Characteristics of Chang 2 reservoir in Resiwan oil region of Zichang oilfield,Ordos Basin
In order to identify the characteristics of Chang 2 reservoir in Resiwan oil region of the Zichang oil-field in the Ordos Basin,based on the study of sedimentary characteristics,this research uses experimental methods such as mercury intrusion,scanning electron microscopy,and thin section identification to systemati-cally analyze the petrology,physical properties,pore types,structures,and diagenesis of Chang 2 reservoir.The results show that Chang 2 oil layer in Resiwan oil region of Zichang oilfield mainly develops braided river fa-cies sediments,which can be further divided into three sedimentary microfacies:core beach,riverbed retention sediment,and flood plain.The lithology is mainly composed of light gray,gray medium sandy feldspar sand-stone,and the significant pores for the reservoir are mainly intergranular dissolution pores and residual interg-ranular pores.The average porosity and permeability of Chang 2 reservoir in the study area are 11.7％and 11.45×10-3μm2,respectively,indicating a low porosity and low permeability reservoir.The pore structure is divided into four types:Class Ⅰ large and medium-sized pore type,Class Ⅱ small and medium-sized pore type,Class Ⅲ small pore type,and Class Ⅳ small microporous type.Among them,Class Ⅱ and Ⅲ are the main types of oil and gas reservoir pores in the study area.The favorable diagenesis for reservoir properties is dissolu-tion,while compaction and cementation have destructive effects on reservoir properties.In addition,sedimenta-ry facies are also an important factor affecting the physical properties of reservoirs,among which the core beach microfacies have the best physical properties,followed by the riverbed retention sedimentary microfacies.
万方数据
维普
