松辽盆地南部幔源CO_2充注成因次生油气藏深、浅层分布差异

在大量总结前人研究成果的基础上得出:松南地区深部层位以富气为特征,烃类气成藏阶段为登二段沉积期及早白垩纪晚期;浅部层位以富油为特征,油气成藏阶段主要集中于明水组沉积末期至古近纪早期;盆地中CO2气主要富集于营城组及泉头组(三、四段),储量丰富且以幔源成因为主,其形成与晚中新世后期火山活动有关;深层与浅层油气成藏时间均早于幔源CO2充注。与深部层位相比,松辽盆地南部浅层具备更完善的幔源CO2充注成因次生油气藏形成条件,可视其为常规油气资源再勘探的有利目标区。

Differences in distributions of mantle- derived CO 2 charging secondary reservoir in deep and shallow layers of southern Songliao Basin

Based on the summary of a large number of known research achievements the following conclusions can be drawn by the authors． The deep formation of southern Songliao Basin is characterised by the enrichment of hydrocarbon gas，and the accumulation stage of hydrocarbon gas focusing on the deposition period of the second member of Denglouku Formation and on the late Cretaceous． The shallow layer of southern Songliao Basin is rich in petroleum，and the accumulation stage of petroleum is mainly from the end of Mingshui Formation to Early Paleogene． The CO2 mainly accumulated in the third and fourth member of Quantou Formation，and the Yingcheng Formation，in which the reserves of CO2 is large with mantle origin． The generation of CO2 is related to volcanic activi- ty during the later- stage of late Miocene． The accumulation periods of shallow and deep formations are earlier than the charging of mantle CO 2 ． The shallow layers have better conditions for the secondary accumulation of petroleum driven by the mantle CO2 charging， which could be regarded as the favorable targets for re-exploration of conventional petroleum．