波阻抗反演在琼东南海域水合物检测中的应用

为了更好地研究天然气水合物的展布形态和赋存情况,对琼东南海域天然气水合物勘探区的地震资料进行波阻抗反演。首先利用基于精细速度分析的高分辨率层速度反演方法来建立低频阻抗模型,然后采用了基于波动方程Born近似的直接反演和基于模型优化的间接反演两种方法进行反演研究。结果表明,研究区数据体波阻抗高低分异明显,地质现象比较清楚,能够比较准确地反映地下水合物矿体的展布情况,且可靠性较高,可用于后续的水合物储层分析及综合研究。本文在无井约束的条件下,采用波阻抗反演技术开展适用于天然气水合物的识别研究,对未来的水合物勘探具有重要的现实意义。

APPLICATION OF WAVE IMPEDANCE INVERSION TO GAS HYDRATES PREDICTION IN SOUTHEAST HAINAN BASIN

In order to make prediction of gas hydrate distribution and occurrence, wave impedance inversion was adopted to process the seismic data from the gas hydrate survey in Sotheast Hainan Basin in this paper. At the very beginning, a low frequency impedance model was established by high resolution interval velocity inversion which depends on precise velocity analysis; then, two inversion methods, the direct inversion based on Born's wave equation and the indirect inversion based on model optimization, were used for impedance inversion. The results show that the wave impedance of seismic data in the study area is easy to be distinguished for geological interpretation, and the distribution of gas hydrate was sound and clearly described. In case there is no well logging data, wave impedance inversion could be used to study gas hydrate and is practical to gas hydrate exploration in the future.