共法向出射点道集三维椭圆展开速度分析方法

3D ellipse development velocity analysis based on common normal emergence point gather

 韦亮¹ 韩文功² 杜启振¹ 李文滨³ 李红梅² 梁鸿贤²

中国石油大学（华东）地球科学与技术学院，山东 青岛 266580 中国石化胜利油田分公司，山东 东营 257000 中海石油（中国）有限公司天津分公司渤海石油研究院，天津 300452

School of Geosciences, China University of Petroleum, Qingdao 266580, China Shengli Oilfield Company, SINOPEC, Dongying 257000, China Bohai Oilfield Research Institute, Tianjin Branch of CNOOC Ltd., Tianjin 300452, China

 椭圆展开速度分析方法是一种有效的叠加速度分析方法，可以解决常规速度分析方法在地层倾斜时引起的共反射点发散问题。现有的椭圆展开速度分析方法都是基于二维地质情况，无法适用于三维实际资料处理，为此，开展了三维椭圆展开速度分析方法研究。文中以椭圆展开理论为基础，推导了三维条件下的椭圆展开方程，将此方法应用到三维情况，并提出一种抽取共法向出射点道集的方法。相较于CMP道集，共法向出射点道集包含更丰富的反映法向出射点的信息。文中基于共法向出射点道集开展三维椭圆展开速度分析，该方法能够适用于地层倾斜的复杂地质条件，得到高精度的均方根速度，适用于实际生产中的交互式速度分析。

 Ellipse development velocity analysis is a developed stack velocity analysis method. This method can avoid the divergence problem of common reflection points that normal velocity analysis methods may meet. But the ellipse development velocity analysis methods now are mostly based on 2D condition, which can′t be applied in 3D real seismic data processing. In order to overcome this shortcoming, we carried out a study on 3D ellipse development velocity analysis. Based on the ellipse development theory, we derived the 3D ellipse development equation to apply the ellipse development velocity analysis in 3D seismic data processing. Then we proposed a method to extract common normal emergence point gather. Compared with CMP gather, this gather contains more information about normal emergence point. On the basis of this gather, we carried out 3D ellipse development velocity analysis. Based on the ellipse development theory and common normal emergence point gather, this method is applied to deal with complex geological conditions and get high precision root-mean-square velocity. Besides, it is applicable to the real seismic data processing.

10.6056/dkyqt201505002