Abstract: Sulige Gas Field in Ordos Basin is the typical representation of tight sand gas reservoir of low permeability. According
to the shapes of capillary pressure curves of core samples，based on self-organizing neural network，the pore structure
automatic discrimination models and permeability interpretation models were established，which highly improved the permeability
calculation precision. According to the research of reservoir conducting mechanism，we adopted the“three water model”
（clay water，micro pore water and free water）for saturation interpretation model，which effectively improved the gas evaluation
precision. Actual log data were processed with this method and its feasibility and veracity are validated by comparing the
processed result with the core analysis result.

Key words: pore structure, permeability classification, three water saturation model, tight sandstone, Sulige Gas Field, OrdosBasin