A kind of hydrophobic association polymer oil displacement agent containing chitosan and preparation method thereof

Abstract

The invention discloses a hydrophobic associated polymer oil-displacing agent containing chitosan and a preparation method of the hydrophobic associated polymer oil-displacing agent. The preparation method of the polymer oil-displacing agent comprises the following steps: sequentially adding an acrylamide monomer, an acrylic monomer and distilled water to a reactor; stirring until the monomers are dissolved, and then controlling the temperature of the solution at 0-10 DEG C; adjusting the pH value of the system to be 5-7 by using NaOH; controlling the temperature of the solution at 5-15 DEG C, and then adding a reaction solution to a quaternary ammonium salt monomer with a hydrophobic side chain; adjusting the water yield, so that the total mass percent of the monomers is 20-30%; slowly dropwise adding an initiator under nitrogen protection; after the temperature of the solution rises to 35-45 DEG C, dropwise adding a sulphur chitosan solution, and then further reacting for 1-3 hours after dropwise adding is ended, so as to obtain a transparent polymer product; washing the product by using methanol for multiple times, drying in vacuum at 35-45 DEG C, and pelleting to prepare the hydrophobic associated polymer oil-displacing agent. According to the hydrophobic associated polymer oil-displacing agent containing chitosan, the solubleness of the polymer and the stability of the solution are improved, and improvement of the oil-displacing efficiency is facilitated.

Description

[0001] Technical field: [0002] The invention relates to a chitosan-containing hydrophobic association polymer oil displacement agent for improving the oil displacement efficiency of oilfield polymer displacement and a preparation method thereof. [0003] Background technique: [0004] In the process of oil and gas extraction, especially in tertiary oil recovery, water-soluble polymers are used in large quantities and cannot be replaced. Now the most widely used are polyacrylamide polymers and xanthan gum, but the problem of polyacrylamide is poor resistance to high temperature, high salt and mechanical shear, while xanthan gum is easy to biodegrade at high temperature And expensive. The hydrophilic part on the hydrophobic association polymer can make the polymer dissolve in the aqueous phase system, and the hydrophobic part can make it aggregate to form a reversible association structure in the solution. Compared with the conventional polymer solution, it has high efficiency...

AI Technical Summary

Problems solved by technology

Now the most widely used are polyacrylamide polymers and xanthan gum, but the problem of polyacrylamide is poor resistance to high temperature, high salt and mechanical shear, while xanthan gum is easy to biodegrade at high temperature and expensive

[0005] However, due to the introduction of the hydrophobic association structure, the water solubility of the polymer is affected to a certain extent. Most hydrophobic association polymers have high viscosity but poor solubility.

Moreover, in the high-temperature and high-salt formation environment, the polymer solution will face degradation and lose viscosity, which greatly reduces its practical use ability. The hydrophobic association and the resulting spatial network structure have not completely solved this problem.

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