【作者】 陈永振；

【导师】 周立发；

【作者基本信息】 西北大学 ， 构造地质学， 2010， 硕士

【摘要】 沙探1井所处的环县沙井子地区,在构造区划上隶属于西缘冲断带与天环坳陷及其接合地带,具有极大的油气勘探前景。但不同构造阶段、不同构造体系的复合叠加,同一构造阶段、不同构造体系的联合控制,使得沙井子-平凉地区现今地质构造及其演化特征极为复杂。沙探1井的部署及近年来地震资料的处理与解释都是建立在沙井子地区的逆掩推覆双层构造模式的基础之上,但是沙探1井的钻探及地质剖面的观察结果基本否定了沙井子地区的传统构造模式。因此,开展沙探1井区的地质构造特征研究对于探讨鄂尔多斯西缘沙井子地区构造样式与成藏模式、评价研究区的含油气远景具有重要的现实意义。此次研究综合利用地面地质、钻井及地球物理等资料,将野外和室内研究相结合,通过区域地质构造剖面图的编制及地震反射剖面的精细解释,再现沙井子地区燕山期及现今的基本构造样式。研究结果表明：沙井子地区的基本构造样式并非逆掩推覆双层构造模式,区内石炭系或二叠系内不存在一重要滑脱面。沙井子地区各个构造带之间均以西倾单向叠瓦状冲断层分隔,新生界和白垩系之下的蓟县系-奥陶系主体呈现出与冲断层相协调的构造形态,指示该地区基本构造样式可能为西倾单向叠瓦状的冲断层组合形式；区域上白垩系广泛不整合覆盖于下伏不同时代地层之上说明在白垩系沉积前研究区的蓟县系-奥陶系已经作为一个相对独立的构造带存在。因此,由蓟县系-奥陶系组成的单斜构造应主要形成于侏罗纪末。燕山期(侏罗纪末)平板结构模式下的基底滑脱型单向冲断构造与喜马拉雅期的右旋剪切走滑构造的复合叠加,是沙井子地区构造形成的基本模式。更多还原

【Abstract】 Preliminary prospecting well Sha-1 located in the Shajingzi district of Huan County, belong to the joint area of overthrust fault belt and Tianhuan depression, with the large potential of petroleum exploration. Different structural layers of different stages of tectonic evolution superimposed with different structural layers in the same stage, controlling the tectonic character and evolution in the district of Shajingzi-Pingliang. Deployment of well Sha-1 and seismic data processing and interpretation, were all basing on the double layers overthrust nappe model, which are not in accordance with those from the drilling and observation of geology section.Study the character of the tectonic is of great practical significance in discussing tectonic patterns, hydrocarbon accumulation models, and hydrocarbon prospective evaluation in the Shajingzi district. On the basis of field investigation and laboratory analysis, this study use abundant geology, geophysical and well data comprehensively. Through mapping the geology section and interpreting the seismic data, we want to reconstruct the structural deformation shapes of Yanshan movement.The result show that the deformation shape is not a double layer overthrust tectonic type, and do not exist a detachment surface in the Permian or Carboniferous formation. Different tectonic zone are divided by imbricate-type thrust faults dip toward west, and in coordinately the Jixian-Ordovician formations deformed with the imbricate-type thrust faults dip toward west under the Cenozoic erathem and Cretaceous formation. All these show that imbricate-type thrust faults dip toward west may be the main tectonic type of the study area. Cretaceous formation overlay discordantly on different formation inferred that the tectonic pattern of Jixian-Ordovician formations was an undependent tectonic zone. Therefore the monoclinal structures of Jixian-Ordovician formations were formed in late Jurassic, and the main pattern is the decollement between basements with imbricate-type thrust faults in the plate structure model in Yanshan movement superimposed with dextral shear slip fault during Himalaya movement.更多还原