三维叠前时间偏移速度场在变速成图中的应用

Application of 3-D Pre-stack Time Migration Velocity Field in Varying Velocity Mapping

常规的变速成图方法是应用叠加速度对水平叠加剖面或叠后偏移剖面上解释的t0层位进行变速成图的。由于叠加速度精度低、叠加速度与偏移域层位跨域匹配等因素的影响,使变速成图精度降低。而通过叠前时间偏移处理有利于获取更加准确的速度场和t0层位,应用优化后的三维叠前时间偏移速度场对偏移域t0层位进行变速成图,同时也避免了跨域匹配的问题。与常规变速成图方法对比表明,该方法可以提高速度变化较大地区的构造成图精度。

Conventional varying velocity mapping technology used stacking velocity to converse t0contour map to depth contour map , and the former was usually obtained from horizontal stacking section or post-stack migration time section. Because of the low precision of stacking velocity , and the influence of cross-domain matching between the stacking velocity and migrated domain , the accuracy of depth contour mapping decreased.Comparatively , pre-stack migration provided more accurate velocity field and to contour mapping , and optimized 3-D pre-stack time migration and t 0 contour mapping were used to make varying velocity mapping and avoid the problem of cross-domain matching.The contrast with conventional varying velocity mapping shows that the new method can effectively enhance the precision of structural mapping conversion in the areas with bigger variations.