A Study On Accumulation Regulations Of Oil Of Chang 7 And Chang 9 Oil-bearing Of Yanchang Formation In Tiebiancheng Area

This article take sequence stratigraphy,sedimentary petrography,oil well logging geology theories as well as other related discipline as the instruction,take the log information as the foundation,the union logging,the core sample,well testing as well as production test data,made researches of stratigraphic classification and correlation,sedimentary facies analysis,reservoir characteristic,fine logging data interpretation,and some studies about accumulation regularity of Chang 7 and Chang 9 formation in Tiebiancheng area.Chang 9 oil-bearing formation in Tiebiancheng area develops the parfacies of delta front,Chang 7 oil-bearing formation belongs to meare-abyss sedimentary environment.Sand body distribution strictly controlled by sedimentary facies.Channel changes continuously lead to sand-mud interbed obviously,continuous network of sand body distribution,strong heterogeneity.Chang 7 and Chang 9 formation is mainly to lithic arkose sandstone,belongs to special low porosity,ultra low permeability reservoir.Analysis of main factors affecting the reservoir physical property are sedimentation and diagenesis.Based on“four properties”to determine the reservoir natural lower limit standard:The porosity is greater than 4.1%,the permeability is greater than 0.05×10^-3?m²;the Chang 9 electronic resistivity is greater than 24?·m,interval transit-time is greater than 207 us/m;the Chang 7 electronic resistivity is greater than25?·m,interval transit-time is greater than 210 us/m.And secondary interpretate the objective layer According to the minimum standards.Comparative analysis the effect of hydrocarbon generating characteristics of source rocks in different layers,It is concluded that the Chang 7 and Chang 9 oil and gas comes from Chang 7 source rocks.The migration distance and migration pathways is the main cause for enrichment differences of Chang 9 reservoir.Sedimentary facies belts control the distribution of reservoir and oil-bearing sandbody.Small nose-shaped uplift have a relation of hydrocarbon accumulation to Chang 9 reservoir.Accumulation mode of Chang 7 reservoir and Chang 9 reservoir was built,while distribution of the reservoir and its controlling factors were clarified.Combined with the study of reservoir forming conditions and control factors,predict seven favorable zone,and deploy seven exploration wells?appraisal wells.