川东武陵山地区龙马溪组页岩气成藏地质条件研究

发布时间：2018-05-20 20:12

  本文选题：页岩气 + 武陵坳陷　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：页岩气是一种非常重要的非常规天然气资源,其勘探开发新理论、新技术和产量的突破将是本世纪各国竞相争夺的高地,对保障我国能源安全和经济高速发展具有非常重要的战略意义。本文主要针对川东武陵山地区龙马溪组,兼顾五峰组泥页岩进行研究,通过开展野外露头剖面实测、主微量元素测试分析、地震资料解释等工作,并以岩石矿物室内试验为手段,综合分析影响页岩气成藏的地质条件,寻找页岩气发育甜点区。研究区经受过多期次构造抬升和剥蚀作用,形成了独特的隔挡隔槽式的地形地貌,断裂和裂缝发育。为了给川东武陵山地区页岩气勘探开发提供科学依据,本文主要分析了泥页岩的沉积环境、泥页岩空间展布特征、烃源岩有机地化特征、储集空间类型、含气性以及页岩气的保存条件等。通过广泛的野外调查和地层对比分析,川东武陵山地区上奥陶统五峰组和下志留统龙马溪组黑色页岩地层普遍发育。利用稀土元素分配模式图和微量元素判别图解证明沉积物源来自上地壳,沉积构造背景以活动大陆边缘为主。沉积相标志和地球化学元素分析表明五峰-龙马溪组黑色泥页岩大多发育于缺氧环境,具有较高的古生产力和生烃潜力。上奥陶统五峰组以斜坡相沉积为主,下志留统龙马溪组以深水陆棚-浅水陆棚沉积为主,深水陆棚相为优势沉积环境。龙马溪组优质页岩主要分布在龙马溪组底部,泥页岩平面展布由北西向南东方向逐渐增厚,以习水-桐梓和秀山-酉阳一带为沉降中心,厚度60~120米。总体埋深1500~4500米,最佳埋深为2500~3500米,优势区域集中在贵北地区道真-正安一带。龙马溪组页岩有机质母岩来源于低等水生生物,有机质类型以Ⅰ和Ⅱ1型干酪根为主。有机质丰度含量变化较大,TOC范围在0.11%~5.04%之间,平均值为1.88%。热演化程度高,Ro在2%~4%之间,总体达到高-过成熟阶段,表现出了良好的页岩气成藏地球化学特征。孔隙度和渗透率都极低,属于低孔低渗气藏。泥页岩现场解析气小于1m3/t,等温吸附气含气量在1.53m3/t~4.76 m3/t之间,具有较好的吸附能力。采用多种地震属性识别五峰-龙马溪组页岩的裂缝发育区,确定向斜是页岩气藏发育的有利位置。通过绘制研究区泥页岩厚度、有机碳含量、成熟度、埋藏深度平面分布等值图,运用多因素叠加分析法优选出习水-桐梓-正安一带和秀山-酉阳-咸丰一带为资源潜力有利区。
[Abstract]:Shale gas is a very important unconventional natural gas resource. The breakthrough of new theory, new technology and production of shale gas will be the high ground competing for each other in this century. It is of great strategic significance to ensure the energy security and rapid economic development of our country. This paper mainly focuses on the Longmaxi formation in Wulingshan area of East Sichuan, and takes into account the mud shale of Wufeng formation. Through the field outcrop profile measurement, the analysis of main and trace elements, the interpretation of seismic data, and so on, Based on the laboratory test of rock and minerals, the geological conditions affecting the formation of shale gas reservoir are analyzed synthetically, and the desserts area of shale gas development is found. The study area has been subjected to multiple tectonic uplift and denudation, resulting in the formation of a unique barrier channel landform, fracture and fracture development. In order to provide scientific basis for shale gas exploration and development in Wulingshan area, East Sichuan, this paper mainly analyzes the sedimentary environment of shale, the spatial distribution characteristics of shale, the organic geochemical characteristics of hydrocarbon source rocks, and the types of reservoir space. Gas bearing and the preservation conditions of shale gas. Through extensive field investigation and stratigraphic correlation analysis, the black shale strata of Wufeng formation of Upper Ordovician and Longmaxi formation of Lower Silurian in Wulingshan area of East Sichuan are generally developed. The REE distribution pattern map and trace element discriminant diagram show that the sediment source comes from the upper crust and the sedimentary tectonic background is mainly active continental margin. The analysis of sedimentary facies and geochemical elements shows that the black shale of Wufeng-Longmaxi formation is mostly developed in anoxic environment with high paleoproductivity and hydrocarbon generation potential. The upper Ordovician Wufeng formation is dominated by slope facies, the lower Silurian Longmaxi formation is dominated by deep-water shelf and shallow water shelf, and the deep-water shelf facies is the dominant sedimentary environment. The high quality shale of Longmaxi formation is mainly distributed at the bottom of Longmaxi formation, and the distribution of shale is gradually thickening from north to west to south to east, with Xishui Tongzi and Xiushan-Youyang as the subsidence center, with a thickness of 60 ~ 120 meters. The total buried depth is 1500 ~ 4500 meters, and the optimum buried depth is 2500 ~ 3500 meters. The dominant area is concentrated in the area of Daozhen-Zhengan in the north of Guizhou. The source rocks of shale organic matter in Longmaxi formation are from low aquatic organisms, and the main types of organic matter are type 鈪，

本文编号：1916058