Reservoir Characteristics Research On Chang6Formation Of The Triassic In West Nanliang Area Of Ordos Basin

The paper targets West Nanliang area as the main research area,and choose.Chang6oil formation as the objective horizon.Applying sedimentology and reservoir sedimentology, combining with generation information of research area,using the stratigraphic division method,we divide the objective horizon accurately.Then combining the outcrop observation with experimental analysis method,such as core observation,casting lamina observation,scanning electron microscope observation and mercury intrusion method,we study the sedimentary system,distribution of sedimentary facies,reservoir characteristics and reservoir type.The purpose is to lay a foundation for later exploration by making clear the reservoir characteristics and types,and the type of reservoir.West Nanliang area mainly developed deep lake facies, delta front subfacies and the transitional shallow lake subfacies in Chang6period.According to the development of microfacies in Chang63,Chang62and Chang61,we use the sedimentary characteristics and logging properties to carry on research.We confirm that the main types of sandstones are feldspathic litharenite and lithic arkose in Chang6oil formation,the main types of cementation are illite,calcite and chlorite by means of casting lamina observation,scanning electron microscope observation and mercury intrusion method.The main types of diagenesis of the sandstone are compaction,cementation, metasomatism and dissolution. The type of Chang6oil formation is characteristic by low-porosity and low-perminablility.The development of reservoir of Chang6oil formation is mainly controlled by the depositional setting,tectonic background,source-reservoir-seal assemblages and diagenesis. The main type of reservoir of Chang6oil formation is the updip dense block reservoirs of lithologic reservoir.