High-maturity gas source rock grading evaluation method and system based on hydrocarbon generation and expulsion simulation

The invention relates to a high-maturity gas source rock classification evaluation method and system based on hydrocarbon generation and expulsion simulation, and belongs to the technical field of unconventional oil and gas source rock classification evaluation, and the method comprises the steps: building a hydrocarbon generation yield change curve based on a hydrocarbon generation thermal simulation experiment; establishing a source rock hydrocarbon expulsion change curve based on a material balance principle; determining a source rock classification boundary based on the hydrocarbon generation yield change curve and the source rock hydrocarbon expulsion change curve; and according to the source rock classification boundary, combining well logging interpretation to obtain different types of source rock space distribution. Through hydrocarbon generation simulation and a methane isothermal adsorption experiment, in combination with burial history and thermal history, a source rock hydrocarbon generation yield