武乡地区构造裂隙发育规律及对页岩气赋存的影响

发布时间：2018-04-20 09:27

  本文选题：武乡地区 + 裂隙特征　； 参考：《中国矿业大学》2017年硕士论文

【摘要】：本文以武乡地区岩层裂隙为研究对象,深入分析了该地区的构造特征并恢复了构造应力场,研究了该地区的构造演化史。主要经历了三期的构造运动,其中燕山期的构造运动对本区奠定了主要的格架。由于受构造作用的控制,使该区的构造裂隙比较发育,并呈现出了一定的规律性。在构造作用下形成的裂隙对页岩气的赋存有着重要的影响。通过对研究区资料收集,对野外节理数据统计,室内薄片鉴定与显微镜下观察等实验对武乡地区裂缝发育特征及对页岩气赋存做了深入的研究,总结了武乡地区构造裂隙的发育规律,并结合该地区页岩气赋存的地质条件,探讨了武乡地区的裂隙发育对页岩气赋存的影响。得出了如下认识:(1)武乡地区的构造演化主要可以划分为Ⅰ(印支期)、Ⅱ(燕山期)、Ⅲ(喜马拉雅期)3个构造层;主要构造行迹为近NS、NE、NW向;武乡地区主要经历印支期、燕山期及喜马拉雅期3期构造运动,印支期主要以近SN向挤压应力为主,燕山期以NW-SE向挤压应力为主,喜马拉雅早期以NW-SE向拉张应力为主,喜马拉雅晚期-现今应力方向转变为NEE-SWW向挤压应力。(2)研究区内主要出露刘家沟组(T1l)、和尚沟组(T1h)、新近系和第四系地层。研究区内构造发育较简单,属于单斜构造,地层倾角较小,主要分布在5~35°,平均为13°。区内节理多属于高角度节理,倾角主要分布在50°~90°之间;并绘制了走向玫瑰花图及等密度图,反映出调查区内主要发育两组节理,走向分别是61°和320°,其中61°属于主要节理方向;通过绘制节理密度等值线,反映研究区内由南向北,节理密度为先减小再增大的趋势。(3)结合以上研究成果和对研究区页岩气赋存的地质条件的研究,主要从泥页岩储层渗透性和含气性两个方面分析了构造裂隙发育规律对页岩气赋存的影响,研究结果表明在现今构造应力场的作用下,61°优势裂隙的发育区、宏观、微观裂隙的较发育区更有利于页岩气的赋存。
[Abstract]:In this paper, the structural characteristics and tectonic stress field in Wuxiang area are deeply analyzed, and the history of tectonic evolution in this area is studied by taking the rock seam fissures in Wuxiang area as the research object. It mainly experienced three stages of tectonic movement, among which the Yanshanian tectonic movement laid the main framework for the area. The tectonic fractures in this area are relatively developed due to the control of tectonism and present certain regularity. Fractures formed under tectonic action have an important effect on the occurrence of shale gas. Based on the data collection of the study area, the statistics of field joint data, laboratory sheet identification and microscopic observation, the characteristics of fracture development and the occurrence of shale gas in Wuxiang area were studied. This paper summarizes the development law of structural fissures in Wuxiang area and discusses the influence of fracture development on the occurrence of shale gas in Wuxiang area according to the geological conditions of shale gas occurrence in this area. It is concluded that the tectonic evolution of Wuxiang area can be divided into three tectonic layers: I (Indosinian), 鈪，

本文编号：1777207