酒泉盆地白垩纪-新生代区域构造演化与油气勘探

酒泉盆地位于祁连造山带北缘西部,是走廊盆地群西端的一个富油气盆地,按区内大地构造环境变迁、祁连造山带的形成演化、盆地内地层分布、构造变形特征,酒泉盆地白垩纪-新生代区域构造演化划分为3个阶段:早白垩世拉张断陷盆地演化阶段,晚白垩世-古新世挤压隆升阶段,始新世-渐新世坳陷和新近纪挤压盆地演化阶段。早白垩世拉张断陷阶段控制了下白垩统烃源岩及储集相带的分布,凸起区有利于形成潜山油气藏;晚白垩世-古新世的挤压隆升形成盆地的反转构造圈闭;始新世-渐新世坳陷和新近纪挤压盆地演化促进了烃源岩成熟演化,形成了众多的构造圈闭,是盆地油气聚集的主要时期。新生代前陆盆地南缘山前冲断带构造油气藏及早白垩世断陷构造-地层、岩性油气藏是酒泉盆地今后油气重点勘探领域。

Cretaceous- Cenozoic regional tectonic evolution in Jiuquan basin and petroleum exploration

Jiuquan basin, rous basin on the western located on the western part of the northern edge of Qilian orogenic belt, is a petrolifeend of the Corridor basin group. According to the changes of tectonic setting, formation and evolution of Qilian orogenic belt, stratigraphic distribution in the basin and characteristics of tectonic deformation, the Cretaceous-Cenozoic regional tectonic evolution in Jiuquan basin can be divided into 3 stages, i.e. the Early Cretaceous extensional rift-faulting stage, Late Cretaceous-Paleocene compressional uplifting stage, and Eocene-Oligocene downwarping and Neogene compressing stage. The Early Cretaceous extensional rift-faulting stage controlled the distribution of Lower Cretaceous source rocks and reservoir facies belts, and the salient areas would be favorable for the formation of buried-hill reservoirs. The Late Cretaceous-Paleocene compresso-uplifting led to the formation of reversed ping and Neogene compressing stage accelerated structural traps in the basin. The Eocene-Oligocene downwarthe maturation and evolution of the source rocks and led to the formation of many structural traps, it was also the major period for accumulation of hydrocarbons in the basin. The structural reservoirs in the piedmont thrust belt on the southern edge of the Cenozoic foreland basin and the structural-stratigraphic and lithologic reservoirs in the Early Cretaceous rifted basin would be the targets of further exploration in Jiuquan basin.