含盐被动陆缘盆地油气输导体系与成藏模式研究——以墨西哥湾南部Burgos和Sureste盆地为例  

Study on hydrocarbon transport systems and accumulation models of salt-bearing passive continental margin basin:A case study of Burgos and Sureste basins in the southern Gulf of Mexico

作　　者：蔡文杰 陈亮 李爱山 张量 CAI Wenjie;CHEN Liang;LI Aishan;ZHANG Liang(CNOOC International Limited,Beijing 100028,China)

机构地区：[1]中国海洋石油国际有限公司,北京100028

出　　处：《中国海上油气》2021年第6期34-43,共10页China Offshore Oil and Gas

基　　金：“十三五”国家科技重大专项“西非-南美海域重点区油气地质评价及关键技术研究(编号:2017ZX05032-001)”;中海石油(中国)有限公司科技项目“墨西哥海域盐构造与第三系大型储集体及油气成藏(编号:YXKY-2018-ZY-01)”部分研究成果。

摘　　要：墨西哥湾盆地为世界著名的含盐被动陆缘盆地,油气资源极为丰富,但是该区域受到复杂盐构造的影响,油气富集规律复杂,对盐相关油气输导体系及成藏模式认识不清,制约了油气勘探部署。基于三维地震、钻井、测井等资料,利用蚂蚁追踪等地球物理方法,研究了墨西哥湾南部Burgos盆地和Sureste盆地典型油气输导体系的静态组合样式及动态输导效率,明确了二者之间油气成藏模式的差异性。研究表明,Burgos盆地主要发育逆冲挤压断层,断层组合样式以"Y"型和反"Y"型、背冲型和叠瓦型为主;逆冲断层在中晚始新世—渐新世活动,与烃源岩排烃期匹配较好,有利于油气成藏,其中"Y"型和反"Y"型断层组合样式输导效率最高;Sureste盆地主要发育盐侧翼-伴生断层复合输导体系和盐侧翼-砂岩层复合输导体系,盐底辟在中新世开始活动,与区域烃源岩排烃期匹配较好,有利于油气运聚,其中主动盐底辟侧翼裂缝更为发育,输导效率更高。在此基础上,建立了Burgos盆地和Sureste盆地油气差异成藏模式,即Burgos盆地主要表现为近源垂向、逆冲断层输导的油气成藏模式,Sureste盆地主要表现为近源垂向、盐底辟和伴生断裂-砂岩层复合输导的油气成藏模式,从而明确了有利的勘探目标类型,对于相似含盐被动陆缘盆地的油气勘探具有重要的指导意义。The Gulf of Mexico basin is a famous salt-bearing passive continental margin basin with extremely abundant oil and gas resources.However,this area is affected by complex salt structures and presents complicated rules of oil and gas enrichment.The vague understandings on salt-related hydrocarbon transport systems and accumulation models hinder the deployment of oil and gas exploration.Based on 3 D seismic,drilling,logging and other data,the static combination mode and dynamic transport efficiency of typical hydrocarbon transport systems in the Burgos and Sureste basins in the southern Gulf of Mexico have been studied by using geophysical methods such as ant tracking,and the difference in the hydrocarbon accumulation models of those two has been clarified.Studies suggest that the Burgos basin mainly developed thrust-compression faults that are dominated by the combination modes of “Y”,inverse “Y”,back thrust and imbricate types.The thrust faults were active in the mid-late Eocene-Oligocene,and matched well with the hydrocarbon expulsion period of source rocks,which is conducive to hydrocarbon accumulation.Among them,the combination mode of “Y” and inverse “Y” fault s has the highest transport efficiency;the Sureste basin mainly developed the composite transport systems of salt flanks-associated faults and salt flanks–sandstone strata.The salt diapir began to be active in the Miocene and matched well with the hydrocarbon expulsion period of regional source rocks,which is conducive to hydrocarbon migration and accumulation.Among them,the active salt diapir flanks have the better developed fractures and the higher transport efficiency.On this basis,a differential hydrocarbon accumulation model was established for the Burgos and Sureste basins,that is,the Burgos basin is mainly characterized by a hydrocarbon accumulation model of vertical near-source and thrust faults transport,and the Sureste basin is mainly characterized by a hydrocarbon accumulation model of vertical near-source,salt diapir and the

关 键 词：含盐 被动陆缘盆地 油气输导体系 成藏模式 Burgos盆地 Sureste盆地 墨西哥湾南部 

分 类 号：TE122.1[石油与天然气工程—油气勘探]