利用纵波方位AVO 技术进行裂缝检测

从理论上讲，利用纵波地震资料反射振幅随方位角的变化可以对近似定向排列的地下裂缝导致的方位各向异性进行描述和预测。研究区的主要目的层为中浅层碳酸盐岩储集层，地震资料具有宽方位、高覆盖、高信噪比的特点。为保持地震波的方位AVO 振幅特征，减少采集和处理因素对地震波振幅的改造和畸变，在地震资料处理过程中采用精细的振幅保持处理，并使用宏面元和叠前时间偏移技术提高目的层的成像质量。通过对5 个不同方位角叠前时间偏移结果的分析，对研究区的裂缝方向和裂缝密度进行了预测。并结合研究区的地质资料和方位AVO 的技术特点对预测结果进行了分析。

Fracture Detection with 3D P-Wave Azimuthal AVO

Theoretically, the anisotropy of subsurface medium resulted from fractures in approximately same strike can be characterized and predicted using the variation of reflection amplitude of P-wave seismic date with azimuth. The target stratum in studied area is carbonate reservoir of shallow-middle depth, which are characterized by the seismic data of wide-azimuth, high-fold and high S/N ratio. The technology of amplitude preservation is carefully used during seismic data processing for preserving amplitude variation from azimuth AVO and avoiding amplitude abnormity produced from acquirement and processing. The technologies of macro-binning and pre-stack time migration (PSTM) are used for improving the imaging quality of target stratum. Based on the PSTM data volumes of 5 different azimuthal angles, the strike and intensity of fractures in studied area are predicted. Along with the geologic data and the characteristic of P-wave azimuthal AVL, the prediction results are analyzed and discussed.