Research On Reservoir Characteristics Of Shan 1 Member In The Southwest Of Ordos Basin

This paper takes the reservoir of Shanxi Formation of southwestern Ordos Basin as the research object,guided by the theory of sedimentary petrology,reservoir geology and other disciplines,through core observation,grain size analysis,casting thin section,scanning electron microscope,Digital logging and mercury intrusion experiments and other analysis and testing methods,divided and compared the formation of Shan 1 Member,systematically studied the sedimentary characteristics,petrological characteristics,diagenesis,pore structure characteristics and characteristics of the reservoir of Shan 1 Member.Diagenesis has equal characteristics.The results show that the reservoir of the Shan 1 Member in the study area develops a lacustrine delta sedimentary system,and the prerequisite for the formation of favorable reservoir sand bodies in the study area is the sedimentary sandstone of the underwater distributary channel(or distributary channel).The main rock types are lithic quartz sandstone,lithic sandstone,and the reservoir rock is mainly composed of lithic metamorphic rock and lithic debris.The overall grain size of the reservoir is relatively coarse and sorted.The pore type is dominated by lithic dissolved pores.The development of intragranular dissolved pores,intergranular pores and intercrystalline micropores that have undergone diagenetic transformation has further improved the properties of the reservoir.The main diagenesis of sediments in the process of burial diagenesis are:compaction,cementation and dissolution.Among them,compaction and cementation are the main reasons for the tightness of the reservoir in the study area.The dissolution pores generated by dissolution have increased Reservoir performance.According to the characteristics of diagenesis in the study area,seven diagenetic facies belts are roughly divided in the study area with reference to various diagenetic indexes.Among them,quartz enlargement-intergranular pore facies,kaolinite filling-intercrystalline pore facies and dissolution facies are favorable diagenesis facies.Phase band.By analyzing the physical properties,lithology,and diagenesis parameters of the reservoirs in the study area,and according to the classification standards of the reservoirs,the reservoirs of the Shan 1 Member classified and evaluated.