海洋地质与第四纪地质2025，Vol.45Issue(2)：133-145,13.DOI:10.16562/j.cnki.0256-1492.2023110102
珠江口盆地白云西凹古近纪沉积古环境重建及其油气地质意义
Paleogene sedimentary paleoenvironmental reconstruction and its petroleum geological significance in Western Baiyun Sag,Pearl River Mouth Basin
摘要
Abstract
In recent years,there have been continuous discoveries and exploration in the Western Baiyun Sag,PRMB(The Pearl River Mouth Basin).However,few studies have been conducted on the characteristics of sedimentary paleoenvironment and there is a lack of systematic reconstruction,which could hinder future exploration of the study area.To systematically reconstruct the Paleogene paleoenvironment including paleoclimate,paleowater depth,and ancient landform,quantitative paleoenvironmental recovery methods were developed based on the paleontology,geophysical logging,geochemical and rock physical properties data of the study area.Results show that,from the Wenchang Formation to the Zhuhai Formation,both paleoprecipitation and paleotemperature decreased,ancient landforms continue to flatten and then stabilized due to the weakening detachment fault activity,and the paleowater depth centers were gradually reduced and migrated to the Baiyun Sag,showing an evolution pattern of from narrow deep basin to wide gentle basin and to wide shallow basin.During the period of the Wenchang Formation,the climate of the Western Baiyun Sag was warm and humid,the supply of organic matter was sufficient.Steeper terrain and several deep-water lakes were developed in the early stage.Material supply is from multi-point combined with near-source supply,which resulted in hydrocarbon sources in medium-deep multi-deepwater-centered lake facies,while in the late stage,the deep-water centers merged,and the supply of sources showed a bi-directional source joined with relatively far sources,which resulted in the medium-shallow lake-facies hydrocarbon source rocks with converging deep-water centers.During the period from the Enping Formation to the Zhuhai Formation,the temperature decreased,and a cooler climate occurred in the late stage.The landform underwent flattening,while the water became shallower.The paleowater depth centers further converged.Source supply changes from intra-basin to intra-and-inter-basin distant source,with relatively less organic matter supply.As a result,there were poorly developed,shallow lake-facies hydrocarbon source rocks in paleowater depth centers.The quantitative reconstruction of paleoenvironment have significant implications for studying the evolution of the lake basin,the source-sink system,and predicting high-quality hydrocarbon source rocks in the Western Baiyun Sag,which will serve as a theoretical foundation for the later stages of regional oil and gas exploration.关键词
古环境定量恢复/湖盆演化/"源-汇"系统/烃源岩预测/古近纪/白云西凹Key words
quantitative paleoenvironmental reconstruction/lake basin evolution/source-to-sink system/source rock prediction/Paleogene/Western Baiyun Sag分类
海洋科学引用本文复制引用
蔡嵩,彭光荣,郑金云,李振升,陈兆明,朱定伟..珠江口盆地白云西凹古近纪沉积古环境重建及其油气地质意义[J].海洋地质与第四纪地质,2025,45(2):133-145,13.基金项目
中国海洋石油有限公司生产性科研项目"开平凹陷-白云西凹成盆、成烃及沉积演化研究"(SCKY-2024-SZ-01) （SCKY-2024-SZ-01）
