论文部分内容阅读
珠海组是珠江口盆地白云凹陷重要的油气储层与区域性疏导层,对其物源的认识是研究优质油气储层发育与有效疏导砂体分布的重要基础。基于大量的三维地震数据和钻井资料分析,提出珠海组沉积期白云凹陷发育北部古珠江(主)、南部隆起(次)、东沙隆起(贡献有限)3个物源区。利用详细的地震相分析、钻井岩心岩石组构分析、泥岩黏土矿物分析及碎屑锆石U—Pb年代学分析,重点对关注度较低的南部隆起物源开展研究。结果表明,白云凹陷西南部云开低凸起上普遍发育由南向北的叠瓦状前积地震相及向北东、东方向延伸的下切河道,指示了由南向北及由西向东的碎屑沉积物的搬运过程;云开低凸起及周缘钻井中的珠海组具有较粗的岩石粒度、泥岩中较高的高岭石含量、碎屑锆石以中生代岩浆锆石为主的特征,这与凹陷北部古珠江物源控制下的细—极细岩石粒度、泥岩中较高的伊利石黏土矿物含量、碎屑锆石以前寒武纪—古生代变质锆石为主的特征截然不同。综合分析认为,南部隆起物源为云开低凸起珠海组提供了充足的沉积碎屑物质,并推进至白云主洼,该物源的发育对云开低凸起的油气运移及成藏具有重要的意义。
Zhuhai Formation is an important hydrocarbon reservoir and regional trap in the Baiyun Depression of the Pearl River Mouth Basin. The understanding of its source is an important basis for studying the development of high-quality oil and gas reservoirs and the effective distribution of sand bodies. Based on a large number of 3D seismic data and drilling data analysis, it is proposed that there are three provenance areas in Zhuhai Formation Baiyun sag developed in the north of the Zhujiang River (main), uplifted in the south and uplifted in the Dongsha uplift. Based on detailed seismic facies analysis, rock core structure analysis of drilling core, clay mineral analysis of mudstone and U-Pb chronological analysis of detrital zircons, the emphasis is placed on the source of southern uplift with low interest. The results show that the seismic facies of the sub-imbricate foredeep from south to north and the down-cut river extending to the east and northeast of the area are generally developed on the Yunkai low protuberance in the southwestern part of Baiyun Depression, indicating that from south to north and from west to east The transport process of clastic sediments; the Zhuhai Formation in the low clouds and the drilling in the peripheral margin have coarse rock grain size and higher kaolinite content in the mudstone, and detrital zircons are dominated by the Mesozoic magmatic zircons , Which is quite different from the fine-ultrafine rock particle size under the control of the ancient Pearl River source in the northern depression, the higher illite clay mineral content in the mudstone, and the predominantly Precambrian-Paleozoic metamorphic zircons of the detrital zircons. The comprehensive analysis shows that the southern uplifting source provides plenty of sedimentary detrital material for the Zhuhai Formation with low cloud bulge in the cloud and advances to the main depression of Baiyun, It is of great significance.