海洋地质前沿2017，Vol.33Issue(10)：32-39,8.DOI:10.16028/j.1009-2722.2017.10004
北部湾涠西南凹陷斜阳斜坡早渐新世低位三角洲沉积及油气地质意义
DEPOSITIONAL CHARACTERISTICS OF THE EARLY OLIGOCENE LOWSTAND DELTA IN XIEYANG SLOPE ZONE OF WEIXINAN DEPRESSION, BEIBUWAN BASIN AND THEIR PETROLEUM GEOLOGICAL SIGNIFICANCE
摘要
Abstract
The W2 Formation of Lower Oligocene in the Weixinan Depression of the Beibuwan Basin,South China Sea,is dominated by a set of muddy deposits formed during the period of lake level ris ing,in which the distribution of thin sand bodies is rather complicated.Petroleum exploration has so far remained in a relatively low stage due to lack of understanding of the origin and distribution of these sand bodies.This time,started from the study of tectonics and infilling history,we reconstructed the cyclic changes of base levels.And three 4th-level sequences,including the upper,the middle,and the lower sequences,are established.Sandstones are mainly concentrated in a positive rhythmic manner in the early stage of the middle sequence.They are the superimposed deposits of traction load formed under stronger water dynamic,and prograded from north to south.Based on the analysis of the tectonic and landform framework,we can find out that it was a very stable large-scale lowstand deltaic system no matter in the sag or on the slope.The deltaic bodies were affected severely by faul ted terraces along the edge of the basin.It is believed that the specific depositional background and the types and characteristics of the reservoir and cover match well with the formation of source rock and the migration and accumulation of oil and gas in this area.A lowstand and transgressive system tract is then put forward for the first time for the deposits formed in the early period of the middle sequence of the W2 Formation.It should be a very important exploration target in the future.关键词
涠西南斜阳斜坡/早渐新世/涠二段中层序/低位三角洲/油气勘探前景Key words
Xieyang Slope of Weixinan Depression/Early Oligocene/middle sequence of W2 Formation/lowstand delta/oil and gas exploration prospect分类
天文与地球科学引用本文复制引用
彭松,李珊珊,胡德胜,盖永浩,李磊,严恒..北部湾涠西南凹陷斜阳斜坡早渐新世低位三角洲沉积及油气地质意义[J].海洋地质前沿,2017,33(10):32-39,8.基金项目
国家重大课题专项(2016ZX05024-006) （2016ZX05024-006）
国家重大课题专项(2016ZX05024-002-009) （2016ZX05024-002-009）
