High-temperature-resistant intelligent expansion core-shell plugging agent as well as preparation method and application thereof

The invention relates to a high-temperature-resistant intelligent expansion core-shell plugging agent and a preparation method and application thereof in the field of oil field chemicals. The high-temperature-resistant intelligent expansion core-shell plugging agent comprises the following components in percentage by weight: 25-38% of an intelligent expansion resin core-shell material; 15-20 wt% of expandable graphite; 20-30 wt% of rigid particles; 20-25 wt% of elastic particles; and 1-3 wt% of fibers. According to the invention, proper components are selected for compounding, and the formed leaking stoppage formula has the characteristics of high temperature resistance, expandability, high pressure bearing capacity and anti-spit property. A high-strength, elastic and high-density plugging layer can be formed in a stratum fracture, the problem of drilling fluid leakage of a fractured stratum is solved, the plugging success rate is increased, the requirement for safe and efficient drilling is met, and the dril