基于局域波分解和约束插值的地震反演

在我国东部油田的勘探开发中,井震联合高分辨率反演是薄互层储层预测的有效方法,将高频测井资料和相对低频的地震资料有机地结合起来,得到与地震资料吻合程度高的层状地质模型是获得好的反演结果的基础.为此,在时间-相位模型约束的井资料外推方法中,引入局域波分解技术来求解地震瞬时相位;通过井旁地层对比,建立测井资料与地震资料之间的联系,把测井信息在地震资料建立的等相面约束下外推出去,以获得高分辨率的属性反演剖面.针对局域波分解方法中的一些不足,提出了一种新的方法--希尔伯特变换均值模式分解法,提高了方法的计算速度和抗噪能力.此外,对测井属性外推插值到井外的方法--基于约束插值的反演理论进行了探讨,从理论上解释了拟测井曲线反演的有效性.将上述方法应用于大庆油田茂2井区,获得的扶余油层的波阻抗、自然伽马、电阻率、砂体隶属度分布等反演剖面的分辨率得到了提高,横向连续性得到了改善.

Seismic inversion based on local wave decomposition and constrained interpolation.

High resolution joint inversion of seismic data and well logging is an effective method to predict the thin interbedded reservoir in the exploration and development of eastern oil field in China. However, the combination of high frequency logging data with relative low frequency seismic data for establishing a stratified geologic model well matching the seismic data is the foundation for obtaining good inversion result. Therefore, local wave decomposition technology was introduced into the logging data extrapolation method constrained by time-phase model to gain the seismic instantaneous phase. The relationship of logging and seismic data was established through the wellside strata correlation. High resolution attributes inversion profiles were generated through the extrapolation of logging constrained by equiphase surface established based on seismic data. Meanwhile, the Hilbert transform mean mode decomposition was proposed to improve the computation speed and noise immunity. The inversion theory based on constrained interpolation (the extrapolation of logging attributes) was discussed and the effectiveness of seislog inversion was interpreted theoretically. After applying the method to Mao2 well area in Daqing oil field, the resolution of the obtained inversion profiles (wave impedance, gamma-ray, electrical resistivity, sand membership degree) was enhanced and the lateral continuity was improved.