基于双相介质的地震流体识别

Seismic fluid discrimination based on two-phase media theory

关键词:  双相介质  流体识别  弹性阻抗  叠前地震反演  频散属性

Key words:  two-phase media  fluid discrimination  elastic impedance  pre-stack seismic inversion  dispersion-dependent attribute

摘要:

为避免间接计算的累积误差,提高储层流体识别精度,根据孔隙弹性介质理论,建立基于弹性阻抗反演的流体因子直接提取方法和固液解耦流体因子叠前地震反演方法。地震波在含烃储层中传播时发生速度频散,根据中观尺度岩石物理理论,提出基于叠前反演的频散属性提取方法,实现频散属性的定量表征,将速度的频散幅度用于流体识别。该方法实际工区应用效果良好。结果表明:以双相介质岩石物理理论为基础建立流体因子,依托叠前地震反演进行储层流体识别的方法精确可靠。

Abstract:

To avoid the cumulative error and to enhance the accuracy of fluid discrimination, a direct extracting approach for fluid factors based on elastic impedance inversion and a novel solid-fluid decoupled way to constructing the fluid factor with poroelastic theory were proposed. Seismic velocity dispersion is persistently observed in hydrocarbon reservoirs. Based on mesoscopic scale rock physics theory, a dispersion-dependent attribute inversion method was developed for reservoir fluid discrimination by using pre-stack seismic data. This method provides quantitative inversion scheme of the dispersion-dependent attributes with high accuracy. Applications on real data show that this fluid discrimination method which combines fluid factor based on the two-phase media theory and pre-stack seismic inversion is more accurate and stable.