四川盆地东南部小河坝组优质储层的形成机制  

Study on the formation mechanism of high-quality reservoir of Xiaoheba Formation in Southeast Sichuan Basin,China

作　　者：胡东风[1] 王良军[1] 施泽进[2] 王勇[2] 

机构地区：[1]中国石化勘探分公司,成都610041 [2]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059

出　　处：《成都理工大学学报（自然科学版）》2017年第5期543-552,共10页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家科技重大专项(2016ZX05002-004-004)

摘　　要：探讨四川盆地东南部下志留统小河坝组砂岩形成优质储层的控制因素及形成机制。以野外剖面测量为基础,通过孔渗分析、薄片鉴定、阴极发光及扫描电镜等手段,结合前人的研究成果,对小河坝组海相碎屑岩的储层形成机制进行分析。认为沉积微相控制了储层形成的先决条件,水下分流河道和远砂坝主要沉积了一套粉砂岩,具有形成储层的先天条件;而分流间湾主要沉积了一套泥岩或粉砂质泥岩,不能形成储层。生烃中心对小河坝组储层具有重要的控制作用,砂岩中沥青的含量与生烃中心的距离具有明显的负相关性。岩性在纵向上的叠置关系也是影响储层形成的重要因素,具有砂泥互层的地层结构,因砂岩不易压实和胶结,可形成相对较好的储层;而厚层的砂岩因压实和胶结作用严重,反而难以形成好的储层。The Lower Silurian Xiaoheba Formation is an important target for oil and gas exploration in Sichuan Basin.The sandstone in Xiaoheba Formation is very tight,but it can form relatively good quality reservoir.Based on the measured natural profiles as well as previous research results,the controlling factors of reservoir quality and mechanism for the formation of relatively high-quality reservoir are studied by means of property testing,thin section identification,cathodoluminescence,scanning electron microscope and other technical methods.It is considered that the sedimentary microfacies are prerequisites for the formation of reservoir.The siltstone deposited in the subaqueous distributary channel and distal bar is favorable for the formation of reservoir,while the mudstone or silty mudstone deposited in the bay between underwater distributary channels are hard to form reservoir.Hydrocarbon-generating center is very important for the formation of reservoir and a negative correlation exists between the solid bitumen content and the distance from sandstone tohydrocarbon-generating center.Superimposed relation among various lithological layers is also an important factor controlling the formation of reservoir.Sandstone intercalated with mudstone can form reservoir easily as the sandstone is not easily cemented and compacted,while the thick bedded sandstone is hard to form high quality reservoir because of its strong compaction and cementation during the diagenesis.

关 键 词：储层 形成机制 小河坝组 四川盆地 

分 类 号：TE122.21[石油与天然气工程—油气勘探]