Study on the standard of the four relationships of reservoir and the lower limit of effective reservoir in Nantun Formation of Oilfield A

Abstract

By using the data of logging, cuttings logging, thin section identification and analysis in the study area to study the four characteristics of the Nantun Formation reservoir and their relationship, the lower limit standard of effective reservoir physical property is established by the logging interpretation model of the reservoir mud content, porosity, permeability and saturation, and the mercury injection method, oil production method, oil test analysis method and cumulative frequency statistics method. The lower limit standard of effective reservoir electrical property is determined by using fluid identification chart. The results show that the lithology of the second member of Nantun Formation is mainly sandy conglomerate, and the first member of Nantun Formation is mainly sandstone, and the sandstone is more developed. The oil content is mainly full of oil, oil spots and oil stains. The reservoir porosity is between 4~20% and permeability is 0.01~100 mD, showing low porosity and low permeability. The lower limit of effective reservoir in Nantun Formation is porosity of 7%, permeability of 0.05mD, sonic time difference of 63μs/ft, density of 2.55 g/cm3 and water saturation of 20%.