Long-acting corrosion inhibitor for gas well acidification, preparation method and application method thereof

The invention discloses a long-acting corrosion inhibitor for gas well acidification, a preparation method and application method thereof. The corrosion inhibitor is composed of the following components in percentage by weight: 10 to 20% of corrosion inhibitor main agent, 10 to 20% of corrosion inhibitor auxiliary agent, 4 to 10% of molybdate, 5 to 15% of cosolvent, and 35 to 71% of solvent, wherein the corrosion inhibitor main agent is dodecyl trimethyl ammonium bromide, the corrosion inhibitor auxiliary agent is oleic acid amino ethyl imidazoline or oleic acid imidazoline, molybdate is sodium molybdate or a mixture of sodium molybdate and sodium tripolyphosphate, the cosolvent is n-butanol, and the solvent is water. The provided long-acting corrosion inhibitor can achieve a high corrosion inhibition rate at a high temperature, is green and environment-friendly, can well protect oil casing from corrosion during the processes of gas well acidification and flowback after acidification, can guarantee the normal production and sustainable development of gas field, is capable of generating prominent economic benefits and social benefits, and thus has a good promotion and application prospect.