西湖凹陷中央背斜带中北部花港组下段粗碎屑沉积体系成因探讨  

Discussion on the Genesis of Coarse Clastic Sedimentary System in Lower Huagang Formation in North-central Part of the Central Anticlinal Belt of Xihu Sag

作　　者：严涛 万丽芬 李昆 陈琳琳 YAN Tao;WAN Lifen;LI Kun;CHEN Linlin(SINOPEC Shanghai Offshore Oil&Gas Company,Shanghai 200120,China)

机构地区：[1]中国石油化工股份有限公司上海海洋油气分公司,上海200120

出　　处：《海洋石油》2024年第3期17-24,共8页Offshore Oil

摘　　要：针对目前西湖凹陷中央背斜带中北部花港组下段的粗碎屑沉积成因不明的问题,该文在花港组下段钻井资料的基础上,通过层序地层学与沉积学相结合动态地解释了花港组下段沉积体系的演化过程及相迁移特征。在目前三级层序格架下,井震结合,将花港组下段进一步细化到体系域级别。在精细的地层格架下,通过物源分析,并依据测录井特征及岩心特征,识别出花港组的沉积体系及展布特征。结果表明,花港组时期,西北物源供给强烈,研究区主要发育北东向长轴方向的辫状河三角洲沉积体系,粗碎屑主要来自于低位体系域的辫状河道和三角洲平原分支河道沉积。该研究深化了中央背斜带北部粗碎屑体的认识,为中央背斜带成藏条件研究奠定基础。Aiming at the problem that the origin of coarse clastic deposits in the lower part of Huagang Formation in north-central part of the central anticlinal belt of Xihu Sag is unclear,on the basis of drilling data,through the combination of sequence stratigraphy and sedimentology,the sedimentary system evolution process and facies migration characteristics of lower Huagang Formation are explained dynamically.Under the current three-level sequence framework,lower Huagang Formation is further refined to the system tract level by combining well-log and seismic data.Under the elaborate stratigraphic framework,the sedimentary system and distribution characteristics of Huagang Formation are identified by source analysis,well logging characteristics and core characteristics.The results show that the northwest provenance supply is strong during the Huagang Formation period.The braided river delta depositional system in the long axis direction of northeast is mainly developed in the study area.The coarse debris mainly comes from braided channel deposits and branched channel deposits of the delta plain in the lower system tract.This study deepens the understanding of coarse clastic bodies in the north-central part of the central anticlinal belt and provides a basis for the study of reservoir formation conditions in the central anticlinal belt.

关 键 词：西湖凹陷 花港组 中央背斜带 粗碎屑体 沉积体系 

分 类 号：P618.13[天文地球—矿床学]