裂陷盆地构造-沉积耦合关系及其控藏作用——以渤海湾盆地埕北凹陷古近系为例  

Coupling relationship between structure and sedimentation and the controlling effect on hydrocarbon accumulation in the rift basin: A case study of the Paleogene in the Chengbei sag, Bohai Bay basin

作　　者：张晓庆 宋明水[2] 侯中帅 郝冉冉 张强[1] 刘一鸣 陈少平[3] 吴智平[1,4] ZHANG Xiaoqing;SONG Mingshui;HOU Zhongshuai;HAO Ranran;ZHANG Qiang;LIU Yiming;CHEN Shaoping;WU Zhiping(School of Geosciences,China University of Petroleum,Qingdao,Shandong 266580,China;Shengli Oilfield Company,Sinopec,Dongying,Shandong 257001,China;BeijingResearch Center,CNOOC,Beijing100028,China;Qingdao National Laboratoryfor Marine Science and Technology,Qingdao,Shandong 266235,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石化胜利油田分公司,山东东营257001 [3]中海石油(中国)有限公司北京研究中心,北京100028 [4]青岛海洋科学与技术国家实验室,山东青岛266235

出　　处：《中国矿业大学学报》2019年第6期1317-1329,共13页Journal of China University of Mining & Technology

基　　金：“十三五”国家科技重大专项(2016ZX05024-002-001);国家留学基金项目(201706450017);中央高校基本科研业务费专项资金项目(16CX06043A)

摘　　要：构造-沉积耦合关系研究对沉积盆地的形成、演化分析以及盆地内构造和各种隐蔽油气藏的预测具有重要启示作用.本文整合中海油、中石化地震、测井和岩心等资料,对埕北凹陷古近系断裂体系、沉积相类型、构造-沉积耦合关系进行综合分析,认为凹陷北洼缓坡带T20、T50等不整合面上覆和下伏地层内、洼陷带周缘岩性上倾尖灭处、陡坡带次级断层发育处为有利的油气勘探区带.研究结果表明:凹陷古近系发育2组走向主干断层,其中NW向分段复活的埕北断层控制了埕北凹陷新生代结构,而NE/NEE走向的"顺坡"断层对凹陷结构起到改造作用;埕北断层存在Es3和Ed两期活动峰值,分别约154 m/Ma和41 m/Ma,而"顺坡"断层主要活动的Es3和Es2+Es1期,其活动速率均小于32 m/Ma;在各组走向断层和郯庐走滑断裂带的控制下,埕北凹陷古近纪构造演化经历了Ek+Es4继承裂陷期、Es3切割改造裂陷期和Es2-Ed走滑改造裂陷期3个阶段;凹陷内主要沉积相类型包括扇三角洲、辫状河三角洲、湖底扇、近岸水下扇和湖泊等5种;构造-沉积耦合关系主要体现在埕北断层分段复活控制地层差异分布、断层演化控制沉积砂体展布和凹陷演化控制沉积体系3方面.基于构造-沉积耦合关系,结合凹陷南洼勘探成果,综合分析认为在凹陷北洼缓坡带、洼陷带周缘和陡坡带可能发育有岩性、地层削截、地层超覆、构造、岩性-构造等5种油气藏.The study of the coupling relationship between structure and sedimentation has important implications for the formation and evolution of sedimentary basins and the prediction of intra-basin structural and various subtle reservoirs. This paper integrated the seismic, well logging and core data from CNOOC and Sinopec, and analyzed the structural characteristics, sedimentary characteristics and the coupling relationship between structure and sedimentation. It is considered that the strata overlaid and underlaid on unconformity interfaces such as T20 and T50, the lithologic uplifting tips around the sag margin, and the secondary fault development areas of the steep slope are the favorable oil and gas exploration zones in the north sub-sag. The results show that there are 2 groups of major faults in the Paleogene of the Chengbei sag. The NW-trending reactivated Chengbei fault controlled the structure of the Chengbei sag, while the NE/NEE-trending faults reconstructed the sag framework. There are 2 peaks of the Chengbei fault activity: one is Es3 with 154 m/Ma;the other is Ed with 41 m/Ma. The main activity periods of NE/NEE-trending faults are the Es3 and Es2+Es1 with no more than 32 m/Ma. Based on the analysis of these major faults and activity of the Tanlu strike-slip fault zone, the Paleogene tectonic evolution of the Chengbei Sag can be divided into 3 stages: Ek+Es4 inherited rifting period, Es3 cutting transformation rifting period, and Es2-Ed strike-slip transformation rifting period. And there are 5 types of main sedimentary facies in the sag including fan delta, braided river delta, sublacustrine fan, nearshore subaqueous fan and lake. The coupling relationship between structure and sedimentation is mainly reflected in 3 aspects: the coupling of segmental reactivation of the Chengbei fault and the distribution of stratigraphic differences, the coupling of the fault evolution and the distribution of sedimentary facies, and the coupling of sag evolution and sedimentary systems. Based on the coupling relationship

关 键 词：构造特征 沉积特征 耦合关系 控藏作用 古近系 埕北凹陷 渤海湾盆地 

分 类 号：TE121[石油与天然气工程—油气勘探]