HTI介质弹性波多参数波形层析反演方法研究

The widely distributed vertical fractures or nearly vertical fractures in fractured hydrocarbon reservoirs can be equivalent to transverse isotropic media with horizontal symmetric axis, i.e.HTI media. Considering the relations between the survey line and the horizontal symmetric axis, two-dimensional three-component wave equations in the survey coordinate system involving the azimuth angles should be constructed. Meanwhile, with taking the azimuth angle into account, more independent elastic coefficients in the tensor matrix are involved, increasing the difficulties in multi-parameter inversion. To solve the above-mentioned difficulties, the sensitivities of the parameters will be analysed, and tuning factors will be designed to balance the sensitivity differences and finally realize stabilized inversion. In addition, during the inversion we are also going to combine the three-component seismic data from different acquisition azimuth angles, and implement step by step and sequential inversion strategies to obtain high-resolution an-isotropic models. This study is theoretically valuable and important for the application of multi-wave multi-component seismic methods in oil and gas exploration.

裂缝性油气储层中广泛发育的垂直或高角度裂缝可用具有水平对称轴的横向各向同性介质等效，即HTI介质。考虑到地震测线方向与HTI介质水平对称轴的位置关系，本项目将构建旋转坐标系下HTI介质的二维三分量波动方程。同时，方位旋转角度的引入使得弹性系数矩阵中独立参数个数增多，多参数联合反演难度增加。本项目将分析方位旋转HTI介质中各参数的敏感性特征，研究调谐因子的设计方法，用以平衡其敏感性差异实现稳定化反演；在反演过程中研究不同采集方位三分量地震数据的联合应用，采用分段、依序的反演策略实现各向异性参数的精确反演。本研究对多波多分量地震技术在能源勘探领域的实际应用具有重要意义。

裂缝性油气储层中广泛发育的垂直或高角度裂缝可用具有水平对称轴的横向各向同性介质等效，即HTI介质。考虑到地震测线方向与HTI介质水平对称轴的位置关系，本项目构建了旋转坐标系下HTI介质的二维三分量波动方程，采用了旋转交错网格有限差分方法实现波场模拟；对比了三组描述方位旋转HTI介质的参数组合，分析了各参数组合中参数的敏感性特征，设计了调谐因子以平衡参数间的敏感性差异，实现了稳定化反演；在反演过程中引入了震源编码方法和MPI并行提高计算效率，采用了低频段到高频段的多尺度策略和两个阶段的反演策略实现了多个参数的精确反演。此外，本项目还研究了全频带拓频方法和结构倾角导向的向量中值滤波方法，分别用于提高地震数据的纵向分辨率和压制噪声、提高信噪比，在实际地震数据的应用中取得了明显的效果。本研究发表国际SCI论文4篇，会议论文3篇，申请并获批软件著作权5项。本项目的研究成果可为裂缝性油气储层描述提供数据基础，多参数同步反演方法为其它复杂介质的多参数反演提供借鉴，拓频方法和去噪方法可为反演和成像提供包含低频分量的高信噪比地震数据，对多波多分量地震技术在能源勘探领域的实际应用具有重要意义。