古地理学报2017，Vol.19Issue(6)：1023-1036,14.DOI:10.7605/gdlxb.2017.06.079
北部湾盆地乌石凹陷东区古近系流沙港组二段砂泥薄互层沉积相特征及演化
Sedimentary characteristics and evolution of thin interbeds of the Member 2 of Paleogene Liushagang Formation in eastern Wushi sag, Beibu Wan Basin
摘要
Abstract
The structure and sedimentary characteristics of the Member 2 of Liushagang Formation in the eastern Wushi sag,Beibu Wan Basin are very complex.The sedimentation is of great variation with sharp lateral changes.The understanding of sediment provenance and sedimentary facies is controversial.Using core,logging,seismic,and laboratory data,the present study attempts to:(1) investigate sediment provenance,sedimentary facies and evolution of the Member 2 of the Liushagang Formation in the study area;(2) determine the distribution and evolution of sedimentary facies in the study area;(3) predict favorable reservoir distribution characteristics;and (4) to better serve the oil and gas exploration and development.Results from this study suggest that the northern high-lying area represents the sediment provenance of the Member 2 of the Liushagang Formation,which is characterized by the delta front-deep lake sedimentary sequence.The normal deltaic sediments were well developed,and the thickness of individual sand bodies is small,which manifests as multilayer interactive distribution.The Member 2 of the Liushagang Formation is divided into four 4th-order sequences from bottom to top.MSC2 and MSC3 sequences formed during the short-term rapid water regression were involved into the process of longer-term water transgression.The sediment supply was sufficient,sand bodies were,thus,well developed.Observations from this work suggest that the buried depth and sedimentary facies play a pivotal role in the modulation of the reservoir properties of the Member 2 of the Liushagang Formation.Reservoir properties of B oil field are better than those of A oil filed.The subaqueous distributary channel and estuary dam developed near the source of the delta front are favorable reservoir distribution areas.关键词
北部湾盆地/乌石凹陷东区/流沙港组/沉积物源/沉积相/沉积演化Key words
Beibu Wan Basin/eastern Wushi sag/Liushagang Formation/sediment provenance/sedimentary facies/sedimentary evolution分类
天文与地球科学引用本文复制引用
孙乐,高明轩,于兴河,李胜利,张辉,何玉林,杨楷乐,乔亚蓉,张文淼,吴子瑾..北部湾盆地乌石凹陷东区古近系流沙港组二段砂泥薄互层沉积相特征及演化[J].古地理学报,2017,19(6):1023-1036,14.基金项目
国家科技重大专项(2016ZX05024-002-002)资助.[Financially supported by the National Science and Technology Major Project of China (No.2016ZX05024-002-002)] （2016ZX05024-002-002）
