH of 9.0-10.3; preferably, the sulfonated asphalt powder contains 81%-83% water-soluble components, with a moisture content <10.0%, and its 2% aqueous solution has a pH of 9.6-10.0.

[0006] A method for preparing a demulsifier for extra-heavy crude oil includes the following steps: weighing raw materials according to a specified ratio, and mixing deionized water, sulfonated asphalt powder, diethylene glycol monobutyl ether, L-64 type propylene glycol block polyether, oleamide polyoxyethylene ether, and sodium octadecylbenzene sulfonate evenly to obtain the demulsifier for extra-heavy crude oil. More specifically, the method includes the following steps:

[0007] Step 1: Weigh the raw materials according to the ratio, pour all the deionized water into the reactor, start stirring at 100r / min-150r / min and start heating. When the temperature reaches 50℃-55℃, add sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then, add diethylene glycol monobutyl ether and L-64 type propylene glycol block polyether to the reactor in sequence, maintain the temperature at 50℃-55℃, and continue stirring for 0.5h-1.0h to obtain a black uniform liquid.

[0008] Step 2: Reduce the stirring speed to 60r / min-90r / min, add oleamide polyoxyethylene ether to the reactor, stir for 10min, then add sodium octadecylbenzenesulfonate, continue stirring for 0.5h-1.0h, cool to room temperature, and the resulting dark brown uniform liquid is the demulsifier for extra-heavy crude oil.

[0009] The application of the above-mentioned demulsifier for extra-heavy crude oil, or the demulsifier for extra-heavy crude oil prepared by the above method, in the demulsification and dehydration of water-in-oil emulsion-type extra-heavy crude oil. The dosage of the demulsifier is 500 mg / L-1500 mg / L.

[0010] Specifically, it is applied to the demulsification of extra-heavy crude oil with an asphalt content of 17%-25%, a resin content of 2%-20%, a water content of 20%-33%, and a viscosity of 490,000 cp-880,000 cp at 20℃.

[0011] The demulsifier of this invention uses L-64 propylene glycol block polyether as the main demulsifier, sulfonated asphalt powder as the demulsifying enhancer, and oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate as auxiliary demulsifying synergists. L-64 propylene glycol block polyether can competitively adsorb at the oil-water interface, replacing the asphaltenes and other emulsifier molecules in the original stable emulsion film, causing small droplets to coalesce into larger droplets for demulsification. However, its demulsification effect is insufficient for very heavy crude oil. Sulfonated asphalt molecules have structures similar to asphaltenes and gums, allowing some sulfonated asphalt to adsorb at the asphaltenes-gum interface, while some can dissolve in the asphaltenes-gum. Furthermore, the high water-soluble content (80%–85%) of sulfonated asphalt powder has strong hydrophilicity, which can change the surface of asphaltenes and gums from oil-wettable to water-wettable, making the emulsion structure of asphaltenes and gums as water-in-oil emulsifiers unstable, thereby enhancing the demulsification effect. Oleamide polyoxyethylene ether has a certain de-clustering and viscosity-reducing effect on asphaltene and gum aggregates, and can change the rheological properties of asphaltene and gum. Sodium octadecylbenzene sulfonate has a certain dispersing effect on asphaltene and gum. The combination of oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate allows the demulsifier to penetrate into asphaltene and gum more efficiently, thereby synergistically exerting the demulsification and enhancement effect.

[0012] Because of the above-mentioned approach, the demulsifier of this invention has excellent demulsification effect on extra-heavy crude oil with asphaltene content of 17%-25%, gum content of 2%-20%, water content of 20%-33%, and viscosity of 490,000 cp-880,000 cp at 20°C. The dehydration rate can reach more than 80%, effectively reducing the difficulty of oil-water separation of extra-heavy crude oil, and the dehydrated water has low oil content. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0014] This invention provides a technical solution: a demulsifier for extra-heavy crude oil.

[0015] The raw materials used in each embodiment are described below:

[0016] Unless otherwise specified, the sulfonated asphalt powder was purchased from Tianjin Summit Chemical Co., Ltd., with a water-soluble content of 81.0%-83.0%, a pH (2% aqueous solution) of 9.6-10.0, and a moisture content of 7.0%-8.0%.

[0017] L-64 type propylene glycol block polyether: purchased from Haian Petrochemical Plant in Jiangsu Province, with a molecular weight of 2900.

[0018] Oleamide polyoxyethylene ether: purchased from Noryon, Amadol CMA4W oleamide polyoxyethylene ether, viscosity 200 mPa·s, HLB value 8.8.

[0019] Example 1:

[0020] This demulsifier comprises the following components: 17 kg of deionized water, 3 kg of sulfonated asphalt powder, 27 kg of diethylene glycol monobutyl ether, 44 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0021] Weigh the raw materials according to the formula, pour 17 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder (which has low moisture content and can be used directly without drying) to the reactor. Stir until a uniform liquid is formed, then add 27 kg of diethylene glycol monobutyl ether and 44 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor, stir for 10 min, then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature. The resulting blackish-brown uniform liquid is the demulsifier sample for extra-heavy crude oil.

[0022] The demulsification performance of the samples was then tested. All demulsifier samples in the examples were tested according to SY / T5280-2018 "General Technical Conditions for Crude Oil Demulsifiers". The extra-heavy crude oil used was extra-heavy crude oil from an oilfield in western China, with a viscosity of 536627 cp at 20°C, an asphaltene content of 22.3%, a gum content of 5.7%, a water content of 27.1%, and a dehydrated crude oil density of 1.008 g / cm³. 3 The dehydration temperature for the demulsification test was 70℃, the concentration of the demulsifier was 500 mg / L, and the dehydration time was 12 h.

[0023] In addition, all demulsifier samples in the embodiments were also subjected to crude oil viscosity reduction tests, with the addition amount being 500 mg / L as above. The viscosity reduction rate of extra-heavy crude oil after adding the demulsifier sample for 1 hour at 70°C was tested.

[0024] The performance indicators of the demulsifier sample in Example 1 are shown in Table 1 below.

[0025] Table 1

[0026]

[0027]

[0028] Example 1 also tested the demulsifier sample at an addition amount of 400 mg / L. At this addition amount, the crude oil dehydration rate was 74.1%, the oil content in the dehydrated water was 257 mg / L, the oil-water interface was clear, and the crude oil viscosity reduction rate was 1.7%. This application indicates that a relatively high addition amount is required to achieve a good demulsification effect for extra-heavy crude oil.

[0029] Example 2:

[0030] This demulsifier comprises the following components: 21 kg of deionized water, 4 kg of sulfonated asphalt powder, 26 kg of diethylene glycol monobutyl ether, 40 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0031] Weigh the raw materials according to the formula, pour 21 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 4 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 26 kg of diethylene glycol monobutyl ether and 40 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor and stir for 10 min. Then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature. The resulting blackish-brown uniform liquid is the demulsifier sample for extra-heavy crude oil.

[0032] The performance indicators of the demulsifier sample obtained in Example 2 are shown in Table 2 below.

[0033] Table 2

[0034] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 80.4 Oil content in the dewatering water (mg / L) ≤300 207 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 2.2

[0035] Example 3:

[0036] This demulsifier comprises the following components: 18 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0037] Weigh the raw materials according to the formula, pour 18 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor and stir for 10 min. Then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature. The resulting blackish-brown uniform liquid is the demulsifier sample for extra-heavy crude oil.

[0038] The performance indicators of the demulsifier sample obtained in Example 3 are shown in Table 3 below.

[0039] Table 3

[0040] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 82.4 Oil content in the dewatering water (mg / L) ≤300 211 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 2.2

[0041] Example 4:

[0042] This demulsifier comprises the following components: 60 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0043] Weigh the raw materials according to the formula, pour 60 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether to the reactor and maintain the temperature at 50℃-55℃. Continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min and add 8 kg of oleamide polyoxyethylene ether to the reactor. Stir for 10 min, then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature. The resulting blackish-brown uniform liquid is the demulsifier sample.

[0044] The performance indicators of the demulsifier sample obtained in Example 4 are shown in Table 4 below.

[0045] Table 4

[0046] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 28.5 Oil content in the dewatering water (mg / L) ≤300 2065 Oil-water interface condition The oil and water interface is clear. The oil-water interface is unclear. Crude oil viscosity reduction rate (70℃, %) - 2.1

[0047] Compared to Example 3, Example 4 did not add L-64 type propylene glycol block polyether, resulting in a very poor demulsification effect. In addition, the oil-water interface was not clear, which may be due to the high oil content of the desorbed water and the mixing of oil and water at the oil-water interface to a certain extent.

[0048] In addition, we increased the amount of demulsifier added to the sample of Example 4 to 1000 mg / L and 1500 mg / L and conducted the same test. When the amount added was 1000 mg / L, the dehydration rate was 28.7%, the oil content in the dehydrated water was 2033 mg / L, and the oil-water interface was not clear. When the amount added was 1500 mg / L, the dehydration rate was only 28.8%, and the oil content in the dehydrated water was 1984 mg / L. The oil-water interface was also not clear, indicating that this application must be based on the main raw material L-64 type propylene glycol block polyether.

[0049] Example 5:

[0050] This demulsifier comprises the following components: 30 kg of deionized water, 42 kg of L-64 type propylene glycol block polyether, and 28 kg of diethylene glycol monobutyl ether, totaling 100 kg. It is obtained according to the following method:

[0051] Weigh the raw materials according to the formula, pour 30 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 28 kg of diethylene glycol monobutyl ether to the reactor. After 10 min, add 42 kg of L-64 type propylene glycol block polyether to the reactor. Maintain the temperature at 50℃-55℃ and stir for 0.5 h. Cool to room temperature. The resulting colorless, slightly yellow, semi-transparent liquid is the demulsifier sample.

[0052] The performance indicators of the demulsifier sample tested in Example 5 are shown in Table 5 below.

[0053] Table 5

[0054] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 56.3 Oil content in the dewatering water (mg / L) ≤300 379 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 0.06

[0055] Compared to Example 3, the sample in Example 5 showed a significant decrease in the dehydration rate of extra-heavy crude oil and a marked increase in the oil content of the dehydrated water, indicating insufficient demulsification of the extra-heavy crude oil. The results of Example 4 suggest that the combination of other components in this application has a strong synergistic effect on the demulsification of L-64 type propylene glycol block polyether in extra-heavy crude oil.

[0056] Example 6:

[0057] This demulsifier comprises the following components: 21 kg of deionized water, 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0058] Weigh the raw materials according to the formula, pour 21 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a colorless and uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor, stir for 10 min, then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature. The resulting light brown uniform liquid is the demulsifier sample.

[0059] The performance indicators of the demulsifier sample tested in Example 6 are shown in Table 6 below.

[0060] Table 6

[0061] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 59.8 Oil content in the dewatering water (mg / L) ≤300 336 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 2.0

[0062] Compared to Example 3, Example 6 did not add sulfonated asphalt powder. Combining the data from Example 5 with the results of Example 6, it can be seen that sulfonated asphalt powder plays a very important role in this application, serving as a fundamental demulsifier component. Regarding the demulsifying and enhancing effect of sulfonated asphalt powder on extra-heavy crude oil in this application, we speculate that the reason may be that the molecular structure of sulfonated asphalt powder contains parts similar to asphaltenes and gums, allowing a larger portion of the sulfonated asphalt powder to be adsorbed at the asphaltenes-gum interface, while a smaller portion can dissolve in the asphaltenes-gum. Furthermore, the strong hydrophilicity of sulfonated asphalt powder can change the surface of asphaltenes and gums from oil-wettable to water-wettable, making the emulsion structure of asphaltenes and gums as water-in-oil emulsifiers unstable.

[0063] Example 7:

[0064] This demulsifier comprises the following components: 26 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0065] Weigh the raw materials according to the formula, pour 26 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 1 kg of sodium octadecylbenzenesulfonate to the reactor, stir for 0.5 h, and cool to room temperature. The resulting blackish-brown uniform liquid is the demulsifier sample.

[0066] The performance indicators of the demulsifier sample tested in Example 7 are shown in Table 7 below.

[0067] Table 7

[0068] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 68.8 Oil content in the dewatering water (mg / L) ≤300 278 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 0.2

[0069] Compared to Example 3, Example 7 did not include oleamide polyoxyethylene ether, resulting in a decrease in dehydration rate and a significant decrease in crude oil viscosity reduction. Therefore, we speculate that the synergistic effect of oleamide polyoxyethylene ether on demulsification may stem from its depolymerization and viscosity-reducing effect on asphaltene and resin aggregates, which can increase the fluidity of asphaltene and resins.

[0070] Example 8:

[0071] This demulsifier comprises the following components: 19 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, and 8 kg of oleamide polyoxyethylene ether, totaling 100 kg. It is obtained according to the following method:

[0072] Weigh the raw materials according to the formula, pour 19 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min and add 8 kg of oleamide polyoxyethylene ether to the reactor. Stir for 0.5 h and cool to room temperature. The resulting black uniform liquid is the demulsifier sample.

[0073] The performance indicators of the demulsifier sample tested in Example 8 are shown in Table 8 below.

[0074] Table 8

[0075] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 71.5 Oil content in the dewatering water (mg / L) ≤300 305 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 1.8

[0076] Compared with Example 3, no sodium octadecylbenzenesulfonate was added in Example 8, resulting in a decrease in dehydration rate. Regarding the synergistic effect of sodium octadecylbenzenesulfonate on the demulsification of this application, we speculate that it is related to the fact that sodium octadecylbenzenesulfonate has good dispersibility, which can better disperse the active components in crude oil.

[0077] Example 9:

[0078] This demulsifier comprises the following components: 18 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of diethylene glycol monolaurate, totaling 100 kg. It is obtained according to the following method:

[0079] Weigh the raw materials according to the formula, pour 18 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor and stir for 10 min. Then add 1 kg of diethylene glycol monolaurate and continue stirring for 1.0 h. Cool to room temperature. The resulting black uniform liquid is the demulsifier sample.

[0080] The performance indicators of the demulsifier sample obtained in Example 9 are shown in Table 9 below.

[0081] Table 9

[0082] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 77.6 Oil content in the dewatering water (mg / L) ≤300 327 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 2.3

[0083] Compared to Example 3, in Example 9, sodium octadecylbenzenesulfonate was replaced with another surfactant, diethylene glycol monolaurate, which has a similar HLB value. As a result, the dehydration rate decreased while the oil content of the dehydrated water increased. Diethylene glycol monolaurate also has some effect as a dispersant in this application, but it is significantly less effective than sodium octadecylbenzenesulfonate.

[0084] Example 10:

[0085] This demulsifier comprises the following components: 18 kg of deionized water, 3 kg of sulfonated asphalt powder (purchased from Qingzhou Tianyi Chemical Co., Ltd., with a water-soluble content of 71%-74%, a pH of 8.6-8.8 for 2% aqueous solution, and a moisture content of 7.0%-8.5%, which can be used directly without drying), 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 type propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained according to the following method:

[0086] Weigh the raw materials according to the formula, pour 18 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder (water-soluble content 71%-74%) to the reactor and stir until a uniform liquid is obtained. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether to the reactor in sequence, maintain 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Reduce the stirring speed to 80 r / min, add 8 kg of oleamide polyoxyethylene ether to the reactor and stir for 10 min. Then add 1 kg of sodium octadecylbenzenesulfonate and continue stirring for 1.0 h. Cool to room temperature and the resulting blackish-brown uniform liquid is the demulsifier sample.

[0087] The performance indicators of the demulsifier sample obtained in Example 10 are shown in Table 10 below.

[0088] Table 10

[0089]

[0090]

[0091] Compared to Example 3, Example 10 replaced the sulfonated asphalt powder raw material with high water-soluble content (81%-83%) from Tianjin Summit Chemical with sulfonated asphalt powder with lower water-soluble content (71%-74%) from Qingzhou Tianyi Chemical. The results showed that the dehydration rate decreased significantly, but it still had a better effect than the example without the addition of sulfonated asphalt powder.

[0092] Example 11:

[0093] The demulsifier comprises the following components: 27 kg of deionized water, 3 kg of sulfonated asphalt powder, 28 kg of diethylene glycol monobutyl ether, and 42 kg of L-64 type propylene glycol block polyether, totaling 100 kg, and is obtained by the following method:

[0094] Weigh the raw materials according to the formula, pour 27 kg of deionized water into the reactor, start stirring at 130 r / min and start heating. When the temperature reaches 50℃, add 3 kg of sulfonated asphalt powder into the reactor and stir until a uniform liquid is formed. Then add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 type propylene glycol block polyether into the reactor in sequence. Maintain the temperature at 50℃-55℃ and continue stirring for 0.5 h to obtain a black uniform liquid. Cool to room temperature to obtain the demulsifier sample for extra-heavy crude oil.

[0095] The performance indicators of the demulsifier sample in Example 11 are shown in Table 11 below.

[0096] Table 11

[0097] Test Project Recommended indicator requirements Test Results Dehydration rate (%) ≥75 68.3 Oil content in the dewatering water (mg / L) ≤300 259 Oil-water interface condition The oil and water interface is clear. The oil and water interface is clear. Crude oil viscosity reduction rate (70℃, %) - 0.1

[0098] Compared to Example 3, Example 11 did not include oleamide polyoxyethylene ether and sodium octadecylbenzenesulfonate. The results showed that the test data of the Example 11 sample was surprisingly close to that of the Example 7 sample (which only lacked oleamide polyoxyethylene ether), and the dehydration rate data was not significantly different from that of the Example 8 sample. This indicates that oleamide polyoxyethylene ether and sodium octadecylbenzenesulfonate have a synergistic effect in this application, and both need to be added together to achieve a strong demulsification and synergistic effect. The presumed reason is that the viscosity-reducing effect of oleamide polyoxyethylene ether and the dispersing effect of sodium octadecylbenzenesulfonate can work synergistically, allowing for better depolymerization and dispersion of asphaltene and resin aggregates, and enabling the demulsifier to penetrate more easily into the asphaltene and resin to exert its effect. Combined with the test results of Example 6, it can be seen that the strong synergistic demulsification and synergistic effect of oleamide polyoxyethylene ether and sodium octadecylbenzenesulfonate requires the presence of the demulsifier L-64 type propylene glycol block polyether and the demulsifier sulfonated asphalt powder.

[0099] It is precisely because of the synergistic demulsification effect of L-64 type propylene glycol block polyether, sulfonated asphalt powder, oleamide polyoxyethylene ether and sodium octadecylbenzenesulfonate that the demulsifier of this application has excellent demulsification effect on extra-heavy crude oil.

[0100] The above description of the embodiments is intended to enable those skilled in the art to understand and use the present invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the principles of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention. The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A demulsifier for extra-heavy crude oil, comprising the following components: 17%-21% deionized water, 3%-4% sulfonated asphalt powder, 26%-28% diethylene glycol monobutyl ether, 40%-44% L-64 type propylene glycol block polyether, 7%-8% oleamide polyoxyethylene ether, and 1% sodium octadecylbenzenesulfonate, the total of the above components being 100%; The sulfonated asphalt powder contains 80%-85% water-soluble components, <10.0% moisture, and its 2% aqueous solution has a pH of 9.0-10.

3.

2. The demulsifier according to claim 1, characterized in that, The sulfonated asphalt powder contains 81%-83% water-soluble components, <10.0% moisture, and its 2% aqueous solution has a pH of 9.6-10.

0.

3. The method for preparing the demulsifier for extra-heavy crude oil according to any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Weigh the raw materials according to the ratio, pour all the deionized water into the reactor, start stirring at 100r / min-150r / min and start heating. When the temperature reaches 50℃-55℃, add sulfonated asphalt powder to the reactor and stir until a uniform liquid is formed. Then, add diethylene glycol monobutyl ether and L-64 type propylene glycol block polyether to the reactor in sequence, maintain the temperature at 50℃-55℃, and continue stirring for 0.5h-1.0h to obtain a black uniform liquid. Step 2: Reduce the stirring speed to 60r / min-90r / min, add oleamide polyoxyethylene ether to the reactor, stir for 10min, then add sodium octadecylbenzenesulfonate, continue stirring for 0.5h-1.0h, cool to room temperature, and the resulting dark brown uniform liquid is the demulsifier for extra-heavy crude oil.

4. The use of the demulsifier for extra-heavy crude oil according to any one of claims 1-2 or the demulsifier for extra-heavy crude oil prepared by the method of claim 3 in the demulsification and dehydration of water-in-oil emulsion type extra-heavy crude oil.

5. The application according to claim 4, characterized in that, The amount of demulsifier added is 500 mg / L-1500 mg / L.

6. The application according to claim 4, characterized in that, Specifically, it is applied to the demulsification of extra-heavy crude oil with an asphalt content of 17%-25%, a resin content of 2%-20%, a water content of 20%-33%, and a viscosity of 490,000 cp-880,000 cp at 20℃.

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