川东石炭系特殊地震反射成因及勘探前景  

Genesis and exploration prospect of Carboniferous special seismic reflection in eastern Sichuan,China

作　　者：鲁建隆 王长城[1] LU Jianlong;WANG Changcheng(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059

出　　处：《成都理工大学学报（自然科学版）》2021年第6期738-746,共9页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金委员会与中国石油化工股份有限公司联合基金项目(40739903);国家自然科学基金项目(42172175)。

摘　　要：研究川东石炭系特殊地震反射的地质模型、形成机制及勘探前景。在对石炭系构造、沉积背景认识的基础上,应用正演模拟、薄层厚度(Widess原理)分析等方法,建立了两类特殊反射的地质模型,根据古岩溶的发育模式和理论分析了其地质成因,并结合周边石炭系钻井资料,明确了其形成机制,探讨了勘探前景。研究表明,两类地震特殊反射均是岩溶作用形成的低速层所导致,该低速度层为发育在岩溶斜坡上的溶沟或溶洞,如未被充填则能够形成较好的储层。石炭系特殊地震反射反映了优质岩溶储层发育,当匹配有较好的盖层和遮挡条件时,可形成岩性圈闭或岩性-构造圈闭,具有较好的勘探前景。Based on the understanding of Carboniferous structure and sedimentary background,the geological model,formation mechanism and exploration prospect of Carboniferous special seismic reflection in eastern Sichuan are studied by using the methods of forward modeling and thin layer thickness(Widess principle)analysis.In this study,two types of special reflection geological models are established and the geological genesis of paleokarst is analyzed according to the development model and theory of paleokarst.The formation mechanism of paleokarst is defined and the exploration prospect is discussed by combining with the drilling data of surrounding Carboniferous system.It shows that the two kinds of special seismic reflections are caused by the low-velocity layer formed by karstification and the low-velocity layer is the solution trench or cave developed on the karst slope,which can form a better reservoir if it is not filled.The special seismic reflection of Carboniferous reflects the development of high quality karst reservoirs.Lithologic traps or lithologic-structural traps of good exploration prospects can be formed if there are better cover and shelter conditions.

关 键 词：石炭系 特殊地震反射 形成机制 勘探前景 

分 类 号：P631.4[天文地球—地质矿产勘探]