四川盆地灯影组岩溶古地貌恢复及意义

发布时间：2018-03-27 16:03

本文选题：古地貌恢复　切入点：印模法　出处：《西南石油大学》2015年硕士论文

【摘要】：震旦系灯影组碳酸盐岩是四川盆地重要的天然气产层,磨溪—高石梯气田的发现再次证明了四川盆地灯影组具有巨大的勘探潜力。受桐湾运动的影响,灯影组内部和顶部遭受过风化剥蚀和大气淡水淋滤作用,目前研究认为叠合风化壳岩溶改造的丘—滩相碳酸盐岩是区内灯影组优质储层形成的主要原因,而有利储层的发育部位受到古岩溶地貌的控制。因此开展碳酸盐岩风化壳岩溶古地貌的恢复及其岩溶储层特征的研究对于寻找碳酸盐岩油气藏具有重要的指导意义。应用川中高石梯地区新钻井资料,以及四川盆地及周缘150余条野外露头剖面资料和30余口钻井的地层划分及对比结果,结合区域地震资料,采用“印模法”恢复震旦系灯影组古岩溶地貌,并在此基础上研究其古地理格局及油气勘探意义。灯影末期—早寒武世四川盆地周缘为古陆/水下高地环抱,具体包括西部的康滇古陆、西北部的松潘古陆、北部的汉南古陆、东南和东北部的黔江—正安、镇巴及巫溪—建始水下高地。盆地向东南和东北分别接入江南盆地和秦岭洋。在盆地内部,受南北向梓潼—筠连裂陷槽以及北东向阆中—通江、重庆—开县坳陷分隔的影响,南北向存在“三隆”(镇巴、川中、黔江—正安)“两坳”(阆中—通江、重庆—开县),而东西向被分隔为相对独立的两个古隆起体系：南北向的绵阳—乐山—西昌古隆起、近北东向的川中古隆起。灯影组古岩溶地貌控制了区内的古岩溶地貌格局,形成了岩溶高地、台地、斜坡、洼地和盆地5个二级岩溶地貌单元,其中岩溶台地和斜坡为岩溶型储集层发育区,为大型气田的形成提供了有利条件。
[Abstract]:The carbonate rock of the Dengying formation of Sinian system is an important natural gas producing layer in Sichuan basin. The discovery of Moxi Gaoshiti gas field proves once again that the Dengying formation in Sichuan Basin has great exploration potential, which is influenced by the Tongwan movement. The Dengying formation was weathered and denudated inside and at the top of the formation and the atmospheric fresh water was leached. At present, it is considered that the main reason for the formation of the high quality reservoir of the Dengying formation is the hump-beach carbonate rock reformed by the superimposed weathering crust. The development of favorable reservoir is controlled by paleokarst geomorphology, so it is important to study the recovery of karst paleogeomorphology in carbonate weathering crust and the characteristics of karst reservoir for finding carbonate reservoir. Application of new drilling data in Gaoshi area, central Sichuan, In addition, more than 150 outcrop profiles of Sichuan Basin and its periphery, stratigraphic division and correlation of more than 30 drilling wells, combined with regional seismic data, are used to restore paleokarst geomorphology of Dengying formation of Sinian system by "impression method". On this basis, the paleogeographic pattern and the significance of oil and gas exploration are studied. The margin of Sichuan basin from late Dengying to early Cambrian is surrounded by ancient land / underwater highlands, including Kangdian ancient land in the west, Songpan ancient land in the northwest, and Hannan ancient land in the north. Southeast and northeast Qianjiang-Zhengan, Zhenba and Wuxi-Jianshi underwater highlands. The basin flows southeast and northeast into the Jiangnan basin and Qinling ocean respectively. In the interior of the basin, it is subjected to the south-north Zitong-Junlian rift trough and the north-east Langzhong-Tongjiang river. The influence of the separation in Chongqing-Kaixian depression, the "Sanlong" (Zhenba, Chuanzhong, Qianjiang-Zhengan) "two depressions" (Langzhong-Tongjiang) exists in the south-north direction. The east-west direction is separated into two relatively independent paleouplift systems: the south-north Mianyang Leshan Xichang uplift and the north-eastward central Sichuan uplift. The paleokarst geomorphology of the Dengying formation controls the paleokarst geomorphological pattern in the region. The karst plateau, platform, slope, depression and basin are five secondary karst geomorphologic units, among which karst platform and slope are karst reservoir development areas, which provide favorable conditions for the formation of large gas fields.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P531

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