叠前AVO特征分析方法在惠州地区油检测中的应用  

Application of pre-stack AVO characteristics analysis on oil detection in Huizhou area

作　　者：陈兆明 

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东广州510240

出　　处：《中国海上油气》2015年第5期43-48,共6页China Offshore Oil and Gas

摘　　要：受地震分辨率的限制,珠江口盆地惠州凹陷东沙隆起区岩性尖灭线的位置很难准确落实,导致岩性圈闭封闭范围很难确定,因此迫切需要对该区的有利砂体进行油的检测,以证实岩性圈闭封闭性与成藏条件。针对惠州地区原油高气油比、低密度的特性,对该区多口已钻井进行叠前AVO正演模拟与分析统计,初步判定研究区的叠前AVO特征,然后对目的层进行流体替换,分析流体变化对AVO特征的影响,进一步界定研究区的叠前AVO特征。分析结果认为,该区油层一般呈III类AVO特征,水层呈IV类AVO特征。据此在该区无井区利用叠前地震数据进行AVO特征分析,有效区分了油层和水层,其检测结果与钻井结果相吻合,减小了勘探风险。It is hard to accurately identify the lithologic pinch-out boundary in the area of Dongsha Massif in Huizhou sub-sag, Pear River Mouth basin, due to the limitation of seismic resolution, which makes it dif- ficult to determine the enclosed scope of lithologic trap. Therefore, oil detection is urgently essential in the favorable sandbody of this area to confirm sealing properties of lithologic trap and accumulation conditions. According to the oil characteristics of high gas-oil ratio and low density in Huizhou subsag, AVO forward modeling and statistical analysis for drilled wells were carried out to estimate the preliminary pre-stack AVO characteristics of this area. Fluid substitution of target layers was conducted to analyze the influence of fluid variation on AVO characteristics, and the pre-stack AVO characteristics of this area were further defined. Analysis results show that oil layers mainly have the III AVO characteristics and water layers have IV AVO characteristics, with which the AVO characteristics are analyzed by using pre-stack seismic data in the area without well, and oil layers are efficiently distinguished from water layers. The detection results are consistent with well results, reducing the exploration risk.

关 键 词：叠前AVO特征分析 AVO正演 流体替换 原油检测 惠州地区 

分 类 号：TE122.2[石油与天然气工程—油气勘探]