【摘要】 依据钻井及地震资料综合解释,奥陶纪末期由于海平面下降,其顶面遭受侵蚀下切,形成一个大型东西向的侵蚀谷。谷底多处零星分布了一套30m左右的玄武岩、凝灰岩。后期该侵蚀谷被志留系下统柯坪塔格组下段填平补齐。柯坪塔格组下段主要分布在塔中I号断裂带以北和塔北隆起之间,东西向展布,最大厚度约1000m,据其厚度和在古沉积斜坡的超覆特征,可分为北部缓坡带、中央深陷带和南部陡坡带三个古构造单元。柯坪塔格组下段早—中期物源受侵蚀谷充填控制主要来自塔东地区,晚期物源则主要来自塔北地区,I号断裂以南的塔中隆起没有提供物源。柯坪塔格组下段经历了从半深海泥到潮控三角洲的过渡型沉积环境,发育三角洲储层和低幅度构造,形成了良好的油气成藏区域。更多还原

【Abstract】 Based on the drilling and seismic data comprehensive interpretation, at the end of the Ordovician, a sea-level fall happened and resulted in the erosion and incise the top surface, forming a large east—west incised valley. At the incised valley base, there is around 30m of basalt and tuff branching northwestward. The incised valley is filled up nearly completely after deposition of the Lower Member of the Kepingtage Formation, Silurian. The Lower Member of the Kepingtage Formation, whose maximum thickness is about 800m, mainly distributes between the Tazhong Ⅰ fauls and North—Tarim Uplifted region. In the light of their thickness and the overlapping gradient of valley, three ancient tectonic units can be divided: the northern gentle slope zone, the central depocenter zone and the southern steep zone. The clastic masses of the Lower Member of the Kepingtage Formation mainly came from the eastern margin of the basin, and secondly northern margin. The Tazhong Uplifted region did not supply sediments to the Shun9 well area. The Lower Member of the Kepingtage Formation expired depositional evaluation from semi-deep sea mud to deltaic deposit, having deltaic reservoir and low amplitude structure, forming a better hydrocarbon accumulation area.更多还原