渝东南地区构造特征及其对页岩气富集的影响

发布时间：2018-03-22 19:39

本文选题：渝东南地区　切入点：构造特征　出处：《中国矿业大学》2017年硕士论文　论文类型：学位论文

【摘要】：渝东南地区作为重要的页岩气勘探开发地,奥陶系五峰组与志留系龙马溪组地层中富有机质泥页岩非常发育,为页岩气成藏提供了物质基础。研究渝东南地区构造发育特征、演化规律、页岩气地质特征及构造特征对页岩气富集的控制,对进一步开展页岩气勘探开发工作具有重要意义。本论文主要以板块构造理论为指导,在充分研究区域地质构造背景基础上,运用传统地质调查方法,配合构造分析、软件模拟等实验技术,对渝东南地区主要地质构造几何学特征、运动学特征及其形成机制展开了全面研究,并探讨了地质构造特征对页岩气富集的影响,主要获得了如下几点认识:(1)渝东南地区主要指齐岳山断裂以东所在的湘鄂西断褶带中南段。区域目的层主要经历了加里东期、海西期、印支期、燕山期、喜马拉雅期等多期构造旋回影响。(2)渝东南地区发育有齐岳山背斜等近23条大型褶曲构造,多数呈NE-NNE向线性展布;发育有齐岳山断裂等17条大型断裂,各断裂系统内小断裂展布规律不一;地表节理走向主要以NE向、NEE向、NW向和近NS向为优选方位。(3)渝东南地区构造在空间展布上存在较大的差异。自中生代以来构造演化史可分为四个阶段:印支早期隆升、印支晚期-燕山早期NW-SE向挤压、燕山晚期-喜马拉雅早期近NNW-SSE向挤压和喜马拉雅晚期NE-SW向挤压。青藏高原运动及雪峰山隆升均对渝东南地区主体构造的形成起着决定性控制作用。(4)渝东南地区五峰组-龙马溪组地层底界埋深分布在0~4500m,五峰组-龙马溪组第一亚段厚度介于0~40m,全区有机质含量介于0.200%~6.703%,平均2.850%,Ro为2.21%~3.30%。目的层自沉积以来主要经历了五个期次的沉积埋藏阶段,有机质热演化主要经历了四个阶段。(5)相较于焦石坝地区而言,渝东南绝大多数地区构造运动强烈,断裂构造极为发育且存在反转期,地层抬升剧烈,目的层系埋藏较浅甚至出露地表,整体保存条件较差,仅在变形程度低,断裂发育较少的地区有可能形成气藏。本文共圈定出9个页岩气富集区,其中一级富集区6个,面积共2358.08km2,次级富集区3个,面积共168.12 km2。
[Abstract]:As an important exploration and development area of shale gas, the organic shale in Ordovician Wufeng formation and Silurian Longmaxi formation is well developed, which provides a material basis for shale gas accumulation. The evolution law, the control of shale gas geological characteristics and structural characteristics on shale gas enrichment is of great significance for further development of shale gas exploration and development. This paper is mainly guided by plate tectonic theory. On the basis of fully studying the background of regional geological structure, using the traditional geological survey method, combined with the experimental techniques of structural analysis and software simulation, the geometric characteristics of the main geological structures in southeastern Chongqing are analyzed. The kinematic characteristics and their formation mechanism are comprehensively studied, and the influence of geological structural characteristics on shale gas enrichment is also discussed. The main results are as follows: (1) the southeast of Chongqing mainly refers to the middle and south section of the fault fold belt in the west of Hunan and Hubei to the east of Qiyueshan fault. The regional target layer has mainly experienced Caledonian, Hercynian, Indosinian, Yanshanian, etc. Near 23 large fold structures such as Qiyueshan anticline, most of which are distributed linearly in NE-NNE direction, and 17 large faults, such as Qiyueshan fault, are developed in the southeast of Chongqing. The distribution of small faults in each fault system is different. There are great differences in the spatial distribution of the structures in the southeast of Chongqing. The tectonic evolution history since the Mesozoic can be divided into four stages: the early uplift of the Indosinian, and the early uplift of the Indosinian. Late Indosinian to early Yanshanian NW-SE compression, The late Yanshanian to early Himalayan NNW-SSE compression and the late Himalayan NE-SW compression. Qinghai-Tibet Plateau movement and Xuefengshan uplift play a decisive role in the formation of the main structure in southeastern Chongqing. The buried depth of the bottom boundary of the Fengzhou-Longmaxi formation is distributed in 0 ~ 4500m, the thickness of the first submember of the Wufeng-Longmaxi formation is between 0 ~ 40m, and the content of organic matter in the whole area is between 0.200 and 6.703, with an average of 2.850g Ro of 2.21 ~ 3.300.The target layer has mainly undergone five sedimentary burial stages since the deposition. Compared with Jiaoshiba area, the thermal evolution of organic matter has experienced four stages. Compared with Jiaoshiba area, the tectonic movement in most areas of southeast Chongqing is strong, the fault structure is extremely developed and there is a reversal period, and the strata are uplifted violently. The reservoir may be formed only in areas with low deformation degree and less fault development. In this paper, 9 shale gas accumulation areas have been delineated, of which 6 are first-grade rich areas. The area is 2358.08km2, the secondary rich area is 3, the area is 168.12 km2.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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