Abstract: In light of complex lithology and serious heterogeneity of volcanic reservoir rock, this paper presents a comprehensive study of petrophysical characteristics of it. By using available well log data and fuzzy mathematical method, a lithologic model for identification of volcanic reservoir is developed. According to recognized fractural types, a model for fractural porosity interpretation is established. By way of correction of small core sample using big sample, relationship between core porosity and effectively estimated well log porosity is built up, obtaining effective porosities. Using different fractural types and dual lateral log data, a model for fluid saturation explanation is set up. Furthermore, these models and measured information are used for feasibility evaluation of them, reaching higher consistency and satisfied results.

Key words: volcanic rock, reservoir, petrophysics, fuzzy mathematics, fractural porosity, effective porosity, saturation