控制异常孔隙带发育的成岩流体类型与活动历史——以琼东南盆地东部宝岛北缘储层为例  

Diagenetic fluid type and activity history of controlling the development of abnormal pore zone:Taking the north margin of Baodao Sag,Qiongdongnan Basin as an example

作　　者：苏奥[1] 杜江民 陈红汉[1] 余雁 雷明珠 

机构地区：[1]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074 [2]河北地质大学资源学院,河北石家庄050031 [3]中国石油华北油田地球物理勘探研究院,河北任丘062552 [4]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《天然气地球科学》2016年第10期1837-1847,共11页Natural Gas Geoscience

基　　金："十二五"国家重大油气专项(编号:2011ZX05023-004-010)资助

摘　　要：基于地质背景和大量钻测资料,利用流体包裹体和成岩矿物组合的地球化学特征,以成岩流体类型和活动历史为视角,综合分析了琼东南盆地东部宝岛凹陷北缘储层异常高孔带的动态成因过程。研究区发育了三段异常高孔带,其中前两段在全区均有发育,第三段仅在BD19-2构造部分井发育。控制该区异常高孔带发育的流体类型为有机酸、大气淡水、烃类、热流体和无机幔源CO_2。在中新世早中期,大气水淋滤引起溶蚀,持续至中新世中期;中新世末期陵一段泥岩生排的有机酸进入储层,再次发生溶蚀形成次生孔,第四纪热流体的溶蚀作用最终形成第一段异常高孔带。中新世末期陵二段泥岩排出的有机酸引起溶蚀,持续到上新世中期,上新世早期天然气充注抑制了碳酸盐胶结物充填孔隙,与此同时热流体活动也引发溶蚀,综合形成第二段异常高孔带。中新世早期下伏崖城组源岩开始生排有机酸引起溶蚀,持续至中新世中期,中新世末期陵二段泥岩开始生排有机酸再次引起溶蚀,持续至上新世中期,中新世中期天然气充注抑制了碳酸盐胶结物充填孔隙,上新世富幔源CO_2的热流体开始活动溶蚀,综合形成第三段异常高孔带。Based on geological background and abundant drilling data,by means of fluid inclusion analysis technique and the geochemical characteristics of diagenetic minerals,this paper has studied the dy-namic formation process of abnormal high pore zones in the eastern Qiongdongnan Basin with perspective of pore fluid source and evolution.There are three abnormal high porosity zones.The previous two zones develop in whole region and the third one only develops in BD19-2structure.Organic acid,atmospheric fresh water,hydrocarbon,thermal fluid and mantle-derived CO_2 are recognized as the geological fluids which affect porosity zones.The leaching of meteoric water during stage of structure uplift in the Miocene and the dissolution of organic acid from source rocks has combined to cause the development of the first abnormal high porosity zone.The dissolution of organic acid in the Middle and Late Miocene,the inhibitor of development of carbonate cements for hydrocarbon filling in Late Miocene and the dissolution of thermal fluid activity in late stage have combined to cause the development of the second zone.The dissolution of organic acid in the late Oligocene,the inhibitor of development of carbonate cements for hydrocarbon filling in the Middle Miocene and the dissolution of thermal fluid which contains mantle-derived CO_2 activity in late stage have combined to cause the development of the third zone.

关 键 词：异常高孔带 成岩流体 活动历史 琼东南盆地 

分 类 号：TE122.23[石油与天然气工程—油气勘探]