【作者】 施辉； 李慧； 刘震；

【Author】 SHI Hui;LI Hui;LIU Zhen;Key Laboratory of Petroleum Resources Research,Institute of Geology & Geophysics,Chinese Academy of Sciences;College of Geosciences,China University of Petroleum;Yangtze University College of Technology&Engineering;

【机构】 中国科学院地质与地球物理研究所油气资源研究重点实验室； 中国石油大学(北京)地球科学学院； 长江大学工程技术学院；

【摘要】 应用三维地震资料对柴达木盆地西南区古近系—新近系坡折带类型、分布和演化进行了系统研究,发现高原咸湖所特有的"短周期沉积坡折带"和断裂坡折带在研究区均有发育,前者大致呈SN分布,除上干柴沟组（N₁）不发育外,其他层段都有分布,控制了低位体系域的发育,是分流河道向水下分流河道或水下分流河道向滩坝或前缘滑塌浊积扇突变的分界线;昆北、阿拉尔、七个泉、红柳泉断层,以及SN向调节断裂阿拉尔东和Ⅷ号断层属持续发育型断裂坡折带,而Ⅺ号断层在上干柴沟组（N₁）沉积期相对不发育,属间断发育型断裂坡折带。向南倾为主的逆向型断裂坡折带以下可容空间增大,向北倾为主的顺向型断裂坡折带以上发育反向小断槽和突起小断隆,下方均是砂体堆积的有利场所,前者控制砂体沿断层走向展布,后者常发育悬浮和跳跃组分为主的滩坝砂体。研究区发现的7个主要岩性油藏都分布于坡折带以下,对油藏进行解剖后发现沉积坡折带和断裂坡折带不仅直接控制了有利砂体的分布,还控制了岩性圈闭和构造—岩性圈闭的发育,另外,两者结合可以组成断裂—砂体复合输导系统,主导了油气运移的路径,因此可以说坡折带具有"控砂"和"聚油"的双重作用,坡折带附近是岩性油藏富集区带,将成为下一步岩性油藏勘探的重点方向。更多还原

【Abstract】 Systerm researches about types,distribution and evolution of Paleogene-Neogene slope-break belts in Southwestern Qaidam Basin have been finished to find that the short cycle sedimentary slope-break belt,propering to plateau salty lake,and the fracture slope break belt are developed.The former exists in almost formations except N₁,and has a NS distribution.This kind of slope-break belts control the LST,and are the mutational boundaries of distributary channels（underwater distributary channels） between underwater distributary channels（beaches and bars or slump turbidite fans）.Kunbei,Alaer,Qigequan,Hongliuquan and Alaerdong,Ⅷ Faults,which are regulatory,have the characteristics of continuous developing.Ⅺfault belongs to the discontinuous belt because it is relatively inactive.Inverse fault slope-break belts,which are south-dipping have a more accommodation below the belts.Nevertheless,following fault slope-break belts,north-dipping,have two increscent accommodations.The first is the small reverse fault trough over belts and the second is below belts,which are the profitable zones for sandbodies.Seven lithologic reservoirs having already been found have been analysised to suggested that they are all below the slope-break belts,which have controled the developments of lithologic traps and structure-lithologic traps.On the other hand,those two kinds of belts can make up fracture-sandbody conducting system,which has dominated the hydrocarbon migration paths.So in a word,slope-break belts have the dual functions of controling sand and accumulating oil and gas.The next key drection of lithologic reservoirs is to explore the zones nearby the slope-break belts.更多还原