六盘山盆地中生界地质特征与油气勘探方向

六盘山盆地位于河西走廊东南端,处于鄂尔多斯盆地西缘,白垩纪是其主要成盆期。受构造运动及其演化的影响,六盘山盆地白垩系发育两期沉积充填旋回,形成了扇三角洲-湖泊和辨状河三角洲-湖泊两种沉积体系,发育多套生储盖组合,其中下白垩统李洼峡组和马东山-乃家河组是盆地的两套有效烃源岩层系;喜山期由于盆地受挤压作用影响,在盆地西南缘发育了较大规模的逆掩推覆,形成了大量的北西向背斜型圈闭,为油气聚集提供了有利场所,是盆地白垩系油气勘探的有利地区。

Mesozoic Geological Characteristics and Hydrocarbon Exploration Direction in Liupanshan Basin

The Liupanshan Basin.which was mainly formed during the Cretaceous.is located in the southeastern tip of the Hexi Corridor and on the west of the Ordos Basin.Due to the basin's tectonism and evolution,two sedimentary filling cycles were developed in the Cretaceous section of the Liupanshan Basin,resulting in a fan deltaic-lacustrine sedimentary system and a braided stream deltaic-lacustrine sedimentary system,which consist of a number of source-reservoir-seal associations.Of them,the Lower Cretaceous Liwaxia Formation and Madongshan-Naijiahe Formation are two series of effective hydrocarbon source rock series of strata.Due to compression during the Himalayan,a large-scale overthrusting on the southwestern margin of the basin was developed,forming numerous NW-trending anticlinal traps favorable for hydrocarbon accumulation and for exploration aimed at the Cretaceous section in the basin.