Reservoir Hierarchy Division And Favorable Block Forecast Of Guantao Formation In The West Of Liulu Area

Guided by high-resolution sequence stratigraphy, sedimentology and some other theory,wavelet analysis tetechnique as an adjunct,through core, well logging and seismic data analysis,it is believed that the third member of Guantao formation in research area is divided into 3 sandbody groups and 13 layers,according to the comprehensive study of key well core observation,laboratory analysis and test data and well logging curves characteristics,it is shown that the reservoir in the area is mainly composed of lithic arkose,subarkose and feldspathic litharenite,with medium-low texture maturity,pore type in the reservoir of the area is mainly primary intergranular pores, and the proportion of dissolved pore type reservoir is low.Most reservoirs have high or medium porosity and medium permeability.Mudstone,siltstone,fine sandstone,coarse sandstone and microconglomerate can be identified through the establishment of logging interpretation crossplots and BP neural network model.Finally,oil bed,water-oil bed and water bed can be recognized by water/oil interpretation chart,and it can be established by well logging data.According to the study of the sandbody development characteristics,in plane distribution characteristics and in three-dimensional characteristics,the fisrt and the third sand group are more developed and lateral continuity is good.Then we are sure that there were 7 main layers（Ng₃31,Ng₃32,Ng₃25,Ng₃11,Ng₃13,Ng₃1,Ng₃16） in the study area.Ng₃31,Ng₃32,Ng₃25 and Ng₃16 showed cutting each other and stacked in longitudinal direction,most of single sandbody is about 8 to 10 meters and lateral continuity was good.Sandbody of Ng₃11,Ng₃13,Ng₃15 existed in isolation and lateral continuity was not good.On the basis of research of reservoir characteristics and sandbody distribution,combined with regional tectonic characteristics and analysis of accumulation conditions,the paper predicted 4 favorable blocks that contained oil and gas（liu58-5-lu4 area,liu97-liu50 area,liu54-2-liu64 area and liu86-liu82-lu65 area）,liu58-5-lu4 area,liu97-liu50 area,liu54-2-liu64 area belong to faulted trap and liu86-liu82-lu65 area belongs to faulted-lithologic trap.