川中-川东北地区上震旦统灯影组大型早期台缘带的发现及其油气勘探意义  

Discovery of the Large Early Platform Margin of Upper Sinian Dengying Formation in Central and Northeast Sichuan Basin and Its Implications for Hydrocarbon Exploration

作　　者：吴仕虎 陈康 李小刚[2] 陈刚 张晨 龙隆[1] 徐少华 Wu Shihu;Chen Kang;Li Xiaogang;Chen Gang;Zhang Chen;Long Long;Xu Shaohua(Exploration and Development Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610041,China;Chongqing Key Laboratory of Complex Oil&Gas Exploration and Development,Chongqing University of Science&Technology,Chongqing 401331,China;College of Resources and Environmental Engineering,Yibin University,Yibin 644000,China)

机构地区：[1]中国石油西南油气田分公司勘探开发研究院,四川成都610041 [2]重庆科技学院复杂油气田勘探开发重庆市重点实验室,重庆401331 [3]宜宾学院资源与环境工程学院,四川宜宾644000

出　　处：《地球科学》2020年第3期998-1012,共15页Earth Science

基　　金：中国石油天然气集团有限公司重大专项(No.2016E-0604);中国石油科技创新基金研究项目(No.2016D-5007-0107);四川省科技计划项目(No.2017JY0315);重庆市自然科学基金面上项目(No.cstc2019jcyj-msxmX0719).

摘　　要：为进一步查明绵阳-长宁拉张槽东侧震旦系灯影组优质碳酸盐岩储层分布、探索新的勘探领域,利用髙石梯-磨溪灯影组的钻井、测井和高精度三维地震资料,采用海侵-海退旋回、层拉平、地震线描及印模法等,识别出灯影组大型早期台缘带及其内部构型.在拉张槽东部的南东-北西向地震剖面上,首次发现灯影组三段对应的三级层序(SQ3)内部普遍发育数个自南东向北西进积的前积体,前积体呈S型、丘型或短轴状,前积体顶部可见SQ4海侵体系域的系列上超点和一个明显的坡折点,越过坡折点向北西SQ3厚度急剧减薄.表明在绵阳-长宁拉张槽东部的碳酸盐岩台地内,存在一个自高石梯开始,经由磨溪、龙女寺、南充、蓬安,向北东一直延伸至龙岗地区中部,长约270 km的大型早期台缘带.这一大型台缘带的发现将为研究区灯影组油气勘探提供一个新的领域,而不再局限于绵阳-长宁拉张槽附近.This study focuses on the distribution of high-quality carbonate reservoirs and new exploration areas in the Dengying Formation(Sinian)on the eastern side of Mianyang-Changning intracratonic sag.Using drilling,logging and seismic data in the Gaoshiti-Moxi,we identify the large early platform margin of Dengying Formation and characterize its internal configuration,based on the theories including the transgression-regression cycle analysis,the layer flattening,the seismic line drawing,the impression method paleogeomorphology,and quality reservoir prediction.It is found that,on the SE-NW seismic profile in the east of Mianyang-Changning intracratonic sag,there are several progradation reflections identified for the first time within the third sequence(SQ3)of Dengying Formation,which prograded from southeast to northwest with a S-shaped,mound or short axis in cross section.At the top of these progradation reflections,there are an obvious slope break point and a series of onlap points of SQ4 transgressive system tract.The thickness of SQ3 from the slope break point to the northwest is sharply thinned and wedge-shaped.The results show that there is a large early platform margin belt about 270 km long in the carbonate platform in the east of Mianyang-Changning extensional trough,which starts from the Gaoshiti,extends northeastward to the middle of Longgang area through Moxi,Longnvsi,Nanchong and Peng'an areas.The discovery of this large platform marginal zone will provide a new area for the oil and gas exploration of the Dengying Formation in the study area,and it will no longer be limited to the vicinity of Mianyang-Changning intracratonic sag.

关 键 词：高石梯-磨溪 灯影组 早期台缘带 层序地层 前积体 石油地质 

分 类 号：P618.13[天文地球—矿床学]