秦南凹陷古近系层序地层和沉积体系研究及油气勘探方向探讨

A study on Paleogene sequence stratigraphy and sedimentary systems and a discussion on hydrocarbon exploration directions in Qinnan depression

秦南凹陷勘探程度比较低。针对该凹陷地层、沉积研究方面存在的主要问题,运用层序地层、古地貌和物源分析相结合的沉积储层预测方法,对区内层序格架及其演化,以及主要目的层段沉积体系的平面展布及其控制因素进行了分析,并从油气运移的角度出发,探讨了古近系油气勘探方向。秦南凹陷古近系沉积体系展布主要受控于秦南2号断裂不同部位形成的沟谷和不同类型坡折带及调节带,秦南2号断裂西部末梢及东部末梢与秦南1号断裂间的调节带(即秦南东洼西北坡)在不同时期均为储集体发育区和输导体发育区,是本区古近系油气勘探的有利区带。

Qinnan depression is relatively lower in exploration maturity,and there are major problems in its stratigraphy and sedimentology.Therefore,the sequence framework and its evolution and the areal distribution of main target intervals and its controls are analyzed by using a reservoir prediction method that integrates sequence stratigraphy,palaeogeomorphology and provenance analysis.Furthermore,the exploration directions are discussed for the Paleogene sequence from hydrocarbon migration.The Paleogene sedimentary systems are mainly controlled by various troughs along Fault Qinnan 2 and different break and accommodation zones.The accommodation zones located from the west and east ends of Fault Qinnan 2 to Fault Qinnan 1 are areas where reservoirs and carriers develop well in diffent times,and these zones are favourable targets for hydrocarbon exploration.