The Research Of Reservoir Characteristics And Its Control Oil Of Chang6 Formation In Wuqi On Ordos Basin

Wuqi area is located in the middle of Shanbei Slope of Ordos Basin,which Chang 6 reservoir is the main oil producing,in order to further grasp the distribution rule of oil and gas,it is necessary to detailedly research reservoir characteristics and its containment factors of Chang 6 oil layer.Based on making full use of logging data,core data logging and experimental analysis,etc,this paper studies strata,structure,sedimentary facies and reservoir of Chang 6 oil formation,and summarizes the main control factors of oil and gas.The result shows that Chang 6 reservoir can be divided into Chang63,Chang 62 and Chang 61 three layers;the area is delta front sedimentary facies,which develops underwater distributary channel and distributary bay microfacies;reservoir rock type is fine-grained feldspar sandstone,which have secondy particle selection and psephicity;reservoir property is poor that considered as low porosity and low permeability reservoir;diagenesis of reservoir is stronger and includes compaction,cementation and dissolution;intergranular pore and feldspar dissolved hole are the main types of pore;heterogeneity is also stronger,by analysis of reservoir evaluation parameters,reservoir can be divided into ultra-low permeability reservoir,dense layer and extra-low permeability three categories;but the area mainly belongs to ultra-low permeability reservoir.By the analysis of geological characteristics,well testing and early production test in the area,the reservoir type is lithological reservoir and structural-lithological reservoir;the sedimentary microfacies,diagenesis and oil source are the main oil-controlling factors;nose-like uplift also plays a supporting role for reservoir oiliness.