The Research On Hydrocarbon Eurichment Regularity And Favorable Areas Prediction Of Chang2Oil-bearing In Jiyuan Area

This essay has studied the stratum Chang2of Triassic Yan’chang Formation in Jiyuan,Ordos basin. By using cyclic sedimentation theory and foundation knowledge of Electricalmeasuring curve, Chang2stratum can be divided into three reservoir segments ie: Chang23、Chang22、Chang21. By analyzing types of sedimentary facies and characteristics ofMicrofacies according to the basic knowledge of logging trace and precipitation facie signs.wecan make sure that Chang2stratum develops delta plain subfacies. For that development ofsand body is controlled by sedimentary facies and sand body in distributary channel occupiesmost space of reservoir bed.By studying reservoir petrology、characteristic of physical property、hole structure ect.We have done some researches on characteristics of Chang2and finally got an conclusion: themain type of rock is feldspar-porphyry sandstone, psephicity is times prismatic and sorting rateis high as well as maturity of deposit structure.The main hole types are thin hole-thinbottleneck and thin hole-tiny thin bottleneck. Low permeability layer and ultra lowpermeability layer stands most part of Chang2stratum.By studying the reservoir accumulation elements and characteristics, For this region ofreservoir having sufficient oil sources、good diagenetic condition、high quality cappingformation ect, we can conclude that hydrocarbon source rocks which develops in Chang7stratum of southern part of studied region provides sufficient material for Chang2reservoir;Sand body in distribution channel is a important palace for storing oil and gas; nosing structurecontrols the distribution of oil and gas; On the basis enrichment pattern studies of oil and gas,for the specific geological conditions of the study area and oil testing data, we can predict thebeneficial exploration region of Chang2stratum and provide geology references for the futureexploration at last.