摘要
为研究白狼城地区延长组长2 砂体叠置样式及沉积特征,利用野外露头、岩芯和测井相分析辫状河沉积相、砂体连通模式、砂体叠置和沉积模式等.结果表明:白狼城地区长2 辫状河主要为河道、泛滥平原亚相,河道亚相可细分为心滩、水道2 种沉积微相,发育槽状交错层理、板状交错层理、平行层理、块状层理等;辫状河砂体为叠覆泛砂体,分布范围广、厚度大、连续性强、物性好、非均质性强,心滩与水道相间分布,具有"滩道相间、宽滩窄道"的特征;辫状河河道亚相是辫状河沉积砂体主要区域,水道砂体与心滩砂体相互叠置,两侧泛滥平原亚相为良好的隔夹层,为油气成藏提供良好的盖层.研究结果对白狼城地区辫状河沉积特征及砂体构型具有指导意义,对不同盆地的辫状河沉积研究具有借鉴意义.
Abstract
To study the sedimentary characteristics and sand body configuration of Yanchang Formation Chang 2 in Bailangcheng area,field outcrops,rock cores,and logging facies were used to analyze brai-ded river sedimentary facies,sand body connectivity patterns,sand body configurations,and sedimenta-ry patterns.The results show that the Chang 2 braided river in the Bailangcheng area can be identified as the subfacies of river channels and flood plains.The river channels subfacies can be subdivided into two sedimentary microfacies:channel bar,channel,with the development of trough shaped cross bed-ding,plate shaped cross bedding,parallel bedding,and block bedding;The braided river sand body is a"superimposed floodplain sand body"with a wide distribution range,large thickness,strong continuity,good physical properties,and strong heterogeneity.The channel bar and channel are distributed alter-nately,with the characteristics of"intertwined bar and channel,wide bar and narrow channel";The braided river channel subfacies are the main areas of braided river sedimentary sand bodies,with chan-nel sand bodies and channel bar sand bodies overlapping each other,exhibiting good physical and het-erogeneous characteristics.The flood plain subfacies on both sides are good interlayers,providing a good cap rock for oil and gas accumulation.The research results have guiding significance for the sedi-mentary characteristics and sand body configuration of braided rivers in Bailangcheng area,and also have reference significance for the study of braided river sedimentation in different basins.
基金项目
延长油田科技计划项目(ycsy2022xjs-C02-11)
国家科技期刊平台
NSTL
万方数据