摘要
长山剖面位于潮水盆地西北缘,为一套含煤碎屑岩沉积,沉积厚度459.6m,前人认为属河湖相沉积。通过对组成该剖面的岩相组合,古生物化石及剖面结构的详细观察和研究,结合对中侏罗世研究区的构造、古气候条件及古地理背景的分析,认识到长山剖面为一套网状河相沉积,该沉积可以识别出河道、天然堤、决口扇、湖泊和沼泽五种沉积微相,其中以河道和沼泽两种微相最为发育。河道砂体是良好的储集层,具有较高的孔隙度和渗透率,而河道间湿地沉积可以成为较好的烃源岩。因此,该网状河沉积具有较好的油气远景。
Changshan section is located in the northwestern border of Chaoshui Basin. It is composed of a set of coal-bearing clastic rock deposits with a thickness of 459. 6 m,and is regarded as fluvial and lacustrine facies deposits by preceding researchers. According to the detailed survey and study of its lithofacies combination,palaeontological fossils and sectional structure,and the detailed analysis of the construction, climate conditions and geographical background of this area in Middle Jurassic ephoch,the authors consider that Changshan section is a set of braided river deposits. Five microfacies of braided river deposit can be recognized,i. e. stream channel,natural levee,crevasse-splay,lake and swamp. Among them,stream channel and swamp are the best developed microfacies. Stream channel sandbody is a better reservoir and has higher porosity and permeability. The fine deposits in stream channels can be better hydrocarbon source rock. Therefore,the braided river deposits have better oil and gas prospect.
出处
《西安石油学院学报》
1997年第4期8-11,共4页
Journal of Xi'an Petroleum Institute
关键词
剖面
网状河
青土井组
潮水盆地
石油地质
braided river,stream channel,lake,swamp/[natural levee,crevasse-splay]
