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针对四川盆地下三叠统飞仙关组层序地层存在多种不同划分方案,以高精度层序地层学理论与方法为指导,以蜀南地区飞仙关组台地相碎屑岩和碳酸盐岩为研究对象,以野外露头剖面、岩芯、钻井、测井、地震等资料为基础,综合应用岩性突变面、沉积相转换面、沉积物空间堆积样式的变化、早期成岩变化、电测井曲线特征以及地震反射特征等标志,识别出不同级次的11个层序界面,据此将本区飞仙关组划分为2个三级层序(TSQ1和TSQ2)和10个四级层序,其中TSQ1可细分出6个四级层序,TSQ2可再分出4个四级层序,并将其与传统地层单位进行对比:三级层序TSQ1和TSQ2分别对应于飞一段+飞二段地层和飞三段+飞四段地层。通过层序地层对比和层序地层格架的建立,指出这些层序在全区均具有良好的可对比性和等时性,每个层序均具有快速海侵到缓慢海退的特点,均由海侵体系域和高位体系域构成,未发现低位体系域和凝缩段。层序与储层关系的研究表明,四级层序Ⅲ和Ⅷ是台内鲕滩这种有利储集相带的主要发育层位,所形成的滩相鲕粒灰岩储层与高位体系域的向上变浅序列和早期暴露及其所导致的大气淡水淋溶改造有关,平面上集中分布于中东部地区。
There are many different schemes for the sequence stratigraphy of Feixianguan Formation in the Lower Triassic in the Sichuan Basin. Guided by the theories and methods of high-precision sequence stratigraphy, with the platform clastic rocks and carbonate Based on the data of outcrop profile, core, drilling, well logging and seismic data, the salt rock is used as the research object. Based on the comprehensive application of the lithologic catastrophic surface, sedimentary facies conversion surface, sedimentary space accumulation pattern change, early diagenetic change, Logging features and seismic reflection features. Eleven sequence boundaries of different levels are identified, and Feixianguan Formation in this area is divided into two third-level sequences (TSQ1 and TSQ2) and ten fourth-level TSQ1 can be subdivided into six fourth-order sequences, TSQ2 can be divided into four fourth-order sequences and compared with traditional stratigraphic units: the third-order TSQ1 and TSQ2 correspond to the first segment + Flying two stratum and flying three + flying four sections of strata. Through the comparison of sequence stratigraphy and the establishment of sequence stratigraphic framework, it is pointed out that these sequences all have good comparability and isochronism in the whole region, and each sequence has the characteristics of rapid transgression to slow receding, Constructed from the transgressive system tract and the highstand system tract, no lowstand system tract and condensation section were found. The study of the relationship between sequence and reservoir shows that the fourth-order sequences Ⅲ and Ⅷ are the main developmental layers of the favorable reservoir facies belt in the oolitic beach in Taiwan, and the formed oolitic-limestone reservoirs and the highstand system tract The uplifting sequence is related to the early exposure and the atmospheric leaching reforming caused by it, and is mainly distributed in the central and eastern regions in the plane.