pH-sensitive temporary plugging agent, preparation method thereof, and use thereof in exploitation of low-permeability oil reservoir

A method for preparing a pH-sensitive temporary plugging agent, comprising:

• mixing raw materials to obtain a final mixed solution, the raw materials comprising, in percentages by mass,
• 3-8% of carboxymethyl chitosan,
• 0.2-0.7% of gelatin,
• 0.1-0.6% of an initiator,
• 5-15% of a toughener, and
• a balance of water,
• wherein the initiator is a solution of AgNO3 in ammonia water having a concentration of 0.1-0.3 mol/L, and
• the toughener is a carboxyl-terminated hyperbranched polyester;
• and
• subjecting the final mixed solution to a crosslinking reaction at 40-60° C. to obtain the pH-sensitive temporary plugging agent.