川西坳陷南区侏罗系层序地层与油气

SEQUENCE STRATIGRAPHY AND HYDROCARBON POTENTIAL OF JURASSIC IN THE SOUTH PART OF WEST SICHUAN DEPRESSION

四川盆地西部坳陷南区 ,即大邑—新津一线以南、龙门山以东、龙泉山以西、名山—丹棱—眉山一线以北约 30 0km2 的地区。近年来在侏罗纪地层中发现了大量工业性天然气藏。侏罗系的层序地层及其与油气关系的研究引起了人们的极大关注。笔者对区内侏罗系采用层序地层学观点进行了详细的野外露头和室内钻井、测井、地震层序分析。在侏罗系中识别出 9个层序界面 ,并划分为 8个三级层序。论文对层序地层与油气关系进行了论述 ,指出区内侏罗系浅气层最有利勘探区为平落坝、大兴西、松花镇、白马庙等地 ,有利勘探区为蒲江、邛西、观音寺等地。

The south part of West Sichuan Depression,being to the south of Dayi-Xinjing,the east of Longmen Mountains,the west of Longquan Mountains and the north of Mingshan-Danling-Meishan,occupies an area of about 300 km 2.In recent years,a large number of commercial gas reservoirs have been found in Jurassic,which arouses a great interest in the research on the sequence stratigraphy of Jurassic and its relation to hydrocarbons.By use of the view points of the sequence stratigraphy,the outcrops and the drilling well-logging and seismic sequence data were analyzed in detail.In Jurassic,nine sequence interfaces were identified and eight tertiary sequences were classified.The relationship between sequences and hydrocarbons is discussed in the paper.It is pointed out that the most favourable regions of exploring for shallow gas in Juassic are Pingluoba,Daxinxi,Songhuazhen and Baimamiao,etc.,and the favourable regions are Pujiang,Qiongxi and Guanyinsi,etc.