川东北地区长兴—飞仙关组沉积相研究

发布时间：2018-04-12 21:15

本文选题：川东北 + 长兴组　；参考：《西南石油大学》2017年硕士论文

【摘要】：本论文从地质学研究的角度展开,根据野外露头、岩芯和薄片的观察,钻录井资料的分析,结合已有的测井、地震及前人研究成果,对川东北地区上二叠统长兴组和下三叠统飞仙关组的沉积相进行了较为系统的研究,核心即沉积环境(相)对礁滩发育的控制。确定研究区沉积相的特征、分布规律和礁滩体的有利分布区,为储层分布预测及后期勘探开发提供地质依据。川东北地区上古生界地层中二叠系保留完整,主要缺失了泥盆系和石炭系,中生界三叠、侏罗系保存完整。研究区长兴组与其上覆飞仙关组和下伏吴家坪组(龙潭组)为整合接触,飞仙关组也与上覆嘉陵江组呈连续沉积。两套地层从古生物组合和岩性、电性特征上都存在明显的差别,整合接触且界线清楚,易识别。研究区发育大量的挤压构造,区内北侧的米苍山呈东西向展布,东侧的川东高陡褶皱带呈北西向的弧状展布。区内飞仙关组和长兴组各经历了2次沉积旋回。晚二叠世期,川东北地区主体为一由西向东水体逐渐变深的碳酸盐岩台地环境,在台地的北部被广元—旺苍陆棚(海槽),东北部被城口—鄂西陆棚(海槽)以及南秦岭洋所围绕。长兴期边缘发育透镜和串珠状生物礁,分布在毛坝、普光、七里北等地。从台地边缘向台地内部,沉积环境逐渐转变为开阔台地环境。早三叠世期,川东北地区基本继承了早期的沉积格局,仍然为陆棚(海槽)—碳酸盐台地环境。由台缘向台地内部,主要分布的是台地内蒸发泻湖沉积,有一定数量透镜状分布的点滩。从台地边缘向深水区,快速演变为开江—梁平和鄂西—城口陆棚(海槽),这两个陆棚(海槽)在罗家寨以南地区具有连通的趋势;陆棚(海槽)与台地边缘之间的斜坡地带狭窄,并围绕台地边缘分布。从整个川东北的沉积背景看,长兴和飞仙关组环陆棚边缘的台缘礁、滩相带,特别是发育厚的地区应是勘探的最有利区。本区储层的分布、发育在很大程度上受控于沉积相的展布,储层主要是颗粒滩及生物礁,这些储集有利区带主要发育于台地边缘相,次要发育于开阔台地、局限台地相中的台内滩(礁)、台内点滩(礁)亚相。值得注意的是,斜坡相带中重力流沉积,其砾石成分为洖粒云岩的,也可作为储集体加以研究。
[Abstract]:This paper from the perspective of geology research, according to the outcrop observation, core and thin section analysis, drilling and logging data, combined with the existing research results of seismic and logging, the previous deposition on the Northeast Sichuan two Permian Changxin formation and lower Triassic Feixianguan Formation in the three phase were studied by the core of the sedimentary environment (facies) of reef development. To determine the characteristics of sedimentary facies in the study area, favorable area distribution and reef, for reservoir prediction and late exploration and development provides the geological basis. Ancient Paleozoic strata in Northeast Sichuan Permian intact, mainly lack of mud. The Devonian and Carboniferous, Mesozoic Triassic Jurassic. Three, to preserve the integrity of Changxin formation in the study area and its overlying Feixianguan Formation and underlying Wujiaping formation (Longtan group) for the integration of contact, Feixianguan and Jialingjiang formation overlying a continuous deposition. Two sets of strata From the biological composition and lithology, there are obvious differences on the electrical characteristics of contact and integration, clear boundaries, easy to identify. A large number of compressional structures developed in the study area, in the area north of the Cangshan meters in an east-west direction, East Sichuan fold belt on the eastern side of the arc in the North West of Feixianguan area distribution. Close the group and Changxin group experienced 2 sedimentary cycles. Late Permian period, the main Northeast Sichuan carbonate platform environment from the west to the East water becomes deep gradually, by Guangyuan Wangcang in the northern continental shelf platform (trough), the northeast by Chengkou exi (trough) on the shelf the South Qinling Mountains ocean and Changxin. During the development of lens and beaded edge reef, located in Puguang, seven miles north of Maoba, etc. from the platform edge to the platform, the sedimentary environment gradually transformed into open platform environment. Three early Triassic period, Northeast Sichuan inherited the early settlement Product pattern, still shelf (trough) - carbonate platform environment. The platform edge to the platform, the main distribution is the evaporation lagoon in the platform, there are a certain number of lenticular distribution point beach. From the mesa edge to the deep water area, the rapid evolution of Kaijiang Liang Ping and West Hubei shelf sea (port city the two shelf trough), (trough) in Luojiazhai area to the South with connected trend; shelf (trough) and platform margin slope zone is narrow, and around the edge of platform distribution. From the background of the deposition in the northeastern Sichuan Basin, platform edge reef Changxin and Feixianguan shelf edge ring, beach facies belt, especially the development of thick regions should be the most favorable exploration area. The distribution of this reservoir, development is largely controlled by sedimentary facies, the reservoir is mainly grain beach and reef, the reservoir favorable zone mainly developed in the platform margin, secondary development in the open Broad platform, restricted platform phase intraplatform (reef), Taiwan Point Beach (reef subfacies). It is worth noting that in the slope facies sedimentary gravity flows, the gravel is Wu grain dolomite, can also be used as a reservoir to study.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;P512.2

【相似文献】