珠江口盆地超深水区LW21-A井烃源岩分子地球化学特征与油气成因  

Molecular geochemical characteristics and hydrocarbon genesis of source rocks in Well LW21-A in ultra-deep water area of Pearl River Mouth Basin

作　　者：朱俊章 黄玉平 陈聪 翟普强 张志琳 韩晋阳 ZHU Junzhang;HUANG Yuping;CHEN Cong;ZHAI Puqiang;ZHANG Zhilin;HAN Jinyang(Shenzhen Branch of CNOOC(China)Ltd.,Shenzhen 518054,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,深圳518054

出　　处：《海洋地质前沿》2024年第5期51-62,共12页Marine Geology Frontiers

基　　金：“十四五”全国油气资源评价项目“中海油矿业权区及周边空白区油气资源评价”(QGYQZYPJ2022-3)课题四;中国海洋石油集团总公司“十四五”重大科技项目“陆缘裂谷盆地深层/超深层油气成藏条件与成藏机制研究:珠江口盆地珠一坳陷”(KJGG2022-0403)。

摘　　要：珠江口盆地超深水区勘探程度低,珠四坳陷仅LW21-A井有油气发现,通过对其进行系统地特征分子地球化学测试与分析,揭示了所钻遇烃源岩的类型和发现油气的成因。该钻井揭示,文昌组和恩平组发育海相(海侵)泥岩和微咸水浅湖相(近海湖盆)泥岩;LW21构造气藏中存在海相(海侵)和湖相2类凝析油;LW21构造气藏中天然气主要成分为CO_(2),属于CO_(2)气藏,含一定量烷烃气;CO_(2)主要是无机幔源型成因气,烷烃气主要是油型气与海相生物气的混合型干气。这一认识对珠江口盆地超深水区珠四坳陷带的进一步评价和勘探决策具有重要意义。The ultra-deep water area of the Pearl River Mouth Basin remains poorly explored,from which only LW21-A well in the Zhusi Depression has oil and gas discovered.Through systematic molecular geochemical testing and analysis,the types of hydrocarbon source rocks encountered were specified and the genesis of oil and gas discovered were revealed.Result shows that the Wenchang Formation and Enping Formation of the well developed marine(transgression)mudstone and brackish shallow lake(offshore lake basin)mudstone.There are two types of condensate in LW21 structural gas reservoir:marine(transgressive)and lacustrine.The main component of natural gas in LW21 structural gas reservoir is CO_(2),which belongs to CO_(2) gas reservoir and contains a certain amount of alkane gas.CO_(2) is mainly inorganic mantle-derived genetic gas,alkane gas is mixed dry gas,mainly the mixture of oil-type gas and marine biogenic gas.This understanding is of great significance to the further evaluation and exploration decision of the Zhusi Depression zone in the ultra-deep water area of the Pearl River Mouth basin.

关 键 词：珠江口盆地 超深水区 烃源岩 CO_(2)气藏 分子地球化学 油气成因 

分 类 号：P744.4[天文地球—海洋科学] P618.13