南海南部海陆过渡相烃源岩的两类分布模式  

Two distribution patterns of the marine-continental transitional source rocks in the southern South China Sea

作　　者：兰蕾 李友川 王一博 LAN Lei;LI Youchuan;WANG Yibo(CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《海洋地质与第四纪地质》2021年第5期173-180,共8页Marine Geology & Quaternary Geology

基　　金：“十三五”国家科技重大专项“海洋深水区油气勘探关键技术”(2016ZX05026-004-004)。

摘　　要：位于南海南部的曾母盆地和文莱-沙巴盆地是南海中南部油气资源最为富集的两个盆地,可采储量相当,但含油气性和油气分布差异巨大。本文在油源对比的基础上,结合古气候、古植被、沉积演化与沉积相带差异,总结了曾母盆地和文莱-沙巴盆地海陆过渡相烃源岩的分布模式。研究认为,曾母盆地近岸一侧原油和文莱-沙巴盆地原油为煤系烃源岩来源,曾母盆地远岸一侧原油为陆源海相烃源岩来源。受古气候、古植被控制,煤系烃源岩具有较强生油能力,受沉积相带控制,曾母盆地和文莱-沙巴盆地海陆过渡相烃源岩存在两种分布模式,分别为"三角洲煤系-陆源海相"烃源岩分布模式和"三角洲-浊积含煤"分布模式。烃源岩分布模式进而控制了油气分布,曾母盆地的原油集中分布于三角洲平原及近岸地区,而文莱-沙巴盆地煤系烃源岩分布受浊积岩分布控制而广泛分布,这可能是文莱-沙巴盆地满盆富油的重要原因。As the largest oil and gas basins in the Southern South China Sea, the Zengmu and Baram-Sabah basins have roughly similar recoverable reserves but great differences in oil and gas ratio, and distribution patterns. Based on the data of oil source correlation, combined with the data of paleoclimate, paleovegetation, depositional evolution and faices differentiation, two distribution patterns for marine-continental transitional source rocks has been concluded by this paper. It suggests that the oil from shore side of the Zengmu Basin and the Baram-Sabah Basin are mainly generated from coaly source rocks, while the oil from offshore Zengmu Basin from terrestrially sourced marine deposits. Up to the paleoclimate and paleovegetation, the coaly source rock has rather strong ability of oil generation. Based on the depositional facies of source rocks, two distribution patterns for the marine-continental transitional source rocks have been recognized by the authors for the first time, which are the "deltaic coaly facies-terrestrially sourced marine facies source rocks" and the "deltaic-turbidite-coaly source rocks". Under the control of the type of source rocks, the oil in the Zengmu Basin is enriched in the delta plain and inshore region, while the oil in the Baram-Sabah Basin has a wide coverage.

关 键 词：海陆过渡相 烃源岩 分布模式 南海南部 

分 类 号：P736[天文地球—海洋地质]