塔里木北部早寒武世同沉积构造——兼论寒武系盐下和深层勘探  

Early Cambrian syndepositional structure of the northern Tarim Basin and a discussion of Cambrian subsalt and deep exploration

作　　者：管树巍[1] 张春宇[1] 任荣[1] 张水昌[1] 吴林[1] 王雷 马培领 韩长伟 GUAN Shuwei;ZHANG Chunyu;REN Rong;ZHANG Shuichang;WU Lin;WANG Lei;MA Peiling;HAN Changwei(Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Korla Branch of Geophysical Research Institute,BGP Inc.,Korla 841000,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油东方地球物理公司研究院库尔勒分院,新疆库尔勒841000

出　　处：《石油勘探与开发》2019年第6期1075-1086,共12页Petroleum Exploration and Development

基　　金：国家重点研发计划项目(2017YFC0603101);中国科学院战略性先导科技专项(A类)(XDA14010101);中国石油天然气集团有限公司项目(2018A-0101)

摘　　要：利用野外地质、钻井和地震资料,结合构造和沉积作用分析,恢复塔里木北部早寒武世原型盆地的结构与古地理,探讨寒武系盐下源-储分布、空间配置的控制因素及有利勘探方向。塔里木北部震旦纪末期的构造变动在不同地区表现为不同的方式,并控制了早寒武世盆地的沉积格局。位于塔北隆起南斜坡和塔中隆起北斜坡的南华纪裂陷在早寒武世发生同沉积断裂活动,形成两个北东东—东西向延伸的沉降和沉积中心,玉尔吐斯组最大预测厚度可达250 m;至肖尔布拉克组沉积期,同沉积断裂上升盘形成镶边型台地。而塔东和满西地区的南华纪裂陷在震旦纪末期遭受抬升和破坏,在早寒武世主要以斜坡形式向沉降中心过渡,前者具有混积型台地的沉积特征,后者具有缓坡型台地的沉积特征。早寒武世同沉积断裂下降盘的玉尔吐斯组黑色页岩与上升盘的肖尔布拉克组台缘礁滩体构成可预测的源-储配置模式,断裂活动强度控制了黑色页岩的厚度和台缘礁滩体的规模。下一步勘探应部署高精度地震,以精确落实同沉积断裂位置,并沿着断裂向西搜索礁滩体,在埋藏较浅的圈闭位置实施风险钻探。Using field geological survey,drilling and seismic data,combined with the study of regional tectonic evolution and structural deformation,as well as lithological and sedimentary analysis,we reconstructed the basin filling process and paleo-geography of north Tarim Basin in Early Cambrian,aiming to analyze the factors controlling the distribution and spatial architecture of the subsalt reservoir and source units and to define the favorable exploration direction.The Late Sinian tectonic activities in the northern Tarim Basin were characterized by different patterns in different areas,which controlled the sedimentary pattern in the Early Cambrian.The boundary faults of Nanhuaian rift basin in the south slope of Tabei uplift and the north slope of Tazhong uplift became reactivated in the Early Cambrian,forming two NEE and EW striking subsidence centers and depocenters,where the predicted thickness of the Yurtusi Formation could reach 250 meters.In the Xiaoerbulake period,the weak rimmed platform was developed in the hanging wall of syndepositional fault.Whereas the Nanhuaian rift system in the Tadong and Manxi areas were uplifted and destroyed in the Late Sinian,and appeared as gently slope transiting toward the subsidence center in the Early Cambrian.The former had the sedimentary features of hybrid facies platform and the latter had the sedimentary features of ramp platform.The black shale of the Yurtus Formation in the footwall of syndepositional fault and the reef bank of Xiaoerbulake Formation platform margin in the hanging wall in Early Cambrian constitute a predicable source-reservoir combination.The activity intensity of syndepositional fault controlled the thickness of black shale and the scale of the reef bank.It is suggested carrying out high accuracy seismic exploration to determine the location of Early Cambrian syndepositional faults,on this basis,to search the reef bank of Xiaoerbulake Formation along the faults westward,and then drill risk exploration wells at sites where traps are shallow in buried d

关 键 词：早寒武世 同沉积构造 层状硅质岩 古地理 盐下勘探 下寒武统玉尔吐斯组 塔里木盆地 原型盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]