To overcome the limitations of using a single T₂ cutoff value for characterizing fluid occurrence and mobility in reservoirs, a method based on multistage centrifugal nuclear magnetic resonance (NMR) experiments is proposed to determine multiple T₂ cutoff values. This method is used to identify fluid types and their distribution characteristics. Combined with constant‑rate mercury intrusion porosimetry and X‑ray diffraction (XRD) analysis, the pore structure and mineral composition of the reservoir are determined, and the occurrence characteristics and controlling factors of movable fluids in the multiscale pore spaces of unconventional reservoirs are investigated. The results indicate that the division method with multiple T₂ cutoff values further subdivides the types and occurrence spaces of movable fluids. The mobility evaluation can better reflect the development characteristics of micron‑nano pore throats and the mineral composition within the reservoir, and shows stronger adaptability to shale and tight sandstone reservoirs, which have more subtle pore structures and more complex mineral compositions. The occurrence characteristics of movable fluids are jointly controlled by three main factors: reservoir physical properties, mineral composition, and the uniformity of pore‑throat distribution.

shale reservoir, tight sandstone reservoir, nuclear magnetic resonance (NMR), movability evaluation; pore structure, occurrence characteristics