珠江口盆地番禺4洼古近系文昌组三元地震构形解释技术_黄军立.pdf

第 35 卷 第 2 期2023 年 3 月岩性油气藏LITHOLOGIC RESERVOIRSVol.35 No.2Mar.2023黄军立等：珠江口盆地番禺 4 洼古近系文昌组三元地震构形解释技术收稿日期：2022-04-28；修回日期：2022-07-04；网络发表日期：2022-09-30基金项目：中海石油（中国）有限公司综合科研项目“番禺 4-2 油田及周边古近系优质储层精细描述”（编号：SCKY-2020-SZ-25）资助。第一作者：黄军立(1983)，男，硕士，高级工程师，主要从事地质、油藏研究等方面的工作。地址：（518000）广东省深圳市南山区后海滨路（深圳湾段）3168 号中海油大厦。Email：。文章编号：1673-8926（2023）02-0103-10DOI：10.12108/yxyqc.20230210引用：黄军立，张伟，刘力辉，等.珠江口盆地番禺 4 洼古近系文昌组三元地震构形解释技术 J.岩性油气藏，2023，35（2）：103-112.Cite：HUANG Junli，ZHANG Wei，LIU Lihui，et al.Ternary seismic configuration interpretation technology of Paleogene Wenchang Formation in Panyu 4 depression，Pearl River Mouth Basin J.Lithologic Reservoirs，2023，35（2）：103-112.珠江口盆地番禺 4 洼古近系文昌组三元地震构形解释技术黄军立1，张伟1，刘力辉2，蔡国富1，曾有良1，孟庆友1，刘浩2（1.中海石油（中国）有限公司深圳分公司，广东 深圳 518000；2.北京诺克斯达科技有限公司，北京 100089）摘要：在源-汇系统格架下，以地震构形分析为基础，对珠江口盆地番禺 4 洼古近系文昌组沉积相、古地貌和地震构形属性切片进行了研究，划分了沉积单元，定性半定量指出了各沉积单元边界，并优选了2 个勘探潜力区带。研究结果表明：珠江口盆地番禺 4 洼古近系文昌组源-汇系统分为 3 类，西北部发育缓坡发散型源-汇系统，纵向上呈扇三角洲湖泊辫状河三角洲动态演化特征，地震上由中强反射过渡到中弱振幅平行反射，再演变为高频中振幅前积反射；西南部发育长轴汇聚型源-汇系统，辫状河三角洲稳定发育，以楔状展布为主；陡坡平行型源-汇系统在控洼断层上盘发育多期叠置的扇三角洲沉积，整体上呈楔形，反映了物源充沛背景下的扇三角洲平原前缘的沉积特征。研究区文昌组沉积期的古地貌整体上具有“东断西超”的格局，文五段文四段沉积期，研究区为强烈断陷期，局部构造运动使西北和东南抬升，中部形成了构造脊和 2 个次洼；文三段文二段沉积期，进入断坳期，沉积中心整体向东迁移，湖盆萎缩，西部遭受剥蚀。研究区缓坡发散型源-汇区发育 7 个沉积单元，主要为扇三角洲前缘叠置连片的水下分流河道和薄层席状砂；长轴汇聚型源-汇区发育 4 个沉积单元，以辫状河三角洲前缘水下分流河道和分布广泛的前缘席状砂为主；陡坡平行源-汇区发育水下扇、扇三角洲前缘和浊积扇等 4 个沉积单元。西南部的长轴汇聚型源-汇系统和西北部缓坡发散型源-汇系统为研究区的勘探潜力区。关键词：源-汇系统；三元地震构形；古地貌；文昌组；古近系；番禺4洼；珠江口盆地中图分类号：TE122.2；P631.8文献标志码：ATernary seismic configuration interpretation technology of PaleogeneWenchang Formation in Panyu 4 depression，Pearl River Mouth BasinHUANG Junli1，ZHANG Wei1，LIU Lihui2，CAI Guofu1，ZENG Youliang1，MENG Qingyou1，LIU Hao2（1.Shenzhen Branch of CNOOC Ltd.，Shenzhen 518000，Guangdong，China；2.Beijing RockstarPetroleum Technology，Beijing 100089，China）Abstract：Under the framework of source-to-sink system，the sedimentary facies，palaeogeomorphology and seismicconfiguration attribute slices of Paleogene Wenchang Formation in Panyu 4 depression of the Pearl River Mouth104岩性油气藏第 35 卷第 2 期Basin were studied based on seismic configuration analysis，the sedimentary units were divided，the boundariesof each sedimentary unit were defined qualitatively and semi quantitatively，and two exploration potential zoneswere selected.The results show that：（1）Three types of source-to-sink systems of Paleogene Wenchang Formation were found in Panyu 4 depression of the Pearl River Mouth Basin.A gentle slope divergent source-to-sinksystem is developed in the northwest，which is characterized by the dynamic evolution of fan delta，lake andbraided river delta in the vertical direction，and the seismic configuration changes from medium-strong reflectionsheet filling to medium-weak amplitude parallel reflection，and then to high-frequency medium amplitude progradation reflection.A long axis convergent source-to-sink system is developed in the southwest，and the braided riverdelta is developed stably，which is mainly wedge-shaped in configuration.A steep slope parallel source-to-sinksystem is developed in the hanging wall of fault controlling depression with stable multi-stage overlapped fandelta，which is generally characterized by a wedge-shaped configuration，reflecting the sedimentary characteristics of fan delta plain-front under the background of abundant sources.（2）The sedimentary palaeogeomorphologyof Wenchang Formation in the study area is generally faulted in the east and superposed in the west.During thedeposition of the fifth and fourth members of Wenchang Formation，it was in a strong fault depression period.Localtectonic movement raised the northwest and southeast，and a structural ridge and two sub depressions formed inthe central part.During the deposition of the third and second member of Wenshan Formation，it entered fault depre-ssion period，the sedimentation center moved eastward as a whole，the lake basin shrank，and the western stratawere denuded.（3）Seven sedimentary units are developed in the gentle slope divergent source-to-sink area of thestudy area，which are mainly superimposed underwater distributary channels and thin sheet sand in fan deltafront.Four sedimentary units are developed in the long axis convergent source-to-sink area，which are dominatedby underwater distributary channels and widely distributed front sheet sand in braided river delta front.In thesteep slope parallel source-to-sink area，there are four sedimentary units，including underwater fan，fan deltafront，turbidite fan.（4）The long axis convergent source-to-sink system in the southwest and the gentle slope diver-gent source-to-sink system in the northwest are the exploration potential areas in the study area.Key words：source-to-sink system；ternary seismic configuration；paleogeomorphology；Wenchang Formation；Paleogene；Panyu 4 depression；Pearl River Mouth Basin0引言番禺 4 洼为珠江口盆地典型的“小而肥”的新生代富生烃洼陷，经过近 40 年以新近系海相地层为主的勘探，寻找出十余个大中型小型的优质油田，勘探成效显著。从已钻探发现的油藏来看，该区域成藏较好的层段主要集中在新近系韩江组和珠江组，经过多年的开发生产，洼陷内大部分油田均进入了高含水期，剩余可采储量快速下降，后期储量替代不足，迫切需要寻找后备储量。剩余的中浅层构造少且小，勘探转向断陷期充填的古近系陆相沉积地层1-