中上扬子地区震旦纪灯影组沉积期碳酸盐岩台地古地理格局及有利储集相带分布规律  

Paleogeographic Pattern of the Carbonate Platform in the Middle-Upper Yangtze Area During the Deposition of the Ediacaran Dengying Formation and Distribution Pattern of the Reservoir Facies

作　　者：丁一[1,2] 刘树根 文龙[4] 文华国 陈代钊 宋金民[1] 王瀚[1,2] 王林康[2] 陈明思[2] 陈荣庆 李智武 DING Yi;LIU ShuGen;WEN Long;WEN HuaGuo;CHEN DaiZhao;SONG JinMin;WANG Han;WANG LinKang;CHEN MingSi;CHEN RongQing;LI ZhiWu(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;Xihua University,Chengdu 610039,China;Research Institute of Exploration and Development,PetroChina Southwest Oil&Gasfeld Company,Chengdu 610041,China;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,成都610059 [2]成都理工大学沉积地质研究院,成都610059 [3]西华大学,成都610039 [4]中国石油西南油气田公司勘探开发研究院,成都610041 [5]中国科学院地质与地球物理研究所新生代地质与环境重点实验室,北京100029

出　　处：《沉积学报》2024年第3期928-943,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42372140,U2344209)。

摘　　要：【目的】中上扬子地区灯影组沉积期碳酸盐岩台地古地理格局及有利储集相带发育分布规律尚存争议,阻碍了灯影组油气勘探领域由绵阳—长宁拉张槽两侧向其他广大地区拓展。【方法】通过中上扬子地区灯影组30余条剖面(钻井)开展岩石类型划分及沉积相分析,【结果】进一步明确丘滩相以块状砂屑/鲕粒白云岩及柱状、穹窿状叠层石白云岩为特征,呈环带状分布在中上扬子台地(或内缓坡)边缘,向外过渡为中—外缓坡风暴岩或斜坡—盆地相区的滑塌角砾白云岩、泥质白云岩、硅质岩等。由于丘滩的阻挡作用,其内侧以低能的潮坪及潟湖沉积环境为主:其中潮坪相主要发育微生物纹层白云岩、穹窿—缓波状叠层石白云岩、凝块石白云岩夹砂屑白云岩、泥晶白云岩,纵向上常常形成米级—厘米级旋回;潟湖相主要由泥晶白云岩、含球粒/砂屑泥晶白云岩组成。相带时空分布表明灯影组在中上扬子地区总体呈现出进积的沉积趋势,内部包含2.5个层序,即三次进积(变浅)和两次退积(变深)旋回。【结论】由于灯影组在台地边缘—斜坡区域普遍遭到剥蚀,以及灯影组沉积期上扬子台地范围远超目前的板块边界,灯影组上部灯四段很少发现高能丘滩相带。在此背景下,局部地区(如松林—岩孔地区、中扬子台地周缘)灯影组中下部灯一段—灯二段(或蛤蟆井段、石板滩段)发育的丘滩相,是重要的有利储集相带。此外,处于海退体系域的灯二段中下部和灯四段上部(或相当层位)在中上扬子台地(或内缓坡)内部广泛发育微生物白云岩,也为储层发育有利相带。在中上扬子台地微生物白云岩广泛分布的背景下,进一步分析优质储层发育机理与分布规律才是找到油气接替区的关键。[Objective]The dispute in the paleogeographic pattern of the carbonate platform and distribution of reservoir facies during the deposition of the Dengying Formation in the middle-upper area,hinders the expansion of the exploration domain from the Mianyang-Changning intracratonic sag to other areas.[Methods]Detailed lithofacies and facies analysis was conducted on more than 30 sections(wells),[Results]further confirming that the mound-shoal is marked by massive peloidal/ooidal dolograinstone and columnar,domal dolostromatolite,which were deposited around the platform(or inner ramp)margin of the Middle-Upper Yangtze Platform gradually shifting outward into tempestite of the middle-outer ramp or slump dolobreccia,argillaceous dolomite and chert of slope-basin facies.Owing to the mound-shoal barrier,its back was dominated by tidal flat and lagoon.Of these,the tidal flat facies were marked by microbial dololaminite,domal dolostromatolite,dolothrombolite with minor peloidal dolograinstone,and dolomudstone,which are commonly arranged into meter-centimeter scale cycles.The lagoon facies were composed mainly of dolomudstone and peloidal dolowackestone.In general,the mound-shoal facies is present in the lower Dengying Formation along the platform to slope transition(or inner ramp to middle ramp transition).In the Upper Yangtze Platform,it occurs in the Deng 1(e.g.,wells Pengtan 1,Ziyang 1,and sections Qingping,Beidoushan)or Deng 2 members at the Baijiaba,Yulin,and Meiziwan sections,or in both the Deng 1 and Deng 2 members at the Songlin-Yankong areas.On Middle Yangtze Platform,it occurs in the Hamajing(e.g.,sections Sancha,Bailuya,and Tianping)or Baimatuo members of the upper Dengying Formation at the Miaohe section.Specifically,the moundshoal facies shows repeated transgressions and regressions and occurs in different stratigraphic position of the Dengying Formation at many sections(Baiguoping,Xiaofenghe,Dengyingxia,Wushan,Xuejiadian,and Dengjiaya).In contrast,the tidal flat and lagoon facies are widely present on the who

关 键 词：中上扬子地区 灯影组 碳酸盐岩台地 古地理格局 储集相带 

分 类 号：P512.2[天文地球—地质学]