摘要
古湖岸线是一定历史时期湖平面与古陆地的交线,即陆上与水下沉积的分界线。古湖岸线的识别过程就是一个沉积环境恢复的过程,识别标志包括地貌特征、特殊岩性、古生物特征、沉积构造、地球化学指标、地震反射特征以及沉积相变等多个方面。沉积盆地中古湖岸线对于砂体和油气的分布具有明显的控制作用,主要表现在:(1)古湖岸线的类型控制了砂体的成因,古湖岸线的位置及迁移控制了砂体的分布和垂向叠加样式;(2)古湖岸线控制了优质储集层的形成与发育,一般情况下水下砂体的储集层物性优于水上砂体;(3)古湖岸线的频繁迁移为形成良好的储盖组合提供良好的沉积条件;(4)古湖岸线附近是地层超覆油气藏、不整合遮挡油气藏及岩性油气藏发育的有利区带,并且油气藏沿古湖岸线呈现裙带状分布。
Lacustrine palaeoshoreline is the intersection between the lake level and the ancient land in geologic time,and the boundary between the onshore deposits and the subaqueous deposits.The identification of lacustrine palaeoshoreline is the process of reconstructing the depositional environment.The identification markers of lacustrine palaeoshoreline include geomorphology,special lithology,palaeontologic characters,sedimentary structures,geochemistry indexes,seismic reflection characters and sedimentary facies changes.The lacustrine palaeoshoreline in the sedimentary basin has a key control on the distribution of the sandbodies and hydrocarbon. （1）The type of lacustrine palaeoshoreline controls the genesis of sandbodies, the location of lacustrine palaeoshoreline controls the distribution of sandbodies and the movement of lacustrine palaeoshoreline controls the vertical superimposed pattern of sandbodies;（2）The lacustrine palaeoshoreline controls the formation and development of the high quality reservoir.Generally,the physical properties of subaqueous sandbodies are better than those of onshore sandbodies;（3）The frequent movement of lacustrine palaeoshoreline supplies excellent deposition conditions for high quality assemblage of reservoir and cap rocks; （4）The areas sourrounding lacustrine palaeoshoreline are favorable for development of stratigraphic reservoirs like stratigraphic onlap hydrocarbon reservoirs and unconformity hydrocarbon reservoirs,which are distributed in apron shape along the lacustrine palaeoshoreline.
出处
《古地理学报》
CAS
CSCD
北大核心
2010年第5期589-598,共10页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金项目(编号:40672078)
高校博士点基金项目(编号:200804910004)联合资助
关键词
古湖岸线
识别标志
储集砂体
储盖组合
圈闭
油气
lacustrine palaeoshoreline
identification markers
reservoir sandbodies
reservoir and cap rock
trap
hydrocanbon
