渤海湾盆地渤中C构造区沙一段混合沉积特征与发育模式  

Mixed sedimentary characteristics and developmental patterns of the first member of Shahejie Formation in Bozhong C structure area,Bohai Bay Basin

作　　者：陈善斌 CHEN Shanbin(Tianjin Branch of CNOOC(China)Limited,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：《复杂油气藏》2024年第1期62-69,共8页Complex Hydrocarbon Reservoirs

基　　金：中海石油(中国)有限公司重大科技专项“渤海中深层复杂油气藏高效开发技术”(CNOOC-KJ 135 ZDXM 36 TJ 03TJ-GD 2020-01)。

摘　　要：渤海湾盆地沙河街组沙一段、沙二段陆源碎屑岩与湖相碳酸盐岩的混合沉积是古近系重要的含油层系之一。为阐明该类储层沉积特征及发育模式,更好服务于勘探开发,以渤中C构造区为例,依据钻井、测井、地震及岩心分析化验等资料,对研究区沙一段混合沉积的岩石学特征、影响因素及其发育模式开展详细研究。结果表明,研究区沙一段混合沉积主要发育生屑云岩和粒屑砂砾岩两种岩石类型,分属于扇三角洲型和生屑滩型混合沉积;其中生屑云岩属于中高孔、中渗储层,是油田产能主要贡献层,该类储层主要受古地貌和古环境等因素影响,基于回剥法精细恢复古地貌,结合实钻结果,提出了“生屑云岩环岛状分布、向阳缓坡好、背阴陡坡差的发育模式”,进而预测研究区南部缓坡区为生屑云岩发育“甜点区”。研究成果成功指导了油田调整及挖潜,对类似油田储层研究具有借鉴意义。The mixed deposition of terrestrial clastic rocks and lacustrine carbonates in the first and second members of the Shahejie Formation in the Bohai Bay Basin is one of the most essential oil-bearing strata in the Paleogene.To clarify the depositional characteristics and development model of this type of reservoir and to better serve the exploration and development,taking the Bozhong C structural area as an example,based on the date from drilling,logging,seismic,and core analysis,it was studied in detail on the petrological characteristics,influencing factors,and development model of the mixed deposition in the first member of the Shahejie Formation in the study area.The results show that the mixed sedimentation of the first member of the Shahejie Formation in the study area mainly develops two rock types:bioclastic dolomite and grainy glutenite,which belong to the fan-delta type and bioclastic beach type of mixed sedimentation.Among them,bioclastic dolomite belongs to the medium-high porosity and medium permeability reservoir,which is the main contribution layer of oilfield productivity.This reservoir type is mainly affected by ancient landscape and paleoclimate factors.Based on the fine restoration of paleogeomorphology by the back-stripping method,combined with the actual drilling results,the development model o“f bioclastic dolomite island-like distribution,good sunny gentle slope and steep slope difference of back-shade”is proposed,and then it is predicted that the southern gentle slope area of the study area is the“sweet spot area”for the development of bioclastic dolomite.The research results have successfully guided the adjustment and potential tapping of the study area,and have reference significance for similar oilfield reservoir research.

关 键 词：混合沉积 古地貌 发育模式 渤海湾盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]