川东南武隆地区五峰—龙马溪组富有机质页岩特征

发布时间：2018-03-20 03:05

本文选题：武隆地区　切入点：五峰-龙马溪组　出处：《成都理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以川东南武隆地区上奥陶统五峰组-下志留统龙马溪组页岩为研究对象,选取武隆及邻区典型露头剖面进行测量、描述、取样,并通过岩矿薄片、X-射线衍射全岩分析,以及有机碳、热解、氯仿沥青、干酪根碳同位素、沥青反射率等地球化学分析,结合对前人相关地质资料的收集分析,系统研究了五峰-龙马溪组页岩的岩石类型、展布发育特征、沉积相、烃源岩特征等页岩气资源条件,取得以下成果和认识:1.通过野外观察、薄片鉴定和X-射线衍射全岩分析,研究区五峰-龙马溪组黑色页岩可划分为四种类型:(1)黑色炭质页岩,污手,主要分布于五峰组底部;(2)黑色、灰黑色硅质页岩,含笔石化石,厚度大,硬度高,主要发育于五峰组上部;(3)黑色页岩,主要分布于龙马溪组下部,含笔石化石;(4)粉砂质页岩,主要发育于龙马溪组上部。页岩矿物组分以石英和粘土矿物为主,其次为钠长石和微斜长石,个别样品见白云石、方解石、黄铁矿,粘土矿物以云母为主,其次为伊利石和石膏。2.根据岩石类型、沉积构造、沉积岩石组合等相标志分析,区内五峰-龙马溪组可划分出浅水陆棚和深水陆棚两类沉积相,沉积相控制着页岩类型及其分布。该区五峰组主要为一套混积深水陆棚相沉积,岩性主要为硅质岩、炭质页岩,局部为硅质页岩与砂质页岩互层状沉积;龙马溪组下部为一套泥质深水陆棚相沉积,岩性主要为黑色页岩,局部含砂质,向上部则过渡为砂泥质浅水陆棚相沉积,岩性以粉砂质页岩为主。3.通过露头剖面、钻井资料及沉积相研究认为,该区五峰-龙马溪组页岩分布具有以下规律:(1)黑色页岩主要发育于呈南西-北东向展布的观音桥-武隆-焦石坝-漆辽菱形区域;(2)两个黑色页岩厚度较大的区域分别为焦石坝-黄莺-巴鱼-观音桥(A带)、漆辽-彭水-秀山(B带);(3)漆辽-武隆黄莺-焦石坝-道真巴鱼-綦江观音桥一带可能为该区五峰-龙马溪期的沉降中心,水体相对较深,有利于有机质富集保存。4.通过有机地球化学测试分析表明,区内五峰-龙马溪组页岩有机质含量总体较高,TOC含量为0.55~10.38%,焦石坝-黄莺-巴鱼-观音桥一带页岩有机质含量最高,整体呈现自西向东有机质含量减少的趋势。有机显微组分、族组成及干酪根δ13Corg分析表明,五峰-龙马溪组黑色岩系沉积有机质母质为以菌藻类等低等浮游生物为主的腐泥型烃源岩,龙马溪组出现少量植物混入;五峰组页岩主要富含Ⅰ型有机质,龙马溪组以Ⅰ型有机质为主,含有Ⅱ1型有机质。页岩甾萜烷、芳烃标志物及Pr/Ph分析结果表明,五峰-龙马溪组页岩有机质母质形成于具有一定盐度的海水中,总体为较强的还原环境,且不同时期不同地区水体深度有所差异。有机质成熟度测试分析表明,五峰-龙马溪组页岩等效镜质体反射率为1.15%~3.06%,平均2.01%,H/C为0.52~0.65,大部分样品达到高成熟阶段,部分为过成熟阶段。5.综合岩石学特征、沉积相、有机地球化学特征等分析认为,川东南武隆地区五峰-龙马溪组黑色页岩有利发育层段为五峰组及龙马溪组下部,有利发育区带为焦石坝、武隆一带,有机质含量普遍大于2%,有机质类型好、热演化程度高并具有高脆性特征,页岩气资源前景良好。
[Abstract]:Ordovician group based on the five peak in Southeast Sichuan Wulong area on the Lower Silurian Longmaxi shale as the research object, selects typical outcrop section of Wulong and adjacent areas were measured, description, sampling, and through the rock wafer, X- ray diffraction analysis of whole rock, and organic carbon, pyrolysis, chlorine asphaltlike. The kerogen carbon isotope geochemical analysis, bitumen reflectance, combined with analysis of previous geological data collection system of the five peak - Longmaxi shale rock types, distribution characteristics, sedimentary facies, source rocks such as shale gas resources conditions, conclusions are as follows: 1. by field observation X-, thin section identification and X-ray diffraction analysis of whole rock, five peak of longmaxiformation shale can be divided into four types: (1) black carbonaceous shale, dirty hands, mainly distributed in the bottom of town group; (2) black, gray and black siliceous shale, containing graptolite fossils, thick Large, high hardness, mainly developed in the upper part of town group; (3) black shale, mainly distributed in the lower part of Longmaxi, containing graptolite fossils; (4) silty shale, mainly developed in the upper part of Longmaxi shale. Mineral components in quartz and clay minerals, followed by albite and micro individual samples of plagioclase, calcite, pyrite, see dolomite, clay mineral mica, illite and gypsum followed by.2. according to the rock type, sedimentary structure, sedimentary rock facies signs analysis, region five peak - Longmaxi formation can be divided into shallow water and deep water shelf shed two types of sedimentary facies, sedimentary facies control a shale type and its distribution. The five peak group in this area is mainly a set of hunji deep shelf facies, lithology is mainly siliceous rocks, carbonaceous shale, siliceous shale and local sandy shale interbedded deposition; the lower part is a set of longmaxiformation shale deep shelf facies, The lithology is mainly composed of black shale, containing local to the upper transition to sandy, muddy and sandy shallow shelf facies, lithology in silty shale mainly through.3. outcrops, drilling data and sedimentary facies study, five peaks - the Longmaxi shale distribution has the following rules: (1) black shale mainly developed in the a SW-NE trending Guanyin Bridge - Wulong - coke dam - paint Liaoning diamond region; (2) two black shale thickness region were larger coke dam - Pakistan fish Oriole (A band) - Guanyin Bridge - Pengshui - Liaoning, Xiushan paint (B); (3) paint Liaoning Wulong Orioles - coke dam - Daozhenba fish - Qijiang Guanyin Bridge area may be five peak in the area of subsidence center Longmaxi period, relatively deep water, is conducive to the preservation of organic matter enrichment test by.4. organic geochemical analysis indicates that the region five peak - Longmaxi shale organic matter content is high the content of TOC is 0.5. 5~10.38%, along the shale content of organic matter in coke dam - Pakistan fish - Oriole Guanyin Bridge is the highest, from west to east to reduce the overall presentation of the content of organic matter. The trend of organic maceral group composition of kerogen, and delta 13Corg analysis showed that the five peak - Longmaxi black rock series of sedimentary organic matter in algae and bacteria etc. low plankton dominated sapropelic source rocks, Longmaxi small plant mixed with five peaks; shale mainly rich in type I organic matter, Longmaxi organic matter is mainly type I, II type 1 containing organic matter. The shale of sterane and terpane, aromatic markers and Pr/Ph analysis results show that the peak of five - Longmaxi shale rocks formed in the salinity of seawater, generally strong reducing environment, and the depth of water in different regions and different periods vary. Organic matter maturity test analysis showed that the five peak - Longmaxi shale equivalent vitrinite counter The emission rate is 1.15%~3.06%, an average of 2.01%, H/C 0.52~0.65, most of the samples reached the high mature stage, as part of.5. comprehensive petrology, sedimentary facies analysis of the mature stage, the organic geochemical characteristics that Southeast Sichuan Wulong area five peak - Longmaxi formation and black shale has five peaks and Longmaxi group the lower, favorable zone for coke dam, Wulong area, the content of organic matter is generally greater than 2%, the type of organic matter, high degree of thermal evolution and has high brittleness, good prospects of shale gas resources.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

【参考文献】