Abstract: The reservoirs of east Benbutu area are mainly distributed in the lower member of Sangonghe formation and the upper member of Badaowan formation of Lower Jurassic in Yanqi basin.Based on the payzone division and correlation, the lithologic and physical characteristics of the Ⅰ-Ⅳ payzones are studied.The lateral changes of payzone thickness and physical characters in the reservoirs are predicted with logging constrained seismic inversion, and the payzone distribution of 3D is described.The result shows that there exist the features of poor sorting, low shale content and poor physical properties in the reservoirs, which belong to low-porosity and extra-low permeability reservoirs.The payzone sands are thicker in the structural high and better in physical property, but become thin and poor towards the structural low.It is concluded that the southeastern Wellblock Tu-301 is well-developed reservoir rock area and favorable for further petroleum exploration.

Key words: Yanqi basin, Jurassic, reservoir, seismic inversion, prediction