Demulsifier for extra-heavy crude oil

Abstract

The invention belongs to the technical field of oil and gas field chemistry, and particularly discloses a demulsifier for extra-heavy crude oil. The demulsifier provided by the invention comprises the following components: 17%-21% of deionized water, 3%-4% of sulfonated asphalt powder, 26%-28% of diethylene glycol monobutyl ether, 40%-44% of L-64 type propylene glycol block polyether, 7%-8% of oleamide polyoxyethylene ether and 1% of sodium octadecyl benzene sulfonate, and the sum of the components is 100%. The dehydration rate of the demulsifier for extra-heavy crude oil can reach 80% or above, the oil-water separation difficulty of the extra-heavy crude oil is effectively reduced, and the oil content of dehydrated water is low.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field chemistry, and particularly relates to a demulsifier for extra-heavy crude oil. Background Art

[0002] The crude oil extracted from the oil well is not pure, but generally exists in the form of water-in-oil emulsion. Extra heavy crude oil refers to crude oil with a density greater than or equal to 0.998 g / cm at 20°C. 3 Asphaltene and colloid are natural emulsifier components. Extra-heavy crude oil has a high asphaltene and colloid content, resulting in high viscosity and increased emulsification stability. Therefore, chemical demulsification of extra-heavy crude oil has always been a challenge. Few demulsifiers in China can achieve a dehydration rate of more than 80% for extra-heavy crude oil. The market is in urgent need of a high-efficiency demulsifier for extra-heavy crude oil. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a demulsifier for extra-heavy crude oil, which can achieve a dehydration rate of over 80% for extra-heavy crude oil, with a clear oil-water interface and an oil content of less than 300 mg / L in the dehydrated water.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] 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 propylene glycol block polyether, 7%-8% oleamide polyoxyethylene ether, and 1% sodium octadecylbenzenesulfonate, the total of which is 100%. The sulfonated asphalt powder has a water-soluble component content of 80%-85%, a moisture content of less than 10.0%, and a pH value of 9.0-10.3 for a 2% aqueous solution thereof. Preferably, the sulfonated asphalt powder has a water-soluble component content of 81%-83%, a moisture content of less than 10.0%, and a pH value of 9.6-10.0 for a 2% aqueous solution thereof.

[0006] A method for preparing a demulsifier for extra-heavy crude oil comprises the following steps: weighing raw materials according to a ratio, and uniformly stirring deionized water, sulfonated asphalt powder, diethylene glycol monobutyl ether, L-64 propylene glycol block polyether, oleamide polyoxyethylene ether, and sodium octadecylbenzenesulfonate to obtain a demulsifier for extra-heavy crude oil. More specifically, the method comprises 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 a speed of 100r / min-150r / min, and start heating. When the temperature reaches 50℃-55℃, add sulfonated asphalt powder to the reactor, stir to form a uniform liquid, and then add diethylene glycol monobutyl ether and L-64 propylene glycol block polyether to the reactor in sequence. Maintain 50℃-55℃ and continue stirring for 0.5h-1.0h to obtain a black uniform liquid;

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

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

[0010] It is specifically used for demulsification of extra heavy crude oil with an asphaltene content of 17%-25%, a colloid content of 2%-20%, a water content of 20%-33% and a viscosity of 490,000cp-880,000cp at 20°C.

[0011] The demulsifier of the present invention is based on L-64 propylene glycol block polyether as the demulsification main agent, sulfonated asphalt powder as the demulsification enhancer, and oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate as auxiliary demulsification synergists. The L-64 propylene glycol block polyether can be competitively adsorbed at the oil-water interface, replacing the asphaltene and other emulsifier molecules of the original stable emulsion film, so that small droplets are aggregated into large droplets for demulsification, but its single use for the demulsification degree of extra-heavy crude oil is insufficient. There is a structure similar to asphaltene and colloid in the sulfonated asphalt molecule, so that a part of the sulfonated asphalt can be adsorbed on the asphaltene and colloid interface, and a part of the sulfonated asphalt can be dissolved in the asphaltene and colloid. In addition, the hydrophilicity of the sulfonated asphalt powder with high water solubility (80% to 85%) is stronger, which can convert the surface of the asphaltene and colloid from oil wettability to water wettability, making the emulsified structure of asphaltene and colloid as oil-in-water emulsifier become unstable, thereby enhancing the demulsification effect. Oleic acid amide polyoxyethylene ether has a certain declustering and viscosity-reducing effect on asphaltene and colloid aggregates, and can change the rheological properties of asphaltene and colloid; sodium octadecylbenzenesulfonate has a certain dispersing effect on asphaltene and colloid. The combination of oleic acid amide polyoxyethylene ether and sodium octadecylbenzenesulfonate enables the demulsifier to penetrate into asphaltene and colloid more efficiently, thereby synergistically exerting a demulsification and synergistic effect.

[0012] Because of the above scheme, the demulsifier of the present invention has excellent demulsification effect on extra-heavy crude oil with an asphaltene content of 17%-25%, a colloid content of 2%-20%, a water content of 20%-33%, and a viscosity of 490,000 cp-880,000 cp at 20°C. The dehydration rate can reach over 80%, effectively reducing the difficulty of oil-water separation of the extra-heavy crude oil, and the dewatered water has a low oil content. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

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

[0015] The raw materials used in each embodiment are introduced as follows:

[0016] If not otherwise specified, sulfonated asphalt powder: purchased from Tianjin Samit Chemical Co., Ltd., water-soluble component: 81.0%-83.0%, pH (2% aqueous solution): 9.6-10.0, moisture: 7.0%-8.0%.

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

[0018] Oleic acid amide polyoxyethylene ether: purchased from Nouryon, Amadol CMA4W oleic acid amide polyoxyethylene ether, with a viscosity of 200 mPa·s and an HLB value of 8.8.

[0019] Example 1:

[0020] The 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 propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. The demulsifier is obtained by the following method:

[0021] The raw materials were weighed according to the ratio, 17 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 3 kg of sulfonated asphalt powder was added to the reactor (its moisture content was low and it could be used directly without drying during use). After stirring into a uniform liquid, 27 kg of diethylene glycol monobutyl ether and 44 kg of L-64 propylene glycol block polyether were added to the reactor in sequence. The temperature was maintained at 50°C-55°C and stirring was continued for 0.5 h to obtain a black uniform liquid. The stirring speed was lowered to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, stirred for 10 min, and then 1 kg of sodium octadecylbenzenesulfonate was added. The stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained dark brown uniform liquid was the demulsifier sample for extra heavy crude oil.

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

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

[0024] Example 1 Demulsifier sample performance index test is as follows Table 1

[0025] Table 1

[0026]

[0027]

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

[0029] Example 2:

[0030] The 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 propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. The demulsifier is obtained by the following method:

[0031] The raw materials were weighed according to the ratio, 21 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 4 kg of sulfonated asphalt powder was added to the reactor and stirred into a uniform liquid. Then, 26 kg of diethylene glycol monobutyl ether and 40 kg of L-64 propylene glycol block polyether were added to the reactor in sequence, and the temperature was maintained at 50°C-55°C. Stirring was continued for 0.5 h to obtain a black uniform liquid. The stirring speed was reduced to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, and stirring was continued for 10 min. Then, 1 kg of sodium octadecylbenzenesulfonate was added, and stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained dark brown uniform liquid was the demulsifier sample for extra heavy crude oil.

[0032] The performance index test of the demulsifier sample obtained in Example 2 is as follows Table 2

[0033] Table 2

[0034] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 80.4 Oil content in desorbed water (mg / L) ≤300 207 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 2.2

[0035] Example 3:

[0036] The 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 propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. The demulsifier is obtained by the following method:

[0037] The raw materials were weighed according to the ratio, 18 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 3 kg of sulfonated asphalt powder was added to the reactor and stirred into a uniform liquid. Then, 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether were added to the reactor in sequence. The temperature was maintained at 50°C-55°C and stirring was continued for 0.5 h to obtain a black uniform liquid. The stirring speed was reduced to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, stirred for 10 min, and then 1 kg of sodium octadecylbenzenesulfonate was added. The stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained dark brown uniform liquid was the demulsifier sample for extra heavy crude oil.

[0038] The performance index test of the demulsifier sample obtained in Example 3 is as follows Table 3

[0039] Table 3

[0040] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 82.4 Oil content in desorbed water (mg / L) ≤300 211 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 2.2

[0041] Example 4:

[0042] The 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 by the following method:

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

[0044] The performance index test of the demulsifier sample obtained in Example 4 is as follows Table 4

[0045] Table 4

[0046] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 28.5 Oil content in desorbed water (mg / L) ≤300 2065 Oil-water interface conditions Clear oil-water interface The oil-water interface is not clear Crude oil viscosity reduction rate (70℃, %) - 2.1

[0047] Compared with Example 3, Example 4 did not add L-64 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 extracted water and the mixing of oil and water to a certain extent at the oil-water interface.

[0048] In addition, we also increased the addition amount of the demulsifier sample in Example 4 to 1000 mg / L and 1500 mg / L for the same test. When the addition amount 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 addition amount was 1500 mg / L, the dehydration rate was only 28.8%, and the oil content in the dehydrated water was 1984 mg / L, and the oil-water interface was also unclear, indicating that this application must be based on the main raw material L-64 propylene glycol block polyether.

[0049] Embodiment 5:

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

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

[0052] Example 5 Demulsifier sample performance index test is as follows Table 5

[0053] Table 5

[0054] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 56.3 Oil content in desorbed water (mg / L) ≤300 379 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 0.06

[0055] Compared with Example 3, the sample of Example 5 significantly reduced the dehydration rate of the extra-heavy crude oil, and the oil content in the dehydrated water was also significantly increased, indicating that the degree of demulsification of the extra-heavy crude oil was insufficient. The results of Example 4 indicate that the combination of other components in this application has a strong synergistic effect on the demulsification of L-64 propylene glycol block polyether in extra-heavy crude oil.

[0056] Example 6:

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

[0058] The raw materials were weighed according to the ratio, 21 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether were added to the reactor in sequence. The temperature was maintained at 50°C-55°C and stirring was continued for 0.5 h to obtain a colorless uniform liquid. The stirring speed was lowered to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, stirred for 10 min, and then 1 kg of sodium octadecylbenzenesulfonate was added. The stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained light brown uniform liquid was the demulsifier sample.

[0059] Example 6 Demulsifier sample performance index test is as follows Table 6

[0060] Table 6

[0061] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 59.8 Oil content in desorbed water (mg / L) ≤300 336 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 2.0

[0062] Compared with Example 3, Example 6 does not add sulfonated asphalt powder. Combined with the data from Example 5, the results of Example 6 show that sulfonated asphalt powder plays a very important role in this application and is a basic demulsification enhancer component in this application. As for the demulsification and synergistic 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 asphaltene and colloid, so that a large part of the sulfonated asphalt powder can be adsorbed at the asphaltene and colloid interface, while a small part of the sulfonated asphalt powder can still dissolve in the asphaltene and colloid. Moreover, sulfonated asphalt powder is highly hydrophilic and can convert the surface of asphaltene and colloid from oil-wet to water-wet, making the emulsified structure of asphaltene and colloid as oil-in-water emulsifier unstable.

[0063] Embodiment seven:

[0064] The 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 propylene glycol block polyether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. It is obtained by the following method:

[0065] Weigh the raw materials according to the ratio, pour 26 kg of deionized water into the reactor, start stirring at a speed of 130 r / min, and start heating. When the temperature reaches 50°C, add 3 kg of sulfonated asphalt powder to the reactor and stir to form a uniform liquid. Then, add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether to the reactor in sequence, maintain the temperature at 50°C-55°C, 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 obtained dark brown uniform liquid is the demulsifier sample.

[0066] Example 7 Demulsifier sample performance index test is as follows Table 7

[0067] Table 7

[0068] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 68.8 Oil content in desorbed water (mg / L) ≤300 278 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 0.2

[0069] Compared with Example 3, Example 7 did not add oleamide polyoxyethylene ether. As a result, the dehydration rate decreased and the crude oil viscosity reduction rate also decreased significantly. Therefore, we speculate that the synergistic effect of oleamide polyoxyethylene ether on demulsification may be due to its certain depolymerization and viscosity reduction effect on asphaltene and colloid aggregates, which can increase the fluidity of asphaltene and colloid.

[0070] Embodiment 8:

[0071] The 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 propylene glycol block polyether, and 8 kg of oleamide polyoxyethylene ether, totaling 100 kg. It is obtained by the following method:

[0072] Weigh the raw materials according to the ratio, pour 19 kg of deionized water into the reactor, start stirring at a speed of 130 r / min, and start heating. When the temperature reaches 50°C, add 3 kg of sulfonated asphalt powder to the reactor and stir to form a uniform liquid. Then, add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether to the reactor in sequence, maintain 50°C-55°C, 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 0.5 h, and cool to room temperature. The obtained black uniform liquid is the demulsifier sample.

[0073] Example 8 Demulsifier sample performance index test is as follows Table 8

[0074] Table 8

[0075] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 71.5 Oil content in desorbed water (mg / L) ≤300 305 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 1.8

[0076] Compared with Example 3, sodium octadecylbenzenesulfonate was not added in Example 8, and the dehydration rate decreased. As for the synergistic effect of sodium octadecylbenzenesulfonate on the demulsification of this application, we speculate that this is related to the fact that sodium octadecylbenzenesulfonate has good dispersibility and can better disperse the active components in crude oil.

[0077] Embodiment 9:

[0078] The 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 propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of diethylene glycol monolaurate, totaling 100 kg. The demulsifier is obtained by the following method:

[0079] The raw materials were weighed according to the ratio, 18 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 3 kg of sulfonated asphalt powder was added to the reactor and stirred into a uniform liquid. Then, 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether were added to the reactor in sequence, and the temperature was maintained at 50°C-55°C. Stirring was continued for 0.5 h to obtain a black uniform liquid. The stirring speed was lowered to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, and stirring was continued for 10 min. Then, 1 kg of diethylene glycol monolaurate was added, and stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained black uniform liquid was the demulsifier sample.

[0080] The performance index test of the demulsifier sample obtained in Example 9 is as follows Table 9

[0081] Table 9

[0082] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 77.6 Oil content in desorbed water (mg / L) ≤300 327 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 2.3

[0083] Compared with Example 3, in Example 9, the raw material sodium octadecylbenzenesulfonate was replaced with another surfactant diethylene glycol monolaurate with a similar HLB value. As a result, the dehydration rate decreased while the oil content in the dehydrated water increased. Diethylene glycol monolaurate also has a certain effect as a dispersant in this application, but it is obviously not as good as sodium octadecylbenzenesulfonate.

[0084] Embodiment 10:

[0085] The 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 component content of 71%-74%, a 2% aqueous solution with a pH of 8.6-8.8, and a moisture content of 7.0%-8.5%, and can be used directly without drying during use), 28 kg of diethylene glycol monobutyl ether, 42 kg of L-64 propylene glycol block polyether, 8 kg of oleamide polyoxyethylene ether, and 1 kg of sodium octadecylbenzenesulfonate, totaling 100 kg. The demulsifier is obtained by the following method:

[0086] The raw materials were weighed according to the ratio, 18 kg of deionized water was poured into the reactor, stirring was started at a speed of 130 r / min, and the temperature was increased. When the temperature reached 50°C, 3 kg of sulfonated asphalt powder (water-soluble content 71%-74%) was added to the reactor and stirred into a uniform liquid. Then, 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether were added to the reactor in sequence, and the temperature was maintained at 50°C-55°C. Stirring was continued for 0.5 h to obtain a black uniform liquid. The stirring speed was lowered to 80 r / min, 8 kg of oleamide polyoxyethylene ether was added to the reactor, stirred for 10 min, and then 1 kg of sodium octadecylbenzenesulfonate was added. Stirring was continued for 1.0 h. The mixture was cooled to room temperature. The obtained dark brown uniform liquid was the demulsifier sample.

[0087] The performance index test of the demulsifier sample obtained in Example 10 is as follows Table 10

[0088] Table 10

[0089]

[0090]

[0091] Compared with Example 3, in Example 10, the sulfonated asphalt powder raw material with a high water-soluble content (81%-83%) of Tianjin Samit Chemical was replaced with the sulfonated asphalt powder with a lower water-soluble content (71%-74%) of Qingzhou Tianyi Chemical. The results showed that the dehydration rate was significantly reduced, but it still had a better effect than the example without adding 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 propylene glycol block polyether, totaling 100 kg, and is obtained by the following method:

[0094] Weigh the raw materials according to the ratio, pour 27 kg of deionized water into the reactor, start stirring at a speed of 130 r / min, and start heating. When the temperature reaches 50°C, add 3 kg of sulfonated asphalt powder to the reactor and stir to form a uniform liquid. Then, add 28 kg of diethylene glycol monobutyl ether and 42 kg of L-64 propylene glycol block polyether to the reactor in sequence. Maintain the temperature at 50°C-55°C 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] Example 11 Demulsifier sample performance index test is as follows Table 11

[0096] Table 11

[0097] Test items Recommended indicator requirements Test results Dehydration rate (%) ≥75 68.3 Oil content in desorbed water (mg / L) ≤300 259 Oil-water interface conditions Clear oil-water interface Clear oil-water interface Crude oil viscosity reduction rate (70℃, %) - 0.1

[0098] Compared with embodiment three, oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate are not added in embodiment 11, it is found that embodiment 11 sample test data is unexpectedly close to embodiment seven samples that do not only add oleamide polyoxyethylene ether, and the dehydration rate data with embodiment eight samples also differ not very greatly, illustrate that oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate two components have synergy in this application, and both need to add together and just have powerful demulsification synergistic effect. It is speculated that the viscosity reduction of oleamide polyoxyethylene ether and the dispersion of sodium octadecylbenzene sulfonate can be coordinated and linked, so that asphaltene, colloid aggregate are better depolymerized and dispersed and demulsifier can more easily penetrate into asphaltene, colloid and play a role. In conjunction with the test result of embodiment six, it is known that oleamide polyoxyethylene ether and sodium octadecylbenzene sulfonate powerful collaborative demulsification synergistic effect need to be based on the basis with demulsification main agent L-64 type propylene glycol block polyether and demulsification enhancer sulfonated asphalt powder.

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

[0100] The above description of the embodiments is intended to facilitate the understanding and use of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to go through creative work. 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 present invention should be within the scope of protection of the present invention. The above description is only a preferred embodiment of the present invention and is 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 in the scope of protection 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 propylene glycol block polyether, 7%-8% oleamide polyoxyethylene ether, and 1% sodium octadecylbenzenesulfonate, the total of which is 100%.

2. The demulsifier according to claim 1, characterized in that The water-soluble component of the sulfonated asphalt powder is 80%-85%, the water content is less than 10.0%, and the pH value of the 2% aqueous solution thereof is 9.0-10.

3.

3. The demulsifier according to claim 2, characterized in that The water-soluble component of the sulfonated asphalt powder is 81%-83%, the water content is less than 10.0%, and the pH value of the 2% aqueous solution thereof is 9.6-10.

0.

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

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

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

7. The use according to claim 5, characterized in that It is specifically used for demulsification of extra heavy crude oil with an asphaltene content of 17%-25%, a colloid content of 2%-20%, a water content of 20%-33% and a viscosity of 490,000cp-880,000cp at 20°C.

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