Method for improving recovery ratio for single-well gas injection huff and puff of cut-off control body reservoir

The invention relates to a method for improving recovery efficiency by gas injection huff and puff of a single well of a fault control body reservoir, which comprises the following steps: S1, quantifying a well-reservoir relationship, specifically, calculating the trajectory submergence degree S of the single well relative to the reservoir, S = L1/L2 * 100%, L1 is the distance from the bottom of the single well to the top end of the reservoir, and L2 is the distance from the top end of the reservoir to the bottom end of the reservoir; s2, establishing a well-reservoir relation gas injection huff and puff model according to the trajectory submergence degree S, when S is larger than or equal to 10%, the gas injection huff-puff model is a top contact model, and when S is larger than or equal to 10%, the gas injection huff-puff model is a non-top contact model; s3, determining influence factors of gas injection huff and puff, wherein the influence factors comprise a gas injection huff and puff model, and whether