Mutation theory yield splitting method based on gas layer lower limit

The invention relates to a mutation theory yield splitting method based on a gas layer lower limit. The method comprises the following steps: establishing a yield splitting mutation index system; obtaining each yield splitting mutation index parameter of all production layers; the gas layer lower limit of the block where the target production layer is located and the minimum formation pressure corresponding to the shallowest medium depth serve as the production layer relative sudden change face; obtaining each yield splitting mutation index parameter of relative mutation surfaces of all production layers; by taking the maximum value of each yield splitting mutation index parameter of all the production layers as a reference, performing normalization processing on each yield splitting mutation index parameter of all the production layers and each yield splitting mutation index parameter of a relative mutation surface of all the production layers; and calculating a system target value of each production layer a