CN110686164A - Method for reducing viscosity of crude oil - Google Patents

Abstract

The invention relates to the field of crude oil transportation, in order to solve the problem of difficulty in crude oil transportation caused by the increase of crude oil viscosity at low temperature, overcome the shortcomings of existing physical and chemical viscosity reduction technologies, and especially improve the existing chemical viscosity reducer at low temperature. The problem of large and weakened viscosity reduction effect makes the viscosity reducer still have good viscosity reduction ability under the low temperature transportation environment. The present invention proposes a method for reducing the viscosity of crude oil: The polymer of oxane or diethylsiloxane is mixed with crude oil by the usual method, which can significantly reduce the viscosity of crude oil, reduce the energy consumption caused by heating and heat preservation in the process of crude oil transportation, and reduce the power of the pump and the crude oil. The resistance in the pipeline reduces the energy consumption during crude oil transportation. The invention has the advantages of simple synthesis method, mild reaction conditions, easy separation and recovery of products, low equipment investment, high equipment utilization rate and easy industrial production.

Description

A method of reducing the viscosity of crude oil

technical field

The invention relates to the field of crude oil transportation, in particular to a method for reducing the viscosity of crude oil.

technical background

Crude oil is a mixture of liquid hydrocarbons or their natural forms directly mined from underground natural oil reservoirs. After removal of water and associated methane and other gaseous compounds in crude oil, crude oil usually presents a flowing or semi-flowing viscous liquid state. Crude oil is a strategic material for various countries. After primary and secondary processing, various commodities can be produced to meet the needs of various sectors of the national economy and people's material life. Crude oil reserves around the world are unbalanced, and my country's crude oil reserves are relatively small and the quality of crude oil is not good. Therefore, in order to meet the huge demand for energy and materials in various sectors of my country's national economy, most of my country's crude oil is imported to solve domestic production and demand. huge gap between. Affected by various factors such as geography, environment and national strategic layout, most of my country's crude oil processing enterprises, such as petrochemical and refining enterprises, are not located in cities with oil terminals such as the coast. It is the primary task to realize oil processing and utilization, and the long-distance pipeline transportation of crude oil is the main form of crude oil transportation in China.

Crude oil is a complex mixture composed of various hydrocarbons, aromatic hydrocarbons and heterocyclic aromatic hydrocarbons. The composition of crude oil produced in different regions is different, resulting in different viscosity of crude oil in different regions. As we all know, the viscosity of the fluid is an important factor affecting the efficiency of pipeline transportation and energy consumption. The greater the viscosity of the fluid, the greater the resistance loss of the fluid in the pump and the pipeline. Long-distance transportation of fluids can only be achieved by setting up intermediate storage tanks at certain distances and pumping the fluids to the next-level transfer station again; the higher the viscosity of the fluids, the higher the energy consumption during transportation. Therefore, reducing the viscosity of crude oil has become one of the key technical problems to be overcome in crude oil transportation.

The viscosity of crude oil decreases as the temperature increases. Therefore, in order to reduce the resistance loss during the transportation process, reduce the power of the pump and prolong the transportation distance, the crude oil transportation pipeline usually adopts the heating and heat preservation method to increase the temperature of the crude oil being transported and reduce the viscosity of the crude oil. However, the heating and heat preservation method not only consumes a lot of energy, but also increases the vapor pressure of each component in the crude oil as the temperature increases. Flash point, volatile, flammable and explosive components will accumulate at the leaking place. If there is an ignition source such as open flame, lightning, etc., it will easily lead to the occurrence of dangerous situations such as fire or even explosion, which will bring harm to the life and property of the country and the people. huge loss.

In addition to heating crude oil for viscosity reduction, there are physical viscosity reduction technologies such as dilution viscosity reduction, microwave viscosity reduction and magnetic treatment viscosity reduction, as well as chemical viscosity reduction such as emulsion viscosity reduction, oil-soluble viscosity reduction agent, and pour point reducer viscosity reduction. technology. Diluted viscosity reduction is to mix some low-viscosity liquid hydrocarbons as diluents with the heavy oil before the crude oil with high viscosity enters the pipeline to reduce the viscosity of the heavy oil for transportation, so as to be transported in the form of a mixture, but mixed with heavy oil. Thin oil viscosity reduction has the defects of limited thin oil resources, increased energy consumption, and increased transportation load. Microwave viscosity reduction uses microwave athermal effect to modify heavy oil, change the chemical composition of heavy oil, and irreversibly improve the flow of heavy oil. denaturation in order to achieve the purpose of rapid viscosity reduction, but microwave viscosity reduction has the problem of uneven distribution of internal temperature macroscopic and microscopic, which easily leads to changes in the chemical structure of crude oil components; magnetic treatment viscosity reduction uses the induction of diamagnetism and magnetization of crude oil The magnetic moment can inhibit the formation and coalescence of wax crystals, so that the wax crystals exist in the heavy oil in the form of small particles, which enhances the fluidity and reduces the viscosity of the heavy oil, but the magnetic treatment is time-sensitive, and the induced magnetic moment increases with time. And gradually disappeared, resulting in the disappearance of the viscosity-reducing effect over time. Emulsification and viscosity reduction By adding surfactants, crude oil is converted from a water-in-oil (W/O) emulsion to an oil-in-water (O/W) emulsion to achieve the purpose of viscosity reduction. The viscosity reduction mechanism mainly includes emulsification. There are two aspects of viscosity reduction and wetting resistance reduction, but emulsification and viscosity reduction have problems such as difficulty in demulsification, difficulty in sewage treatment, strong selectivity of emulsifier to crude oil, and crude oil composition affects the effect of emulsification and viscosity reduction. Adhesive molecules have strong hydrogen bond forming ability, enter between colloid and asphaltene sheet molecules through penetration or dispersion, partially dismantle the aggregates formed by overlapping planes, and construct random stacking, New hydrogen bond aggregates with loose structure, low degree of order and small spatial extension to achieve the purpose of reducing the viscosity of crude oil. The main monomers of oil-soluble viscosity reducers are ethylene, vinyl acetate, styrene, maleic anhydride, (methyl) base) acrylates and α-olefins, etc., but the viscosity reducer is selective for crude oil, and a viscosity reducer cannot be applied to other crude oils; the viscosity reduction agent uses its molecular structure to be the same as the molecular structure of the wax in crude oil or Similarly, it can eutectic or adsorb with wax crystals during the nucleation and growth of wax, preventing the growth of wax crystals and inhibiting the network structure of wax, thereby reducing the apparent viscosity of crude oil, but only when the pour point depressant is used. When the molecular structure of the oil is the same as or similar to the molecular structure of the wax in the crude oil, the viscosity reduction effect will occur, so the pour point depressant also has a certain selectivity to the crude oil. Viscosity reduction effect.

It can be seen that both the existing physical viscosity reduction technology and chemical viscosity reduction technology have certain technical defects, resulting in an unsatisfactory crude oil viscosity reduction effect. Among them, the existing chemical viscosity reduction technology is more affected by the origin of crude oil and the composition of crude oil. In addition, the main components of the emulsifiers, oil-soluble viscosity reducers and pour point reducers used in the existing chemical viscosity reduction technology are mostly compounds or polymers composed of carbon-carbon bonds. It increases rapidly, which greatly reduces its original viscosity reduction ability.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the existing physical and chemical viscosity reduction technologies, especially the existing chemical viscosity reducers at low temperatures have the problems of increased viscosity and weakened viscosity reduction effect, the present invention proposes a method for reducing the viscosity of crude oil, which can significantly reduce the viscosity of crude oil. Reducing the viscosity of crude oil can reduce the energy consumption caused by heating and heat preservation during the crude oil transportation process, reduce the power of the pump and the resistance of the crude oil in the pipeline, and reduce the energy consumption during the crude oil transportation process.

The present invention is achieved through the following technical solutions: a method for reducing the viscosity of crude oil is to mix cyclosiloxane or diethylsiloxane containing diethylsiloxane chain units (-(C ₂ H ₅ ) ₂ SiO-) The polymer of the chain unit (-(C ₂ H ₅ ) ₂ SiO-) is mixed with crude oil by a usual method. In the process of catalytic hydroreforming and catalytic cracking of the mixed crude oil, the additions will be cracked into methane, ethane and high boilers, and methane and ethane are the inherent products of crude oil or its processing into gasoline and diesel. The boiling point of the high-boiling organosilicon is higher than the boiling point of the colloidal substances such as asphalt obtained after the cracking of crude oil, and can be used together with asphalt in the fields of building materials. Therefore, it contains diethylsiloxane (-(C ₂ H ₅ ) ₂ SiO-) cyclosiloxane or polymer of diethylsiloxane (-(C ₂ H ₅ ) ₂ SiO-) mixed with crude oil does not affect the use of crude oil.

Said cyclosiloxane containing diethylsiloxane is selected from hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, decaethylcyclopentasiloxane, dodecylcyclopentasiloxane One or more of hexasiloxanes.

The polymer containing diethylsiloxane chain units is selected from one of the oligopolysiloxanes shown in structural formula (I) and the copolysiloxanes shown in structural formula (II),

In formula (I) and (II), R ₁ , R ₄ are independently selected from Me, Me ₃ SiO-, Et, Ph; R ₂ , R ₃ , R ₅ , R ₆ are independently selected from Me , one of Et, wherein Me represents a methyl functional group, Et represents an ethyl functional group, and Ph represents a phenyl functional group; R _a and R _b are independently selected from methyl, ethyl, trifluoropropyl, and phenyl. One, and R _a and R _b are not simultaneously ethyl or trifluoropropyl;

In formula (I), n represents the degree of polymerization of the oligomer, n=1～100,

In formula (II), x ₁ is the degree of polymerization of diethylsiloxane, x ₂ is the degree of polymerization of other diorganosiloxane units, x ₁ =1-30, x ₂ =1-100, and x ₁ +x ₂ =1-120, the structural formula (I) and the structural formula (II) are collectively abbreviated as ethyl silicone oil.

Preferably, the viscosity (η ₂₀ ) at 20° C. of the oligomeric siloxane containing diethylsiloxane is 5 to 500 mPa·s. The viscosity (η ₂₀ ) at 20° C. of the copolysiloxane containing diethylsiloxane segments is 5 to 1000 mPa·s.

The mass ratio of the diethylsiloxane-containing cyclosiloxane or diethylsiloxane-containing polymer with crude oil is 0.000005-0.50:1, preferably 0.00001-0.01:1.

The temperature when the cyclosiloxane containing diethylsiloxane chain unit or the polymer of diethylsiloxane chain unit is mixed with crude oil is -40 to 60°C, preferably -30 to 40°C.

Different from dimethyl silicone oil, the main product of the current silicone industry, cyclosiloxane, oligosiloxane or copolysiloxane containing diethylsiloxane have good compatibility with crude oil and disperse rapidly in crude oil , saving the mixing processing time of the existing viscosity reducer and crude oil; and the cyclosiloxane, oligomeric siloxane or copolysiloxane containing diethylsiloxane chain units is directly mixed with crude oil, and does not need to be like acrylic higher alkyl The base ester viscosity reducer needs to be polymerized and then formulated into an aqueous solution for use, which not only reduces the usage amount, reduces the transportation load, and correspondingly improves the transportation capacity of the crude oil pipeline, but also avoids the introduction of water into the crude oil and reduces the emulsification of crude oil. risk and save the operation cost of the follow-up link.

Compared with the prior art, the present invention has the beneficial effects that the viscosity of the crude oil can be significantly reduced, the energy consumption caused by heating and heat preservation during the crude oil transportation process can be reduced, the power of the pump and the resistance of the crude oil in the pipeline can be reduced, and the Energy consumption during crude oil transportation.

Description of drawings

Fig. 1 is the hydrogen nuclear magnetic spectrum of trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer;

Fig. 2 is the schematic diagram of the compatibility experiment of the present invention;

Fig. 3 is the influence of the amount of ethyl silicone oil on the viscosity of crude oil at different temperatures;

Fig. 4 is the influence of the dosage of hexaethylcyclotrisiloxane on the viscosity of crude oil at different temperatures;

Figure 5 shows the effect of the amount of dimethicone in the comparative example on the viscosity of crude oil at different temperatures.

Detailed ways

The present invention is described in further detail below by the examples, but the examples are not limitations to the protection scope of the present invention, and the raw materials used in the examples are all commercially available or prepared by conventional methods.

Preparation Example 1: Trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer

61.2 g of hexaethylcyclotrisiloxane (D ₃ ^Et ) was added to a 250 mL three-necked flask with mechanical stirring, a temperature control device, a nitrogen bottom tube and a reflux condensing device, and the temperature was raised to 50° C., and then Dehydration was carried out under the protection of a trace amount of N ₂ for 1 h; then 5.5 g of the dried solid superacid was added to the three-necked flask mixed with the above materials, the temperature was raised to 80 ° C, and the ring-opening reaction was carried out for 4 h, and then eight Methyltrisiloxane (MDM) 48.8g was subjected to end-capping reaction for 3h, then the material in the kettle was lowered to room temperature, the solid superacid catalyst was removed by filtration, and the filtrate was transferred to the de-lowing reaction kettle. Under the protection of trace nitrogen, Gradually increase the vacuum degree of the system to -100kPa, then gradually heat up to 220 ° C and maintain at this temperature for 8 hours to remove low boilers in the reaction system. The material was collected and weighed to obtain 75.9 g of trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer.

The viscosity of the obtained trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer was measured by Brookfield DV2TRVTJO rotational viscometer at 20°C to be 42.5mPa.s, measured by GPC The trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer had a number average molecular weight Mn of 1419, a weight average molecular weight Mw of 2379, and a polydispersity index PDI value of 1.67. According to the results of nuclear magnetic analysis and the structural formula of the polymer, it is calculated that the degree of polymerization x1 of the diethylsiloxy link in the copolymer is 3.80, and the degree of polymerization x2 of the dimethylsiloxane link is 1.

Test Example 1

The hydrogen nuclear magnetic spectrum ( ¹ HNMR) of the prepared trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer is shown in Figure 1, and the mass fraction of ethyl groups in the silicone oil is calculated as: 32.7%.

Preparation Example 2: Trimethylsiloxy-terminated polydiethylsiloxane oligomer

61.2g of hexaethylcyclotrisiloxane ( ^D3Et ) was added to a 250mL _three -necked flask with mechanical stirring, temperature control device, nitrogen bottom tube and reflux condenser, and the temperature was raised to 60°C, then Under the protection of a trace amount of N ₂ , dehydration was carried out under -100kPa vacuum for 0.5h; then 8.0 g of the dried solid superacid was added to the three-necked flask mixed with the above materials, and the temperature was raised to 80 °C to open the ring. After 3 hours of reaction, 34.0 g of hexamethyldisiloxane (MM) was added to carry out the end-capping reaction for 5 hours, then the material in the kettle was lowered to room temperature, the solid superacid catalyst was removed by filtration, and the filtrate was transferred to the de-lowering reaction kettle. , under the protection of a trace amount of nitrogen, gradually increase the vacuum degree of the system to -100kPa, then gradually heat up to 220 ° C and maintain at this temperature for 6 hours to remove low boilers in the reaction system, after the removal is completed, under nitrogen protection The system material was lowered to room temperature, and the material was collected and weighed to obtain 60.6 g of a trimethylsiloxy-terminated polydiethylsiloxane oligomer.

The viscosity of the obtained trimethylsiloxy-terminated polydiethylsiloxane oligomer at 20°C was measured by a Brookfield DV2TRVTJO rotational viscometer to be 46.9 mPa.s, and the trimethylsiloxane was measured by GPC. The group-terminated polydiethylsiloxane oligomer had a number average molecular weight Mn of 1846, a weight average molecular weight Mw of 2964, and a polydispersity index PDI value of 1.61. The mass fraction of ethyl group in the silicone oil was calculated to be 35.8% from the hydrogen nuclear magnetic spectrum ( ¹ H NMR) of the trimethylsiloxy-terminated polydiethylsiloxane oligomer. According to the structural formula, the calculated polymerization degree n of the oligomer is 16.5.

Preparation Example 3: Trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer

60g octamethylcyclotetrasiloxane, 28.7g hexaethylcyclotrisiloxane (D ₃ ^Et ) were added to a 250 mL three-necked flask with mechanical stirring, temperature control device, nitrogen insert tube and reflux condensing device , the temperature was raised to 55°C, and then under the protection of trace N ₂ , dehydration was carried out under -100kPa vacuum for 1.5h; then 5.4g of the dried solid superacid was added to the three-necked flask mixed with the above materials, The temperature was raised to 85°C, and the ring-opening reaction was carried out for 2 hours. Then 20.0 g of octamethyltrisiloxane (MDM) was added to carry out the end-capping reaction for 6 hours. Then, the contents in the kettle were lowered to room temperature, and the solid superacid catalyst was removed by filtration. Then transfer the filtrate to the de-lowering reaction kettle, under the protection of trace nitrogen, gradually increase the vacuum degree of the system to -100kPa, then gradually heat up to 218 ° C and maintain at this temperature for 5 hours to remove low boilers in the reaction system. , after the de-lowering was completed, the system material was lowered to room temperature under nitrogen protection, and the material was collected and weighed to obtain 69.6 g of trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer.

The viscosity of the obtained trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer was measured by Brookfield DV2TRVTJO rotational viscometer at 20°C to be 122.3 mPa.s, measured by GPC The number-average molecular weight Mn of the trimethylsiloxy-terminated polydiethylsiloxane oligomer was 3871, the weight-average molecular weight Mw was 6423, and the polydispersity index PDI value was 1.65. The mass fraction of ethyl group in the silicone oil was calculated by the hydrogen nuclear magnetic spectrum ( ¹ H NMR) of the trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer to be 14.45%. Based on the results and the structural formula of the polymer, it was calculated that the degree of polymerization x1 of the diethylsiloxane units in the copolymer was 9.35, and the degree of polymerization x2 of the dimethylsiloxane units was 36.25.

Preparation Example 4: Trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer

59.3 g of octamethylcyclotetrasiloxane, 15.3 g of ^{hexaethylcyclotrisiloxane (D3Et} ₎ and 12.4 g of octamethyltrisiloxane (MDM) were added together at room temperature with mechanical stirring. , temperature control device, nitrogen bottom tube and reflux condensing device in a 250mL three-necked flask, raise the temperature to 65°C, and then under the protection of trace N ₂ , carry out dehydration under -100kPa vacuum for 2.0h; 4.3 g of the solid superacid was added to the three-necked flask mixed with the above materials, the temperature was raised to 150 ° C, and the reaction was carried out for 4 h, then the material in the kettle was lowered to room temperature, and the solid superacid catalyst was removed by filtration, and then the filtrate was transferred to the dehydration In the low reaction kettle, under the protection of trace nitrogen, gradually increase the vacuum degree of the system to -100kPa, then gradually heat up to 200 ° C and maintain at this temperature for 4 hours to remove low boilers in the reaction system. The system material was lowered to room temperature under nitrogen protection, and the material was collected and weighed to obtain 60.1 g of a trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer.

The viscosity of the obtained trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer was measured by Brookfield DV2TRVTJO rotational viscometer at 20°C to be 91.0mPa.s, measured by GPC The number-average molecular weight Mn of the trimethylsiloxy-terminated polydiethylsiloxane oligomer was 9515, the weight-average molecular weight Mw was 22744, and the polydispersity index PDI value was 2.39. The mass fraction of ethyl groups in the silicone oil was calculated from the hydrogen nuclear magnetic spectrum ( ¹ H NMR) of the trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer to be 15.68%. Based on the results and the structural formula of the polymer, it was calculated that the degree of polymerization x1 of the diethylsiloxane units in the copolymer was 14.96, and the degree of polymerization x2 of the dimethylsiloxane units was 29.30.

Example 1(1)

Mix 1.9877 g of trimethylsiloxy-terminated poly(dimethyl-diethyl) siloxane copolymer (referred to as ethyl silicone oil) prepared in Preparation Example 1 with 8.0 g of light crude oil imported from Saudi Arabia at room temperature. Mix well.

Example 1(2)

2.0125 g of the trimethylsiloxy-terminated polydiethylsiloxane oligomer (referred to as ethyl silicone oil) prepared in Preparation Example 2 and 8.0 g of light crude oil imported from Saudi Arabia were mixed uniformly at room temperature.

Example 1(3)

Mix 1.9907 g of trimethylsiloxy-terminated poly(dimethyl-diethyl) siloxane copolymer (referred to as ethyl silicone oil) prepared in Preparation Example 3 with 8.0 g of light crude oil imported from Saudi Arabia at room temperature. Mix well.

Example 1(4)

Mix 1.9883 g of trimethylsiloxy-terminated poly(dimethyl-diethyl) siloxane copolymer (referred to as ethyl silicone oil) prepared in Preparation Example 4 with 8.0 g of light crude oil imported from Saudi Arabia at room temperature. Mix well.

Example 2

2.0089g of hexaethylcyclotrisiloxane (abbreviated as ethyl ring body) and 8.0g of light crude oil imported from Saudi Arabia were mixed uniformly at room temperature.

Comparative Example 1

2.0134 g of trimethylsiloxy-terminated polydimethylsiloxane with a viscosity (η ₂₀ ) of 50 mPa·s (dimethicone for short) and 8.0 g of crude oil were mixed uniformly at room temperature.

Test Example 2: Compatibility Experiment

After placing the mixed crude oil prepared in Example 1 (including 1(1), 1(2), 1(3), 1(4)), Example 2, and Comparative Example 1 for 2 days, the samples obtained respectively are as shown in the figure 2(a), Fig. 2(b), Fig. 2(c), as can be seen from Fig. 2(a), the different ethyl silicone oils prepared in Preparation Example 1-Preparation Example 4 are completely miscible with crude oil and have good compatibility. ; It can be seen from Figure 2(b) that hexaethylcyclotrisiloxane and crude oil are completely miscible with each other and have good compatibility; from Figure 2(c), it can be seen that there is a certain layering between dimethyl silicone oil and crude oil, and the compatibility Not as good as ethyl silicone oil and hexaethyl cyclotrisiloxane.

Example 3 - Example 34

Take out the light crude oil without impurities, clear and transparent at room temperature, add the trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer (referred to as ethyl silicone oil) prepared in Preparation Example 1, The mass ratio of ethyl silicone oil/crude oil is shown in Table 1, and it is mixed well.

Test Example 3: Trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane copolymer viscosity reduction experiment (1) Variation of crude oil viscosity with temperature

The viscosity of light crude oil was measured in the range of -20 to 40 °C using a DV2TRVTJO rotational viscometer, equipped with a rotor suitable for the viscosity measurement range, and the results are shown in Figure 3(a).

(2) Changes in viscosity of ethyl silicone oil with temperature

Using a DV2TRVTJO rotational viscometer, equipped with a rotor suitable for viscosity measurement, in the range of -20 to 50 °C, the viscosity of the ethyl silicone oil synthesized in Preparation Example 1 was measured as a function of temperature. The results are shown in Figure 3(b).

(3) Changes in viscosity of light crude oil mixed with ethyl silicone oil

Put the light crude oil mixed with ethyl silicone oil prepared in Example 3-11 into the sample measuring tube of the DV2TRVTJO type rotational viscometer, select the appropriate rotor and shear rate, set the temperature of the external low temperature thermostat, and wait for the sample After the temperature in the measuring tube reaches the set value, measure the viscosity of the ethyl silicone oil/crude oil mixture. After the viscosity value is stable, record the measurement results, as shown in Table 1.

Figure 3(c) shows the effect of the amount of ethyl silicone oil on the viscosity of crude oil when T=-20 °C. It can be seen from Figure 3(c) that adding a small amount of diethyl silicone oil has a very significant viscosity reduction effect on the viscosity of crude oil; Figure 3(d) shows the effect of reducing the amount of ethyl silicone oil on the viscosity of crude oil when T=-20 °C. It can be seen that adding a small amount of ethyl silicone oil can effectively reduce the viscosity of crude oil;

Figure 3(e) The effect of ethyl silicone oil content on the viscosity of crude oil when T=-18℃;

Figure 3(f) The effect of ethyl silicone oil content on the viscosity of crude oil when T=-16℃;

Figure 3(g) The effect of ethyl silicone oil content on the viscosity of crude oil when T=-13℃; from the analysis of experimental data and from Figure 3(a), it can be seen that the viscosity of crude oil decreases rapidly with the increase of temperature; At the same time of high temperature, adding a certain quality of ethyl silicone oil can further reduce the viscosity of crude oil, but as the temperature increases, the effect of adding a similar proportion of ethyl silicone oil to reduce the viscosity of crude oil tends to decrease. The amount of large ethyl silicone oil can enhance the viscosity reduction effect of crude oil;

Figure 3(h) When T=-10℃, the effect of ethyl silicone oil content on the viscosity of crude oil; Figure 3(i) When T=-10℃, the effect of increasing the content of ethyl silicone oil on the viscosity of crude oil;

Figure 3(j) The effect of ethyl silicone oil content on the viscosity of crude oil when T=0℃; Figure 3(k) The effect of ethyl silicone oil content on the viscosity of crude oil when T=10℃; Figure 3(1) T=30 The effect of ethyl silicone oil content on the viscosity of crude oil at ℃.

It can be seen from the figure that at different temperatures, adding ethyl silicone oil can reduce the viscosity of crude oil, but as the temperature increases, the effect of ethyl silicone oil on the viscosity of crude oil gradually decreases.

Table 1

Example 35 - Example 92

According to the method for preparing crude oil mixture described in Example 3, hexaethylcyclotrisiloxane was used instead of ethyl silicone oil prepared in Preparation Example 1, and it was uniformly mixed with crude oil according to different mass ratios shown in Table 2-Table 8.

Test Example 4: Viscosity Reduction Experiment of Hexaethylcyclotrisiloxane on Crude Oil

(1) Variation of viscosity of hexaethylcyclotrisiloxane with temperature

The melting point of hexaethylcyclotrisiloxane is 14°C. When the temperature is lower than this value, hexaethylcyclotrisiloxane will crystallize and its viscosity cannot be measured. The viscosity of hexaethylcyclotrisiloxane between 20°C and 50°C was measured using a DV2TRVTJO rotational viscometer equipped with a rotor suitable for the viscosity measurement range. The results are shown in Figure 4(a).

(2) Influence of the dosage of hexaethylcyclotrisiloxane on the viscosity of crude oil

At T=-20℃, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.4038, the viscosity of crude oil decreased from 11230mPa.s to 1707mPa.s, hexaethylcyclotrisiloxane The effect of the mass ratio of crude oil on the viscosity of crude oil is shown in Table 2. Figure 4(b) shows the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of crude oil (T=-20°C).

Table 2:

Hexaethylcyclotrisiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 11230 0 -20 Example 35 0.0054 10680 4.9 -20 Example 36 0.0101 10340 7.93 -20 Example 37 0.0206 8617 23.27 -20 Example 38 0.0323 6875 38.78 -20 Example 39 0.0418 5580 50.31 -20 Example 40 0.0533 4758 57.63 -20 Example 41 0.0497 5483 51.18 -20 Example 42 0.1002 3331 70.34 -20 Example 43 0.1516 2760 75.42 -20 Example 44 0.2023 2103 81.27 -20 Example 45 0.3028 1900 83.08 -20 Example 46 0.4034 1707 84.8 -20

At T=-10°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.3061, the viscosity of crude oil decreased from 616mPa.s to 271mPa.s, hexaethylcyclotrisiloxane The effect of the mass ratio of crude oil on the viscosity of crude oil is shown in Table 3. Figure 4(c) shows the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of crude oil (T=-10°C).

table 3

Hexaethylcyclotrisiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 616 0 -10 Example 47 0.0051 594 3.57 -10 Example 48 0.0096 584 5.19 -10 Example 49 0.0199 553 10.23 -10 Example 50 0.031 535 13.15 -10 Example 51 0.0427 522 15.26 -10 Example 52 0.0544 505 18.02 -10 Example 53 0.1055 450 26.95 -10 Example 54 0.1558 408 33.77 -10 Example 55 0.2061 354 42.53 -10 Example 56 0.255 302.1 50.96 -10 Example 57 0.3061 271 56.01 -10

At T=0°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.4302, the viscosity of crude oil decreased from 164.3 mPa.s to 73.25 mPa.s, hexaethylcyclotrisiloxane The effect of alkane/crude oil mass ratio on the viscosity of crude oil is shown in Table 4. Figure 4(d) is the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of crude oil (T=0°C).

Table 4

At T=10°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.4299, the viscosity of crude oil decreased from 75.5mPa.s to 37.25mPa.s, hexaethylcyclotrisiloxane The effect of the alkane/crude oil mass ratio on the viscosity of the crude oil is shown in Table 5. Figure 4(e) shows the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of the crude oil (T=10°C).

table 5

Hexaethylcyclotrisiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 75.5 0 10 Example 69 0.0528 59.5 21.19 10 Example 70 0.1124 57.25 24.17 10 Example 71 0.1773 53 29.8 10 Example 72 0.2511 48.5 35.76 10 Example 73 0.3347 44.5 41.06 10 Example 74 0.4299 37.25 50.66 10

At T=20°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.429, the viscosity of crude oil decreased from 39mPa.s to 23.5mPa.s, hexaethylcyclotrisiloxane The effect of the mass ratio of crude oil on the viscosity of crude oil is shown in Table 6. Figure 4(f) shows the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of crude oil (T=20°C).

Table 6

At T=30°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.4286, the viscosity of crude oil decreased from 20.79mPa.s to 15.3mPa.s, hexaethylcyclotrisiloxane The effect of the alkane/crude oil mass ratio on the crude oil viscosity is shown in Table 7, and Fig. 4(g) is the effect of the amount of hexaethylcyclotrisiloxane on the crude oil viscosity (T=30°C).

Table 7

Hexaethylcyclotrisiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 20.79 0 30 Example 81 0.0526 20.44 1.68 30 Example 82 0.1111 20.26 2.55 30 Example 83 0.1766 18.98 8.71 30 Example 84 0.2505 17.12 17.65 30 Example 85 0.3335 16 23.04 30 Example 86 0.4286 15.3 26.41 30

At T=40°C, when the mass ratio of hexaethylcyclotrisiloxane/crude oil increased from 0 to 0.4287, the viscosity of crude oil decreased from 15.68mPa.s to 11.68mPa.s, hexaethylcyclotrisiloxane The effect of the alkane/crude oil mass ratio on the viscosity of the crude oil is shown in Table 8. Figure 4(h) shows the effect of the amount of hexaethylcyclotrisiloxane on the viscosity of the crude oil (T=40°C).

Table 8

The data on the change of crude oil viscosity with hexaethylcyclotrisiloxane/crude oil mass ratio measured at different temperatures above show that with the addition of hexaethylcyclotrisiloxane, the crude oil viscosity gradually decreases; The more significant the effect of ethylcyclotrisiloxane on the viscosity of crude oil, the better the effect of reducing the viscosity of crude oil after adding hexaethylcyclotrisiloxane.

Example 93 - Example 102

Take out the light crude oil without impurities, clear and transparent at room temperature, add the trimethylsiloxy-terminated polydiethylsiloxane oligomer (referred to as ethyl silicone oil) prepared in Preparation Example 2, ethyl silicone oil/crude oil The mass ratio is shown in Table 9, and it was mixed uniformly.

Put the light crude oil mixed with ethyl silicone oil prepared in Example 93-Example 102 into the DV2TRVTJO type rotational viscometer sample measuring tube, select a suitable rotor and shear rate, and set the temperature of the external cryostat, After the temperature in the sample measuring tube reaches the set value, measure the viscosity of the ethyl silicone oil/crude oil mixture. After the viscosity value is stable, record the measurement results, as shown in Table 9.

Table 9

Ethyl silicone oil/crude oil mass ratio Viscosity reduction/% temperature ℃ Example 93 0.005 13.11 -20 Example 94 0.01 26.84 -20 Example 95 0.02 38.45 -20 Example 96 0.035 61.12 -20 Example 97 0.04 63.31 -20 Example 98 0.05 72.67 -20 Example 99 25×10^-6 11.61 -20 Example 100 48×10^-6 15.47 -20 Example 101 72×10^-6 19.86 -20 Example 102 99×10^-6 22.74 -20

Example 103 - Example 112

Take out the light crude oil without impurities, clear and transparent at room temperature, and add the trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane oligomer (referred to as ethyl silicone oil) prepared in Preparation Example 3. , the mass ratio of ethyl silicone oil/crude oil is shown in Table 10, and it is mixed evenly.

Put the light crude oil mixed with ethyl silicone oil prepared in Example 103-Example 112 into the sample measuring tube of the DV2TRVTJO type rotational viscometer, select the appropriate rotor and shear rate, and set the temperature of the external low temperature constant temperature tank, After the temperature in the sample measuring tube reaches the set value, measure the viscosity of the ethyl silicone oil/crude oil mixture. After the viscosity value is stable, record the measurement results, as shown in Table 10.

Table 10

Ethyl silicone oil/crude oil mass ratio Viscosity reduction/% temperature ℃ Example 103 0.005 12.23 -20 Example 104 0.01 25.31 -20 Example 105 0.02 36.79 -20 Example 106 0.035 59.54 -20 Example 107 0.04 62.64 -20 Example 108 0.05 71.59 -20 Example 109 26×10^-6 11.21 -20 Example 110 51×10^-6 14.97 -20 Example 111 71×10^-6 18.91 -20 Example 112 103×10^-6 21.91 -20

Example 113 - Example 122

Take out the light crude oil without impurities, clear and transparent at room temperature, and add the trimethylsiloxy-terminated poly(dimethyl-diethyl)siloxane oligomer (referred to as ethyl silicone oil) prepared in Preparation Example 4. , the mass ratio of ethyl silicone oil/crude oil is shown in Table 11, and it is mixed evenly.

Put the light crude oil mixed with ethyl silicone oil prepared in Example 113-Example 122 into the sample measuring tube of the DV2TRVTJO type rotational viscometer, select a suitable rotor and shear rate, and set the temperature of the external low temperature constant temperature tank, After the temperature in the sample measuring tube reaches the set value, measure the viscosity of the ethyl silicone oil/crude oil mixture. After the viscosity value is stable, record the measurement results, as shown in Table 11.

Table 11

Example 123 - Example 133

According to the method for preparing crude oil mixture described in Example 3, octaethylcyclotetrasiloxane was used to replace the ethyl silicone oil prepared in Preparation Example 1, and it was uniformly mixed with crude oil according to different mass ratios shown in Table 12.

At T=-20°C, when the mass ratio of octaethylcyclotetrasiloxane/crude oil increased from 0 to 0.4000, the viscosity of crude oil decreased from 11230mPa.s to 1958mPa.s, octaethylcyclotetrasiloxane The effect of the crude oil mass ratio on the crude oil viscosity is shown in Table 12.

Table 12:

Octaethylcyclotetrasiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 11230 0 -20 Example 123 0.0050 10710 4.63 -20 Example 124 0.0100 10410 7.3 -20 Example 125 0.0201 8655 22.93 -20 Example 126 0.0305 6920 38.38 -20 Example 127 0.0402 5670 49.51 -20 Example 128 0.0500 4862 56.71 -20 Example 129 0.1000 5623 49.93 -20 Example 130 0.1500 3471 69.09 -20 Example 131 0.2000 2906 74.12 -20 Example 132 0.3000 2264 79.84 -20 Example 133 0.4000 1958 82.56 -20

Example 134 to Example 144

According to the method for preparing crude oil mixture described in Example 3, decaethylcyclopentasiloxane was used instead of the ethyl silicone oil prepared in Preparation Example 1, and it was uniformly mixed with crude oil according to different mass ratios shown in Table 13.

At T=-20°C, when the mass ratio of decaethylcyclopentasiloxane/crude oil increased from 0 to 0.4000, the viscosity of crude oil decreased from 11230mPa.s to 2164mPa.s, decaethylcyclopentasiloxane The effect of the crude oil mass ratio on the crude oil viscosity is shown in Table 13.

Table 13:

Decaethylcyclopentasiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 11230 0 -20 Example 134 0.0050 10980 2.23 -20 Example 135 0.0100 10560 5.97 -20 Example 136 0.0200 8823 21.43 -20 Example 137 0.0300 7061 37.12 -20 Example 138 0.0402 5734 48.94 -20 Example 139 0.0500 4994 55.53 -20 Example 140 0.1000 5762 48.69 -20 Example 141 0.1500 3605 67.9 -20 Example 142 0.2000 2994 73.34 -20 Example 143 0.3000 2431 78.35 -20 Example 144 0.4000 2164 80.73 -20

Example 145 - Example 155

According to the method for preparing crude oil mixture described in Example 3, dodecylcyclohexasiloxane was used instead of the ethyl silicone oil prepared in Preparation Example 1, and it was uniformly mixed with crude oil according to different mass ratios shown in Table 14.

At T=-20°C, when the mass ratio of dodecylcyclohexasiloxane/crude oil increased from 0 to 0.4000, the viscosity of crude oil decreased from 11230mPa.s to 2286mPa.s. The effect of oxane/crude oil mass ratio on crude oil viscosity is shown in Table 14.

Table 14:

Dodecylcyclohexasiloxane/crude oil mass ratio Viscosity/mPa.s Viscosity reduction/% temperature ℃ 0 11230 0 -20 Example 145 0.0050 10920 2.76 -20 Example 146 0.0100 10610 5.52 -20 Example 147 0.0200 8850 21.19 -20 Example 148 0.0300 7180 36.06 -20 Example 149 0.0402 5864 47.78 -20 Example 150 0.0500 5026 55.24 -20 Example 151 0.1000 5906 47.41 -20 Example 152 0.1500 3784 66.3 -20 Example 153 0.2000 3055 72.8 -20 Example 154 0.3000 2593 76.91 -20 Example 155 0.4000 2286 79.64 -20

Comparative Example 2

(1) Changes in viscosity of dimethyl silicone oil with temperature

Trimethylsiloxy-terminated polydimethylsiloxane (dimethicone for short, η ₂₀ =50mPa.s) with a viscosity value similar to that of the ethyl silicone oil synthesized in Preparation Example 1 was selected, and the DV2TRVTJ0 rotational viscosity was used. The meter was equipped with a rotor with a suitable viscosity measurement range, and the change of the viscosity of dimethicone oil with temperature between -20 and 40 °C was measured. The results are shown in Figure 5(a).

(2) Influence of dimethyl silicone oil on the viscosity of crude oil

According to the method of preparing the crude oil mixture described in Example 3, the ethyl silicone oil prepared in Example 1 was replaced by commercially available dimethyl silicone oil with a viscosity of 50 mPa.s at 20°C. The viscosity of hexaethylcyclotrisiloxane/crude oil mixture was measured at -20°C, -10°C, 0°C, 10°C, 20°C, 30°C and 40°C, and the results are shown in Figures 5(b) to 5(h, respectively ) shown.

From Figures 5(b) to 5(e) (corresponding to the temperature range of -20°C to 10°C), it can be seen that between -20°C and 10°C, with the increase of the mass ratio of dimethyl silicone oil/crude oil, the The viscosity of the silicone oil/crude oil mixture gradually decreased, and the addition of dimethyl silicone oil had a more significant effect on the viscosity of crude oil when the temperature was lower; but when the temperature increased, as shown in Figures 5(f)-5(h) ( Corresponding to the temperature range of 20°C to 40°C), with the increase of the mass ratio of dimethyl silicone oil/crude oil, the viscosity of the mixture of dimethyl silicone oil/crude oil increases, indicating that the addition of dimethyl silicone oil cannot reduce the viscosity of crude oil, showing A completely opposite trend to that of the embodiments of the present invention occurs.

Due to the small viscosity-temperature coefficient of dimethyl silicone oil, the viscosity of dimethyl silicone oil does not change much with temperature, while the viscosity of crude oil changes very significantly with temperature, so dimethyl silicone oil mainly dilutes the viscosity of crude oil at low temperature; the temperature rises When the viscosity of the crude oil is lower than the viscosity of the dimethyl silicone oil at this temperature, the viscosity of the dimethyl silicone oil/crude oil mixture varies with the quality of the dimethyl silicone oil/crude oil. The ratio increased with the increase, indicating that dimethicone could not effectively reduce the viscosity of crude oil.

Comparative Example 1 shows that the compatibility of dimethicone with crude oil is also poor, so dimethicone does not have the effect of reducing the viscosity of crude oil like ethyl silicone oil and hexaethylcyclotrisiloxane.

Because crude oil contains volatile substances, there may be errors in the measurement process, but it does not change the addition of cyclosiloxane or diethylsiloxane chains containing diethylsiloxane (-(C ₂ H ₅ ) ₂ SiO-) Decrease trend of crude oil viscosity after polymerization of nodes (-(C ₂ H ₅ ) ₂ SiO-).

Claims (7)

1. A method for reducing the viscosity of crude oil, characterized in that cyclosiloxane containing diethylsiloxy units or a polymer of diethylsiloxy units is mixed with the crude oil.

2. The method for reducing the viscosity of crude oil according to claim 1, wherein the cyclosiloxane containing diethylsiloxane chain units is one or more selected from hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, decaethylcyclopentasiloxane, and dodecaethylcyclohexasiloxane.

3. The method of claim 1, wherein the polymer containing diethylsiloxane chain units is selected from the group consisting of an oligomericsiloxane of formula (I) and a copolysiloxane of formula (II),

in the formulae (I) and (II), R₁、R₄Each independently selected from Me and Me₃SiO-, Et and Ph; r₂、R₃、R₅、R₆Each independently selected from one of Me and Et; r_a、R_bAre respectively and independently selected from one of methyl, ethyl, trifluoropropyl and phenyl, and R_aAnd R_bIs not ethyl or trifluoropropyl at the same time;

wherein n is 1 to 100,

in the formula (II) x₁＝1～30，x₂1 to 100, and x₁+x₂＝1～120。

4. The method for reducing the viscosity of crude oil according to claim 3, wherein the viscosity of the oligomeric siloxane containing diethylsiloxane chain units at 20 ℃ is 5 to 500 mPa.s.

5. The method for reducing the viscosity of crude oil according to claim 3, wherein the viscosity of the copolysiloxane containing diethylsiloxane chain units at 20 ℃ is 5 to 1000 mPa.s.

6. The method for reducing the viscosity of crude oil according to any one of claims 1 to 5, wherein the mass ratio of the cyclic siloxane containing diethyl siloxane chain segments or the polymer containing diethyl siloxane chain segments when mixed with the crude oil is 0.000005-0.50: 1.

7. The method for reducing the viscosity of crude oil according to claim 6, wherein the temperature of the mixture of the cyclic siloxane containing diethylsiloxane chain segments or the polymer containing diethylsiloxane chain segments and the crude oil is-40 to 60 ℃.

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