扩展弹性阻抗反演在深海扇含气储层识别中的应用

Application of EEI Inversion Technique to Submarine Gas Reservoir

深海扇A区块的纵波阻抗对气水层的分辨能力低,利用常规叠后波阻抗难以有效预测流体展布范围,为此采用了叠前扩展弹性阻抗反演技术。扩展弹性阻抗反演技术是弹性波阻抗反演的进一步推广,其包含更丰富的岩性和流体信息,是一种有效的流体检测技术。在简介扩展弹性阻抗的概念以及反演方法原理的基础上,着重分析了研究区流体检测敏感参数,优选了流体检测的最优理论角度,最终计算生成了用于流体检测的扩展弹性阻抗曲线。对研究区实际资料进行的扩展弹性阻抗反演的实际应用效果表明,扩展弹性阻抗反演在深海扇储层的流体识别,特别是气水判别方面具有良好的效果,由此为深海扇储层的含流体性质建立了一种有效的判别方法。

In submarine Block A, traditional post-stack wave impedance cannot effectively predict the fluid distribution range because of low ability of P-impedance to identify gas and water. In this paper, we adopt the pre-stack extended elastic impedance （EEI） inversion technique. EEI inversion technique including more information about lithology and fluids is an effective technique for the fluid detection and recognition. On the basis of briefly presenting the concept, method and principle of EEI,we use this inversion method to the submarine Block A. We check the sensitive parameters for fluid detection,optimize the optimal theo- ry angles for fluid detection,and calculate the EEI curves for fluid detection. The results show that the pre stack extended elastic impedance inversion is favorable for the submarine reservoir fluid identification, especially for the gas and water detection. So the effective fluid identification is established for deep sub marine fans.