Sandstone core self-absorption experiment method based on NMR scanning

The invention discloses a sandstone core self-absorption experiment method based on NMR (nuclear magnetic resonance) scanning. The sandstone core self-absorption experiment method comprises the following steps: scanning by using a nuclear magnetic resonance scanning device to obtain vertical axial layering and parallel axial grey-scale maps of a sandstone core sample in an initial state when the sandstone core sample does not absorb water; scanning by using a nuclear magnetic resonance scanning device to obtain vertical axial layered images and parallel axial grey-scale maps of the sandstone core sample at moments corresponding to different soaking times in the self-absorption device and T2 curves at different self-absorption times; window width and window level adjustment is carried out on DCM data of the obtained imaging result, color codes of all grey-scale images are adjusted to obtain an optimal pseudo-color image, and hydrogen signal intensity of the sandstone core sample in different positions in the a