Method for determining full-scale aperture of tight reservoir

The invention discloses a method for determining the full-scale aperture of a tight reservoir. The method comprises the following steps: preparing a sample lt; after drying, testing the adsorption pore size distribution of the liquid nitrogen; taking a crushed sample with the side length of 10mm-15mm, drying the crushed sample, and testing the pore size distribution by a mercury intrusion method; respectively drawing pore size distribution curves obtained by a liquid nitrogen adsorption method and a mercury intrusion method; drawing a pore diameter curve and an accumulated pore volume curve respectively; solving the difference value of the accumulated pore volumes; when the pore diameter interval is small enough, the pore volume difference value corresponding to the interval is the pore volume under a certain pore diameter; drawing a curve between the pore diameter and the corresponding pore volume under a certain pore diameter; determining intersection points between the curves obtained by different methods;