摘要
北部湾盆地涠西南凹陷始新统流沙港组一段发育一套斜交前积结构地层。利用地质、测井和地震等资料,通过单井相、连井对比和地震相特征等沉积相的综合研究,证实这套地层为强制湖退沉积体。该强制湖退沉积体在单井相上具有自下而上沉积水体明显变浅的特征,在连井对比中表现为多期三角洲纵向叠置横向有序迁移,而地震反射同相轴则表现出明显的斜交前积特征。进一步的研究表明,沉积基底局部构造抬升是流一段发生强制湖退的主控因素。这套强制湖退沉积体的发现不仅解决了涠西南凹陷涠三段和流一段区域地层划分与对比存在的分歧,同时在强制湖退沉积体系域内找到了浊积体、湖底扇和进积三角洲等多类型岩性圈闭,并发现了油气藏,拓展了凹陷找油新领域。
An oblique progradational sequence occurs in the 1st Member of Liushagang Formation in Weixi’ nan Sag, Beibuwan Basin.A comprehensive analysis of single well facies,multi-well correlation,and seismic facies based on geo-logical,logging and seismic data reveals that it belongs to lacustrine forced regressive deposits.It is characterized by obvi-ous upward shallowing in respect of singe well facies,vertical overlapping and lateral sequential migration of multi-phase deltas in multi-well correlation,and significant oblique progradation reflection configuration on seismic profiles.Local up-lifting of the basement is the main controlling factor for the development of lacustrine forced regression.The identification of the lacustrine forced regressive deposits helped to eliminate the disputes concerning stratigraphic division and correla-tion of the 3rd Member of Weizhou Formation and the 1st Member of Liushagang Formation in Weixi’nan sag.Meanwhile, it also led to the recognition of lithologic traps such as turbidite,sublacustrine fan,and progradational delta and the dis-covery of several reservoirs within the lacustrine forced regression system tracts,thus expanding new domains for oil and gas exploration in this sag.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2016年第4期520-527,共8页
Oil & Gas Geology
基金
国家"十二五"重点科技攻关项目(2011ZX05025-002)
关键词
强制湖退
沉积体
流沙港组
涠西南凹陷
北部湾盆地
lacustrine forced regression
deposit
Liushagang Formation
Weixi’ nan Sag
Beibuwan Basin
