河控型浅水三角洲前缘河道砂体结构特征--以渤海湾盆地黄河口凹陷BZ34油区明下段Ⅱ油组为例  

Geomorphology of channel sandbodies in fluvially dominated shallow water delta front:taking the Lower Member of the Minghuazhen Formation in BZ34 Oilfield of the Huanghekou Sag,Bohai Bay Basin as an example

作　　者：赵汉卿 李超 郭诚 岳红林 张正龙 ZHAO Hanqing;LI Chao;GUO Cheng;YUE Honglin;ZHANG Zhenglong(Tianjin Branch of CNOOC(China)Ltd.,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300452

出　　处：《海洋地质前沿》2024年第2期20-27,共8页Marine Geology Frontiers

基　　金：国家科技重大专项“渤海海域大中型油气田地质特征”(2011ZX05023-006-002);中海石油(中国)有限公司科技重大专项“渤海双高油田挖潜关键技术研究”(YXKY-2018-TJ-04)。

摘　　要：新近系明化镇组下段(明下段,N1ml)为黄河口凹陷BZ34油区的主力含油层段,该时期主要发育河控型浅水三角洲前缘沉积。为更好地表征前缘砂体的结构特征及展布规律,以BZ34油区明下段Ⅱ油组为例,综合应用岩芯、地震属性和测井等资料,分析总结了该地区的砂体沉积类型、砂体结构及沉积模式。研究结果表明:BZ34油区明下段Ⅱ油组砂体以浅水三角洲前缘水下分流河道为主;依据测井形态和叠置关系,将其砂体结构类型划分为4种:块状切叠型河道、层状叠置型河道、层状孤立型河道和指状孤立型河道;砂体结构展布特征及成因主要受古地形、沉积物供给速率、基准面旋回和古气候等因素影响。BZ34油区的水下分流河道沉积,具有垂向上交错叠置、平面上摆动连片的分布特征,与鄱阳湖现代河控浅水三角洲河道的沉积特征类似。该研究对BZ34油区后期部署加密调整井和剩余油挖潜工作具有指导意义。The Lower Member of the Neogene Minghuazhen Formation(N1ml)is the main oil-bearing sand body unit in the BZ34 Oilfield in Huanghekou Sag,Bohai Bay Basin,North China,in which delta front deposits in flu-vially dominated shallow waters were developed.To better characterize the structural characteristics and distribu-l tion of the front sand bodies,taking the second oil unit of N1m as an example,the sedimentary types,geomorpho-logical structures,and depositional models of the sand body were analyzed based on the data from coring,seismic profiling,and logging.Results show that the sand bodies are dominated by underwater distributary channels in shallow water delta front.According to the logging curves and overlapping of the sand bodies,four channel types were recognized:massive incised river channel,layered overlapping channel,layered isolated channel,and finger-shaped isolated channel.The distribution and genesis of the sand bodies were affected mainly by paleotopography,sediment supply rate,base level cycle,and paleoclimate.The underwater distributary channel deposits in the BZ34 Oil Field are characteristic of incisive superposition in vertical direction and meandering patchy distribution in ho-rizontal,which is similar to the modern case of fluvially dominated shallow water delta channels in Poyang Lake,South China.This study provided a guidance for infill adjustment and potential tapping in later stage for the re-maining oil in BZ34 Oilfield.

关 键 词：河控型浅水三角洲 砂体结构 明下段 BZ34油区 黄河口凹陷 

分 类 号：P736[天文地球—海洋地质] P618.13[天文地球—海洋科学]