A kind of preparation method of temperature-resistant, salt-resistant nano oil displacement agent

[0022] In a three-necked flask, add 20 g of nano silicon dioxide and 12 mL of vinyltrimethoxysilane coupling agent, and stir for 3 hours. Weigh 18g of acrylamide and dissolve it in 125mL of water. After it is completely dissolved, add the above mixing system, add 1.2g of potassium persulfate, raise the temperature to 65°C, and react for 3 hours to obtain polyacrylamide-modified silica nanoparticle dispersion liquid;

[0023] Add 18g of sodium hydroxide and 20g of sodium lauryl sulfate to the polyacrylamide-modified silica nanoparticle dispersion prepared above in sequence, and stir for 4 hours at room temperature to obtain a temperature-resistant and salt-resistant Nano oil displacing agent.

[0025] In a three-necked flask, add 15 g of nano silicon dioxide and 8 mL of vinyltriethoxysilane coupling agent, and stir for 3 hours. Weigh 25g of acrylamide and dissolve it in 180mL of water. After it is completely dissolved, add the above-mentioned mixing system, add 1.8g of potassium persulfate, raise the temperature to 75°C, and react for 4 hours to obtain a polyacrylamide-modified silica nanoparticle dispersion liquid;

[0026] Add 28g of sodium carbonate and 15g of sodium lauryl sulfate into the above-prepared polyacrylamide-modified silica nanoparticle dispersion in sequence, and at room temperature for 5 hours, a temperature-resistant and salt-resistant nano-flooding Oil agent.

[0028] Into a three-necked flask, 18 g of nano-silica and 12 mL of γ-methacryloxypropyltrimethoxysilane coupling agent were added, and stirred for 3 hours. Weigh 29g of acrylamide and dissolve it in 175mL of water. After it is completely dissolved, add the above-mentioned mixing system, add 1.2g of potassium persulfate, raise the temperature to 75°C, and react for 5 hours to obtain a polyacrylamide-modified silica nanoparticle dispersion liquid;

[0029] Add 23g of potassium carbonate and 19g of sodium dodecylsulfonate in sequence to the above-prepared polyacrylamide-modified silica nanoparticle dispersion, and at room temperature for 5 hours, the temperature-resistant and salt-resistant nanoparticle oil repellant.