渤海海域辽西凹陷南洼烃源岩发育主控因素  

Main controlling factors of source rock development in the south sag of Liaoxi depression, Bohai Sea, China

作　　者：王军 王德英 冯冲 柳屿博 燕歌 WANG Jun;WANG Deying;FENG Chong;LIU Yubo;YAN Ge(CNOOC Tianjin Company,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司

出　　处：《成都理工大学学报（自然科学版）》2019年第6期678-689,共12页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家科技重大专项(2016ZX05024-002-006)

摘　　要：应用已钻井烃源岩评价、次洼沉积特征对比、油源对比和地震特征对比,对渤海海域辽西凹陷南洼南、北次洼烃源岩进行预测。南、北次洼在可容纳空间增长速率相似的条件下,外部大型物源区位置、输砂通道、局部物源类型、洼间链状岛的遮挡作用联合控制了南次洼的沉积过程,为过充填沉积,导致了较低的古生产力水平、较高的沉积速率和开放氧化的水体环境,不具备优质烃源岩形成的基本条件,北次洼为平衡充填沉积;油源对比表明围区部分原油来源于北次洼烃源岩,证实了优质烃源岩存在;地震特征对比表明沙河街组有效烃源岩主要分布在北次洼陡坡带。辽西凹陷南洼北次洼具有较好的勘探前景。Hydrocarbon source rocks in the south sag of Liaoxi depression is predicted by evaluation of drilled source rocks,comparison of sedimentary characteristics,oil source correlation and comparison of seismic characteristics.Under the condition of similar growth rate of accommodation space in the south and north sub-sags,such factors as the location of external large provenance,sand transporting channels,local provenance types and block of inter-sag chain islands controlled the filling depositional process.The low level of paleo-productivity,high sedimentation rate and open oxidized water environment resulted in an unfavorable condition for the formation of quality source rocks.The northern subsag is characteristic of balanced filling deposition.Oil source correlation shows that part of the crude oil in the surrounding area is generated by source rocks in the northern subsag and therefore,high quality source rocks are likely to occur in the area.The comparison of seismic characteristics shows that the effective source rocks of Shahejie Formation mainly distribute along the steep belt of the northern subsag and northern subsag in the southern sag of Liaoxi depression and possess a good prospect for hydrocarbon exploration.This study provides reference for source rock prediction in brink depressions with few or without drilling wells.

关 键 词：边缘凹陷 烃源岩预测 充填模式 生源构成 水体环境 

分 类 号：TE122.112[石油与天然气工程—油气勘探]