层序地层学在油气勘探中的应用——以海拉尔盆地查干诺尔凹陷白垩系为例

APPLICATION OF SEQUENCE STRATIGRAPHY TO PETROLEUM EXPLORATION:AN EXAMPLE FROM THE CRETACEOUS IN CHAGANNUOER SAG,THE HAILAER BASIN

层序地层学在我国各大油气田的应用已经相当广泛,为油气勘探作出了贡献。以层序地层学理论为指导,综合岩心、测井、录井和地震资料,将海拉尔盆地查干诺尔凹陷早白垩世地层划分为一个超层序,形成于凹陷断陷发育期,其自下而上可划分为5个三级层序。并在层序框架内对各成藏要素进行了详细研究,预测可能发育的油气藏类型,并对油气勘探有利区带进行了预测。预测凹陷可能发育8种类型的油气藏以及3个有利区带。研究结果指出:各个断阶带、斜坡带沉积的冲积扇、扇三角洲砂体、超层序水进域发育的湖底扇砂体是油气储集的良好场所,也是有利的勘探目标。

Wide application of sequence stratigraphy has made great contribution to petroleum exploration of the large oil and gas fields in China.Based on the theories and methods of sequence stratigraphy and through integration of core,log and seismic data,the Early Cretaceous in Chagannuoer sag of the Hailaer basin is recognized as a supersequence.It was formed during fault subsidence and can be divided,from bottom to top,into 5 third-order sequences.The factors influencing hydrocarbon pooling are studied in detail within the framework of sequence stratigraphy,eight reservoir types are predicted,and three favorable plays for exploration are identified.The alluvial fans and fan deltas deposited in fault step zones and slope zones,and the sublacustrine fans deposited in the transgressive system tract of the supersequence are favorable for hydrocarbon accumulation,thus are targets of exploration.