Relationships between lithofacies-logging facies and sandbody reservoir properties and the petroleum geological significance of lithofacies-logging facies horizontal distribution of Xiashihezi Formation in Daniudi gas field,Ordos Basin,China

Taking Xiashihezi Formation in the Daniudi gas field as the research object and using the data of the drilling cores,logging,properties and productive capacity,etc.,this paper studies the relationship between different lithofacies-logging facies and reservoir sandbody properties and productive capacity in detail.The results show that the reservoir sandbody containing pebbly coarse-grained sandstone lithofacies whose gamma well log is box shape has the best physical property and the highest productive capacity,that the reservoir sandbody containing coarse-grained sandstone and medium-grained sandstone facies whose gamma well log is bell shape or dentation box shape has better physical property and middle productive capacity,and that the reservoir sandbody containing fine-grained sandstone facies whose gamma well log is funnel shape has poor physical property and low productivity.Based on the statistical analysis of the superior lithofacies-logging facies,of more than 700 wells in study area and according to the plane distribution characteristics of the sedimentary microfacies and the sandbody,taking the He 3-1 small layer for example,the authors make the lithofacies-logging facies plane distribution map of the He 3-1 small layer,and depict the plane distribution characteristics of the superior lithofacies-logging facies of the He 3-1 small layer.The plane distribution map reflects the distribution rule of the physical property and production ability and also highlights the plane distribution of the gas reservoir sandbody.The achievements provide the forecast basis for appraising the traps of lithology.