阅读说明：本技术 用于稠油热采的高效水溶性降粘洗油剂及其制备方法 (High-efficiency water-soluble viscosity-reduction oil washing agent for heavy oil thermal recovery and preparation method thereof ) 是由 钱钦 郑万刚 翟勇 徐鹏 孙克己 赵晓 刘廷峰 郑昕 邹斌 郝婷婷 于 2019-10-14 设计创作，主要内容包括：本发明涉及一种稠油开采过程中使用的化学剂,具体是一种用于稠油热采的高效水溶性降粘洗油剂及其制备方法。该降粘洗油剂由甲苯二异氰酸酯与聚甲基硅氧烷反应生成中间体,随后再与聚氧乙烯醚反应生成。所述的甲苯二异氰酸酯、聚甲基硅氧烷和聚氧乙烯醚的摩尔比为1：0.4～0.5：1～1.2,优选为1:0.45:1.05。本发明的降粘洗油剂兼具高效洗油和乳化降粘的双重作用,在1000ppm浓度下可降低普通稠油和特稠油的粘度＞98％,静态洗油率＞50％；同时具有耐盐耐温性能强,适合稠油热采开发,耐盐达到100000mg/L以上,耐温达到320℃以上,完全能够满足常规热采稠油油藏现场应用条件。(The invention relates to a chemical agent used in a thick oil recovery process, in particular to a high-efficiency water-soluble viscosity-reduction oil washing agent for thick oil thermal recovery and a preparation method thereof. The viscosity-reducing oil washing agent is prepared by reacting toluene diisocyanate with polymethylsiloxane to generate an intermediate and then reacting the intermediate with polyoxyethylene ether. The molar ratio of the toluene diisocyanate to the polymethylsiloxane to the polyoxyethylene ether is 1: 0.4-0.5: 1 to 1.2, preferably 1:0.45: 1.05. The viscosity reduction oil washing agent has the dual functions of high-efficiency oil washing and emulsification viscosity reduction, and can reduce the viscosity of common thick oil and extra thick oil to be more than 98% and the static oil washing rate to be more than 50% under the concentration of 1000 ppm; meanwhile, the salt-resistant and temperature-resistant performance is strong, the thick oil thermal recovery development is suitable, the salt resistance is more than 100000mg/L, the temperature resistance is more than 320 ℃, and the field application condition of the conventional thermal recovery thick oil reservoir can be completely met.)

1. The efficient water-soluble viscosity-reducing washing oil agent for heavy oil thermal recovery is characterized in that the viscosity-reducing washing oil agent is prepared by reacting toluene diisocyanate with polymethylsiloxane to generate an intermediate and then reacting the intermediate with polyoxyethylene ether, and the molecular formula of the viscosity-reducing washing oil agent is as follows:

wherein: m is 7 to 12, and n is 4 to 8.

2. The efficient water-soluble viscosity-reducing oil washing agent for heavy oil thermal recovery according to claim 1, wherein m is 9, and n is 6.

3. The preparation method of the high-efficiency water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 1 or 2, characterized by comprising the following steps:

(1) adding toluene diisocyanate, polymethylsiloxane and solvent water into a four-neck flask with a thermometer, a reflux condenser tube and a stirrer, heating while stirring at the speed of 400-550 rpm at the heating temperature of 30-60 ℃, introducing nitrogen for 3-7 min, slowly adding a catalyst into the four-neck flask, continuously introducing nitrogen, heating the four-neck flask to 80-95 ℃, adjusting the stirring speed to 500-600 rpm, continuously reacting for 4-5 h, and then cooling to room temperature to obtain an intermediate mixed solution;

(2) adding polyoxyethylene ether into the intermediate mixed solution, adjusting the stirring speed to 500-600 rpm, adjusting the temperature to 75-90 ℃, uniformly mixing, reacting for 2-4 h, and cooling to 25-30 ℃ to obtain a final product mixed solution;

(3) and removing solvent water from the final product mixed solution by using a rotary evaporator, washing the obtained crude product for 3-5 times by using absolute ethyl alcohol, removing unreacted reactants, and then placing the product in an oven at the temperature of 80-100 ℃ for constant temperature for 24-48 hours to obtain orange yellow viscous liquid, namely the viscosity-reducing oil washing agent.

4. The preparation method of the high-efficiency water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 3, wherein the molar ratio of the toluene diisocyanate to the polymethylsiloxane to the polyoxyethylene ether is 1: 0.4-0.5: 1 to 1.2.

5. The preparation method of the efficient water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 4, wherein the molar ratio of the toluene diisocyanate to the polymethylsiloxane to the polyoxyethylene ether is 1:0.45: 1.05.

6. The preparation method of the high-efficiency water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 3, wherein the amount of the absolute ethyl alcohol is 3-6 times of the mass of the toluene diisocyanate.

7. The preparation method of the high-efficiency water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 3, wherein the catalyst is dibutyltin laurate, and the using amount of the catalyst is 0.5-1.5% of the mass of toluene diisocyanate.

8. The preparation method of the high-efficiency water-soluble viscosity-reducing oil washing agent for thick oil thermal recovery according to claim 3, wherein the amount of the solvent water is 7-12 times of the mass of the toluene diisocyanate.

Technical Field

The invention relates to a chemical agent used in a thick oil recovery process, in particular to a viscosity reduction oil washing agent which is used in thick oil thermal recovery and has the functions of stripping crude oil from rocks and reducing viscosity through emulsification.

Background

The thick oil accounts for a large proportion of the oil and gas resources in the world. According to statistics, the reserves of the world heavy oil, super heavy oil and natural asphalt are about 1000 multiplied by 10⁸t. China heavy oil asphalt resource is widely distributed, more than 70 heavy oil fields are found in 12 basins, and the amount of the China heavy oil asphalt resource can reach 300 multiplied by 10⁸t is more than t. At present, the main methods for exploiting the thick oil in China are steam huff and puff and steam flooding. Steam flooding is one of the technically and economically successful heavy oil reservoir mode conversion and development technologies at present.

However, the main problem faced by the current heavy oil steam flooding is that the reservoir heterogeneity and the difference of the working system of each production well cause the steam breakthrough phenomenon at first in the production well with high permeability direction, high yield and small injection-production well distance, and the heat utilization rate and the economy of the oil reservoir cannot be effectively guaranteed. The enhanced thermal recovery auxiliary agent can effectively reduce the viscosity of the heavy oil, reduce the tension of an oil-water interface, increase the energy of a reservoir and reduce the saturation of residual oil, thereby achieving the purpose of improving the development effect of the heavy oil reservoir.

The high temperature resistant chemical agent reported at present, such as the high temperature resistant foaming agent which is popularized in a victory oil field in a large scale at 300 ℃, and the resistance factor under the condition of residual oil is more than 20; the interfacial tension of the developed high-temperature resistant oil displacement agent at 300 ℃ is reduced to 10^-3The ultra-low level of the grade generally has obvious precipitation and oil increasing effects in the first period in field implementation, has no obvious effect when the second period and the third period are repeatedly implemented, and subsequently further improves the recovery efficiency and the fatigue. At present, the chemical agent mostly starts from reducing the viscosity of the heavy oil or improving the sweep efficiency of the oil reservoir, so the development idea and idea need to be changed, a novel agent system needs to be researched and developed, and the development effect of the thermal recovery heavy oil reservoir in the later period is improved.

Disclosure of Invention

The invention provides a high-efficiency water-soluble viscosity-reducing oil washing agent for heavy oil thermal recovery and a preparation method thereof aiming at the defects of the prior art. The viscosity reduction oil washing agent can resist temperature of over 320 ℃, the mineralization resistance of over 100000mg/L, the viscosity reduction rate of common thickened oil and extra-thickened oil is more than 98%, the static oil washing rate is more than 50%, and the requirement of thickened oil thermal recovery development can be completely met.

The invention aims to disclose a high-efficiency water-soluble viscosity-reducing oil washing agent for heavy oil thermal recovery, which is prepared by reacting toluene diisocyanate with polymethylsiloxane to generate an intermediate and then reacting the intermediate with polyoxyethylene ether, wherein the molecular formula of the viscosity-reducing oil washing agent is as follows:

wherein: m is 7-12, preferably m is 9;

n is 4 to 8, preferably 6.

The molar ratio of the toluene diisocyanate to the polymethylsiloxane to the polyoxyethylene ether is 1: 0.4-0.5: 1 to 1.2, preferably 1:0.45: 1.05.

The invention also aims to provide a preparation method of the viscosity-reducing oil washing agent, which specifically comprises the following steps:

(1) adding toluene diisocyanate, polymethylsiloxane and solvent water into a four-neck flask with a thermometer, a reflux condenser tube and a stirrer, heating while stirring at the speed of 400-550 rpm at the heating temperature of 30-60 ℃, introducing nitrogen for 3-7 min, slowly adding a catalyst into the four-neck flask, continuously introducing nitrogen, heating the four-neck flask to 80-95 ℃, adjusting the stirring speed to 500-600 rpm, continuously reacting for 4-5 h, and then cooling to room temperature to obtain an intermediate mixed solution.

(2) And adding polyoxyethylene ether into the intermediate mixed solution, adjusting the stirring speed to 500-600 rpm, adjusting the temperature to 75-90 ℃, uniformly mixing, reacting for 2-4 h, and cooling to 25-30 ℃ to obtain the final product mixed solution.

(3) And removing solvent water from the final product mixed solution by using a rotary evaporator, washing the obtained crude product for 3-5 times by using absolute ethyl alcohol, removing unreacted reactants, and then placing the product in an oven at the temperature of 80-100 ℃ for constant temperature for 24-48 hours to obtain orange yellow viscous liquid, namely the viscosity-reducing oil washing agent.

Preferably, the amount of the solvent water is 7-12 times of the mass of the toluene diisocyanate; the catalyst is dibutyltin laurate, and the using amount of the catalyst is 0.5-1.5% of the mass of the toluene diisocyanate; the dosage of the absolute ethyl alcohol is 3-6 times of the mass of the toluene diisocyanate.

The preparation formula of the viscosity-reducing oil washing agent is as follows:

the invention relates to a viscosity-reducing oil washing agent, belonging to organosilicon surfactants. The long silica chain on the molecule has lipophilicity and rock adsorption performance, the silicon atom is both rock-philic and oleophilic and can be inserted between the rock and the oil film, and the high-efficiency oil washing function is realized by changing the interfacial property of the rock surface and stripping the thick oil film; the rigid structure of the benzene ring can realize the high temperature resistance of molecules; the hydrophilic group (polyether chain) of the long carbon chain can increase the volume of a hydrophilic center, reduce the adsorption capacity of the surfactant on the unit area of the surface of the solution, and simultaneously, the flexibility of the hydrophilic group can coat the stripped thick oil to realize the emulsification and viscosity reduction of the thick oil; the molecule belongs to a non-ionic surfactant, and high salt resistance can be realized. Therefore, the viscosity reduction oil washing agent realizes thick oil stripping by changing the interface property between crude oil and minerals, realizes thick oil emulsification by changing the interface property between the crude oil and water, and finally realizes high-efficiency oil washing and emulsification viscosity reduction performance.

Compared with the prior art, the invention has the following beneficial effects and advantages:

(1) the viscosity-reducing oil washing agent has the advantages of wide raw material source, simple synthesis process, clean and pollution-free process, and easily obtained, transported and stored products;

(2) the viscosity reduction oil washing agent has the dual functions of high-efficiency oil washing and emulsification viscosity reduction, and can reduce the viscosity of common thick oil and extra thick oil to be more than 98% and the static oil washing rate to be more than 50% under the concentration of 1000 ppm;

(3) the viscosity-reducing oil-washing agent has strong salt resistance and temperature resistance, is suitable for heavy oil thermal recovery development, has salt resistance of more than 100000mg/L and temperature resistance of more than 320 ℃, and can completely meet the field application conditions of conventional heavy oil reservoirs for thermal recovery.

Detailed Description

The present invention is described in further detail below with reference to specific examples and with reference to the data. It will be understood that these examples are intended to illustrate the invention and are not intended to limit the scope of the invention in any way.