【摘要】 四川盆地震旦系—下古生界位于叠合盆地底部,其保存条件和烃源条件均佳,优质储层的形成与保存是油气能否成藏的关键。通过岩石学、流体地球化学等手段研究了四川盆地震旦系—下古生界优质储层形成与保存机理。研究结果表明:震旦系—下古生界滩相沉积环境普遍有利于早期优质储层的形成,而膏溶作用与表生岩溶作用是该时期早期优质储层的主要形成机理。另外,适时的油气充注、适宜的构造位置、相对稳定的构造、较少的流体混合、弱的水—岩反应及较低的含油饱和度等是早期优质储层的保存机理。震旦系—下古生界后期优质储层的形成机理则主要有深埋岩溶作用及有机酸导致的重结晶和构造挤压破裂作用等。更多还原

【Abstract】 The Sinian-lower Palaeozoic strata in Sichuan Basin,which locate at the bottom of the superposed basin,have excellent hydrocarbon source and reservation conditions.Formation and conservation of high quality reservoirs were the keys for hydrocarbon reservoirs’ forming.Based on the discussion of lithological and fluid geochemical characteristics,the formation and conservation mechanism of the high-quality reservoirs in Sinian-lower Palaeozoic were researched in the studied area.The bank facies in Sinian-lower Palaeozoic was favorable to the formation of early high quality reservoirs.Gypsum dissolution and epigenic karstification were the main formation mechanisms for the early high quality reservoirs.Moreover,timely hydrocarbon-filling,proper structural position,relatively stable structure,rare fluid mixing,under-reaction of water-rock and low oil-bearing saturation,etc.,were the conservation mechanisms for the early high quality reservoirs.Karstification at deep burial depth,recrystallization caused by organic acid and fracturing by tectonic compression were the main formation mechanisms for the late high quality reservoirs of the lower combination in Sichuan Basin.更多还原