珠江口盆地白云凹陷东部地区油气充注历史  

Oil and Gas Charge History of Eastern Baiyun Sag, Pearl River Mouth Basin

作　　者：张丽丽 张向涛 刘可禹 翟普强 孙辉 张应鳞 杨鹏 Zhang Lili;Zhang Xiangtao;Liu Keyu;Zhai Puqiang;Sun Hui;Zhang Yinglin;Yang Peng(Shenzhen Branch of CNOOC Ltd.,Shenzhen 518054,China;CNOOC Deepwater Development Ltd.,Shenzhen 518054,China;National Laboratory of Deep Oil and Gas,China University of Petroleum,Qingdao 266580,China;Laoshan Laboratory,Qingdao 266237,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东深圳518054 [2]中海石油深海开发有限公司,广东深圳518054 [3]中国石油大学深层油气全国重点实验室,山东青岛266580 [4]崂山实验室,山东青岛266237

出　　处：《地球科学》2025年第1期158-171,共14页Earth Science

基　　金：青岛海洋科学与技术试点国家实验室“十四五”重大项目(No.2021QNLM020001);中海石油(中国)有限公司综合科研项目(No.KJZH-2021-0003-00);中国石油大学(华东)自主创新科研计划项目(No.22CX06045A)。

摘　　要：白云凹陷位于珠江口盆地南部,是我国海洋深水油气勘探热点区,明确该地区的油气充注历史对于指导油气勘探至关重要.在油气藏解剖工作的基础上,基于流体包裹体分析、PVT和盆地模拟等手段,对白云凹陷东部的油气充注历史开展系统分析.研究结果表明:(1)白云凹陷东部以凝析气藏为主,局部发育少量油藏,整体表现出“上气下油”的分布格局,构造高点凝析气干燥系数和GOR相对较高;(2)储层中发育两类不同的石油包裹体组合(OⅠA):Ⅰ类OⅠA在室温条件下呈气-液两相,发黄白色、黄绿色荧光,气体充填度一般小于10%,均一温度为86.2~93.2℃,伴生盐水包裹体均一温度和冰点温度分别为100.9~104.1℃以及-4.3~-4.2℃;Ⅱ类OⅠA为气-液或气-液-固三相,呈黄绿色、蓝绿色以及蓝白色等荧光,气体充填度为10%~30%,均一温度为71.1~112.4℃,伴生盐水包裹体的均一温度和冰点温度分别为96.8~108.6℃和-2.8~-2.4℃;(3)Ⅰ类石油包裹体对应的油气充注事件大约发生在10.8 Ma,整体表现为常压充注;Ⅱ类石油包裹体对应的油气充注年龄为2.8 Ma左右,整体表现出弱超压;(4)白云凹陷东部在珠江组-韩江组沉积期形成一些油藏,粤海组沉积期至现今,深层天然气沿断裂与砂体输导通道向上运移调整,并对早期的油藏进行改造,通过运移分馏作用形成现今一系列的凝析气藏.The Baiyun Sag,situated in the southern part of the Pearl River Mouth Basin,is an area for active deep-water oil and gas exploration in China.Insight into the oil and gas charge history in the area is crucial for further oil and gas exploration.Based on detailed investigation of oil and gas reservoirs in the eastern Baiyun Sag,this study aims to provide a better understanding of the oil and gas charge history through an integrated fluid inclusion analysis,PVT and basin modeling.The results indicate that:(1)The eastern Baiyun Sag is dominated by gas condensate with some locally developed oil reservoirs.The overall distribution pattern shows that gas occurs in the shallow reservoirs while oil in the deeper reservoirs.In structural highs,gas condensate reservoirs are characterized by relatively high gas dryness coefficient and gas-oil ratio(GOR).(2)Two different types of oil inclusion assemblages(OIAs)have been identified in the reservoirs:TypeⅠOIA is characterized by gas-liquid phases at room temperature,emitting yellowish white and yellowish green fluorescence.The vapor filling degree is generally less than 10%,and the homogenization temperature(Th)is 86.2-93.2℃.The Th and final ice-melting temperature(Tm)of the coeval aqueous inclusions are 100.9-104.1℃and-4.3℃to-4.2℃,respectively.TypeⅡOIA is featured by gas-liquid or gas-liquid-solid phases at room temperature,with yellowish green,blue-green,and blue-white fluorescence.The vapor filling degree ranges from 10%to 30%,and the Th values are in the range of 71.1℃to 112.4℃.The Th and Tm values of the coeval aqueous inclusions are 96.8-108.6℃and-3.2℃to-2.7℃,respectively.(3)The oil and gas charge event corresponding to TypeⅠOIA occurred at approximately 10.8 Ma under a normal hydrostatic pressure condition,whereas the equivalent oil and gas charge timing of TypeⅡOIA was around 2.8 Ma,under a weak overpressure condition.(4)Some oil reservoirs were entrapped in the eastern Baiyun Sag during the Zhujiang-Hanjiang Formation depositional periods.Fro

关 键 词：油气充注历史 运移分馏 流体包裹体 PVT模拟 白云凹陷 珠江口盆地 石油地质学 

分 类 号：P618.13[天文地球—矿床学]