摘要
通过岩心描述以及粒度、薄片资料的综合分析,结合区域古地貌特征、地震相研究成果,详细论述了琼东南盆地陵水凹陷北部梅山组砂质碎屑流砂岩沉积构造特征及识别标志,并在此基础上建立了研究区砂质碎屑流沉积模式。研究区梅山组砂质碎屑流砂岩主要为厚层块状构造粉砂岩-极细砂岩以及具有丰富同生变形构造的粉砂质泥岩、泥岩与粉砂岩互层2种岩性组合,成因为陆架坡折之上的三角洲前缘、前三角洲沉积物发生整体性“冻结”滑动、滑塌再沉积所形成,其平面分布主要受陆架坡折所控制,大致呈平行于陆架坡折带分布的舌形形态。结合区域油气成藏要素研究认为研究区砂质碎屑流砂岩可通过沟源断层沟通深部烃源岩,形成下生上储型岩性油气藏,为琼东南盆地大中型油气藏勘探突破的重点领域。
Through comprehensive analysis of core description,core slice observation and grain size data,in combination with regional palaeogeomorphology and seismic facies study,the sedimentary structure characteristics and its identification mark of the Meishan Formation sandy debris flow in northern Lingshui Sag of Qiongdongnan Basin were discussed in details.The sedimentary model of sandy debris flow in the study area is then established based on its sedimentary environment and characteristics.Two main lithological associations developed in sandy debris flow sedimentation in the Meishan Formation,which were thick massive bedding siltstone to very fine sandstone without sedimentary structure and silty mudstone,mudstone and siltstone interbeds with abundant contemporaneous deformation structure.These lithological associations formed during the process when the sediments of the delta front and the pre-delta on the shelf went frozen sliding as whole and collapsed and deposited again as sandy debris flow.Their distribution was mainly controlled by the shelf break and roughly distributed parallel to the shelf break showing tongue shaped outline.Combined with regional hydrocarbon accumulation elements study,it was thought the sandy debris flow sandstone in the study area could form lower-generation and upper-reservoir type lithological reservoirs with faults connecting to deep source rock,and this would be an important exploration break through to realize the exploration breakthrough in finding large and medium-sized oil and gas reservoirs in Qiongdongnan Basin.
作者
李安琪
叶绮
王真真
李明
陈奎
Li Anqi;Ye Qi;Wang Zhenzhen;Li Ming;Chen Kui(Research Institute of CNOOC Ltd.Zhanjiang Branch,Zhanjiang Guangdong 524057,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2021年第1期110-118,共9页
Bulletin of Geological Science and Technology
基金
国家重大科技专项“大型油气田及煤层气开发”子课题“莺琼盆地高温高压天然气富集规律与勘探开发关键技术”(2016ZX05024-005)。
关键词
砂质碎屑流
琼东南盆地
陵水凹陷
沉积构造
油气勘探意义
sandy debris flow
Qiongdongnan Basin
Lingshui Sag
sedimentary structure
significance of hydrocarbon exploration
