【摘要】 基于对四川盆地乐山—龙女寺古隆起演化和震旦系沉积相、烃源岩、储集层、盖层等成藏条件的研究,分析四川盆地震旦系天然气勘探潜力。四川盆地震旦系具备形成大气田的成藏条件:①大型继承性古隆起为震旦系油气形成、聚集提供了条件;②稳定的沉积背景奠定了储集体和烃源岩大面积发育的基础;③灯二段、灯三段和灯四段3套储集层相互叠置,大面积发育;④多套烃源岩纵向叠置,大面积分布,与储集层呈"三明治"互层结构;⑤区域性泥岩盖层厚度大、盆地内断裂不发育,保存条件好。根据不同区域有利成藏条件的不同,优选了4个震旦系有利勘探远景区:乐山—龙女寺古隆起远景区、川东南远景区、川东远景区和川西北远景区,其中乐山—龙女寺古隆起远景区成藏条件最为有利,其核部的继承性古构造圈闭为勘探首选,斜坡部位的地层-岩性气藏值得探索。更多还原

【Abstract】 Exploration potential of natural gas in the Sinian,Sichuan Basin,was analyzed based on the research on evolution of Leshan-Longnüsi palaeouplift and reservoir forming conditions such as sedimentary facies,source rocks,reservoirs and caprocks.The Sinian has a potential to form large gas fields in the Sichuan Basin:(1) A large-scale inherited palaeouplift provides conditions for oil/gas formation and accumulation.(2) Stable sedimentary environment guarantees the extensive development of source rocks and reservoirs.(3) Sinian Deng-2,Deng-3 and Deng-4 reservoirs overlap each other and are developed widely.(4) Multiple source rocks overlay vertically and are distributed widely,superimposed between reservoirs like "sandwiches".(5) The Sinian has good preservation conditions,regional mudstone cap rocks are thick and faults are not developed.Considering favorable reservoir forming conditions,four favorable prospective areas are selected: Leshan-Longnüsi Palaeouplift,Southeast Sichuan,East Sichuan,and Northwest Sichuan.The Leshan-Longnüsi palaeouplift is the most favorable area,where inherited palaeostructural traps in the core are first priority and the litho-stratigraphic gas reservoirs in the slope deserve exploration.更多还原