基于叠前扩展弹性阻抗的波形指示反演技术在西湖凹陷C油田深层薄互层储层刻画中的应用  

Application of waveform indication inversion technique based on pre-stack extended elastic impedance in deep thin interlayer reservoir characterization in C oilfield,Xihu Sag

作　　者：廖恒杰 娄敏 何贤科 刘江 段冬平 李炳颖 包全 LIAO Hengjie;LOU Min;HE Xianke;LIU Jiang;DUAN Dongping;LI Bingying;BAO Quan(Shanghai Branch of CNOOC(China)Co.,Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《石油地质与工程》2025年第1期74-80,86,共8页Petroleum Geology and Engineering

基　　金：国家科技重大专项“东海厚层非均质性大型气田有效开发关键技术”(2016ZX05027-004)。

摘　　要：储层的精细刻画对油气田的高效开发具有重要的意义,受地震资料分辨率低和砂泥岩纵波阻抗叠置影响,常规储层预测方法难以实现对砂体的准确预测及精细刻画。基于叠前扩展弹性阻抗的波形指示反演技术可以大大提高薄互层储层刻画的准确度和精度。该技术首先通过测井岩石物理分析不同旋转角度岩性与弹性属性的相关性,求取最佳拟合角度,获得反映岩性的扩展弹性阻抗曲线;然后利用CRP地震道集数据计算截距和梯度属性体,根据最佳拟合角度求取扩展弹性阻抗反射系数体;最后在扩展弹性阻抗反射系数体的基础上,用波形指示反演方法获得高分辨率储层预测成果。西湖凹陷C油田应用结果表明,储层反演结果不仅保留了厚砂岩趋势,而且大幅提高了薄互层储层以及泥岩夹层的预测能力,反演成果与砂岩吻合率高,目的层10m以上砂体预测符合率90%;5m以上砂体预测符合率80%。证实了该技术可较好解决薄互层储层预测中砂泥岩阻抗叠置且分辨率不高的问题,大大提高薄层反演的精度和准确性,具有广阔的应用前景。Fine characterization of reservoirs is meaningful for the efficient development of oil and gas fields.Due to the low resolution of seismic data and the superposition of longitudinal wave impedance of sandstone and mudstone,conventional reservoir prediction methods are difficult to achieve accurate prediction and fine characterization of sand bodies.Based on pre-stack extended elastic impedance,the waveform indication inversion technique greatly improves the accuracy and precision of characterizing thin interbedded reservoirs.Firstly,the correlation between lithology and elastic properties of different rotation angles is analyzed by logging petrophysics,the best fitting angle is obtained,and the extended elastic impedance curve reflecting lithology is obtained.Then,using CRP seismic trace data,intercept and gradient attribute volumes are calculated,and the extended elastic impedance reflection coefficient volume is obtained based on the best fitting angle.Finally,based on the expansion of the elastic impedance reflection coefficient volume,high-resolution reservoir prediction results were obtained using waveform indication inversion method.The application results of C oilfield in Xihu Sag show that the reservoir inversion results not only retain the trend of thick sandstone,but also greatly improve the prediction ability of thin interlayer reservoir and mudstone interlayer.The inversion results have a high coincidence rate with sandstone,and the prediction coincidence rate of sand body above 10 m and 5 m in the target layer is 90% and 80% respectively.It has been confirmed that this technology solves the problem of sandstone shale impedance overlap and low resolution in predicting thin interbedded reservoirs,greatly improving the accuracy and precision of thin-layer inversion,and has a broad application prospect.

关 键 词：西湖凹陷 波形指示反演 叠前扩展弹性阻抗反演 高分辨率反演 薄互层储层刻画 

分 类 号：P631[天文地球—地质矿产勘探]