2017年河套盆地临河坳陷油气勘探取得重要发现,基于区域中生代以来大地构造演化系统梳理,以钻井与地震对照、研究区与邻近盆地类比为研究方法,划分河套盆地临河坳陷南部吉兰泰凹陷中生代构造层,并绘制其分布范围,探讨其赋存特征与意义。结果表明:研究区中生界除三叠系外发育齐全,厚度巨大,且白垩系自上而下可细分为K1 I、K1 II和K1III三个构造层;除K1I构造层全区广覆式发育外,其它构造层呈楔状—缓楔状,长轴沿主控断裂NNE向延伸;研究区自中生代以来盆地性质经历了早中侏罗世断陷、早白垩世早期断陷、早白垩世中期断拗转换和早白垩世晚期拗陷的演化过程;F 3和F 7断层之间的K1 II和K1 III构造层、F 7断层东部的J构造层均具良好的油气勘探前景。
Significant discoveries of petroleum exploration have been achieved in 2017 in the Linhe Depression, Hetao Basin. Based on a literature review of the tectonic evolution of the study area since the Mesozoic, combined methods of well-seismic comparison and basin analogy, the Mesozoic tectostratigraphic units of Jilantai Sag have been determined, and their occurrence and significance have also been studied. The results show that, except for the Triassic, the Mesozoic strata were well developed in the study area. Particularly, the Cretaceous strata can be further divided into three tectostratigraphic units, i.e., K1I、K1II and K1
III; The K1 I is characterized by abroad sedimentation unit covering the whole study area, while the other tectostratigraphic units are wedge-shaped with major axes aligning along the NNE main faults; The Mesozoic basin type of the Jilantai Sag have experienced rift stage during the Early-Middle Jurassic, rift stage during the early Early Cretaceous, transitional stage from rift to depression during the middle Early Cretaceous, depression stage during the late Early Cretaceous; The strata of the K1 II and K1 III tectostratigraphic units located between the faults F3 and F 7, and the Jtectostratigraphic unit located in the east of fault F 7 show great potential of petroleum exploration.