1、地球科学 Earth Sciencehttp:/第 48 卷 第 2期2 0 2 3 年 2 月Vol.48 No.2Feb.2 0 2 3https:/doi.org/10.3799/dqkx.2022.458珠江口盆地文昌 A凹陷深层珠海组不同构造单元油气充注期次及差异性分析史肖凡1，罗静兰1*，陈林2，符勇1，徐守立2，严敏1，刘芳21.西北大学大陆动力学国家重点实验室，陕西西安 7100692.中海石油（中国）有限公司湛江分公司，广东湛江 524057摘要：珠江口盆地文昌 A 凹陷深部的古近系珠海组油气资源丰富，但不同区带油气成藏分布复杂，油气成藏时期的关键证据包裹体的研究相对薄弱.为
2、了准确厘定文昌 A 凹陷珠海组烃类充注时期，以研究区珠海组砂岩储层中的烃包裹体及其伴生盐水包裹体为研究对象，利用荧光光谱测定、激光拉曼光谱分析、显微测温等实验测试，结合包裹体捕获压力计算、埋藏史、热演化史、生烃演化史等分析，开展了凹陷中心及近珠三南断裂带油气成藏期次与差异性研究.结果表明，储层砂岩中烃包裹体及其伴生盐水包裹体成分主要为 CH4、C2H6、CO2和 H2O，同期盐水包裹体均一温度集中分布于 95180.断裂带与凹陷中心均存在 3 期烃类充注，但油气充注时间有差别.其中，凹陷中心第 1 期发生在 21.913.9 Ma，第 2 期油充注发生在 12.08.9 Ma，第 3期油气充注
3、时间 7.84.8 Ma；断裂带第 1期油充注发生在约 21.710.2 Ma，第 2期油充注发生在约 9.14.9 Ma，第 3期油气充注时间约为 3.91.5 Ma.差异性构造沉降导致的烃源岩埋深的差异，以及多期断裂活动强度及其时空配置关系的不同，是造成凹陷中心及断裂带烃源岩生烃高峰的差异及油气成藏时间有先后之分的主要原因.该结果为研究区油气勘探目标的选取与部署提供科学依据.关键词：流体包裹体；油气充注时期；珠海组；古近系；文昌 A凹陷；珠江口盆地；石油地质.中图分类号：P618.13 文章编号：1000-2383(2023)02-776-17 收稿日期：2022-12-04Hydroca
4、rbon Charging Stages and Their Differences in Different Structural Units of the Deep Zhuhai Formation in Wenchang A Sag,Pearl River Mouth BasinShi Xiaofan1，Luo Jinglan1*，Chen Lin2，Fu Yong2，Xu Shouli1，Yan Min2，Liu Fang11.State Key Laboratory of Continental Dynamics，Northwestern University，Xian 710069
5、，China2.Zhanjiang Branch of CNOOC Ltd.，Zhanjiang 524057，ChinaAbstract:The Paleogene Zhuhai Formation in the deep Wenchang A Sag of the Pearl River Mouth Basin is rich in oil and gas resources,but the distribution of oil and gas reservoirs in different regions is complex,and the study of inclusions,t
6、he key evidence of oil and gas accumulation period,is relatively weak.In order to accurately determine the hydrocarbon charging periods of Zhuhai Formation in Wenchang A Sag,the hydrocarbon inclusions and their associated brine inclusions in the sandstone 基金项目：国家自然科学基金面上项目（No.41972129）；国家科技重大专项课题（No
7、s.2016ZX05026003005；2016ZX05024005）.作者简介：史 肖 凡（1998-），男，硕 士 研 究 生，从 事 碎 屑 岩 储 层 沉 积 学 及 石 油 地 质 学 研 究.ORCID：0000000176308763.Email：*通讯作者：罗静兰,ORCID：000000029780267X.Email：引用格式：史肖凡，罗静兰，陈林，符勇，徐守立，严敏，刘芳，2023.珠江口盆地文昌 A 凹陷深层珠海组不同构造单元油气充注期次及差异性分析.地球科学，48（2）：776-792.Citation：Shi Xiaofan，Luo Jinglan，Chen Lin
8、，Fu Yong，Xu Shouli，Yan Min，Liu Fang，2023.Hydrocarbon Charging Stages and Their Differences in Different Structural Units of the Deep Zhuhai Formation in Wenchang A Sag，Pearl River Mouth Basin.Earth Science，48（2）：776-792.第 2 期史肖凡等：珠江口盆地文昌 A凹陷深层珠海组不同构造单元油气充注期次及差异性分析reservoirs of Zhuhai Formation in th
9、e study area were taken as the research object.Fluorescence spectroscopy,laser Raman spectroscopy,micro thermometry and other related experiment were used,combined with the analysis of inclusion capture pressure calculation,burial history,paleogeothermal evolution history,and thermal evolution histo
10、ry of hydrocarbon source rocks.The research on hydrocarbon charging stages and their differences in the central depression and the fault zone has been carried out.The results show that there are three kinds of inclusions,including highdensity singlephase oil inclusions,twophase of gasliquid hydrocar
11、bon inclusions and twophase of gasliquid saline inclusions in the sandstonereservoir.The components of hydrocarbon inclusions and the associated brine inclusions are mainly CH4,C2H6,SO2,CO2 and H2O,and the homogenization temperature of brine inclusions distributed mainly from 95 to 180.Three stages
12、of hydrocarbon filling occurred both in the central depression and the fault zone,but the hydrocarbon filling time is different.The first hydrocarbon charging occurred in the central depression rangesfrom 21.9 to 13.9 Ma,the second oil filling occurred at 12.0 to 8.9 Ma,and the third oil and gas fil
13、ling occurred at 7.8 to 4.8 Ma.However,in the fault zone,the first oil charging occurred at 21.7 to 10.2 Ma,the second one occurred at 9.1 to 4.9 Ma,and the third oil and gas filling was about 3.9 to 1.5 Ma.The difference of source rock burial depth,multistage fault activity and their spatio tempora
14、l configuration caused by different tectonic subsidence is the main reason for the difference of hydrocarbon generation peak and hydrocarbon accumulation time in the central depression and fault zone.The research results provide a scientific basis forselection and deployment of oil and gas explorati
15、on targets in the study area.Key words:fluid inclusion;oil and gas filling period;Zhuhai Formation;Paleogene;Wenchang A sag;Pearl River Mouth Basin;petroleum geology.0 引言 油气成藏期次对于研究油气成藏过程及油气藏的分布具有重要意义，是油气成藏研究的热点问题之一.随着科学技术的发展，油气成藏期次的厘定已逐渐由单一成藏要素确定法发展到以烃源岩生烃史为基础，结合流体充注历史分析等多种方法综合判定成藏期次（鲁雪松等，2012；Ping
16、 et al.，2017；Yong et al.，2019）.成岩过程中伴随流体运移捕获的大量包裹体，反映了不同时期成岩流体的性质，也记录了不同时期地层流体的信息，如温度、成分、压力等，可作为揭示油气藏充注历史及分布规律的重要工具（Volk et al.，2003；操应长等，2014）.由于油包裹体在紫外可见光下的荧光特性通常反映了所含芳烃类型的不同（斯尚华等，2018），可借助油包裹体的荧光特性，对包裹体内不同有机质成熟度进行划分，结合包裹体拉曼光谱分析、盐水包裹体均一温度及捕获压力测算等方法，精确厘定油气成藏时期.文昌 A 凹陷位于我国珠江口盆地珠三坳陷内，是一个构造演化复杂、内部断裂带发育且油气资源十分丰富的“箕状”断陷（李辉等，2014）.凹陷内发育文昌组、恩平组两套湖相烃源岩，生烃潜力大；古近系渐新统珠海组发育的扇三角洲前缘-潮坪相储层为凹陷内主要的深层储集层系之一，具有良好的勘探开发前景.但区内构造活动强烈，不同区带油气富集规律有明显的差异，油气成藏特征十分复杂（林兴荣和孙志鹏，1999；王柯，2014；王柯等，2014）.前人对文昌 A 凹陷的油气成藏期次主要是通过包裹体