【作者】 帅燕华；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2001， 硕士

【摘要】 构造演化是地质历史事件在地质体上的再现。一个地质体经历了长期的演化发展，能否成为有利的储集体，不仅决定于它沉积时的特征，而且决定于它在地质历史中的演变，及遭受的地质事件的性质。它是各种现象综合作用的结果。因此，从构造演化的观点处理研究鄂尔多斯盆地中央古隆起东北部斜坡区奥陶系马家沟组晚五期的含气性，是动态、整体演化的一个体现。本文在综合分析前人研究成果基础上，分析处理了研究区内200余口探井资料，对奥陶系天然气成藏的有利条件及分布特征做了分析，从构造演化方面剖析了本区储集层位发育的特点。研究结果表明：中央古隆起经历了隆升、发展和消失三个阶段；研究区内奥陶系马家沟组地质特征主要受控于中央古隆起。沉积时，它控制了斜坡区的岩相岩性；风化时，它决定着风化的强度和性质。隆起区遭受剥蚀强烈，斜坡区内部，侵蚀沟槽处，剥蚀亦非常严重；古风化作用控制着研究区储集体的形成和演化，亦即控制着天然气聚集。斜坡区是最有利储集体发育区，洼地区则形成封堵盖层。本区的构造演化过程表明本区主导圈闭不是构造圈闭，而是岩性圈闭、古地貌圈闭及二者联合作用组成的复合圈闭。更多还原

【Abstract】 Structural evolution is the resurgence of geological events in geological body. A geological body can or not turn to be reservoir, not only being decided by the sedimentary characters, but also by its evolution in geological history and the personalities of all events. So, it is the composite effect of all phenomena. From this view, the study on possibility of gas-bearing of beds in late fifth phase of majiagou formation is much more scientific and dynamic.The research is based on the fore studies about this theme, and based on the analysis about 300 drills’ data. And in this paper, all the convenient conditions to gas accumulation in Ordovician, the spreading form and the characters of reservoir beds have been involved.Through the study, some conclusions have been drawed. Firstly, the structural evolution of central palaeohigh has been divided into three stages: uplift stage, development stage and extinction stage. Secondly, the geological characters of majiagou formation had been mainly controlled by central palaeohigh, in sediment period, its lithofacies and lithologies having been effected, during weathering age, the intensity and character of weathering influenced in different areas. Thirdly, the area in uplift had been weathered strongly, so had some regions of clino where there were erosion valleys or furrows. The form and the evolution of reservoir was dominated by the weathering, and the gas accumulation was dominated by the reservoir in different areas. Majiagou formation was good reservoir in clino and turned to be capping bed in depression. At last, the main trap manifested by the structure evolution in the area is not structural trap, but lithological trap, ancient landform trap and combination trap.更多还原