川中地区凉高山组滩坝沉积特征及模式

摘要

基于野外露头和岩芯观察,结合粒度分析、测井相和地震相等典型相标志分析,对川中地区凉高山组沉积特征进行研究.结果表明,川中地区凉高山组上段主要为浅湖沉积环境,滩坝砂体广泛发育.滩坝可进一步识别出砂滩和砂坝两种微相,在平面上滩坝沿湖岸线分布,且砂坝分布于砂滩内部.在此基础上,建立了四川盆地凉高山组沉积模式,并指出砂坝微相砂体为川中地区凉高山组上段致密油勘探“甜点”储层分布区.%The sedimentary characteristics of Lianggaoshan Formation in central Sichuan Basin was studied based on field outcrop and core observation,combined with grain size analysis,well log and seismic facies analysis.The result showed that the upper Lianggaoshan Formation was deposited in lacustrine environment in central Sichuan Basin,with beach-bar sand bodies extensively developed.The beach-bar can be divided into two types of microfacies,i.e.sand beach and sand bar.In the plan view,beach-bar distributed along the lake shoreline,whereas the sand bar distributed in the sand beach.On this basis,the sedimentary model of Lianggaoshan Formation in Sichuan Basin was built,and the sand bar sand body was identified as the "sweet spot" for tight oil exploration of upper Lianggaoshan Formation in central Sichuan Basin.