渝东北下古生界页岩气构造保存条件研究

发布时间：2018-05-27 17:02

本文选题：渝东北 + 保存条件　；参考：《西南石油大学》2015年硕士论文

【摘要】：该论文以渝东北下古生界下寒武统水井沱组和上奥陶统五峰组—下志留统龙马溪组页岩为对象分析页岩气构造保存条件,这对渝东北页岩气的勘探前景具有参考价值。通过文献调研认为重庆经历的构造沉积演化有扬子准地台褶皱基底生成阶段、槽台分野阶段和陆内改造阶段。渝东北地区的沉积岩,除泥盆系、石炭系和古、新近系缺失外,从新元古界明月组到第四系地层都有出露。以城口断裂作为界线将大巴山弧形构造带进行构造单元的划分：北大巴逆冲推覆构造带和南大巴复合前陆褶皱—冲断带。根据运动学特征及变形特征、断层和褶皱的组合类型及其发育程度,对其进行次级构造单元的划分。渝东北城口断裂以北区域的主要构造样式特征是褶皱和断层显著发育,形成半花状构造,发育一系列纵断裂,往北西向延伸并两端被城口断裂截切。以野外地表进行地质调查作为基础,运用Lowell和Harding构造样式分类方案,渝东北城口断裂以南区域中的主要构造样式是“盖层滑脱型”中的“逆冲褶皱组合”,其发育3类构造组合：逆冲断层系统、冲断褶皱系统和滑脱褶皱系统,从横向上看分别是以坪坝断裂、鸡鸣寺断裂为界线的叠瓦冲断带、冲断褶皱带、滑脱褶皱带构造单元的典型构造组合,从纵向上看也分别是以三叠系膏盐岩层、志留系泥岩为界线的下构造层、中构造层、上构造层的典型构造组合。叠瓦冲断带以断裂为主,褶皱少见,常见叠瓦状逆冲断层、反冲断层、冲起构造、构造三角带和双重构造等。冲断褶皱带断裂和褶皱发育程度大致对等,常见断层相关褶皱。滑脱褶皱带主要发育滑脱褶皱,见少量逆冲断层,该区一个最主要的特点就是见典型的穹隆构造。通过野外的勘察、对岩心和镜下薄片的观察,见裂缝较发育,裂缝对页岩气的保存有双重作用。通过野外地质调查和测量,水井沱组泥页岩厚度较大,普遍62m—253m；五峰组—龙马溪组泥页岩厚度较大,普遍25m—73m。根据对渝东北地区构造特征和下古生界页岩气盖层特征的分析,优选渝东北下古生界水井沱组、五峰组—龙马溪组页岩气构造保存有利区。优选4个水井沱组页岩气构造保存有利区,即庙堂乡一带、汾河一鸳鸯乡一带、蓼子乡一带、满月乡南侧一带；五峰组—龙马溪组页岩气构造保存有利区是巫溪咸水乡—龙台乡一带和奉节县界附近,可以作为将来勘探的优选区域。
[Abstract]:The paper takes the lower Cambrian Shui Jing Tuotuo formation and the five peak shales of the lower Ordovician to the Lower Silurian Long Ma Creek formation in the lower Paleozoic in Northeast Chongqing as an object to analyze the preservation conditions of the shale gas structure, which is of reference value for the exploration prospect of shale gas in Northeast Chongqing.
Through literature research, it is believed that the tectonic sedimentary evolution of Chongqing has the stage of the formation of the folds of the Yangzi quasi platform fold, the division stage of the trough platform and the stage of the intracontinental transformation. The sedimentary rocks in Northeast Chongqing, except the Devonian system, the Carboniferous and the ancient and the Neogene, have been exposed from the Ming moon formation in the Neoproterozoic to the Quaternary.
Taking the Chengkou fault as the boundary line, the dababan arc tectonic zone is divided into structural units: the dababa thrust nappe belt and the South Daba complex Foreland Fold and thrust belt. According to the characteristics of the kinematics and deformation, the types and development of the faults and folds, the subdivision of the secondary tectonic units is carried out.
The main structural styles in the north area of the Chengkou fault in Northeast Chongqing are characterized by folds and faults, forming a semi flower structure, developing a series of longitudinal faults, extending to the North West and cutting at the two ends of the city mouth fault. Based on the geological survey of the field surface, the Lowell and Harding structural styles are classified and the northern city of Chongqing is broken. The main structural style in the southern part of the split is the "thrust fold combination" in "cover slide type", which develops 3 types of structural combinations: thrust fault system, thrust fold system and slip fold system. From the lateral view, the thrust fold belt, thrust fold belt, and slip fold belt, respectively, are divided into Pingba fault and Jiming Temple fault line. The typical structural combinations of the unit are also in the longitudinal direction of the Triassic gypsum salt rock layer, the Silurian mudstone as the boundary of the lower tectonic layer, the middle tectonic layer and the upper tectonic layer. The thrust belt is characterized by faults, rare folds, common imbricate thrust faults, backflushing faults, thrust structures, tectonic triangle belts and double structures. The fault and fold development of the thrust fold belt are roughly equivalent, common fault related folds. The slip folds mainly develop slipping folds and a few thrust faults. One of the most important features of this area is the typical dome structure. Through field investigation, the fracture is more developed in the observation of the core and under the microscope sheet, and the fracture is to shale. The preservation of gas has a double effect.
Through field geological survey and measurement, the shale thickness of Shuijing formation is large, generally 62m - 253m; the thickness of shale in the five peak group - the long Ma Xi formation is large, and 25m - 73m. is generally.
According to the structural features of the Northeast Chongqing and the characteristics of the shale gas cover in the lower Paleozoic, the lower Paleozoic Shui Jing Tuo formation, the five peak group and the long Ma Creek formation shale gas structure in the northeast of Chongqing is preferred, and the favorable areas for the preservation of the 4 Shui Jing Tuo formation shale gas structures are preferred, namely, the Temple Township, the Fen River Yuanyang area, the Polygonum Village area, and the full moon township. In the south side, the favorable areas for the preservation of the shale gas structure of the five peak - Longma Creek formation are in the vicinity of the Wuxi salty water Township Longtai Township and Fengjie County, which can be used as the preferred area for future exploration.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

【参考文献】