东北石油大学学报2026，Vol.50Issue(4)：58-73,16.DOI:10.3969/j.issn.2095-4107.2026.04.005
莺歌海盆地乐东区上新统坡折带演化特征及有利区预测
Evolutionary characteristics of the slope-break belts and prediction of favorable zones in the Ledong Area of the Yinggehai Basin during the Pliocene
摘要
Abstract
During the deposition of the first member of the Yinggehai Formation(Ying-1 Member)in the Ledong Area of the Yinggehai Basin,the shelf margin prograded continuously seaward,resulting in dep-ositional systems controlled by slope breaks with diverse types and complex spatial configurations.Based on high-resolution 3D seismic and drilling data,we delineated the migration trajectories of the shelf-edge slope-break belts,analyzed the evolutionary characteristics of the slope-break belts and their sand-control depositional models in the Ledong Area,identified the distribution of favorable facies belts,and predicted favorable zones.The results show that the migration angle of the slope-break belts in the study area initially increases and then decreases,and the slope breaks can be classified into three types of shelf-margin migration trajectories:flat,low-angle rising,and high-angle rising.These trajectory types reflect the ratio of the rate of change in accommodation space to sediment supply.Eight types of micro-facies are recognized:basin-floor fans,mass-flow deposits,slope fans,slump fans,slumps,beach bars,turbidite channels,and turbidite lobes.Three corresponding sand-control depositional models were established:the flat,low-angle rising,and high-angle rising shelf-margin migration trajectory models.Under the flat trajectory model,large-scale instability and slumping tend to occur at the shelf edge,generating widely distributed slump and debris-flow deposits on the continental slope.The low-angle rising trajectory promotes sediment differentiation along a long,gentle slope,forming slope-fan depositional systems.The high-angle rising trajectory favors vertical aggradation and preservation of strata but delivers relatively limited sediment downslope.The late stage of the Ying-1 Member deposi-tion is a critical period for the development of favorable sand bodies.The low-angle rising shelf-margin migration trajectory represents the favorable slope-break belt type,with beach bars and slope fans ser-ving as good reservoir bodies.Potential favorable targets include lithologic traps within beach-bar en-richment zones above the slope-break belts on diapir flanks,and lithologic traps between the slope-fan development areas on the slope-break belts and the gas fields.These results provide a basis for integrat-ed exploration and development target evaluation in the study area.关键词
莺歌海盆地/乐东区/莺一段/坡折带/迁移轨迹/沉积微相/控砂沉积模式Key words
Yinggehai Basin/Ledong Area/first member of the Yinggehai Formation/slope-break belts/migration trajectory/depositional microfacies/sand-control mechanism分类
能源科技引用本文复制引用
付文俊,周伟,张冲,尹璐璐,严晗,陈之贺..莺歌海盆地乐东区上新统坡折带演化特征及有利区预测[J].东北石油大学学报,2026,50(4):58-73,16.基金项目
国家科技重大专项(2025ZD1407400) （2025ZD1407400）
海南省"南海新星"科技创新人才平台项目(NHXXRCXM202368) （NHXXRCXM202368）
