【作者】 李华启；

【导师】 姜在兴； 夏斌；

【作者基本信息】 中国科学院研究生院（广州地球化学研究所） ， 地球化学， 2003， 博士

【摘要】 论文以陆相层序地层学、沉积学为理论基础，以测井、地震、地质等多种学科分析为手段，对四川盆地西部须家河组进行了层序地层学、沉积体系、成岩作用、成藏模式的研究，提出了前陆盆地可容空间转换系统的概念，并对须家河组可容空间转换系统进行了分析。 论文首先根据区域地质背景和地震资料，在须家河组建立层序地层格架，在此基础上对层序体内部的体系域、准层序组、准层序进行识别和划分，并与地震资料、地质资料相互验证、修改完善；然后从标准剖面出发，由点到面、点面结合，从而对整个须家河组开展了层序地层学研究。须家河组一共识别出四个三级层序，其中层序Ⅰ和层序Ⅱ是论文研究的重点。层序Ⅰ湖侵体系域因其有机碳丰富、泥岩厚度大，为主要烃源岩及区域盖层；层序Ⅰ下降体系域和层序Ⅱ低位体系域，由于砂岩孔渗性相对较好，可为储集层。 在层序地层学格架研究基础上，本文对四川盆地中西部上三叠统须家河组沉积相进行了分析。研究区沉积相可划分为河流相、风暴沉积相、三角洲相、海湾相、湖泊相和冲积扇相、扇三角洲相等类型，其中三角洲、扇三角洲是研究区的主要骨架砂体。论文首次发现并分析了川西须家河组风暴岩形成的地质背景和沉积序列，研究了风暴岩的沉积学和岩石学特点，并建立了其沉积模式。 根据对12口井的钻井岩心观察、薄片、物性、扫描电镜、X射线衍射、阴极发光等分析，同时，收集了川中地区部分井的相关研究资料等，对研究区储集岩成岩作用、储集特征等进行了研究。 论文对川西前陆盆地可容空间转换系统进行了分析。对野外露头资料、取心井的岩心进行细致的观察描述、分析，结合粒度、古生物以及薄片等微观鉴定分析，进行单井可容空间转换系统分析，然后进行剖面对比可容空间转换系统分析，从而建立了全区可容空间转换系统分析模式。川西前陆盆地须家河组须二段可容空间转换系统平面上可以划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅶ等7个带，它们分别是主可容空间转换带(Ⅰ)、主可容空间增加带(Ⅱ)、主可容空间转换带(Ⅲ)、主可容空间减小带(Ⅳ)、次可容空间转换带(Ⅴ)、次可容空间增加带(Ⅵ)、次可容空间减小带(Ⅶ)。 须家河组天然气成藏受层序地层格架的控制。论文提出了三种油气成藏模式，认为不仅川西地区须家河组沉积环境向西存在着相变，而且因该区存在印支及燕山期古构造，也就存在油气规模聚集成藏的条件。本文同时指出须家河组油气成藏属于构造裂缝和岩性复合圈闭成藏类型。研究认为，层序界面、体系域界面、准层序组界面复合控制本区油气藏的形成；层序Ⅱ低水位体系域准层序组Ⅴ是油气藏发育的重要层段。在平面上可容空间转换带和次级可容空间转换带最有利于油气成藏。更多还原

【Abstract】 Based on terrestrial sequence stratigraphy, sedimentology and data of log, seism, rock and mineral experiment and geochemistry, this paper has delta with the sequence stratigraphical framework, sedimentary systems, accommodation transformational system and reservoir models of the exploration of subtle traps in the western Sichuan basin.Xujiahe Formation consists of 4 sequences . The paper emphasizes more sequence I and sequence II. Based on microfacies of cores and sand body types as well as facies analysis, the main types of sedimentary facies in the Upper Triassic sequence of western Sichuan Basin have been identified. The delta and fan delta facies dominate reservoirs. With correlation of sedimentary provenance, sand body geometry and environmental parameter, the depositional systems and sedimentary facies sequence are described in detail.During the evolution of a basin, the changes of accommodation in different areas are not always consistent. There is a deposition梕rosion neutral spot in a basin. On one side of the spot the accommodation increases and on the other side it decreases. Based on this phenomenon, the concept and research methods of accommodation transformational system are put forward.The accommodation transformational system is composed of accommodation transformational system and accommodation transformational Body, which includes Increasing Body, and Decreasing Body. Accommodation transformational system can be used to resolve the disunities during the developing of a basin. The accommodation transformational systems in the foreland basin can be divided into 7 orders. On the plane, the accommodation transformational system can be divided into 2 parts, i.e., increasing belt and decreasing belt. The accommodation transformational systems in Longmenshan foreland basin have been studied in terms of spot, line surface and body. Accommodation transformational system of the Xujiahe Formation is analyzed more carefully and it consists of a unified increasing body and a disunited body. On the plane, there are some relativities between accommodation transformational system and tectonics, sediments, sedimentary facies, paleo梬ater depth, and the types and distribution of sandbodies.The transformational belts in a accommodation transformational system has a close relation to the oil and gas occurrence in Longmenshan foreland basin. The formation of the gas pools in Xujiahe Formation was controlled by sequence stratigraphic framework. Through the analysis of sedimentary facies , the distribution of sandstone and the tectonic evolution in the Xujiahe Formation, the author point out that tectonic fracture and lithology complex trap types control the reservoir formation.更多还原