阿南油田阿四段河口水下扇砂体储层沉积相及含油性

Sedimentary Facies and Oil bearing Feature of River Mouth Subaqueous Fan Sandbody Reservoir of A IV Member in A′nan Oil Field

根据阿南油田近百口钻井剖面的岩性组合、电性特征和测试结果，近２０口井的岩心观察、沉积构造、韵律性质，大量岩矿鉴定结果、岩石组构、储层物性分析资料和油气显示，对阿四段的砂体成因、沉积特征、微相划分、孔隙结构、储集结构、储集性能及其油气关系，进行综合分析．认为本区砂岩储层属河口水扇成因，细分为扇根、扇中和扇端三个亚相．它发育在同生断层下降盘和湖侵高潮阶段早期，存在牵引流成因在沉积构造和正韵律层为主的剖面特征，具有多物源、近物源、粗碎屑、低成分成熟度、低结构成熟度和低孔、低渗型的储层特征．沉积微相控制储集性能和油气藏分布，扇中水下河道储集条件和含油性最好，是油气勘探、开发的有利相带．

The sandbody genesis,depositional feature,microfacies classification,pore configuration,reservoir property and hydrocarbon feature of A IV member in A′nan Oil Field are synthetically analysed according to the lithological combinations,electrical properties and testing results of the drilling profiles of about 100 wells,the abservation results of cores,sedimentary structures and rhythmic properties of about 20 wells,a lot of rock identification results,rock texture,the analysis of reservoir property and oil and gas shows.It is held that the sand body reservoir is of river mouth subagueous fan genesis,and the fan can further be divided into three subfacies of fan foot,fan middle and fan end.It developed at the downthrow block of contemporaneous fault in the early period of the lake generation climas.It has the tractional current sedimentary structures and the main profile characteristic of positive rhythm bed.The reservoir is characterized by multiple facies,proximal facies,coarse fragment,low compositional maturity,low structural maturity,low proposity and low permeability.The sedimentary microfacies determine reservoir characteristics and hydrocarbon distribution.The best oil bearing tract is the subagueous channels in fan middle,so it has good prospects for oil gas exploration and development.