EEI反演技术在西非深水砂岩储层岩性预测中的应用

Application of EEI inversion technology in the lithology prediction of deep water sand reservoir in West Africa

扩展弹性阻抗(EEI)是对弹性阻抗(EI)的改进,融合了叠后声波阻抗(AI)和叠前AVO技术的优势。阐述了EEI方法的基本原理,介绍了关键的流程步骤,包括储层预测前的数据准备、EEI最优角度的确定、反演模型的建立与实施反演,并针对西非深水某研究区的浊积砂岩储层目标进行了实例应用,对EEI反演的效果进行了分析。根据研究区地层、岩性的特点,采用EEI方法,结合岩性敏感参数GR曲线,进行角度扫描求取最优岩性角度及EEI曲线,同时结合叠前地震道集反演的EEI体,预测岩性、刻画优势砂体平面展布特征,其结果实现了有利岩性圈闭和储层的预测,有效支持了勘探目标潜力评价和区块优选。

Extended elastic impedance(EEI)is an improvement on elastic impedance(EI),combining the advantages of post-stack acoustic impedance(AI)and prestack AVO technology.This paper expounds the basic principle of EEI method,and introduces the key process steps,including the data preparation before the reservoir prediction,the determination of EEI optimal Angle,the establishment of inversion model and the implementation of inversion.Aiming at a prospect of deep water turbidite sandstone reservoir in a certain west African study area,the EEI inversion is applied and the EEI inversion result is analyzed.Based on the characteristics of the strata and lithology in the study area,the EEI method,combining with the lithology sensitive parameter GR,scans the angle to calculate the optimal angle of lithology and the related EEI curve.At the same time,combining the inverted the EEI volumn by prestack seismic traces,This paper predicts the lithology and depicts the lateral distribution of the predicted sand body.The prediction of the favorable lithologic trap and reservoir is realized,which effectively supports the potential evaluation and optimization of the exploration prospect and the block.