Research On Sedimentary Microfacies Of Benxi Group Of Yanchang Area Of Ordos Basin

With studying Gushihezi Shanxi group atmosphere in2006,, the carboniferous Benxi group of gas logging abnormal display and overflow in the drilling process and good testing scale gradually aroused people’s attention. This discovery has opened up a new gas bearing strata for natural gas exploration in this area, shows a good exploration prospect.This topic proposed using sedimentary facies reservoir research multidisciplinary combination of methods, combined with modern test and analysis methods and advanced means of test and analysis, on the basis of the existing results, the comprehensive geological, drilling, well logging data, through further study of the large scale, upper palaeozoic sedimentary micro facies reservoir characteristics, establishing depositional model, clear the main factors affecting reservoir prediction and evaluation of favorable reservoir development zone,Research shows that the Benxi group barrier bar main bar in north north east-south distribution, small bar are scattered; Sand flat in the north west-south east distribution, this type of sandstone and the12basic similar, is mainly quartz sandstone, sandstone detrital component is given priority to with quartz. Filler content mainly cement, low content of mixed base, give priority to with kaolinite cement, cement in pore type cementation and regeneration-pore type cementation. One barrier island and sand flat quartz sandstone better properties. Sandstone reservoir generally belongs to low porosity, low permeability reservoir. By looking for sand body development belt and high porosity, high permeability zone in combination with characteristics of capacity and logging data for the purpose of each layer of the composite in the studied area the prediction of favorable area, divided into I advantageous area and II favorable area.