摘要
针对油气勘探中深水扇富砂/富泥特征预测的难题,本文应用三维地震和少量的钻井资料,综合采用地震相分析、地震波形分析和地震反演的方法,对珠江口盆地白云凹陷SQ13.8层序细粒深水扇的内幕结构展开精细解剖,结合该扇体在层序格架中的位置、沉积微相的构成、岩性组成和储层特征的细致分析,建立了深水扇的沉积模式。SQ13.8层序沉积期,白云凹陷发育大型低位体系域斜坡扇,斜坡扇的主体由多条大型下切水道及大型水道之间的天然堤堆积构成,长期的重力流水道向下游方向迁移而形成多条大型下切水道,后续发育的不同期次、不同规模、不同充填物重力流水道完全受限在大型水道内,在大型水道内迁移、摆动、叠置、侵蚀或卸载;该类扇体沉积物粒度细,以泥岩为主,发育少量粉砂岩和细砂岩,较细粒的泥质沉积分异在水道两侧的天然堤上,细砂及更粗粒的砂岩储层主要发育较低部位的下切水道内。这种精细解剖深水扇内幕结构进行储层预测的方法,以及在此基础上建立的具有复杂内幕结构的深水扇沉积模式与有利储层分布预测,对南海深水油气勘探具有良好的借鉴和指导意义。
Aiming at the difficulty in predicting the characteristics of deep-water sand/mud-rich fans in oil and gas exploration,by using three-dimensional seismic and a small amount of drilling data,and in combination with seismic facies analysis,seismic waveform analysis,and seismic inversion,this paper carried out a precise analysis on the inner structure of the deep-water fine-grained fan in SQ13.8 sequence of Baiyun sag.A deep-water fan sedimentary model was hereby established through precisely dissecting the position of the fan body in the sequence framework,the composition of sedimentary microfacies,the lithological composition,and reservoir characteristics.During the depositional period of SQ13.8,a large low-stand system tract slope fan was developed in the Baiyun sag.The main body of slope fan was composed of multiple large-scale incised channels and the natural levee accumulation between large-scale channels.The long-term migration of gravity flow channels towards the downstream direction formed several large-scale undercut channels that restricted the subsequently developed gravity flow channels with different stages,different scales,and different filling.All the migration,swinging,overlapping,erosion or unloading of the subsequently channels occurred within the previously formed large channels.This type of fan sediments is fine-grained,dominated by mudstone,and followed by a small amount of siltstone and fine sandstone.The fine-grained muddy deposits were differentiated on the natural levees on both sides of channel,and fine sandstone and coarser sandstone reservoirs were mainly developed in the incised channels in the lower position.This reservoir prediction method of finely dissecting the inner structure of deep-water fans,as well as the further established deep-water fan sedimentary model with complex inner structures and the predicted distribution of favorable reservoirs,have a good reference and guiding significance for deep-water oil and gas exploration in the South China Sea.
作者
陈亮
冯轩
韩晋阳
王家豪
CHEN Liang;FENG Xuan;HAN Jinyang;WANG Jiahao(CNOOC China Limited,Shenzhen Branch,Shenzhen,Guangdong 518054,China;Faculty of Earth Resources,China University of Geosciences(Wuhan),Wuhan,Hubei 518054,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2020年第5期36-43,共8页
China Offshore Oil and Gas
基金
“十三五”国家科技重大专项“海洋深水区油气勘探关键技术”课题3“珠江口盆地陆缘深水区油气地质及勘探关键技术(编号:2016ZX05026-003)”部分研究成果。
