【摘要】 珠江口盆地北部坳陷带文昌组分布广泛,是该区主要烃源岩发育层段。对文昌组的划分以及分布规律的认识,是洼陷评价的基础。通过井—震标定,从单井资料入手,结合地震反射特征分析,认为文昌组顶、底界面在洼陷边缘为不整合面,洼陷中央为整合面,具有4种类型;根据井—震标定将文昌组分为2~3段,洼陷陡坡带发育扇三角洲相(楔状、杂乱、弱反射)和冲积扇(楔状、杂乱、强反射),深陷带发育滨浅湖相(中—低频、中等连续性、弱反射)和中深湖相(低频、连续、强反射),缓坡带发育三角洲相(前积结构、中—高频、中等连续、中—弱反射);文昌组沉积物纵向表现为粗—细—粗的特征,洼陷底部为冲积扇—扇三角洲相,中部过渡为滨浅湖—中深湖相,顶部为扇三角洲—滨浅湖相。受物源、水体以及后期剥蚀作用,不同洼陷沉积环境不同。更多还原

【Abstract】 The source rock of Wenchang Formation is widely distributed in northern depression of Zhujiangkou basin.The recognition of division and distribution rules is the base of sag evaluation.Based on correlation of well data and seismic reflection,we hold that the top boundary and the bottom boundary of Wenchang Formation are unconformities but conformities towards sag center.The characters of Wenchang Formation boundaries can be divided into four types.Wenchang Formation can be divided into two-three segments on the base of seismic reflection.Through seismic facies and sedimentary environment analysis,we can recognize fan delta(wedgelike,clutter,weak reflection) and alluvial fan(wedgelike,clutter,bright reflection) in the actic region,lacustrine facies(low-frequency,continue,weak to bright reflection towards sag center) in the center of sag and delat(high-frequency,middle continue,weak reflection) in the slope region.Owing to tectonic activities′s diversity,size of grain of sediments is coarse-fine-coarse.更多还原