北部湾盆地福山凹陷烃源岩地球化学特征及地质意义  

Geochemical features and geologic significance of source rocks in Fushan sag,Beibuwan basin

作　　者：陈善斌[1] 甘华军[1] 时阳 赵迎冬[1] 王祥[1] 

机构地区：[1]中国地质大学(武汉)资源学院,湖北武汉430074 [2]中国石油南方石油勘探开发有限责任公司,广东广州510240

出　　处：《油气地质与采收率》2015年第1期14-19,25,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家自然科学基金青年基金"北部湾盆地涠西南凹陷含烃流体运移特征及其地温异常效应分析"(41202074);中国博士后科学基金"川东南志留系页岩气储层评价及成藏条件分析"(201104465)

摘　　要：福山凹陷烃源岩地球化学特征对资源量评价及勘探目标优选具有重要意义。福山凹陷流沙港组烃源岩地球化学特征多参数分析和对比研究表明,流三段烃源岩主要发育于淡水、弱氧化湖泊环境,有机质丰度较高,有机质类型以Ⅱ1—Ⅱ2型为主,属于优质烃源岩;流二段烃源岩形成于淡水—微咸水、弱氧化—弱还原的湖泊环境,有机质丰度高,以Ⅱ1型有机质为主,属于优质—高丰度烃源岩;流一段烃源岩主要沉积于淡水、弱氧化的湖泊环境,有机质丰度较高,有机质类型以Ⅱ2型为主,属于次优质烃源岩。福山凹陷流沙港组烃源岩在流一段沉积晚期(38 Ma)开始生油,涠一段沉积早期(30 Ma)进入生油高峰期,新近系早期(20 Ma)进入生气门限,目前仍处于大量生烃阶段。白莲次凹现今生烃强度高于皇桐次凹,白莲含油气子系统的下部含油气子系统是最佳含油气系统,环白莲次凹油气聚集带的流三段一亚段—流二段储盖组合具有较大勘探潜力。Geochemical features of source rocks have great significance on resource evaluation and exploration target optimization in Fushan sag. Multiple geochemical parameters analysis and comparison of the source rocks in the Liushagang Formation of Fushan sag suggest that hydrocarbon source rocks in the 3rdmember of the formation developed in freshwater lakes,weak oxidation environments with high abundance of organic matter which is type Ⅱ1-Ⅱ2. They are high quality source rocks. The source rocks in the 2ndmember of the Liushagang Formation developed in freshwater or brackish water,weak oxidation or slightly deoxidization environments with higher abundance of organic matter which is mainly type Ⅱ1.They are high quality and high abundance source rocks. The source rocks in the 1stmember of the Liushagang Formation developed in freshwater,weak oxidation sedimentary environment with high abundance of organic matter which is type Ⅱ2.They are secondary high quality source rocks. Source rocks of the Liushagang Formation entered into its oil generation threshold at the late depositional stage of the E2l1Formation(about 38 Ma),reached the peak period of oil generation at the early depositional stage of E3w1(about 30 Ma),and entered into its gas generation threshold at the early depositional stage of N(about 20 Ma),and it is still in the stage of a large amount of hydrocarbon generation. At present,hydrocarbon-generating intensity of Bailian subsag is higher than that of Huangtong subsag. The geochemcial features of source rocks show that the lower petroleum system of Bailian subsag is the best in Fushan sag,and the exploration potential in the E2l31andE2l2 Formation in Bailian is greater with better reservoir-seal assemblage.

关 键 词：流沙港组 烃源岩 地球化学特征 北部湾盆地 福山凹陷 

分 类 号：TE112.113[石油与天然气工程—油气勘探]