Difference between eastern and western Paleogene sedimentary systems in deep waters off the northern South China Sea continental margin and its effect on source rock distribution

被引:0
|
作者
Chen Y. [1 ]
Han Y. [2 ]
Bian L. [3 ]
Zeng Q. [1 ]
Guo S. [1 ]
Ji M. [1 ]
Yang D. [1 ]
Wang L. [1 ]
机构
[1] CNOOC Research Center, Beijing
[2] Taihe Petroleum Engineering Co., Ltd., Xianyang, 712000, Shaanxi
[3] School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210093, Jiangsu
来源
Oil and Gas Geology | 2020年 / 41卷 / 05期
关键词
Basinal structure; Deep waters off the northern South China Sea; Delta-bay system; Marine-to-continental facies; Paleogene; Provenance; Sedimentary system; Source rock;
D O I
10.11743/ogg20200513
中图分类号
学科分类号
摘要
The striking discrepancy of oil-gas exploration results in deep waters of the Pearl River Mouth and Qiongdongnan Basins in northern South China Sea is rarely interpreted in terms of formation mechanism.With a view to objectively assessing the resource potential of the deep waters off the northern South China Sea, the study analyzes the conditions for basin formation and hydrocarbon generation based on the essential geological factors such as the basinal structure, provenance and sedimentation and charging, with the focus on the main sedimentary characteristics of the hydrocarbon source rock development during the Paleogene, and on the distribution patterns of the source rocks.The two basins are significantly different in terms of their Early Oligocene sedimentary systems, which may be traced back to the different basinal structures and provenances at that time.The major pay source rocks of the deep waters off the northern South China Sea were developed during the Early Oligocene, when the deep-water zone of the Pearl River Mouth Basin was filled with rifts and depressions, and the Baiyun and Liwan Sags in it had their respective depocenters and subsidence centers receiving sediments from surrounding uplift zones and the paleo-Pearl River system outside the basin and developing large delta systems of bay facies.Meanwhile, the deep waters of the Qiongdongnan Basin were a faulted depression with multiple rows of separated small sag groups developed on the terrace of both sides and the central lowlands of the basin.These sag groups subsequently formed barrier-coast systems and small-scale deltas in receiving short-range provenances from waters off the southern Hainan Island and Thu Bon river in Vietnam in a closed-semi-closed bay setting.In all, the sedimentary systems control the types and distribution patterns of the source rocks in the basins, so it is of great significance to the discussion of the distribution patterns and favorable zones of source rocks in the deep waters off the two basins from the perspective of the differences in sedimentary system architecture. © 2020, OIL & GAS GEOLOGY Editorial Board. All right reserved.
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页码:1028 / 1037
页数:9
相关论文
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