Fine Description Of Reservoirs Of Tight Sandstone In Northern Shaanxi

Block You Gou is developed the first block in Wuqi oil factory,Block You Gou had begun rolling development since 2003,in recent years,facing lack of natural energy,production wells with low productivity,declining quickly,difficulty to stabilize the production.Basised on the electric measuring curve data,core analysis data report,and oil test,production test and production data,it has been waked clear of the distribution characteristics of the oil and water,favorable area aggregation rules and provided powerful technical support for the next step development,after researching the Chang7 of Yanchang Formation of stratigraphic correlation,sedimentary facies and permeability sand body distribution,reservoir characteristics,non homogeneity characteristics,reservoir characteristics.This paper obtains the main achievement and understanding:?The study area is a west-dipping monoclinal structure,development 3-4 small nose structure;? Research area in chang7 stage is mainly delta front facies and semi-deep lake�deep lake,underwater distributary channel and turbidite rock are the storage layer of sand body;?Ther are gray,dark gray fine-grained feldspar sandstone,pore throat is type of low�extra low porosity,micro roared,belonging to the whole ultra-low permeability reservoir;experienced compaction,cementation,replacement,dissolution,etc,the reservoirs and stone has reached the late diagenesis B period,the main reservoir space feldspar are dissolved pore and intergranular corrosion hole.? Chang7 reservoir is with characteristics of low density,low viscosity,low solidifying point;formation water with CaCl2,neutral;belonging to the low temperature,low pressure,lithologic reservoir;oil/water distribution,the vertical concentrate in Chang72,Chang71,strong heterogeneity;?the comprehensive evaluation of reservoir in Wuqi oilfield oil groove Chang71 and Chang72 mainly to good,secondary reservoir,Chang73 to poor reservoir and non reservoir mainly.According to the results of Chang7 reservoir evaluation,the favorable exploration area are optimized and provide geological basis for further exploration and development.