Research On The Characteristics Of Low Permeability Reservoir In Chang6Oil-bearing Formation, In The Northern Part Of Zhidan, In Shannxi

This dissertation researched for characteristic of low permeability reservoir in Chang6oil group, in the Mesozoic Zhidan area. According to the logging data, well logging information, rock core datum and aboratory analysis technique in region of interest, based on previous researches, and by means of describing precipitation facies pictures, sands distribution pictures, and other geological maps and tables, this original analysed the reservoir features, its affecting factors, and then making synergistic evaluation, this original analysed the reservoir characteristics and its influencing factors, and synergistic appraisal.The results show that, long-fine-grained sandstone is the mainly type of sandstone in Chang6oil group; Subfacies is the delta front, which can be further divided into four Plane, the underwater distributary channel, mouth bar, distal bar, and distributary bay; The diagenesises, affecting the Chang6reservoir are early mechanical compaction, pressure solution, the late dissolution, authigenic mineral filling cementation, replacement, and so on; The average length of porosity in Chang6sandstone of this study area is low-especially low porosity, The average permeability is extremely low-low permeability, the physical property of reservoir is poor, and it is mainly affected by sedimentary (micro) facies, diagenesis, and micro-pore structure effects.