辽西低凸起中段古近系东营组第二段沉积模式与勘探新发现

New sedimentary model and exploration discovery of Paleogene Dongying Formation in the middle section of the Liaoxi lower arch,China

运用层序地层分析、古地貌分析、物源分析等方法探讨了辽西SZ36-1-A井区古近系东营组第二段沉积体系,认为东二层序时期辽西低凸起并未完全形成,物源水系完全可以通过断层调节带从西部向SZ36-1-A井区推进。新的沉积相成果判定主要含油层段为东二层序低位域,改变了该区储层相对不发育的勘探局面,也印证了储层/砂体特征是影响富生烃凹陷隐蔽油气藏规模的关键因素。

The deposition system of Paleogene Dongying Formation in the well area of SZ36-1-A is restudied on the basis of a comprehensive analysis of stratigraphy sequence,palaeogeomorphology and sediment source.The research shows that the main oil-bearing segment is the lowstand system tract in Dongying Formation.The Liaoxi lower arch did not formed completely in this period.The water system could definitely inpour the well area of SZ36-1-A from the west through the fault accommodation zone.The new sedimentary facies achievements change the exploration situation which the reservoir did not develop relatively in this area and open a new exploration prospect in the well area of SZ36-1-A.The preliminary calculation estimates that the oil resource scale is about 37.795×106 m3 based on the finding of a series of sand bodies.The above research also verifies that the characteristics of a sand body are a key factor to control subtle reservoir size in a petroliferous depression.