莺歌海凹陷梅山组海底扇的沉积特征及控制因素

Sedimentary Characteristics and Controlling Factors of Submarine Fan in Meishan Formation of Yinggehai Sag

莺歌海盆地的莺歌海凹陷是富生烃凹陷,在其东方区黄流组海底扇的勘探已发现大气田,应进一步往深层探索梅山组海底扇。基于东方区的钻井资料和三维地震资料,以经典层序地层学为指导,分析东方区梅山组海底扇的物源特征、外部形态特征、内部期次划分、控制因素及勘探潜力。综合考虑坡折带、区域海平面变化及充足的物源供应等因素对海底扇的控制,建立了东方区梅山组"双向物源、坡折控扇、低洼汇聚"的沉积模式。盆地发育东西双向物源,在东方区对应发育东西物源海底扇。东西两个方向的大型海底扇在纵向上均可分为3期扇体,垂向上各期扇体相互叠置,具有良好的油气成藏条件。

Yinggehai sag inYinggehai Basin is hydrocarbonrich sag.Large gas fields have been discovered in the exploration of the submarine fan of the Huangliu Formation in Dongfang area,and the submarine fan of the Meishan Formation should be further explored.Based on the drilling,3 D seismic data of Dongfang area,the provenance characteristics,external morphological characteristics,internal division,control factors and the exploration potential of submarine fan are analyzed in Meishan Formation in the Dongfang area,guided by classical sequence stratigraphy.Consideringthe slope fold zone,regional sea level change and the control of the submarine fan with sufficient source supply,the sedimentary model of″two-way source of east and west,fan controlled by the slope folding,and submarine fans converge at low altitudes″in Meishan Formation ofDongfang area is established.Yinggehai Basin has the developmental characteristics of two-way source,and the east-west provenance submarine fan develops correspondingly in Dongfang area.The large submarine fan in the east and west directions can be divided into three stages in the vertical direction,and the fans in each stage are superimposed on each other in the vertical direction,which have good oil and gas accumulation conditions.