渤海湾盆地石臼坨凸起秦皇岛27-3大型油田发现与地质新认识  

Discovery and geological insights into QHD 27-3 large oilfield in Shijiutuo uplift of Bohai bay basin

作　　者：周家雄 徐春强 杨海风 张宏国 张震 柳永军 张德龙 ZHOU Jiaxiong;XU Chunqiang;YANG Haifeng;ZHANG Hongguo;ZHANG Zhen;LIU Yongjun;ZHANG Delong(CNOOC China Limited,Tianjin Branch,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《中国海上油气》2024年第1期14-25,共12页China Offshore Oil and Gas

基　　金：中海石油(中国)有限公司“七年行动计划”重大科技专项课题“渤海油田上产4000万吨新领域勘探关键技术(编号:CNOOC-KJ 135 ZDXM 36 TJ 08 TJ)”部分研究成果。

摘　　要：渤海湾盆地石臼坨凸起历经50余年勘探,在凸起高部位背斜区发现了3个浅层亿吨级大油田,而低部位斜坡区浅层由于构造圈闭不发育,勘探程度较低,近10年无规模性发现。随着渤海海域勘探程度提高,现已全面进入岩性勘探阶段,针对石臼坨凸起东段顺向断裂斜坡区浅层油气运移、岩性圈闭刻画和油气成藏规律等展开了深入系统研究。研究认为:(1)研究区南北两侧被富生烃凹陷夹持,凸起边界大断层晚期强烈活动和陡坡带近源扇体普遍发育使凸起区成为规模性油气运聚的最终指向区;(2)凸起边界大断层在馆陶组开启系数最小,馆陶组含砾砂岩输导层是石臼坨凸起之上主要的油气横向运移通道;(3)馆陶组输导脊坡度和切脊断层组合控制顺向斜坡区油气的垂向输导,当坡度小于1°且断层长度大于2.50 km、成藏期断距大于40 m时斜坡区可产生规模性的油气垂向运移,突破顺向断裂斜坡区“过路不留”的传统认识;(4)在凸起斜坡区,与构造脊方向斜交的砂体有利于油气保存,同时,提出井约束谱蓝化整形高分辨率处理技术,实现了对斜坡区岩性圈闭有效刻画,优选出保存条件较好的斜向砂体开展钻探部署。基于上述新认识、新技术,2023年在石臼坨凸起东段顺向斜坡区成功评价了秦皇岛27-3亿吨级油田,实现了勘探老区浅层挖潜的重大突破,为渤海湾盆地高成熟探区持续油气发现提供了借鉴。After more than 50 years of exploration in Shijiutuo uplift within Bohai bay basin,three large oilfields with 100 million tons reserves have been discovered in the anticlinal traps of higher structural position.Conversely,the slope region in the lower structural position exhibits no significant discoveries in the last decade due to the lack of structural traps and the relatively less exploration efforts.As the improvement of exploration activities in Bohai sea area,the focus has transitioned comprehensively into the lithological exploration phase.A profound and systematic study has been undertaken to investigate the shallow hydrocarbon migration,lithological trap characterization,and the hydrocarbon accumulation law in the axial fault slope region of the eastern segment of Shijiutuo uplift.The results show that:(1)The northern and southern flanks of the study area are gripped by hydrocarbon-rich depressions.The late-stage vigorous activities of major faults along the uplift boundary and the widespread development of near-source fans in the steep slope zones make the uplifted area as the final direction of substantial hydrocarbon migration and accumulation.(2)The major fault along the uplift boundary exhibits the lowest opening coefficient in Guantao Formation,where the conglomeratic sandstone reservoir serves as the main lateral migration transportation for hydrocarbon migration atop Shijiutuo uplift.(3)The combinations of transport ridge gradient and cutting ridge fault in Guantao Formation control the vertical migration of hydrocarbon in the axial slope region.Under the conditions of slope gradient less than 1°,and the fault length surpasses 2.50 km,along with the fault distance exceeding 40 m during the accumulation period,the slope region is conducive to the occurrence of significant vertical hydrocarbon migration,challenging the traditional understanding of“no retention during passage”in the axial fault slope region.(4)In the uplift slope region,the sand bodies obliquely intersecting the structural ridg

关 键 词：秦皇岛27-3 顺向斜坡区 油气运聚 岩性圈闭刻画 石臼坨凸起 渤海海域 浅层 油田发现 

分 类 号：TE122.1[石油与天然气工程—油气勘探] P744.4[天文地球—海洋科学]